United States
Department of
Commerce
National Oceanic af>d
Atmosoheric Administranon
Seattre WA98115
United States
Environmental Protection
Agency
Office of Environmental
Engineering and Technology
Washington DC 20460
EPA-600/7-82-004
February 1982
Research and Development
-AGE
A Synthesis of
Biological Data from the
Strait of Juan de Fuca
and
Northern Puget Sound
Interagency
Energy/Environment
R&D Program
Report
Prose::/ Oi
Environmental Proia
Library
? 1383
12CO ijix'.n Ave
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-M
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A SYNTHESIS OF BIOLOGICAL DATA
FROM THE STRAIT OF JUAN DE FUC|
AND NORTHERN PUGET SOUND
by
Repository Material
« 611)13118111
Editor: Edward R. Long
Pacific Office, Office of Marine Pollution Assessment
National Oceanic and Atmospheric Administration
Contributors:
Alice B. Benedict
Western Washington University
Robert D. Everitt ^
Washington Department of Game 9^
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co >> «•
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Bruce S. Miller
University of Washington
Carl F. Nyblade
University of Washington
Charles A. Simenstad
University of Washington
Steven M. Speich ^ °
Burlington, Washington
Terence R. Wahl
Bellingham, Washington
Herbert H. Webber
Western Washington University
Prepared for the MESA (Marine Ecosystems Analysis) Puget Sound Project
Seattle, Washington in partial fulfillment of
EPA Interagency Agreement No. D6-E693-EN
Program Element No. EHE625-A
This study was conducted as part of the
Interagency Energy/Environment Research and Development Program
Prepared for
OFFICE OF ENVIRONMENTAL ENGINEERING AND TECHNOLOGY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
February, 1983
RX000037683
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Completed as a research task of:
PUGET SOUND ENERGY-RELATED RESEARCH PROJECT
MARINE ECOSYSTEMS ANALYSIS PROGRAM
OFFICE OF MARINE POLLUTION ASSESSMENT
NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
by
NOAA - Office of Marine Pollution Assessment
Pacific Office
7600 Sand Point Way N.E.
Seattle, Washington 98115
DISCLAIMER
This work is the result of research sponsored by the Environmental
Protection Agency and administered by the National Oceanic and Atmospheric
Administration.
The National Oceanic and Atmospheric Administration (NOAA) does not
approve, recommend, or endorse any proprietary product or proprietary
material mentioned in this publication. No reference shall be made to NOAA
or to this publication furnished by NOAA in any advertising or sales
promotion which endorses any proprietary product or proprietary material
mentioned herein, or which has as its purpose an intent to cause directly or
indirectly the advertised product to be used or purchased because of this
publication.
11
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FOREWORD
Increased petroleum transfer and refining activities are expected in
northern Puget Sound and the Strait of Juan de Fuca in the future which will
increase the chances of oil spills into the marine environment. A five-year
multidisciplinary research project, titled "An Environmental Assessment of
Northern Puget Sound and the Strait of Juan de Fuca," was initiated in 1975
to provide information usable in solving environmental questions pertaining
to increased petroleum-related activities. This project was funded by the
U.S. Environmental Protection Agency and administered by the Marine
Ecosystems Analysis (MESA) Puget Sound Project, a part of the National
Oceanic and Atmospheric Administration. This report summarizes the
biological data collected in this research project as well as those collected
in a similar program conducted by the Washington Department of Ecology,
titled "North Puget Sound Baseline Study." The report was prepared by the
principal investigators who originally collected the biological data.
iii
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ABSTRACT
This report summarizes the biological data collected during a five-year
research project, titled "An Environmental Assessment of Northern Puget Sound
and the Strait of Juan de Fuca." This Project was funded by the U.S.
Environmental Protection Agency and administered by the U.S. National Oceanic
and Atmospheric Administration. This report also incorporates biological
data collected during a similar program conducted by the Washington Depart-
ment of Ecology, titled "North Puget Sound Baseline Study."
The report provides an overview of the geography, geology, oceanography,
and habitat characteristics of the study area. Summarized information on
food webs, biological communities, migrations, reproductive processes, and
natural stresses is provided. Major habitat types are defined and character-
ized by physical and biological parameters. Descriptions are provided for
the structures of biological communities associated with each major habitat
type; major trophic interactions; trends in organism density, community
biomass and species richness; the occurrence of migrants; and the sources and
magnitudes in community variability. Factors important in evaluating the
relative significance of sites having certain habitat characteristics are
presented. The known and potential interactions of biological communities
and perturbations are discussed on a habitat type basis. Finally, an
evaluation of the data base is given along with recommendations for
strengthening it.
iv
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CONTENTS
Foreword
Abstract iv
Figures viii
Tables x
Appendix Figures xi
Appendix Tables . xii
Acknowledgments xv
Summary and Conclusions xvi
I. Introduction 1
II. Characteristics of the Study Area 3
A. Scope 3
B. Geologic History ..... 3
C. Geologic Setting ; 6
D. Physical Oceanography 7
E. Biological Oceanography 10
F. Biogeography 12
III. Biological Community Organization and Major
Ecological Processes: An Introduction 14
A. Concept of Biological Communities 14
B. Food Web Structure 15
C. Trophic Levels 15
D. Community Stability 18
E. Reproduction and Dispersal 18
F. Migrations and Movements 20
G. Natural Stresses 24
IV. Biological Characterization of Major Habitat Types
of Northern Puget Sound and the Strait of Juan de Fuca 26
A. Intertidal/Subtidal . . . 26
1. Habitat Definitions 26
2. Spatial Extent 30
3. Major Biological Assemblages 30
a. Dominant and characteristic species of
intertidal/shallow subtidal benthic habitats .... 30
b. Trophic organization 42
c. Species richness, abundance and biomass 51
d. Migrants 67
e. Variability between and within habitat types .... 70
B. Nearshore Waters 80
1. Habitat Definitions 80
2. Spatial Extent 80
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3. Biological Associations 80
a. Community composition 80
b. Trophic organization 87
c. Density, biomass, species richness 90
d. Migrants 92
e. Variability 96
C. Offshore Waters 97
1. Habitat Definitions 97
2. Spatial Extent 101
3. Biological Associations per Habitat Type 101
a. Community description 101
b. Trophic organization 108
c. Density, biomass species richness 110
d. Migrants 113
e. Variability 116
V. Identification of Areas of Biological Importance 117
A. The Need for Identifying Areas of Importance 117
B. Importance Factors and Description of Examples 117
1. Rationale for Approach 117
2. Description of Importance Factors and Criteria 119
3. Factors Important in Evaluating Each Habitat Type .... 123
C. Ecological Relationships 136
1. Habitat-to-Habitat Relationships 136
2. Importance of Each Habitat to Total System 137
3. Importance of Study Area to NE Pacific 138
4. Unique Features 139
VI. Potential Interactions of Habitat Types and Known
or Proposed Types of Perturbations 142
A. Summary of Present Pollution Status 142
1. Oil Spills and Other Industrial Accidents 143
2. Oil Refineries and Transshipment Facilities 143
3. Habitat Modification 144
4. Upland Modification 144
5. Forest Products 144
6. Domestic Wastes 144
7. Commercial and Sports Fisheries 145
8. Mariculture 145
9. Recreation, Educational Activities,
Scientific Collection 145
B. General Perturbation Effects on Biological
Communities 146
C. Perturbation Types and Their Possible Effects 147
1. Oil Spills and Other Industrial Accidents ........ 147
2. Petroleum Refining, Transshipment and
Utilization 157
3. Habitat Modifications 158
4. Upland Modification 158
5. Forest Products 159
6. Domestic Wastes 159
7. Commercial and Sports Fisheries 160
vi
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8. Mariculture 160
9. Recreation, Educational Activities,
Scientific Collection .... 161
10. Miscellaneous 161
D. Potential for Cumulative and Long-term
Subtle Effects 162
VII. Data Evaluation, Data Gaps, Recommendations 166
A. Evaluation of the MESA/ WDOE Data Set 166
B. Data Gaps 167
C. Recommendations for Further Research 168
References 170
Appendix I - Availability and Accessibility of Data Sets 179
II - Dominant Species per Intertidal/Subtidal Habitat
Type and Representative Data from Specific
Sampling Sites 199
III - Percent Occurrence, Mean Density and Standard
Deviation for Common Bird Species in Intertidal/
Subtidal, Nearshore and Offshore Habitat Types 251
vii
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FIGURES
Number Page
1 Primary study area 2
2 General characteristics of an exposed unconsolidated
beach 4
3 Profile view of net circulation at mid-channel in summer
between the Pacific Ocean and the head of Puget Sound .... 9
4 Simplified example of a detritus-based shallow subtidal
food web 17
5 Examples of exposed and protected unconsolidated intertidal/
subtidal habitat categories 28
6 Examples of intertidal rock and cobble habitat categories ... 29
7 Estimated spatial extent of major intertidal/subtidal
habitat types in the study area 31
8 Characterization of rock/cobble intertidal/subtidal
habitat food web 44
9 Characterization of exposed unconsolidated intertidal/
subtidal habitat food web 47
10 Characterization of protected unconsolidated intertidal/
subtidal habitat food web 49
11 Numbers of species of intertidal/subtidal fish and birds
in the winter at (a) protected habitats, (b) exposed
habitats, and (c) rock and cobble habitats .• . . 54
12 Numbers of species of intertidal/subtidal fish and birds
in the spring at (a) protected habitats, (b) exposed
habitats, and (c) rock and cobble habitats 55
13 Numbers of species of intertidal/subtidal fish and birds
in the summer at (a) protected habitats, (b) exposed
habitats, and (c) rock and cobble habitats 56
14 Numbers of species of intertidal/subtidal fish and birds
in the fall at (a) protected habitats, (b) exposed
habitats, and (c) rock and cobble habitats 57
15 Abundance of intertidal invertebrates, subtidal inver-
tebrates, fish and birds in the winter at (a) protected,
(b) exposed, and (c) rock and cobble habitats 58
viii
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Number
16 Abundance of intertidal invertebrates, subtidal inver-
tebrates, fish and birds in the spring at (a) protected,
(b) exposed, and (c) rock and cobble habitats 59
17 Abundance of intertidal invertebrates, subtidal inver-
tebrates, fish and birds in the summer at (a) protected,
(b) exposed, and (c) rock and cobble habitats 60
18 Abundance of intertidal invertebrates, subti'dal inver-
tebrates, fish and birds in the fall at (a) protected,
(b) exposed, and (c) rock and cobble habitats 61
19 Biomass of intertidal invertebrates, subtida'l inverte-
brates, fish and birds in the winter at (a) protected,
(b) exposed, and (c) rock and cobble habitats 63
20 Biomass of intertidal invertebrates, subtidal inverte-
brates, fish and birds in the spring at (a) protected,
(b) exposed, and (c) rock and cobble habitats . 64
21 Biomass of intertidal invertebrates, subtidal inverte-
brates, fish and birds in the summer at (a) protected,
(b) exposed, and (c) rock and cobble habitats 65
22 Biomass of intertidal invertebrates, subtidal inverte-
brates, fish and birds in the fall at (a)protected,
(b) exposed, and (c) rock and cobble habitats 66
23 Characterization of nearshore habitat food web 89
24 Mean species richness per pair of hauls for fish caught
in tow nets 91
25 Mean fish density (No./n3) per pair of hauls for fish
caught in tow-nets 93
26 Mean fish biomass (grams/in3) per pair of hauls for fish
caught in tow-nets 94
27 Number of species of fish caught per season at nine near-
shore sites along the Stait of Juan de Fuca, 1976-1979 ... 98
28 Density (No./m3) of fish caught per season at nine near-
shore sites along the Strait of Juan de Fuca, 1976-1979 ... 99
29 Biomass (grams/m3) of fish caught per season at nine near-
shore sites along the Strait of Juan de Fuca, 1976-1979 . . . 100
30 Characterization of offshore habitat food web 109
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TABLES
Number Page
1 Intertidal/subtidal, nearshore and offshore study
sites per habitat type .32
2 Major haul-out areas of pinnipeds in the study area .... 35
3 Number of feeding groups and mean annual standing crop
in marine habitats of northern Puget Sound and the
Strait of Juan de Fuca 52
4 Examples of mean abundance and coefficients of
variation for selected invertebrate species at
several intertidal sites in summer 75
5 Extent of nearshore and offshore waters within the
study area 81
6 Predominant distribution of commonly occurring bird
species feeding within nearshore and offshore water
columns 83
7 The 10 most common neritic fishes of northern Puget
Sound and the Strait of Juan de Fuca ranked accord-
ing to occurrence, abundance and biomass, 1974-1976 ... 85
8 Percentage of estimated total winter populations of
major marine birds by species or species groups for
selected offshore regions and total densities per
region, 1978-1979 103
9 Percentage of selected major wintering bird species
occurring in offshore waters in the study area 104
10 Importance factor/habitat matrix and sites exemplifying
each habitat type 118
11 Major perturbation types and their possible effects in
the study area 148
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APPENDIX FIGURES
Number
I-A Locations of plankton-collection sites (1-9)
and intertidal/subtidal/nearshore sampling
sites for benthos and fish (1-56) 191
I-B Location of marine bird survey transects 192
I-C Location of marine bird shore census sites 193
I-D Location of marine mammal survey sites and
transects . 194
xi
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APPENDIX TABLES
Number Page
I-A Publications resulting from NOAA/MESA and WDOE
biological studies 183
I-B Biological synthesis report: data sets 187
I-C NODC file type formats for biological data collected
in MESA studies 189
I-D Sampling site names for Appendix Figure I-A 190
II-A Dominant species of marine mammals 196
II-B Dominant species of marine birds 197
II-C Dominant species of fish 203
II-D Dominant species of intertidal benthos 209
III-A Percent occurrence, mean density and standard
deviation for common bird species in intertidal/
subtidal rock (exposed rock) habitat ... 248
III-B Percent occurrence, mean density and standard
deviation for common bird species in intertidal/
subtidal rock (protected rock) habitat 250
III-C Percent occurrence, mean density and standard
deviation for common bird species in intertidal/
subtidal rock (cobble) habitat 252
III-D Percent occurrence, mean density and standard
deviation for common bird species in intertidal/
subtidal exposed unconsolidated (mixed coarse)
habitat 254
III-E Percent occurrence, mean density and standard
deviation for common bird species in intertidal/
subtidal exposed unconsolidated (sand) habitat 256
III-F Percent occurrence, mean density and standard
deviation for common bird species in intertidal/
subtidal protected soft (mud-gravel, mixed fine)
habitat 258
xii
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Number Page
III-G Percent occurrence, mean density and standard
deviation for common bird species in intertidal/
subtidal protected soft (mud-sand, mixed fine)
habitat 260
III-H Percent occurrence, mean density and standard
deviation for common bird species in intertidal/
subtidal protected soft (mud) habitat 262
III-I Percent occurrence, mean density and standard
deviation for common bird species in nearshore waters,
less than 20 m exposed unconsolidated (mixed coarse)
habitat 264
III-J Percent occurrence, mean density and standard
deviation for common bird species in nearshore waters,
less than 20 m exposed unconsolidated (sand) habitat .... 266
III-K Percent occurrence, mean density and standard
deviation for common bird species in nearshore waters,
less than 20 m protected soft (mud-gravel, mixed fine)
habitat 268
III-L Percent occurrence, mean density and standard
deviation for common bird species in nearshore waters,
less than 20 m protected soft (mud-sand, mixed fine)
habitat 270
III-M Percent occurrence, mean density and standard
deviation for common bird species in nearshore waters,
less than 20 m protected soft (mud) habitat 272
III-N Percent occurrence, mean density and standard
deviation for common bird species in nearshore waters,
less than 20 m rock (exposed rock) habitat 274
III-O Percent occurrence, mean density and standard
deviation for common bird species in nearshore waters,
less than 20 m rock (protected rock) habitat 276
III-P Percent occurrence, mean density and standard
deviation for common bird species in nearshore waters,
less than 20 m rock (cobble) habitat 278
III-Q Number of species, total density and total biomass for
birds occurring in nearshore habitats in spring 1978
and 1979, combined 280
III-R Number of species, total density and total biomass for
birds occurring in nearshore habitats in summer 1978
and 1979, combined 281
xiii
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Numb er PaSe
III-S Number of species, total density and total biomass for
birds occurring in nearshore habitats in fall 1978
and 1979, combined 282
III-T Number of species, total density and total biomass for
birds occurring in nearshore habitats in winter 1978
and 1979, combined 283
III-U Percent occurrence, mean density and standard
deviation of common birds in offshore waters, greater
than 20 m (bays) 284
III-V Percent occurrence, mean density and standard
deviation of common birds in offshore waters, greater
than 20 m (passages, narrow) 286
III-W Percent occurrence, mean density and standard
deviation of common birds in offshore waters, greater
than 20 m (passages, broad) 288
III-X Percent occurrence, mean density and standard
deviation .of common birds in offshore waters, greater
than 20 m (open waters) 290
III-Y Number of species, total density and total biomass
for birds occurring in offshore habitats in spring
1978 and 1979, combined 292
III-Z Number of species, total density and total biomass
for birds occurring in offshore habitats in summer
1978 and 1979, combined 293
III-AA Number of species, total density and total biomass
for birds occurring in offshore habitats in fall
1978 and 1979, combined 294
III-BB Number of species, total density and total biomass
for birds occurring in offshore habitats in winter
1978 and 1979, combined 295
xiv
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ACKNOWLEDGMENTS
The U.S. Environmental Protection Agency provided funding for the
Environmental Assessment of the Strait of Juan de Fuca and Northern Puget
Sound. Dr. Howard S. Harris, Project Manager, provided encouragement and
prodding to complete this synthesis document.
Advice, input, and guidance were provided by Mr. Fred Gardner
(Washington Department of Ecology), Dr. Rick D. Cardwell (Washington
Department of Fisheries, now with Envirosphere Co.), Mr. John Sainsbury (U.S.
Environmental Protection Agency), and Dr. Alan J. Mearns (U.S. N.O.A.A.,
Office of Marine Pollution Assessment). Mr. Ronald P. Kopenski (U.S.
N.O.A.A., Office of Marine Pollution Assessment) provided a discussion on
physical oceanography and Dr. Robert E. Burns (U.S. N.O.A.A., Office of
Marine Pollution Assessment) provided a discussion on geologic history. Ms.
Joy Godfrey and Ms. Ginny May (U.S. N.O.A.A., Pacific Marine Environmental
Laboratory) prepared the illustrations and Ms. Sharon Giese prepared and
edited the manuscript. Mr. Sidney Stillwaugh (U.S. N.O.A.A., Environmental
Data and Information Service) and Mr. Michael Crane (U.S. N.O.A.A.,
Environmental Data and Information Service) provided discussions on data
management.
XV
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SUMMARY AND CONCLUSIONS
An extensive qualitative and quantitative data base has been collected
for the study area. The data emphasize the algae, invertebrates, fish,
birds, and mammals of the intertidal/subtidal and nearshore habitats. Though
some topical and geographic gaps in the data base exist, a relatively compre-
hensive understanding of the biology of the area has been developed.
The study area lies within the U.S. portion of the inland marine waters
of the Strait of Juan de Fuca and northern Puget Sound (San Juan Islands and
southern Strait of Georgia). Water circulation in the area is driven pri-
marily by freshwater runoff, causing estuarine flow of surface waters out to
the Pacific Ocean and deep water replacement by highly saline ocean water.
This circulation pattern is modified by winds, storms, tides, and local
topography.
The characteristics of the biological communities are highly dependent
upon the nature of the habitats the communities are associated with. In the
intertidal/shallow subtidal zones the habitats are primarily defined by the
geomorphology of the shoreline. Certain communities often associate with
individual shoreline types in a more or less predictable fashion. Major
habitat types include: rock (including cobble), protected unconsolidated
(including mud-gravel), and exposed unconsolidated (including sand and
gravel). Several more narrowly-defined habitat categories exist under each
major type. Habitat types are usually not discrete but, rather, grade into
each other. About 50% of the shoreline is occupied by exposed unconsolidated
substrates, about 40% by rock and cobble, and about 10% by protected
unconsolidated substrates.
The study area is part of a large temperate biotic province that
includes much of the West Coast of North America. None of the biota found in
these studies are endemic to the area, though many are restricted in geo-
graphic distribution to the temperate province of the West Coast. Some biota
(especially birds and mammals) are migrants and, thus, spend part of their
life cycles in the study area and part elsewhere.
The 21 species of marine mammals found in the study area did not appear
to have distinct habitat preferences. Harbor seals, the most common species,
haul out on all intertidal habitat types where protection from human
disturbance and access to prey are afforded.
Some of the species of marine birds found in the study area showed
distinct habitat preferences, while others did not. Bird species richness,
abundance, and biomass were generally highest in protected areas, including
XVI
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those with muddy intertidal habitats. Abundance was generally highest in the
fall and winter and lowest in summer.
Many of the adult and juvenile nearshore fishes encountered in the study
occupy several similar habitat types. Their habitat preferences often change
during their life cycle. Species richness and abundance of fish were highest
at protected mud-gravel habitats, such as found at Beckett Point in Discovery
Bay. Biomass was highest at protected rocky reef and protected mud-gravel
sites.
Intertidal benthic organisms, those occurring between the +2 m and -10 m
tidal levels, were most abundant at protected unconsolidated rock and cobble
sites. Since many of the species in protected unconsolidated habitats were
small (e.g., oligochaetes) and those in rock habitats were large and had
shells, biomass was highest at rock sites and lower tidal zone cobble sites.
Species richness of benthos was highest among rock/cobble sites in the
intertidal zone, intermediate at protected unconsolidated sites, and lowest
at exposed unconsolidated sites. Eelgrass meadows are likely important
sources of primary production. Exposed unconsolidated beaches were the most
impoverished habitats because of the abrasive action of the constantly moving
beach material.
Migrants may be very important to the biology of some habitat types.
For example, protected unconsolidated habitats were found to be important for
migratory seabirds. Pacific herring were common (in the spring) at specific
sites with coarse gravel or cobble intertidal habitats. Juvenile salmon were
found at exposed unconsolidated habitats. Two species of migratory sea lions
occupied certain rocky sites.
Rock/cobble intertidal habitats have highly complex and diverse food web
structures. Herbivorous and suspension-feeding invertebrates were common at
most sites. High standing stocks of predators such as seastars, gastropods,
and fish were common, preying upon herbivores and suspension-feeders. Food
webs at exposed unconsolidated habitats are based upon detritus transported
from adjacent kelp beds, eelgrass beds, and saltmarshes. Detritus-consuming
invertebrates were most common in this biologically impoverished habitat and
are often preyed upon by carnivorous invertebrates, birds, and fish. Food
webs are highly diverse in protected unconsolidated habitats and are based
upon detritus generated from macroalgae, eelgrass, and saltmarsh plants
growing in the habitat and elsewhere. Deposit-feeding polychaetes and
bivalves and suspension-feeding bivalves are preyed upon by carnivorous
seastars, fish, and birds, Epibenthic zooplankton are also very important
prey items for nearshore fishes in this habitat type,
The sources of variability in biological characteristics of each habitat
type differed among the biotic groups. Some variability was due to sampling
and data interpretation procedures; other sources were related to the natural
seasonal, annual, geographic, and cyclical processes that occur among marine
biota.
Nearshore habitats, defined here as the water column from the high tide
line to the 20 m depth contour, supported numerous birds, fish, and mammals.
xv n
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Food webs are primarily based upon phytoplankton production. Herbivorous
(suspension-feeding) zooplankton are preyed upon by carnivorous zc^plankton
and fish, which, in turn, are prey for birds and mammals. Bird density a.iid
biomass in summer appeared to be highest in nearshore waters at exposed mixed
coarse and protected rock sites. In the winter nearshore waters at protected
rock and protected mud-gravel had highest bird density and biomass.
Nearshore fish density, biomass, and species richness varied widely due
to episodic catches of schooling fish. Species richness was highest in
spring at most sites and in the protected regions of the eastern Strait of
Juan de Fuca. Densities were highest at rock and cobble sites in the spring
and summer and along the Strait. Density values generally followed those of
species richness. Harbor seals occurred in all nearshore habitats year-
round. Some cetaceans (whales and porpoises) frequented these areas while
foraging, and sea lions were found there in winter months, especially in the
Strait.
The offshore waters, defined here as greater than 20 m deep, occur in
the outer parts of bays, in narrow passages, in broad passages, and in open
regions (e.g., western Strait). About 88% of the water surface in the study
area covers depths greater than 20 m.
The offshore food webs are similar to those of the nearshore waters;
they are based upon phytoplankton production and successive consumption by
zooplankton, fishes, birds, and mammals. Diatoms contribute to much of the
phytoplankton biomass. Large quantities of copepods, juvenile fish, fish
eggs, and invertebrate larvae occurred among the zooplankton. Offshore bird
populations were composed of large numbers of a relatively few species when
compared to nearshore habitats. Loons, grebes, murres, cormorants, ducks,
and gulls were common. The majority of many of these species wintered in
offshore waters. Small populations of minke and killer whales and sea lions
were important top carnivores in offshore waters. Western Grebes were
abundant in offshore bay waters; Brandt's Cormorant, Bonaparte's Gulls, and
Arctic Loons were abundant in narrow passages; Common Murres and Rhinoceros
Auklets were common in broad passages and open waters.
The factors which are important in evaluating the relative biological
significance of a site vary according to the habitat type. A list of
"Importance Factors" was generated and described and examples were given.
Though some sites with definable habitat characteristics may be found to be
highly important to marine biota, ail sites and all habitats are parts of an
overall system and, as such, are not necessarily expendable. The importance
of some sites with certain habitat types goes beyond the study area. For
example, migratory salmon, seabirds, and marine mammals enter the area yearly
from other North American areas or other continents. Many populations of
invertebrates are important as brood stock for colonization of adjacent
areas. At least 12 subregions are identified as unique in terms of the
abundance and/or type of biota found there.
The study area is generally free of pollution and other human
perturbations, though the effects of some human activities have been docu-
mented. The actual and potential effects of perturbations vary according to
the type of stress. The habitats most susceptible to stress also vary
xvili
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accordingly. However, protected bays and unconsolidated intertidal/subtidal
habitats appear to be most sensitive, especially to the effects of oil. The
consequences of oil spills and other perturbations may be either immediate
and acute or long-term and subtle; and they may be either magnified or
partially mitigated by sc.as other stress.
While the data set collected during the Washington Department of Ecology
(WDOE) and Marine Ecosystems Analysis (MESA) studies is extensive, a number
of data gaps became apparent during the studies and during this synthesis.
Nearby geographic areas where no similar comprehensive data set was collected
include the Saratoga Passage/Skagit Bay area, outer coast, Admiralty Inlet,
the central and southern basins of Puget Sound, and Hood Canal. Topical gaps
include characterizations of: meiofauna; saltmarshes; offshore deep benthos;
nearshore plankton; offshore fish; nearshore/rocky kelp bed fish; and ceta-
ceans. Additional data are also needed to understand the ecological
relationships of the biological communities in the study area and the rates
and limiting factors in processes, such as primary, consumer, and detritus
production.
XIX
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I. INTRODUCTION
An extensive biological data base has been developed in the Strait of
Juan de Fuca and northern Puget Sound area (Figure 1) under research programs
sponsored by the U.S. Environmental Protection Agency (EPA), administered by
U.S. National Oceanic and Atmospheric Administration (NOAA) and the
Washington Department of Ecology (WDOE). Data were collected during numerous
separate studies conducted from 1974 through 1979. These studies were
initiated in response to anticipated increases in the use of the area for
transport and/or processing of crude oil. The objectives of the studies were
to characterize the major components of the marine biota of the area and, if
possible, to establish a quantitative baseline against which changes caused
by any significant petroleum-related perturbation could be measured.
The majority of data-collecting activities were terminated by the end of
1979, though some monitoring activities will likely continue into the 1980s.
Research was conducted to characterize the algae, macroinvertebrates, fish,
birds, marine mammals, and plankton. The results have been published in a
series of technical documents (Appendix Table I-A) and two summary reports
(Gardner, 1978; Long, 1980) available through the respective sponsoring
agencies. However, since each technical document only deals with a
restricted biologic group, their utility individually in shoreline manage-
ment, project planning, and habitat protection decisions is restricted.
Also, the utility of all the documents together is limited, since the indi-
vidual studies were not always conducted in the same areas, during the same
times, or using comparable or compatible methods. Finally, some of the
observations made and conclusions formed by the individual investigators were
not necessarily reported in any of the technical documents, and thus are not
readily available to users.
The overall objective of this document is to provide a compilation and
synthesis of the major results of the biological studies performed under the
sponsorship of EPA/NOAA and WDOE, such that the results can be more easily
used in decisions and policies regarding shoreline management, resource
utilization planning, research project planning, and habitat protection.
Though these data were collected with the primary intent of applying them to
estimates of potential and actual biological changes caused by petroleum-
related activities, they can also be used in assessing other types of
projected perturbations.
This document was planned, assembled, and written by a multidisciplinary
team, composed of the original principal investigators of the EPA/NOAA and
WDOE sponsored biological studies. The expertise of the team included marine
mammalogy, ornithology, fish ecology, benthic ecology, and trophic dynamics.
-------
Each team member was responsible for providing his or her expertise to the
team, as well as analyses and interpretations of other data sets.
STRAIT
OF
'••L GEORGIA
VANCOUVER
VANCOUVER
ISLAND
CANADA
Blame
ERRY PT.
JKV. Bellingham
3 DJW
VICTORIA"V vr»t^^>«®yRMACORTES
AWest Beac
Partridge Pt.
PORT ANGE
Admiralty Inlet
Puget Sound
Figure 1. Primary study area (shaded)
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II. CHARACTERISTICS OF THE STUDY AREA
II. A. Scope
This document focuses upon the U.S. waters and shorelines of the Strait
of Juan de Fuca, San Juan Islands, and southern Strait of Georgia (Figure 1).
This area extends from Cape Flattery east to Point Wilson, north to the
Canadian border. The area includes the marine waters between Bellingham and
Anacortes, but excludes the areas east of Whidbey Island. The relationships
of the study area to Puget Sound, Admiralty Inlet, Pacific Ocean, and
Canadian portions of the Strait of Juan de Fuca and Strait of Georgia will be
expressed where data are available.
Emphasis wirJ.- be placed upon the intertidal/shallow subtidal (+2 m to
-10 m) benthos and tidepool fish; nearshore (0 to -20 m) fish, marine birds
and marine mammals; and open water ( > 20 m) birds and mammals of the region
(Figure 2). Some open water plankton, pelagic fish, and deep benthos data
will be included, but not emphasized. Since the majority of the data were
collected in nearshore and intertidal habitats, those areas will be
emphasized.
Quantitative data collected as components of the NOAA and WDOE sponsored
projects will be used as the primary information sources, supported by other
data sets that are applicable to the area and the objectives of this
synthesis. Most quantitative data were archived in standardized computer
formats by investigators supported by the NOAA/MESA Puget Sound Project.
Additional NOAA sponsored research concerning the oceanography of the
Strait of Juan de Fuca, the behavior of surface drifters, the existing levels
of petroleum hydrocarbons, the processes that influence the fate of
hydrocarbons, and the effects of crude oil upon recovery of intertidal
communities has been conducted. These research projects have been reported
elsewhere and will not be included in this synthesis, though some conclusions
from these projects will be utilized in discussions of the oceanography of
the area and of the consequences of oil spills. Reports of these projects
are available through the NOAA/MESA Puget Sound Project Office.
II. B. Geologic History
The geologic history of the study area has involved three basic kinds of
processes. The basic structure is the result of regional tectonic processes,
where the movements of the earth's crustal plates have resulted in stresses
upon and upheavals of the surface. The major landforms and shape of the
surface are the result of glaciation during the Pleistocene Epoch. The shape
-------
Intertidal
Subtidal
Nearshore
-I-2m
tide level
0 tide level
Offshore
-20m'depth •'••"•'•"
Figure 2. General characteristics of an exposed unconsolidated
beach.
-------
of beaches and shorelines has been further modified by post-glacial sea-level
changes and the action of riverine and marine shoreline erosion.
The structural development of the western ranges of North America,
including the Cascades and Olympics of Washington and the Insular Mountains
of Vancouver Island, took place during the Cordilleran mountain-building
process. During a period beginning about 200 mybp (million years before
present), interactions between western North America and the oceanic area of
the Pacific took place in a zone of crustal convergence marking the inter-
section of two crustal plates. This convergent interaction gave rise to a
sequence of events which resulted in a westward building (accretion) of North
America's western boundary as new crust was added to the continent.
However, several anomalous features do not clearly fit into a general
description of the major structures, principally the transverse (east-west)
trend of the Strait of Juan de Fuca and the extreme age of some of the rocks
found in the San Juan Islands. These local structural trends appear to be
related to differences in rates and type of convergent plate processes caused
by interaction of the Juan de Fuca plate and the western margin of North
America. At any rate, the fundamental structural framework was established
by 50-25 mybp with the development of the Olympic Mountains.
Pleistocene glaciation had a major effect on shaping the surface form of
the study area. On a global scale, the Pleistocene was marked by four major
advances of glacial ice moving across northern North America and Europe.
Locally, this epoch was marked by persistent glaciation by alpine glaciers in
the Cascades, Olympics, and Insular Mountains, but the dominant invasion of
the region was by the Cordilleran Ice Sheet. This center of glaciation
occurred during the same period of time as the major continental glaciers
that moved over central and eastern North America. However, it was
independent in origin, resulting from accumulation of glacial ice originating
in the mountains of British Columbia and on Vancouver Island. This
accumulation of ice filled the Georgia Depression and, impeded by the Insular
Mountains of Vancouver Island, moved out of the Georgia Depression around
Vancouver Island. The southward moving ice overran the San Juan Islands,
scouring even the highest hills, and moved to the eastern end of the Strait
of Juan de Fuca. Here its progress was stopped by the Olympic Mountains and
the ice split into two lobes. One, moving south into the Puget Lowland, is
termed the Puget Lobe and played a dominant role in the formation of Puget
Sound. The other, the Juan de Fuca Lobe, moved seaward out through the
Strait of Juan de Fuca.
The effects of this glacial activity are very evident in the study area.
The smoothing and rounding of the San Juan Islands, erosional deepening of
Haro Strait, East Sound, and Rosario Strait, and glacial grooving in many
places are evidence of the erosive power of the ice which covered the San
Juans to a depth of more than 700 meters. Depositional processes left much
of the eastern and southern portion of the Puget Lowland buried under a great
thickness of glacial deposits. To a lesser degree, the deposits from the
Juan de Fuca Lobe are found along the shoreline of the Strait in many
localities. Many of today's shoreline features and marginal deposits along
-------
Whidbey Island, near Dungeness Spit, on northern Quimper Peninsula, and
elsewhere show clear evidence of their glacial origin.
Following the final retreat of the Cordilleran Ice Sheet, recent and
on-going wave action, worldwide sea-level changes, and deposition of riverine
sediments modified the shorelines to today's conditions. The relative
importance of the processes varies geographically. Vigorous wave action has
eroded rocky headlands and formed wave-cut benches in the western Strait of
Juan de Fuca. Recent increases in sea level have resulted in submergence of
some shoreline features. Deposition of riverine sediments has created broad
tidal flats in some areas, particularly in the Bellingham Bay/Padilla Bay
area.
II. C. Geologic Setting
The coastline of the study area consists of distinct forms: rocky
shores, sand, gravel and cobble beaches; gravel and sandspits; mudflats and
mixed mud beaches in protected bays and harbors. The recent material that
formed the shorelines has come from three main sources: (a) erosion of rocky
headlands (e.g., the San Juan Islands and much of the Strait of Juan de
Fuca); (b) redistribution of unconsolidated material deposited by glacial
action (e.g., Whidbey Island); and (c) deposition of riverine sediments
(e.g., Padilla Bay).
Rocky headlands erode slowly relative to unconsolidated shorelines and
bluffs. The rate of erosion, however, is increased by abrasion from
waterborne materials such as logs, sand particles and flotsam; waves;
repeated freezing and thawing of water in the cracks of rocks; and the boring
activities of animals such as urchins and molluscs. Tides and storms also
greatly increase the rate of wave erosion. The large waves driven by storm
winds during periods of high tides most likely carry the maximum of
waterborne materials. In some areas, such as the western part of the Strait
where large waves are common, wave-cut terraces occur commonly on rocky
shores.
Waves, winds, and repeat freezing and thawing also cause erosion of
glacial deposits, usually found in the area as bluffs. Where wave action and
littoral drift (long-shore currents) are adequate to suspend the eroded
material, transport and redistribution take place. Littoral drift is
produced by the energy of waves striking the shore at an angle, tidal
currents, winds, and net estuarine flow. Transport of these materials will
occur as long as sufficient turbulence exists to keep them suspended.
Deposition often occurs in areas of low turbulence, such as in the lee of a
sand spit or in a protected embayment. This deposition may lead to further
growth of a sand spit, such as at Dungeness Spit. Resuspension may occur
during episodes of strong winds, waves, or currents. The finest, lowest
density particles remain suspended the longest.
The beach is not well-developed in areas with active erosion. A wavecut
terrace is usually the dominant feature of the intertidal zone at erosional
beaches. The beach proper is generally a narrow belt near or at the high
tide line. There is no backshore development. At beaches where there is
-------
neither active erosion nor accretion of material, but where longshore
transport is present, the foreshore is relatively steep, no offshore bar
forms, and the backshore is not well-developed. In areas of active accretion
of sediments, beaches show their greatest development: the foreshore is
well-developed and relatively wide, offshore bars may be present, and the
backshore is characterized by berms and sand dunes (Figure 2).
Riverine particles consisting of glacial deposits, sediments eroded from
uplands, and organic debris arrive at the estuaries in greatest volume during
periods of high flow. Where these particles are exposed to adequate long-
shore currents and energy, they remain suspended for a considerable time, are
transported for many kilometers, and may be eventually deposited in a bay or
harbor or some other area where currents are weaker. However, where river-
borne sediments enter a protected estuary, they are rapidly deposited in the
mixing zone where freshwater and saltwater meet. Marshes and/or deltas with
shallow offshore flats may then be produced. Eelgrass and marsh plants tend
to accelerate sedimentation by reducing wave energy and long-shore currents.
Due to the forces of erosion and accretion, the coastline is constantly
changing with time. In some areas the change is rapid. Actively eroding
cliffs and sand or gravel spits may increase or decrease up to a meter per
year. Other areas such as rocky shorelines erode slowly. Gravel or sand
beaches acting primarily in sediment transport may accrete or erode only
millimeters per year.
II. D. Physical Oceanography
The study area is decidedly marine in character with water salinity
approaching that of the Pacific Ocean (29 to 31 parts per thousand ° /oo )•
Salinity is often lowest in the eastern and northern portions due to the
influence of the Fraser River and other freshwater sources. Surface
temperatures range between 8 °C and 11° C; the west portion of the Strait of
Juan de Fuca is warmest due to the influence of Pacific Ocean water.
Temperature and salinity are often relatively uniform from the surface to the
bottom in the deep channels during the winter. During the summer a weak
pycnocline (density layer) often forms at 50-100 meters, and surface-to-
bottom temperature differences approximate 4^ and salinity differs by about
3°/oo . This water column structure appears to be influenced mainly by
salinity and is easily disrupted by fall and winter storms, at which time
considerable vertical mixing is possible. Small-scale horizontal variations
in water characteristics can be influenced by tributaries, tidal eddies,
upwelling, downwelling, local winds, tidal fronts, bathymetry, and embay-
ments.
The Strait of Juan de Fuca is a weakly stratified, partially mixed
estuary with a surface-to-bottom salinity difference of 2-3%o , a 3-4 meters
spring tide height, and strong tidal currents of 77-154 cm/sec (1^-3 knots)
(Herlinveaux and Tully, 1961; Rattray, 1967). The estuarine circulation in
the Strait consists of a well-developed two-layer pattern, with near-surface
velocities directed westward at 20-40 cm/sec and deep layer velocities
directed eastward at 10 cm/sec. Over time scales of 4-6 hours, tidal
currents dominate the flow regime. Currents of 200-250 cm/sec (4-5 knots)
-------
are common in the more restricted passageways of the San Juan Islands and in
Admiralty Inlet. The along-strait mean flow is characterized by the
classical estuarine circulation with westward transport near the surface and
eastward transport near the bottom (Figure 3).
The circulation of the southern Strait of Georgia and San Juan Islands
area is poorly documented. However, the influence of the Fraser River is
very evident and adds to the net southward transport of surface water through
Haro and Rosario Straits and, to a lesser degree, through the San Juan
Archipelago.
Nearshore currents (or littoral drift) are poorly known in the study
area. However, a few generalizations can be formed from existing data.
Eastward transport of suspended sediments and floating materials along the
southern shore of the strait is indicative of the eastward drift there. Ediz
Hook and Dungeness Spit have formed by deposition of material originating
from the west. Littoral drift in the southern Strait of Georgia and San Juan
Island area is highly variable, but net transport is southward.
Water currents in the area are caused by freshwater runoff, tides, and
winds. The circulation in the deep channels is maintained by river water
which enters and sets up a longitudinal sea-surface slope directed seaward.
The near-surface flow is driven primarily by this slope, while the deeper
flow is driven by the longitudinal density gradient. These two driving
forces are balanced by the internal and bottom frictional forces generated by
the strong tidal mixing. Freshwater input is primarily from the Fraser River
through the Strait of Georgia and tributaries to the main basin of Puget
Sound. The Fraser River accounts for approximately 70-75% of the freshwater
discharging into the Strait of Juan de Fuca (Herlinveaux'and Tully, 1961).
Most of the riverine drainage areas are high mountain regions, and winter
snow storage plays a major role in establishing the runoff which normally
commences with spring thaws in March and attains maximum discharge in July.
Prior to entering the eastern basin of the Strait of Juan de Fuca, these
diluted freshwater sources are tidally mixed in the passages leading through
the San Juan Archipelago and across Admiralty Inlet. This tidal mixing,
therefore, has a moderating effect on the seasonal salinity fluctuations in
the strait.
Tidal currents dominate the flow regime in the study area. They
constitute navigational hazards and tend to disperse floating and dissolved
constiuents away from shorelines and to concentrate them in nearshore eddies
and fronts. Both the diurnal and semidiurnal tides enter the strait from the
Pacific Ocean as a progressive wave and propagate eastward where their
interactions lead to semidiurnal mixed tidal currents in the eastern basin.
As each wave propagates through the topographically complicated San Juan
Archipelago, it produces complex current patterns in this region with strong
tidal currents in Haro and Rosario Straits and Admiralty Inlet.
The predominant winds along the Washington coast are southwesterly (from
the southwest) in the winter and northwesterly in summer paralleling the
general coastline. In the Strait of Juan de Fuca the winds are strongly
influenced by orographic (mountain) effects and tend to be directed along the
8
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OCEAN
ENTRANCE
0
E
.x
X0.5 -
0.
Ld
Jl
.0
DISTANCE
100 200
J_
NLAND (km)
300
STRAIT OF
JUAN DE FUCA
400
MAIN BASIN
GREEN POINT-
VICTORIA SiLL
Figure 3. Profile view of net circulation at mid-channel in
summer between the Pacific Ocean and the head of
Puget Sound (from Ebbesmeyer et al., 1979).
Notation: dashed line equals depth of no-net-
motion (approximately 50 m).
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axis of the Strait. During summer, the northwest coastal winds are funneled
up-strait (eastward) and generally decrease in strength with distance
eastward. Over 75% of all winds at Port Angeles during summer are from the
western quadrant. Winds over the San Juan Island/southern Strait of Georgia
area are generally from the south or southwest, except in the winter when
northerly winds occur over Haro Strait and west of it.
Winds play only a weak role in modifying near-surface circulation
(Holbrook et al., 1980). However, results from surface drift sheet and drift
card studies (Ebbesmeyer et al., 1979) suggest surface winds are an important
small-scale factor in the dispersion and transport of surface trapped
contaminants. By contrast, strong southwesterly winds associated with
episodic storms dramatically affect near-surface circulation (Holbrook and
Halpern, 1977; Holbrook et al., 1980). The effect of these storms in the
Strait of Juan de Fuca is that the usual seaward estuarine flow in the
surface layer is reversed, causing eastward intrusions of warmer ocean water
and retention of surface water within the system. The intrusions have been
observed for periods of up to 10 days with maximum speeds of 20 cm/sec as far.
east as Dungeness Spit and they occurred during 35% of the time observations
were made. Satellite infrared imagery indicate the intrusions may reach
eastward as far as Whidbey Island. Although intrusions of coastal water
generated by coastal southwesterly winds are common during winter, they have
been observed year-round.
The complex oceanographic processes outlined above are further
complicated in numerous local areas by upwelling, downwelling, tidal fronts,
eddies, and other features. In the event of an oil spill these highly
unpredictable features could play a significant role in the transport of oil.
II. E. Biological Oceanography
All the biological communities and processes to be discussed in this
report are directly or indirectly influenced by numerous oceanographic
processes. Some of the physical oceanographic processes were discussed
above. Unfortunately, very little is known of the biological oceanography of
the study area, though data exist for the adjacent waters of the Puget Sound
central basin and the Strait of Georgia.
The factors that control phytoplankton production are numerous and the
relative importance of each varies geographically. Stockner et al. (1979)
ranked grazing, nitrates, and light in decreasing order of importance for the
Strait of Georgia. Winter et al. (1975) found that nitrates control and
stimulate primary productivity and rarely, and only briefly, become exhausted
and limiting following intense blooms in the Puget Sound central basin.
Certainly, all these factors and others work in combination to regulate the
timing and rates of primary productivity. Stabilization and stratification
of the water column and increased sunlight are necessary in the spring to
stimulate phytoplankton blooms. Replenishment of depleted nutrient levels
during the fall and winter months must occur so that elevated nutrient levels
exist when the sunlight and water column conditions are optimal. Nutrient
replenishment occurs primarily as a result of advection and mixing of oceanic
10
-------
water (Winter et al., 1975) or, in the vicinity of major rivers such as the
Eraser, as a result of runoff (Stockner et al., 1979).
Water column stratification is most distinct in the deeper areas and
rarely occurs in the narrow and shallow channels and passages separating land
masses. Stockner et al. (1979) found that a distinct halocline existed
during the winter throughout the Strait of Georgia, except in the turbulent
passages of the San Juan Islands and Canadian Gulf Islands. They found that
nutrient levels were highest in these well-mixed areas. Turbulence and
mixing in these passages is a result of strong tidally-induced currents.
Phytoplankton blooms in the area seem to begin most often in April or
May (Stockner et al., 1979; Winter et al., 1975) though a major bloom was
noted in June of 1976 and none was observed during bimonthly surveys in 1977
(Chester et al., 1980). Stockner et al. (1979) estimated that mean annual
production varied from 150 g C/m2 in the Fraser River plume to over 500 g C/m2
in sheltered waters of inlets and averaged 345 g C/m2 for the Strait of
Georgia, but, later, estimated annual production at 250-350 g C/m2 (Stockner
et al., 1980). Parsons et al. (1970) estimated annual productivity to be
about 120 g C/m2 and, later, argued that the estimates of Stockner and
associates were incorrect (Parsons et al., 1980). Winter et al. (1975)
estimated annual productivity for Puget Sound to be about 465 g C/m2 and
attributed the high rate to persistent upwelling of nutrients and viable
algal cells.
Diatoms appeared to be the major component of Strait of Juan de Fuca
phytoplankton communities during the mid-spring and early summer; whereas
microflagellates were dominant in late fall and winter months (Chester et
al., 1980). Diatoms appeared to be dominant in the Strait of Georgia during
the spring and fall, while dinoflagellates were common in August (Stockner et
al., 1979). Drastic changes in phytoplankton composition and density occur
spatially and over short (two week) periods, as many species seem to occur in
patches.
While water temperatures, nutrient levels, and salinities generally are
uniform throughout the study area, local phenomena such as the influence of
rivers, upwelling in turbulent passages, sewage outfalls, and tidal fronts
may cause considerable variations in these parameters in small areas. The
productivity and composition of biological communities often vary in response
to these local situations. For example, nutrients and prey are brought to
the surface by turbulence in narrow channels and over sills, and thus create
attractive feeding areas for marine birds. Productivity is also often high
in protected embayments where nutrients and organic matter are delivered by
rivers or sewage inputs or produced by in situ degradation or organic debris.
Water temperatures are often relatively high in protected embayments due to
warming by the sun and negligible flushing, possibly increasing microbial
degradation rates.
Production of macroalgae which occur over much of the hard-substrate
intertidal, subtidal, and nearshore zones, although limited in areal extent
to the lighted depths, may actually match or surpass that of phytoplankton.
The contribution of attached plants to total carbon production is greatest in
11
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shallow bays where eelgrass (Zostera marina) thrives, along rocky or cobble
shores and over shallow rocky reefs where macroalgae are abundant.
Webber (1981) summarized the small amount of plant productivity data
available for the study area. Most marine plants are annuals. Growth begins
in early spring, is maximum in spring and summer, and declines to a minimum
in winter. Timing of growth and productivity varies from species to species.
A production rate of up to 100 g wet weight biomass per day per plant was
measured in May for Laminaria saccharina in experiments conducted near
Anacortes. In the same studies, a rate of 250 g wet weight biomass per day
per plant was measured in August and September for Nereocystis luetkeana.
The eelgrass Zostera marina is estimated to cove'r about 9% of the bottom
of Puget Sound or some 4.5 x 10 m2 (Phillips, 1974). He calculated that
eelgrass beds fixed 1.5 g C/m2/growing season day, resulting in an annual
production of 187-1078 g/m2.
While much of the plant material produced in the marine environment is
consumed by grazers, 35-40% of the gross production may be liberated into the
sea as dissolved organic matter. Perhaps the most important contributions
that marine plants make to the ecosystem are as a source of detritus and as
shelter and a substrate for attachment for a wide variety of organisms.
II. F. Biogeography
The study area is part of a large temperate biotic province that
includes much of the West Coast of North America. There is considerable
disagreement concerning the boundaries and name of the province. The area
lies roughly in the middle of the Temperate Northwest American faunal
province which extends from the Aleutian Islands, Alaska south to Point
Conception, California (Sverdrup et al., 1942). Several authors suggest the
area is included in either an Aleutian, Oregonian, Temperate, or Oregonic
province that variously extends from as far north as the northern end of the
Gulf of Alaska south to Cape Flattery or thereabouts (Hedgpeth, 1957). The
most inclusive boundaries may be particularly reasonable for mobile animals
such as some fishes, birds, and marine mammals since they are the groups
least restricted in geographic range. The habitats of the study area
apparently support very few or no endemic species; but many of the
invertebrate and fish species found there occur only in protected marine or
estuarine waters. The study area represents one of the largest expanses of
protected, relatively shallow water of an estuarine character found along the
West Coast of North America. Therefore, it is of considerable importance to
marine biota that require a protected environment. All occur extensively in
the temperate latitudes of the West Coast of North America and in some cases
beyond to other continents.
The study area may represent the end of the southern or northern range
of some species. Except for migratory animals, the biological communities in
the study area are very dissimilar to those found in the tropics, but some
species found in the area also occur in the colder boreal latitudes.
12
-------
The phytoplankton and zo op lank ton of the study area are not endemic, but
represent a varying mixture of species which are typically associated with
open-ocean, protected marine and estuarine environments. Many of the
attached flora are endemic to the West Coast of North America (Abbot and
Hollenberg, 1976). The kelps are notable in this respect, although many
genera have representative species elsewhere. The seagrasses (e.g., Zostera
marina) are not endemic (Kikuchi and Peres, 1977).
Among fishes in coastal North America, the order Scorpaeniformes is
particularly well-represented. The families Scorpaenidae, Cottidae,
Agonidae, and Liparidae all have many endemic West Coast species. The family
Embiotocidae is endemic to the North Pacific, and nearly all of its species
are found in North American waters (Ekman, 1953). Several other groups,
including salmonids, osmerids, and clupeids, also have characteristic species
in this region.
Among marine mammals there is also a reasonably distinct northeast
Pacific fauna. Many of the species that are present in other parts of the
world are represented in this area by distinct subspecies. Some of the
species undertake long migrations from breeding areas to richer northern
feeding areas, and their contribution to the species assemblage of a
particular location is highly seasonal. Gray whales, for example, migrate
annually between Alaska and Mexico (Everitt et al., 1980).
Marine birds are even more mobile than fishes or most mammals, and do
not fit as well into the biogeographical boundaries that are useful for other
groups. Almost all species found in Puget Sound migrate seasonally to some
extent. The most prevalent pattern is migration n orth and south along the
North American coasts, dispersing inland in early summer to nest in boreal
and arctic North America. Nearly all species which breed in the area,
including various alcids, cormorants, and the Glaucous-winged Gull, nest on
relatively small coastal islands. A few species, such as the Lesser Snow
Goose and Common Pintail, have populations that migrate to eastern Siberia to
nest and winter in coastal North America (Palmer, 1976).
Although this high degree of mobility complicates efforts to
characterize bird species assemblages, several points emerge. First, very
few species that winter here are restricted to the West Coast of North
America, and none are unique to Puget Sound. Second, most of the species
found along the North American coasts are primarily found in relatively
shallow, protected waters. Concentrations of food in estuaries and along
tidal fronts may also constitute preferred habitats, and allow increased
species richness and abundance over open water habitat. Finally, the timing
of migration creates assemblages of species which vary substantially over
time and space, but which are nevertheless reasonably predictable over an
annual cycle.
13
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III. BIOLOGICAL COMMUNITY ORGANIZATION AND MAJOR
ECOLOGICAL PROCESSES: AN INTRODUCTION
III. A. Concept of Biological Communities
A suite or group of closely ecologically associated organisms compose a
biological community. Ecologically closely associated communities, in turn,
form the biological component of an ecosystem. The biota composing these
communities, in interaction with the physical processes, are described in
composite as an ecosystem. This sytem is characterized by a trophic
structure (food web), energy flow through that structure, cycling and
recycling of minerals, diversity patterns in time and space, community
control processes (e.g., predation, reproduction, competition), succession,
and internal control processes. The primary focus of this synthesis is the
biological components of the marine ecosystems of the study area, and the
following discussions will focus upon distinguishable biological communities
which have been identified and characterized.
Since functional processes, rather than geographical boundaries,
characterize biological communities, we have attempted to view communities on
the basis of organization and trophic relationships. Thus, those biota which
illustrate similar community structure and function, although often
physically separated in the region, will be considered as representing a
common biological community. Thus, any single community may be found at
numerous locations.
Biological communities will be categorized primarily according to the
dominant physical conditions. That is, a number of diverse habitats
represented on a relatively large regional scale will be used to illustrate
differences in biological communities. For example, intertidal/subtidal
communities will be categorized according to sediment type and exposure.
Where the habitat is characterized by a single, visibly prominent feature
(e.g., kelp beds and eelgrass meadows), these terms will be used to delineate
the biological communities or modify the category.
The use of physical habitats to delineate communities is justified since
many species show distinct preferences for certain physical conditions.
Comunity structure and trophic structure can be fairly similar at widely
separated places when physical conditions are similar. Therefore, each
habitat type can support distinct groups of organisms although boundaries
between these communities usually are not clear-cut. Habitats typically
grade one into the other; and, therefore, the communities do as well.
Biological communities described in this report are thus representative of
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the continuum of habitat, community structure, and function throughout the
study area.
III. B. Food Web Structure
Organic matter and energy are transferred and changed in biological
communities primarily by feeding or "trophic" interactions among producer,
decomposer, and consumer organisms. The pattern of material and energy flow
from the production and decomposition levels through the various consumer
levels is commonly referred to as a "food web." Food webs are typically
complex. Most predators consume many species of prey, often at several
trophic levels. Any single prey species may be eaten by many predators.
Lateral linkages, where one species consumes another of an equivalent trophic
level, or feedback linkages, where prey-predator relationships are reversed
during certain life history stages, may occur. The early concept of a food
chain, with single species prey-predator linkages, is now considered an
oversimplification, as such a food chain is relatively uncommon in nature.
III. C. Trophic Levels
Food web structure is characterized by organisms which synthesize,
decompose, or consume organic matter. The synthesizers (or producers) and
decomposers each constitute a "trophic level," while several trophic levels
may occur among the consumers.
Primary producers, plants which fix carbon by means of photosynthetic
processes, compose the "lowest" trophic level. The process of photosynthesis
involves conversion of carbon dioxide and water, using light as an energy
source in the presence of chlorophyll, into organic matter, with a
corresponding release of molecular oxygen. The principal primary producers
found in the study area include bacteria, phytoplankton, benthic diatoms,
various macroalgae (including the large kelps and foliose red, brown, and
blue-green algae), and vascular flowering plants such as marsh plants and
seagrasses. Since photosynthesis is light-dependent, primary production in
the study area is greatest in spring and summer and lowest in the winter.
Decomposers occupy a trophic level parallel to that of the primary
producers. Decomposers (or reducers) are microorganisms, usually bacteria or
fungi, which break down complex organic material into the simpler compounds
necessary for primary producers; this process may be either aerobic (with
oxygen) or anaerobic (without oxygen). Decomposition may be facilitated by
physical abrasion and grinding.
Consumer organisms can be categorized by the types and number of trophic
linkages occurring between them and a source of primary production. Animals
consuming primary producers directly are considered primary consumers, also
termed grazers or herbivores. Further categorization may be made based upon
the organisms' feeding strategies and the size of the food particles
consumed. Suspension feeders remove suspended phytoplankton and other food
particles from the water, while true grazers directly ingest particles of
attached microalgae, macroalgae, or vascular plants. Thus, primary consumers
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can include organisms from the smallest pelagic copepods which "graze" on
phytoplankton to geese which feed on seagrasses.
Secondary and higher level consumers are animals which prey upon other
animals and are referred to as carnivores. Primary carnivores feed on
primary consumers, secondary carnivores feed on primary carnivores, and so
on. The animals which occupy the top of this network of trophic levels are
termed the top carnivores and are not consumed by other carnivores. In short
food webs, the top carnivores may constitute only secondary consumers but
typically are tertiary carnivores.
Dead organic matter and the bacteria which break it down provide a food
base for a series of trophic levels similar to those based upon primary
production. A variety of feeding strategies are known for detritivores
(detritus consumers). Some species can directly graze on organic particles,
some on the bacteria, and some can prey upon other detritivorous animals.
The "classical" marine food web was historically considered to be based
upon autotrophic production of carbon by phytoplankton; consumption of
phytoplankton by herbivorous zooplankters with subsequent consumption by
carnivorous zooplankters; and so on up the food web. This classical food web
was based upon offshore research and appears to be correct for open water
pelagic systems. This early concept has changed with the recent shift in
research emphasis from oceanic ecosystems to emphasis on shallow nearshore
ecosystems. It appears now that shallow water marine food webs are largely
based upon the heterotrophic processing of detritus produced by the
senescence of marine algae and estuarine and saltmarsh vascular plants. The
contribution of eelgrass to the pool of detritus has been especially
implicated as a major source of organic carbon to nearshore food webs in the
temperate waters of the North Pacific Ocean (McRoy, 1970; Kikuchi and Peres,
1977; McConnaughey and McRoy, 1979a,b). Although grazing herbivores such as
sea urchins, isopods, and brachyuran crabs directly consume macroalgae and
vascular plant vegetation in the nearshore environs, most of the primary
level consumers appear to be detritivores (Simenstad et al., 1979). Thus,
while some algal organic matter is directly transferred to upper trophic
levels via these grazers, most of it reaches maturity, becomes detached, and
ends up decomposing on .the beaches and in shallow subtidal zones. It
eventually forms a pool of suspended and dissolved organic carbon available
for colonization by microflora. Not all detritus is directly utilizable by
marine detritivores because most marine invertebrates lack adequate enzymes
to digest it. Thus, structural- and nutritional decomposition of the
particles by marine bacteria and fungi appears to be a critical process in
conditioning the detritus for use by detritivorous fauna. In fact, recent
studies have suggested that the associated microflora may be the actual food
source of the detritivores (Mann, 1972a,b; Brown and Sibert, 1977; Mclntyre,
1969; Seki, 1966).
A simplified example of a shallow subtidal marine food web
characteristic of Puget Sound, with an energy flow based principally upon
detritus, is illustrated in Figure 4.
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Detritus
Par Ii c I e
Figure 4. Simplified example of a detritus-based shallow subtidal food web.
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III. D. Community Stability
A persistent question has been the existence of a relationship between
the complexity of biological communities or their food webs and their
"stability"—i.e., their resistance to collapse into a different, usually
less diverse, structure in the event of a perturbation involving the removal
of prey-predator linkages. Complex food webs are usually those having many
species and many prey-predator linkages. Another question is whether food
webs are actually "unstructured," in which case consumers randomly utilize
energy from the pool of available, catchable prey species in trophic levels
above that of primary production (Isaacs, 1972, 1973).
Considerable disagreement continues between those scientists who accept
the established theory of increasing stability with increasing food web
diversity and those who believe that randomly connected systems tend to
become less stable as the connectance (number of linkages) increases. There
are very few empirical data derived from laboratory or field studies where
the relationship of food web structure and perturbations has been tested.
The closest example of experiments directed toward these ends is that of
Paine's (1966) manipulation of rocky shore communities of Washington's
exposed coast in which removal of certain community dominants and their
associated food web linkages was found to result in dramatic alterations
(changed diversity and connectance) of the community and food web structure.
Thus, relatively complex food webs cannot be considered any more stable
than less diverse food webs if removal of ecologically important taxa or
trophic groups can have an identical restructuring effect. (Ecologically
important species are those that are critical in maintaining the structure of
a community.) Those species which are ecologically important either:
(1) provide the majority of the energy sources for consumer organisms at some
time; (2) provide unique processes of converting or transferring organic
matter to states or trophic levels in which it is available to other
consumers; or (3) are "keystones" in the composition of the community and in
the direction and rate of food web energy flow, typically through selective
predation or grazing. In all cases, these organisms are responsible for what
might be considered "critical linkages" in the unperturbed food web, and the
structure of the community is predicated upon their presence in sufficient
numbers to exert a keystone effect.
III. E. Reproduction and Dispersal
Reproduction and dispersal patterns of individual species can have an
important influence upon the structure of biological communities. Factors
such as fecundity (number of offspring produced per individual), timing of
reproduction, availabilty of breeding areas, and ability and tendency of
young to disperse themselves can be as important as trophic relationships in
determining the ways that communities respond to disturbances. Reproductive
and dispersal patterns differ among biotic groups.
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III. £. 1. Marine Mammals. Of the nine marine mammal species considered
common in the study area, only three species (river otter, harbor seal, and
killer whale) have been observed breeding here, although two other cetaceans
may (harbor porpoise and minke whale). River otters and harbor seals give
birth to their pups primarily on land, while killer whales give birth in the
water. Pupping occurs annually in the spring and early summer for river
otters and mid-summer for harbor seals. A female killer whale may give birth
only once every three to four years. Pupping in river otters and harbor
seals is limited to specific sites, generally on undisturbed small islands,
making their regional reproductive success vulnerable to perturbation.
The dispersal ability of marine mammals as adults is excellent because
of their tremendous mobility. Many of the species found here occur along the
entire coast of North America; some have a worldwide distribution.
III. E. 2. Marine Birds. Twelve species of marine birds out of the
approximately 80 species regularly reported breed in this region. All
breeding species nest every year in the spring. Generally, nesting is
localized, site-specific, and on small islands or other remote areas free of
human and other mammal disturbance. Ninety-four percent of the approximately
30,000 regional breeding pairs nest on a group of islands off Lopez Island
and on Smith/Minor, Protection, and Tatoosh Islands.
The dispersal ability of marine birds in most cases is superb because of
their flying ability. The young birds of the year may wander far from their
hatching site. The instigation of breeding is usually delayed for two or
more years, varying among the species. From what little is actually known,
site attachment varies from very strong to weak among both experienced adults
and birds returning to their natal colony to breed for the first time.
III. E. 3. Marine Fish. Most marine fish of this region disperse eggs into
the water during spawning. Some species spawn on intertidal beaches or
deposit eggs among marine vegetation. Some members of the family
Embiotocidae (sea perches) and a few other species develop eggs internally
and release their young as fry. Eggs of most species remain near the bottom
with the major exception of members of the family Pleuronectidae (flounders),
in which the eggs drift near the surface. Larvae of virtually all species
are small and planktonic. Except for members of the genus Hexagrammos
(greenlings) in which larvae drift near the surface, fish larvae are
distributed throughout the water column.
Marine fish here reproduce generally once a year in the late winter and
early spring. Spawning and egg brooding in species which guard eggs are
often localized and habitat specific. Herring spawning, for example, is
restricted to intertidal cobble beaches. Reproduction success varies
tremendously from year to year among those commercial species studied by
fisheries biologists.
Unlike marine mammals and birds which disperse only as adults, or
young-of-the-year, marine fish have excellent dispersal ability both as
adults and larvae. Eggs and larvae may drift considerable distances before
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metamorphosis and maturation take place. All species have strong swimming
capabilities and wide geographic ranges.
III. E. 4. Marine Benthos. Among the benthic plants and animals of this
region, the method of reproduction varies across the entire spectrum known to
biologists: asexual, sexual, haploid/diploid phases, direct development, or
complex life histories with several larval phases.
Benthic organisms reproduce at least once each year and reproduction in
most is strongly seasonal, usually peaking in late winter to early spring.
In general, reproduction occurs where he adults are found, not in different,
specialized breeding areas. Reproduction success among some benthic
organisms in this region is known to occur in multi-year cycles and, thus,
can be highly unpredictable.
While planktonic invertebrates have a high dispersal ability as larvae
and adults, virtually all adult benthic organisms have very limited or no
dispersal ability. For many of them reproduction involving a planktonic
larval stage is critical for dispersal and recruitment to new areas. Despite
the importance of planktonic larvae for dispersal, a planktonic larval stage
is not universal among benthic organisms. Many produce eggs which develop
into benthic or epibenthic larval or juvenile forms. Nonplanktonic life
cycles are almost universal among small benthic crustaceans, nematodes,
flatworms, and oligochaetes. They are very common among polychaetes and
occur even among some bivalves, gastropods, sea stars, and sea cucumbers.
III. F. Migrations and Movements
In normal use, the word migration simply means to move from one place to
another. When applied to animals, it has a special meaning: a migration is
a repeated movement with the seasons, and implies a "once-a-year"
periodicity. The most obvious examples of migrants are provided by birds.
Birds have been classified and reclassified as to types of migratory
movement. Unfortunately, many of these schemes are too rigid to apply to
mammals and fish. Small fish may be carried passively hundreds of miles by
oceanic currents and what may be no more than a dispersal could then have all
the appearance of a true migration. The relative importance of active
migration versus passive transport has been difficult to assess among fish.
The definition of migration as a class of movement which impels migrants
to return to the region from which they have migrated is used here. Note
that no distinction is made between active and passive migrations. The word
"impel" is used in the sense of biological necessity. The more spectacular
migrations are usually for feeding or spawning purposes, although another
reason might be to secure more suitable climatic conditions.
III. F. 1. Marine Mammals. The term migration as it applies to marine
mammals (and many terrestrial mammals as well), refers to long distance
movements of a specific population or major segments of a specific population
(often differentiated by age-class or sex), usually in response to specific
biological or environmental factors. Availability of food resources and,
secondarily, breeding areas, appear to be major factors which induce
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migrations (e.g., gray whales). Shorter, "local" movements of animals from
one feeding area to another nearby or from nonbreeding to breeding areas are
generally not considered migrations (e.g., killer whales in Puget Sound).
Both of these generalized movements have been documented in the study area
for certain species of marine mammals.
Cetaceans (whales, porpoises, and dolphins) are observed in northern
Puget Sound most frequently in the spring and summer months. The reduced
frequency of observations in fall and winter months suggests there are
seasonal movements to and from the area. The extent of these movements and
the numbers of animals involved are poorly known. It would be premature at
this time to consider most cetaceans as being migratory through the study
area. The biases within the existing data (generally greatly reduced
censusing effort in winter months) make it difficult to know what these
movements represent (Everitt et al., 1980).
The migratory behavior of the gray whale, which passes through
Washington coastal waters, are well-known. Essentially the entire population
of 11,000-15,000 animals passes through Washington coastal waters southbound
to breeding areas in Baja California, Mexico in November and December and
northbound to feeding areas in the Bering and Chukchi Seas from February to
April. Occasionally, individuals or small groups of animals wander into the
Strait of Juan de Fuca and Puget Sound during these migration periods. ;.
The natural history of the pinnipeds (seals and sea lions) frequenting
the study area is better understood than that of cetaceans. Thus, seasonal
movements are easier to detect. The most abundant marine mammal in the study
area, the Pacific harbor seal, is essentially nonmigratory. The California
sea lion and northern sea lion are seasonal migrants with individuals of both
species appearing in the study area in the fall following the breeding season
and leaving the area by late spring. Two other pinnipeds, the northern
elephant seal and northern fur seal, occur rarely in the study area during
offshore movements in the spring and fall.
It is presumed that the greatest species diversity of marine mammals
occurs in spring-summer with greatest abundance in mid- to late summer. This
influx of animals most probably is in response to increasing abundance and
diversity of suitable prey throughout the study area.
III. F. 2. Marine Birds. The term migration in reference to marine birds
generally means the movement of birds over large geographical areas, i.e.,
the North American continent, the Western Hemisphere, the Pacific Coast of
North America, or the North Pacific Ocean. Migration is a twice-annual
event, with one movement in the spring from wintering areas to breeding
grounds, and the other in the fall, when birds move from breeding areas to
wintering areas. In some species there is essentially no migration, with
adults and young staying relatively close to the nesting area, but this is
not common.
The rate at which migration occurs is variable between species, and
varies in date from year to year. Adults in some species migrate before
young birds are ready to leave nest areas. Some species move slowly, with
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one or more stop-over areas In which they forage or may even molt, before
continuing on the migration. Other species fly nonstop for tremendous
distances, often without feeding or stopping.
Large-scale migrations occur in the study area, though actual migratory
movements are not often readily apparent but are chiefly evidenced by
presence/absence patterns which may change overnight or within a few days.
Imbedded within these large-scale movements are other movements, often of
major local proportions, i.e., movements from one feeding area to another,
movements from night roosting to daytime foraging areas.
Many of the birds that breed in the study area appear to spend the
winter in the area. Dispersal by young birds from a breeding colony may be
rapid and extensive, while adults may move more slowly and for short
distances; e.g., many immature Glaucous-winged Gulls appear to leave the
area, while locally-nesting adults may not. Perhaps because of the mild
winter in the study area and adequate food supplies most individuals of most
breeding species appear to remain in the inland marine waters. However, the
vast majority of the Rhinoceros Auklets leave the area for the winter, as do
the Tufted Puffins.
The Puget Sound region (and the study area in particular) is very
important as a wintering area and stop-over area for many birds migrating
along the Pacific Coast. There are many species that stop here, with many
individuals remaining for the winter while others continue south. This is
the case with the Black Brant, with some staying here in a few locations all
winter while most of the population continues south to winter in California
and Mexico.
There are only a few species (e.g., a number of shorebirds) that appear
here only as migrants on their twice-annual passages through the area. These
species are generally long-distance migrants, some breeding on the Arctic
slope and wintering in southern South America.
There are no species which have populations wintering exclusively within
the study area. , However, there may be currently unrecognized subpopulations
that do reside here exclusively during the winter. There is evidence of
individually marked birds (leg- or neck-banded waterfowl) or birds of rare
species (presumably the same individuals) wintering at the same location over
several years. It is also probable that individual long-lived marine birds
or populations retrace their migration routes quite closely each year.
III. F. 3. Marine^ Fish. The research conducted in the study area indicates
that fish migrations can usually be reduced to a simple triangular pattern:
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Adult Feeding Ground
recruitment
B
Spawning Eggs, larvae Nursery
area (passive drift) area-juveniles
A -» B is with the water currents
B-» C, and C -»• A are against the currents
A-» C is with the currents
Some biologists theorize that the most abundant fishes (which are generally
the commercially important fishes) are nearly always migratory fishes because
of the evolutionary necessity of separating the three major life history
stages (eggs/larvae, juveniles, adults) to provide maximum numbers.
There are many kinds of migrations and movements of marine fish in the
study area which must be taken into account when considering the importance
of various habitats. Three examples will be given to support this statement.
Juvenile pink and chum salmon, migrating from freshwater streams and
rivers to the ocean, spend much of the first six months of the year (usually
the spring and summer) along the beaches and shorelines feeding on epibenthic
organisms. Although these are "transient species," they are present every
year at approximately the same time.
Pacific herring spawn in the same marine areas year after year and on
similar dates. Some of these areas, such as some of the ones classified as
cobble and gravel habitats of low productivity, obviously present ideal
conditions for both egg and early larval survival; there is little dispute
among the scientists studying the early life history of fish that the key to
larval survival is an abundant availability of the right kinds and densities
of food.
Lingcod make annual spawning migrations from deep water to the nearshore
waters of the rocky reef habitat. This migration occurs from about December
through May and although the female spends little time in the shallow water
once her eggs are deposited, the male guards one or more nests and may spend
many weeks in the upper subtidal rocky habitat. Removal or abandonment of
nests by male lingcod, for whatever reason, will usually result in the
destruction of these nests.
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III. G. Natural Stresses. As described in the section on Biogeography, the
flora and fauna of the study area are similar to that of the larger North
Eastern Pacific province. However, as one proceeds into the study area from
the mouth of the Strait of Juan de Fuca, species richness decreases among
benthic invertebrates. There are a number of natural stresses in the study
area that may, in part, explain the decrease in species richness in the study
area compared to the open coast. These natural stresses also affect how
marine biological communities respond to human-caused perturbations. In some
cases they may cause biological changes that exceed in magnitude those that
may be caused by pollutants or other perturbations. Species richness for
fish and birds increases due to increased protection and habitat diversity.
As one proceeds eastward through the Strait of Juan de Fuca and into the
San Juan Islands, the mean wave energy decreases. Those species adapted to
more exposed conditions, particularly those living in the intertidal zone,
are not always replaced by species more adapted to quiet water; therefore,
species richness is decreased.
Exposure of intertidal habitats during tidal cycles has a profound
effect on the distribution of organisms. In all habitats the strata
submerged only during high tides are virtually barren of organisms. Species
richness, total abundance and biomass usually increase in the lower tidal
strata. Regional differences in the extent of stress from tidal exposure
occur. The time of lowest tide in spring and summer near the Pacific Coast
is in the early morning, while in fall and winter the lowest tides are in
midday. More easterly in the study area (i.e., the San Juan Islands), the
timing of maximum exposure is reversed. Spring and summer lowest tides are
in midday or early afternoon, and winter time lowest tides are during the
night. This means that the intertidal area in summer is exposed to maximum
insolation and exposure stress and in winter is exposed to lowest temperature
and the greatest risk of freezing. The effect of intense summer insolation
is evident in the "summer burn off" of algae. In rock and cobble habitats
relatively rich growths of brown and green algae that can be found in the
lower intertidal in March and April are very much reduced in July and August.
Although estuaries are rich and productive areas in their own right, the
reduced salinity caused by fiver flow is a stress to many organisms and
species richness can be relatively low. Small localized estuaries are found
throughout the study area (i.e., Pysht River, Elwha River). The Fraser River
discharges the greatest amount of freshwater to the study area. Depressed
salinity in the freshwater/seawater.mixing zone is a stress to many species
adapted to more saline conditions. Smaller scale lower-salinity stresses may
occur where groundwater seepage, springs, small creeks, and storm drains
occur. As a result of reduced salinity, some species normally occurring in
the area may be missing from communities located near the source. They may
or may not be replaced by other species more tolerant of low salinity.
Uprooted trees and cut logs commonly occur in the study area and can be
a stress to intertidal biota. Particularly during storms, logs scour the
intertidal areas and may cause extensive damage, particularly, to rock and
cobble habitats. This "natural" stress is even more pronounced on the open
coast and has been documented by Dayton (1971). Log scouring may create new
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space for colonization by removal of existing biota. It also may increase
the diversity of habitat types by modifying the substrate type. The
magnitude of effects varies with the amount of wave action.
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IV. BIOLOGICAL CHARACTERIZATION OF MAJOR HABITAT
TYPES OF NORTHERN PUGET SOUND AND THE
STRAIT OF JUAN DE FUCA
IV. A. Intertidal/Subtidal
IV. A. 1. Habitat definitions. In designing a sampling program for marine
communities, with the exception of mammals and to some extent birds, it is
not possible to sample the entire biota of a region. An alternative approach
is to use a habitat-by-habitat sampling design. Therefore, using this
design, the range of habitats within the study area was first determined and
then typical areas representative of each type were selected for sampling.
The bird and mammal censuses were conducted areawide and the habitat types
noted for each standard subregion. A number of classifications of the
nearshore habitat of this region have been developed recently by various
state and federal agencies. In reviewing these and the data gathered to date
on the biological communities of the region, the range of habitats was
divided into three major types labeled according to sediment type and
exposure to wave action and tidal currents. These are:
(1) exposed unconsolidated sediments (coarse sand and gravel),
(2) protected unconsolidated sediments (mud and mud mixtures), and
(3) rock (including cobble).
Several points must be kept in mind with regard to intertidal/subtidal
habitat designations. First, both exposure and sediment types are physical
characters with continuous gradients, not a series of discrete states. The
communities characteristic of each habitat type are also present in
continuous gradients, not in discrete states implied by these treatments in a
classification scheme. Another important point to keep in mind is that the
habitat found in the intertidal zone at a given site may not be the same as
that in the subtidal zone. Generally, sampling or direct observation is
necessary to determine the subtidal habitat type.
IV. A. 1. a. Exposed unconsolidated sediments. This habitat type (Figure 5)
is defined by its exposure to moderate-to-severe wave and/or tidal current
action. This severity of exposure precludes the accumulation of fine
sediments, so the substrate ranges from sand to gravel to small cobble. The
sediments are not stable. They are either in constant motion or in motion
during severe wave or current conditions. This motion is sufficient to
preclude the development of a surface community of attached macroscopic
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organisms. This absence of live organisms and more generally even the
absence of evidence of organisms such as tubes, casts, or shells is a
diagnostic surface feature. The beach gradient or slope is steep; therefore,
the beach is narrow. The backshore is usually limited in development. The
beach geomorphology is erosional, often associated with feeder bluffs and
longshore sediment movements.
Within this general habitat type two subcategories are recognized, based
largely on sediment type. The first is defined by exposed mixed coarse
sediment, primarily gravel and small cobble with little or no sand. The
sediment is in constant motion but the large between-grain pore size may
provide refuge space for some small organisms, including meiofauna. This
sediment motion also functions as a grinding mill, reducing the particle size
of trapped detritus. The other subcategory of exposed unconsolidated
sediments is exposed sand, primarily medium to coarse. This sediment is
somewhat more stable than that described above and the slope less steep. The
pore or interstitial space is much more restricted, and it usually occurs in
areas slightly less exposed than those with mixed coarse.
IV. A. 1. b. Protected unconsolidated sediments. The overriding
characteristic of this habitat type (Figure 5) is the protection from strong
wave and/or tidal current action. This is the habitat of the bays and
harbors of this region. Protection from waves allows for the accumulation of
fine sediment, mud, and silt, often mixed with some sand and gravel. The
beach surface and sediments are stable. The diagnostic surface feature of
this habitat type is the presence of abundant live organisms, their holes,
casts, and tubes.
The beach gradient is low and the width is relatively great. The
backshore is often very well-developed and occasionally associated with
marshes. The geomorphology of these beaches is accretional; the sources of
fine sediment are rivers, streams, or erosional bluffs.
Within this major habitat category the subcategories of protected
gravel/mud, sand/mud, and mud may be recognized by their dominant sediment
type, reflecting the influence of increasing percent mud. Pore size
decreases, retention of organic debris increases, and the degree of
protection increases as grain size decrea'ses from gravel/mud to mud.
IV. A. 1. c. Rock. The exception to continuous gradients of sediment
substrata discussed above is the discrete substrate of rock. The diagnostic
feature of this habitat type (Figure 6) is the presence of the solid rock
surface. This surface provides a stable substrate for organisms which can
attach to it (epifauna and epiflora) regardless of the severity of exposure
to tidal current and wave action. Therefore, exposure in the habitat type
covers the range from protected to extremely exposed. The beach slope of
rock habitats varies from medium to steep, although some areas are
characterized by a fairly broad wave-cut terrace.
Three subcategories of this major habitat are recognized. The first two
are characterized by the presence of solid rock and represent the extremes of
the wave exposure gradient: protected rock and exposed rock. The third
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a. Rock habitat
b. Cobble habitat
Figure 6. Examples of intertidal rock and cobble habitat categories.
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Exposed unconsolidated habitat
b. Protected unconsolidated habitat
Figure 5. Examples of exposed and protected unconsolidatad intertidal/subtidal
habitat categories.
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subcategory is more complex: the cobble habitat (Figure 6). This habitat is
characteristic of erosional beaches where the eroded material contains large
cobbles, resistant to movement by wave or tidal action, that cover a wave-cut
terrace and allow the accumulation of finer sediments under the rocks. This
subcategory is a hybrid between the rock habitat and the protected
unconsolidated habitat in that it supports both an infaunal and an epifaunal
biotic component. Because of the heterogeneous character of the cobble
habitat, it is considered by many to be a unique and distinguishable habitat
category. However, in this report it will be considered as a subcategory of
"rock," reflecting the strong influence of the epibiota in the composition of
the community associated with it.
IV. A. 2. Spatial extent. Rough estimates of the distribution of the three
major habitat types are shown in Figure 7. These estimates were based upon
shoreline type designations provided in the Washington Coastal Zone Atlases.
Exposed unconsolidated habitats occupy about 50% of the shoreline. This
habitat type is common along the eastern portion of the Strait; the west
coast of Whidbey Island; around parts of Lopez, Guemes, and Lummi Islands;
and along parts of the shore extending between Sandy Point and Boundary Bay.
Rock (and cobble) occupy about 40% of the shoreline. Major rock areas
occur along the western portion of the Strait and around many parts of Orcas,
San Juan, Shaw, and Stuart Islands.
The remaining shoreline (about 10%) is occupied by protected
unconsolidated sediments. This habitat type is restricted to embayments such
as Discovery, Dungeness, Padilla, Samish, Birch Bays, and Drayton Harbor.
Very little protected unconsolidated habitat occurs along the Strait and in
the San Juan Islands.
IV. A. 3. Major biological assemblages. Study sites at which intertidal/
subtidal data were collected are listed in Table 1 along with the habitat
type that each site represented. The locations of these sites and the
geographic extent of the data base are shown in Appendix Figures I-A through
I-D. The following discussions were derived from syntheses of data collected
at these sites. Individual data sets were archived in technical reports and
on magnetic tapes (Appendix Table I-A). The tape formats are listed in
Appendix Table I-B.
IV. A. 3. a. Dominant and characteristic species of intertidal/shallow
subtidal benthic habitats.
IV. A. 3. a. (1) Rock/cobble habitat.
Marine mammals; Harbor seals were the most important marine mammals to
use this habitat type, followed by the sea lions (northern and California)
(Appendix Table II-A). This habitat was very important at low tide for
haul out, resting, breeding, and pupping for harbor seals. All the important
rock haul-out sites were located on islands (Table 2), thereby affording
these animals some protection and isolation from human disturbance. The rock
habitat was used by 68% of the local harbor seal population during the period
30
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Boundory Bay
49°-
Exposed unconsolidated sediments: mixed coarse,
sand
Protected unconsolidated sediments: mud-gravel,
mud-sand, mud
"""""m Rock: exposed rock, protected rock, cobble
Figure 7.
Estimated spatial extent of major intertidal/subtidal habitat types in the study area.
-------
Table 1. Intertidal/subtidal, nearshore and offshore study sites per habitat type.
Benthos
Fish
Birds* Marine Mammals
Habitat/Site
Intertidal/
Intertidal Subtidal Subtidal Nearshore
CO
ro
A. Intertidal/subtidal
1. Exposed unconsolidated
a. Mixed coarse
Legoe Bay
Guemes Island South
Ebey's Landing
Twin Rivers
Dungeness Spit
South Beach
Deadman Bay
b. Sand
Eagle Cove
West Beach
North Beach
Kydaka Beach
Alexander's Beach
2. Protected unconsolidated
a. Mud-gravel
Webb Camp
Beckett Point
b . Mud-sand
Birch Bay
Jamestown/Port Williams
c. Mud
Westcott Bay
Drayton Harbor
Padilla Bay
Fidalgo Bay
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
A
X
A
X
X
A
A
s
A
A
B
X
S
X
B
S
X
S
A
A
A
A
A
A
A
A
A
A
Continued
-------
Table 1. (Contd.)
co
CO
Benthos Fish Birds* Marine Mammals
Habitat/Site
3. Rock/cobble
a. Exposed rock
Neah Bay
Slip Point
Pillar Point
Tongue Point
Observatory Point
b. Protected rock
Migley Point
Fidalgo Head
Cantilever Pier
Barnes Island
Point George
Allan Island
c. Cobble
Cherry Point
Shannon Point
Partridge Point
North Beach
Morse Creek
B. Nearshore (Neritic)
1. Exposed
Kydaka Beach
Twin Rivers
Pillar Point
Morse Creek
Dungeness Spit
Intertidal/
Intertidal Subtidal Subtidal
X
X
X X
XX X
X
X
X X
X
X
X X
X
XXX
X
X X
XXX
XXX
Nearshore
X
A
A
A
A
A
X
X
B
X
X
X
A
X
X A
X A
X A
X A
X X
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
A
Continued
-------
Table 1. (Contd.)
CO
Habitat/Site
B.
C.
1. Exposed (Contd.)
Jamestown/Port Williams
Beckett Point
West Beach
Alexander's Beach
South Beach
Deadman Bay
Eagle Cove
Burrows Island
2. Protected
Birch Bay
Cherry Point
Lummi Bay
Migley Point
Legoe Bay
Guemes Island East
Padilla Bay
Guemes Island South
Shannon Point
Point George
Westcott Bay
Offshore
1 . Bays
2. Broad Passages
3. Narrow Passages
4. Open Waters
Benthos Fish
Intertidal/
Intertidal Subtidal Subtidal Nearshore
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Birds*
X
X
X
X
A
A
B
S
X
S
A
A
B
X
X
B
X
X
X
X
Marine Mammals
A
A
A
A
A
A
A
A
A
A
A
A
A
*X indicates sites where multiple bird censusing methods were used; A indicates aerial censuses only;
B indicates boat surveys only; S indicates shore censuses only.
-------
Table 2. Major haul-out areas of pinnipeds in the study area
Site
General Location
Habitat Type
Harbor seals
Sentinel Island
Ripple Island
Cactus Island
White Rock
Skipjack Island
Bare Island
Sucia Island
Matia Island
Puffin Island
Peapod Rock
Bird Rock
Buck Island
Barnes Island
' Dinner Island
Smith-Minor Islands
Protection Island
Dungeness Spit
Dungeness Bay
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
San Juan Islands
Eastern Strait
Eastern Strait
Eastern Strait
Eastern Strait
Rock
Rock
Rock
Rock
Rock
Rock
Rock
Rock
Rock
Rock
Rock
Rock
Rock
Rock
Cobble,
Cobble,
Exposed
gravel
gravel
unconsolidated
Protected unconsolidated
Race Rocks
Chain Islets
Becher Bay
Padilla Bay
Samish Bay
Bellingham Bay
Sea Lions
Race Rocks
Sombrio Point
Port Gardner*
Tatoosh Island
Eastern Strait
Eastern Strait
Eastern Strait
North Sound
North Sound
North Sound
Eastern Strait
Eastern Strait
Eastern Strait
Western Strait
Rock
Rock
Rock
Protected unconsolidated
Protected unconsolidated
Protected unconsolidated
Rock
Rock
Protected unconsolidated
Rock
*0utside main study area, sea lions haul out on grounded barge.
35
-------
of peak abundance (August) and by all sea lions. Race Rocks and Sucia Island
were highly important rock sites for harbor seals. Race Rocks was also the
most important rock site for sea lions. River otters are known to forage in
rocky intertidal/shallow subtidal areas.
Birds; The most common groups of birds observed at rock/cobble sites
were gulls, shorebirds, and ducks (Appendix Table II-B). Many species are
migrants or winter visitors. Glaucous-winged Gulls were observed in 100% of
the surveys (Appendix Tables III-A-C). Surf scoters were very common,
especially in the winter, occurring in up to 100% of the surveys. The other
common species were Bonaparte's Gull, Harlequin Duck, Bufflehead, and
White-winged Scoter (Appendix Table II-B).
While a number of birds (e.g., cormorants and gulls) are known to roost
on rocks above normal tidal levels, very few species forage directly in the
solid rock intertidal and shallow subtidal habitats themselves. The
ubiquitous Glaucous-winged Gull accounts for much of roosting usage, and
Great Blue Herons, Harlequin Ducks, and scavenging Bald Eagles along with
small numbers of a few rock-foraging shorebird species represent almost all
the foraging usage.
In general, the density of birds in rock/cobble habitats was usually
much lower than in other habitats. Density and biomass varied greatly in
locations where seasonal herring spawning attracted large numbers of some
birds, particularly Surf Scoters and other diving ducks.' Relatively few
wading birds appear to use this habitat. This apparently is one of few
habitats supporting nonbreeding populations of diving birds in summer.
Fish: About 18 species of fish were found in this habitat type,
including sea perch, sculpin, and juvenile forms of various rockfish,
flatfish, and cod. Some species were commonly found only in the tidepools of
the rock/cobble habitat (high cockscomb, calico sculpin, mosshead sculpin,
northern clingfish, and black prickleback) (Appendix Table II-C). Another
species (the tidepool sculpin) was found commonly both in tidepools and at
other habitats. Where Nereocystis luetkeana kelp beds were present in the
shallow subtidal area, a group of fishes (including sea perch, rockfish,
greenling, lingcod, sculpins, and gobies) was commonly found that was not
found at other habitats.
Intertidal benthos; The dominant benthic species found at the rock and
cobble habitats are listed in Appendix Table II-D. Some 83 taxa of algae and
macroinvertebrates were dominant at the rock habitat, while about 81 were
dominant at the cobble habitat. The primary producers include macro- and
microalgae. The dominant macroalgae were distributed primarily in the mid-
to low-tide zones (and were usually more extensive in the shallow subtidal
area). They included species of 53 Alaria, Fucus, Microcladia. and Gigartina
in the intertidal elevations and species of Desmarestia, Plocamium. Pterygo-
phora, and Costaria in subtidal zones. Macroalgae were characterized by
relatively large standing stock biomass and were not extensively used by
herbivores. Microalgae (mostly benthic diatoms) were common in the mid- to
high-tide areas.
36
-------
When dominant, macroalgae were an important factor in community
structure and relative abundance of other species at the rock/cobble
habitats. Macroalgae can provide a three-dimensional component to the basic
two-dimensional rocky surfaces. Similar to the trees of a forest, some
macroalgae, such as Laminaria, Egregia, and Alaria, may be considered as
canopy species. The "shading" created by the canopy species dissipates some
of the energy of waves and thus provides some relief from exposure and
encourages the growth of red algae species that find lower light intensity
conditions optimal for growth. Where algae species such as Alaria, Iridaea,
and Polysiphonia were important, tube building amphipods, such as
Ampithoe sp. were also found. Algae such as Corallina Vancouveriensis or
Endocladia muricata can support large numbers of small mussels, small worms,
and other wormlike species.
If barnacles predominate, species inhabiting crevices, such as
Typosyllis adamantea and the nemertean Emplectonema gracile may be more
abundant. Amphipod species, such as Hyale sp., which can nestle in crevices,
are also more abundant. Thus, dominance has a functional as well as a
descriptive aspect in these habitats.
The three-dimensional effect of macroalgae in the rock/cobble habitat
was found to be most well-developed at sites in the western areas of the
Strait. At cobble sites, the extent of the three-dimensional effect of algae
was also related to cobble size; cobbles must be large enough to remain
stationary.
A group of herbivorous urchins (Strongylocentrotus franciscanus and
S_. droebachiensis), snails (Littorina sitkana, I,, scutulata, and Collisella
pelta), and chitons (Katharina tunicata and Cyanoplax dentiens) were common
intertidal animals but were not found as dominant species in subtidal areas.
Although some herbivores (i.e., chitons) may eat macroalgae, most apparently
rely upon the microalgae and sporlings of macroalgae as food. Herbivores
were distributed throughout the intertidal zone and were the most commonly
encountered large animals in the mid- to high-tide zones.
Predators common to the rock/cobble habitats include anemones,
flat-worms, polychaetes, nemerteans, snails, and seastars. Four predators
that were not frequently sampled (because of patchiness and mobility) have an
important impact on community structure of the rock/cobble habitat. These
are the snails (e.g., Fusitriton oregonensis, Nucella lamellosa, and
N. emarginata) and the seastars (e.g., Pisaster ochraceus, Dermasterias
imbricata, Solaster stimpsoni, and Leptasterias hexactis.) Under optimal
conditions, these snails can remove all of the juvenile barnacles and mussels
that attach as larvae in any given year. The seastars may also dramatically
affect community structure by preying upon barnacles, mussels, and snails.
Suspension feeders include barnacles, mussels, bivalves, and spirorbid
polychaetes. Where large mussels were common (primarily in the western
Strait), a three-dimensional effect (similar to that of the macroalgae) was
found. Where fine sediments were trapped in mussel beds, suspension feeders
(bivalves) and deposit/suspension feeders (polychaetes, crustaceans) were
found.
37
-------
At cobble sites, the spaces between the cobbles and the finer sediments
that collect between and below the cobbles provided habitat for suspension
and deposit feeders. In general, more species of suspension and detritus
feeders were found at cobble sites compared with rock sites, possibly because
of the greater habitat diversity.
Subtidal benthos: At most sites where rock or cobble were sampled in
the intertidal zone, some different substrate was found in the subtidal area.
Thus, the data base for subtidal benthos associated with rock and cobble is
relatively weak. About 92 taxa were dominant in subtidal rock and cobble
habitats (Appendix Table II-D). The shallow subtidal area of the rock/cobble
habitat, in general, has similar functional characteristics to the intertidal
area. However, the species are different and there are often more of them.
Intertidal algae, such as Fucus, Enteromorpha, and Porphyra, were often
replaced in the shallow subtidal zone by Laminaria, Nereocystis. and
Costaria. Red algae were more common, often dominant, in subtidal areas than
in intertidal areas. At exposed sites the eelgrass Phyllospadix scouleri was
a dominant plant in the shallow subtidal. At some cobble sites, patches of
the eelgrass Zostera marina species were common. However, this species was
much more common in the protected unconsolidated habitats.
Herbivores at shallow subtidal areas were not as common as in the
intertidal zone. On the other hand, suspension and deposit feeders (mostly
bivalves and polychaetes) were more common at subtidal areas than intertidal.
IV. A. 3. a. (2) Exposed unconsolidated habitat.
Marine mammals: A number of small isolated areas, specifically
Smith-Minor Islands, Protection Island, and Dungeness Spit, were found to be
very important haul-out and pupping areas for harbor seals (Table 2, Appendix
Table II-A). The largest single counts of harbor seals were made at these
sites. Protection Island and Minor Island account for nearly 20% of the
observed harbor seal population during the period of peak abundance (August).
Bird_s; The groups of birds using this habitat type included the gulls,
terns, ducks, alcids, and shorebirds (Appendix Table II-B). Surf Scoters,
White-winged Scoters, and Glaucous-winged Gulls were the most widespread and
abundant species, followed by the Bufflehead, Mew Gull, and Bonaparte's Gull.
Densities were higher in mixed coarse subtidal sites than in unconsolidated
sand locations, and greatest seasonal use occurred in winter (Appendix Tables
III-D and III-E). Censuses over these habitats also recorded high seasonal
densities of several gulls. However, gulls often used locations like
Dungeness Spit and West Beach as daytime roosts adjacent to offshore foraging
areas; thus, these figures may not reflect biological productivity of the
intertidal/subtidal habitats themselves. There was relatively low use of
these habitats by shoreline foragers like shorebirds, probably reflecting low
densities of prey species.
Fish: This habitat appears to support fewer fish species than any other
habitat. About 36 dominant species were found, including sea perch,
sculpins, flounders, gunnels, greenlings, and juveniles of the Pacific
tomcod, cabezon, and English sole (Appendix Table II-C). Although there were
38
-------
relatively few demersal species found in the shallow subtidal and the
intertidal zones, the habitat appears to be important to some neritic
species. Gravel and sand beaches in the shallow subtidal zone are known to
be used by some species for spawning (i.e., Pacific herring).
Few species occurred at exposed sand beaches and exposed gravel beaches;
the least occurred at sandy sites. Where an exposed unconsolidated site was
adjacent to another habitat type, the species composition of fish was
affected. For example, the Twin Rivers site was gravel and sand in the
shallow subtidal, but cobble and rock substrates border the beach seine site
and the fish species were characteristic of these other habitats.
Sites with intertidal exposed unconsolidated habitat often had different
sediments in the shallow subtidal area. Most of the shallow subtidal
substrate at exposed unconsolidated sites had large cobbles with attached
epiflora and fauna (i.e., Ebey's Landing, Guemes Island South, Legoe Bay).
Many more fish species were often found at such sites. Many species of sea
perch, gunnels, sculpins, poachers, and flatfish were dominant (including
juveniles of Pacific tomcod, walleye pollock, copper rockfish, cabezon, and
English sole). It is of interest to note that the fish fauna found at-these
exposed mixed coarse sites was very similar to the fish fauna of the
protected unconsolidated habitat.
Intertidal benthos; Compared to other habitats, the intertidal flora
and fauna at the exposed unconsolidated habitat was impoverished. Only 21
taxa were dominant at this habitat (Appendix Table II-D). Except for diatom
films (not measured) and occasional bands of the green algae (Monostroma
or Ulva) that may be found on patches of cobble in the low intertidal, no
attached plants were dominant at this habitat. Only two herbivores—the
amphipod Anisogamtnarus pugettensis and the snail Lacuna variegata—were
dominants. Most remaining species were deposit feeders—polychaetes,
amphipods, isopods, nematodes, oligochaetes, and bivalves. These species
probably feed on detritus imported from other habitats. Compared to other
habitats, polychaetes were poorly represented due to sediment instability and
the relative lack of fine material in the sediment. Nemerteans were often
the top carnivore found in this community.
There is generally a higher spatial variability in dominant forms at
this habitat than in the others. Conditions of desiccation and substrate
instability are often extreme. Colonization is usually difficult and
patchiness of distribution is correspondingly large.
Although the general benthic biomass of this habitat was low, notable
exceptions have been observed. Amphipods of the genus Paraphoxus and
Paramoera were seasonally very numerous. For example, up to 40,000 Paramoera
mohri per square meter were consistently found in the summer at Ebey's
Landing.
Subtidal benthos: Only three sites with exposed unconsolidated
sediments in the shallow subtidal area were sampled: Dungeness Spit, Twin
Rivers, and West Beach (Appendix Table II-D). The substrate in the subtidal
zone of the study area was more often cobble with high substrate stability.
19
-------
Fine sediments often occurred between and under the cobbles. Ebey's Landing
and Legoe Bay exemplified this habitat type and are discussed above.
At the sites with exposed unconsolidated substrate in the shallow
subtidal area, the benthos often illustrate a pattern similar to that of the
intertidal zone. That is, relatively few species were found as dominants. A
total of only 14 species were dominant at Dungeness Spit and West Beach.
None were primary producers. Deposit and suspension feeders were often less
common than at other habitats, although there were more species in the
subtidal areas than in the intertidal areas (probably related to increased
protection and finer sediments in the subtidal substratum). The small
bivalves Mysella tumida and Psephidia lordi were common as were sand dollars,
Dendraster excentricus. More deposit feeding polychaetes were found in the
subtidal compared to the intertidal zones. However, polychaetes were more
numerous in the protected unconsolidated and rock/cobble habitats. It
appears that substrate instability may prevent the occurrence of tube
building polychaetes in the exposed unconsolidated habitat.
IV. A. 3. a. (3) Protected unconsolidated habitat.
Marine mamma 1 s: Mud and sandflats are used for haul-out by harbor
seals, and apparently no other species (Appendix Table II-A). Sites observed
to be important for haul-out included Padilla Bay, Samish Bay, Dungeness Bay,
and Jamestown (Table 2). Some of these areas, for example Padilla Bay, were
used for haul-out only at low tide when the mudflats were exposed. Drainage
channels are often used for escape from disturbance. Though sea lions were
observed in a muddy area of Port Gardner, they were hauled out on a barge.
Birds: Gulls, terns, ducks, geese, sandpipers, and grebes were found to
be the dominant groups of birds in this habitat type (Appendix Table II-B).
This habitat supported some of the highest seasonal densities and biomass of
marine birds within the study area (Appendix Tables III-F-H). In addition to
high numbers of the widely occurring diving ducks, eelgrass-associated
species like Black Brant and wigeon formed very large components of the
populations in winter and during migrations. Gulls also foraged in large
numbers in these areas at low tidal stages.
The tables in Appendix III, representing the 10 most-frequently observed
species in each season, do not reflect the great relative importance of these
habitats to shorebird populations or the fact that seasonal species richness
in these habitats was greater than other subtidal/intertidal habitat types.
Most usage of these habitats was by winter resident and migrant species.
Breeding species generally do not nest adjacent to these habitats (except at
Padilla Bay, Jamestown, and Drayton Harbor); i.e., nest sites are generally
not available, so summer usage is relatively low. However, resident
Glaucous-winged Gulls often forage in large numbers on exposed intertidal
flats during the summer.
•
These protected unconsolidated habitats are also heavily used,
particularly in summer, by Great Blue Herons. Several nesting colonies were
located adjacent to protected embayments in the study area. The data in
40
-------
Appendix III represent averages from censuses taken at" all tidal stages and,
since herons were not present at all during high tides, densities of this
species were understated for areas near nesting colonies. For example, at
Padilla Bay or Samish Bay 300± birds were observed foraging at low tides in
summer.
Fish; Twenty-eight species were dominant at sites representing this
habitattype: sculpins, the tube-snout, various sea perch and juvenile
Pacific tomcod, English sole, and starry founders (Appendix Table II-C). The
common fish fauna at this habitat was similar to that of sites where the
shallow subtidal sediment was exposed mixed coarse. Beckett Point samples
often had the most species, greatest density, and greatest biomass of any of
the sites that were studied.
Intertidal benthos; The intertidal benthos of the protected
unconsolidated habitat was generally more species-rich than the
unconsolidated exposed habitat, and less species rich than the rock/cobble
habitat. Some 75 dominant taxa of benthos were found at this habitat
(Appendix Table II-D).
Most primary production was from eelgrass meadows of Zostera marina,
although eelgrass meadows had their maximum abundance in the shallow subtidal
depths. Eelgrass in the intertidal zone was restricted to the +3 foot tide
height or lower. Where eelgrass meadows were found, a three-dimensional
structure was added to the community and epifaunal species (particularly
amphipods) were commonly found. Eelgrass appeared to be a very important
habitat for epibenthic zooplankton.
Benthic herbivores were not common in the intertidal zone at this
habitat. Platynereis bicanaliculata (a polychaete) was found in the infauna.
Other herbivores (i.e., Littorina spp. and Lacuna sp.) were found only at
those sites having a cobble-like substrate at higher tidal elevations or on
eelgrass.
Polychaetes were very well-represented at the protected unconsolidated
habitat. Some 30 dominant taxa were found in the intertidal areas. Most were
deposit feeders, with some predators and a few suspension feeders. Bivalve
molluscs were also well-represented at this habitat._ Some 11 dominant
species (primarily suspension feeders) were common at this habitat.
In protected habitats, predominant species can be divided into those
which are numerically abundant, but which, because of their small size, have
low biomass; and those which are not particularly numerous, but whxch
contribute a major portion of the standing crop. The former category
includes such groups as oligochaetes, small polychaetes, and amphipods; while
large bivalves such as Ma coma nasuta, Clinocardium nuttallii, Protothaca
staminea. and Mya arenaria, and the mud shrimp, Upogebia pugettensis fall
into the latter category. A few species were found to be important in both
senses in some locations. These included the polychaetes Abarenicola sp. and
Owenia fusiformis. The relative functional importance of species having high
density but low collective biomass versus species having high collective
41
-------
biomass but low density is not clear, especially since information on rates
of reproduction is lacking.
The upper tidal elevations of the protected unconsolidated habitat had a
variable flora and fauna that were related to site specific substrate
variations. Some sites (i.e., Birch Bay, Padilla Bay) had sandy or gravelly
sediment in the upper intertidal zone and were found to have almost no flora
or fauna. Other sites (Fidalgo Bay, Drayton Harbor) had cobble or rocky
surfaces at higher intertidal elevations and had typical rock/cobble flora
and fauna. At these sites, dominant epiflora and epifauna species included
algae (Enteromorpha and Fucus), herbivorous snails (Littorina) and barnacles
(Balanus glandula). At yet other sites (e.g., Westcott Bay) with protected
unconsolidated habitat, marsh vegetation (not measured) was found beyond the
upper intertidal elevations. At this site, bivalves (Mya arenaria, Macoma
balthica), polychaetes (Abarenicola sp.), amphipods (Corophium spp., and
tanaeids (Leptochelia dubia) were all commonly found at the +5 feet and
+6 feet tidal elevations. Species richness and total abundance at these
tidal elevations were greater at the high intertidal than at any other site
in any habitat. At Westcott Bay, marsh vegetation continued from the +7 feet
to +9 feet tide heights and beyond. Oligochaetes, nematodes, and dipteran
larvae were found in this vegetation.
Subtidal benthos: Most taxa found in subtidal benthos were burrowing or
tube-dwelling organisms. Few attached biota were found. Fewer dominant taxa
of benthos (48) were found at the subtidal protected unconsolidated habitat
compared to the intertidal (75 species). This trend is a reverse of that
observed at most exposed unconsolidated and cobble habitats. Brown and red
algae were occasionally found at this habitat, although the bulk of primary
productivity occurred within eelgrass meadows.
Polychaete species were well-represented in the subtidal area of this
habitat (24 dominant species) as well as in the intertidal zone (30 dominant
species). Although most species in the subtidal area were deposit feeders
(as in the intertidal zone), species composition differed between the
subtidal and intertidal zones. Bivalve molluscs (suspension-feeders and
carnivores) were common along with gammarid amphipods. Crabs seeking shelter
among algal fronds and other debris were common.
IV. A. 3. b. Trophic organization.
IV. A. 3. b. (1) General background.
Trophic or food web structure of the biotic communities characterizing
each broad habitat type have been described previously in Simenstad et al.
(1979), where the relative importance of linkages between nodes (elements of
the various trophic levels) were subjectively weighted by the occurrence of
food items in the diet of the consumer. At that time no attempt was made to
weight the relative importance of the producer or consumer in the community.
A thorough evaluation of the organization and flow of organic matter through
a food web, however, must consider the proportional production and
utilization of organic carbon by the various components of the community.
The availability of production and consumption rate information for organisms
42
-------
in this region is unfortunately too sparse and inconsistent to permit such a
food web synthesis. As an alternative, though less than optimal, approach we
have utilized the standing stock (the quantity of living material present per
unit area at a selected point in time) of organisms in representative feeding
categories to illustrate their relative role in the community.
While comparisons within trophic levels are feasible, standing stock
estimates in different trophic levels should not be considered comparable nor
used to imply energy flow due to the usually dramatic differences in
production rates. That is, orders of magnitude differences exist in the
generation times of phytoplankton versus herbivorous zooplankton versus
zooplanktivorous fishes and birds. These differences are best illustrated by
the production/biomass (P/B) ratio which has been shown by Petipa et al.
(1970) to range in the Black Sea from 63 for primary producers, to 65 for
herbivores, to 47 for primary carnivores, to 6 for secondary and tertiary
carnivores in one epibenthic community. The implication from these data is
the plants, because of their high turnover rate, produce much more organic
matter than members of the higher trophic levels.
Even the standing stock data are incomplete in this region, especially
for the lower trophic levels. Standing stock data for primary producers are
the most limited. Macroalgae, sea grass, and saltmarsh plant standing crop
values were obtained from averaging data from the WDOE and MESA intertidal/
subtidal data sets over a year's sampling period. Although detritus was a
food source of obvious importance, estimates of the proportional sources,
rate of accumulation and standing stock of detrital carbon are nonexistent.
All other data on the standing stock of macroalgae, grazing herbivores,
carnivores and other predators, omnivores and parasites originated directly
from the WDOE and MESA intertidal/subtidal data sets, both published
(Nyblade, 1977, 1978, 1979a/b; Smith and Webber, 1978; Webber, 1980; Smith,
1979; Everitt et al. , 1979/1980; Manuwal et al., 1979; Miller et al. ,
1978/1980; Simenstad et al., 1977/1979/1980; Cross et al., 1978), and through
further synthesis of these existing data. The taxonomic groups and species
considered important below in the trophic organization of intertidal/subtidal
habitats may not always agree with those considered important above in the
community organization. The prey found in stomach content analyses were
often dissimilar to the organisms found in benthos samples taken at the same
sites.
IV. A. 3. b. (2) Rock-cobble habitats.
These habitats were characterized by high complexity and diversity in
food web structures compared to other habitat types, including the offshore
and nearshore neritic habitats. Detritus was found to be the most prominent
source of organic carbon, based simply upon the number of food web linkages
(Figure 8). Quantitative comparison of the standing stock of the four
sources of organic detritus, inicroalgae, macroalgae, eelgrass, and
phytoplankton, were not possible because the data only exist for two sources,
the macroalgae and eelgrass. The macroalgae community was extremely diverse,
including 24 prominent" taxa in the intertidal zone and 31 taxa in the
subtidal. Microalgae (mostly benthic diatoms) were most common in the upper
43
-------
MOO «/
,213)
INTERTIDAL/SUBTIDAL- ROCK /COBBLE
PISCIVOROUS
MARINE
MAMMALS
o
o
o~
o-
o
8ENTH1VOSOUS
BIRDS
(0.51)
O '^5
O o.i-
DECOSIT DEIBITI-/HEBBI-
FEEDINC VOHOUS /VOROUS
AMPHI-
PODS
(10.931
SUSPENSION
FEEDING
TANAIDS
15.79)
EELSRASS
(296.91)
I f I
Figure 8. Characterization of rock/cobble intertidal/subtidal habitat food web.
of major taxa represented in parentheses(grams/m2 or grams/m3).
Average biomass
-------
tidal zones where they were grazed upon by herbivorous amphipods, gastropods,
and polychaetes.
Benthic infauna associated with sediments under and around cobbles and
epibenthic primary• consumers utilize three food sources (suspended matter,
detritus, and attached plants) to some extent, with the suspension feeders
illustrating the highest standing stock. Despite the high exposure and
well-flushed habitat, detritus feeders are often numerous and suggest that
the high relief of the substrate, with cracks, crevices and algae holdfasts,
is conducive to the retention of large detritus particles in the sediments
associated with cobbles. Polychaetes (including most often Polydora
pygidialis and Thelepus crispus) and decapods (Pagurus spp.) were found to be
the prevalent detritivores, with gammarid amphipods and insect (dipteran)
larvae being secondary in importance among the 10 detritivore-fceding groups.
Gastropods, chitons, and echinoderms made up about 90% of the standing crop
of herbivores feeding upon macroalgae and microalgal scums. Barnacles
(Balanus spp.) and bivalves (including Mytilus spp., Saxidomus giganteus, and
Clinocardium spp.) dominated the suspension feeders, composing 68% and 28% of
the total standing crop of that group, respectively.
Omnivorous decapods (Hemigrapsus spp.) utilized both detrital and
macroalgal food sources.
The high standing stock of sessile suspension feeders was reflected in
the secondary consumer level, which was characterized by high standing stocks
of their predators, including echinoderms and gastropods. These two groups
together comprised 89% of the total estimated standing stock at that trophic
level. Polychaetes (Pholoe minuta), decapods (Cancer oregonensis), and
nemerteans composed the remainder of the secondary consumers.
Among the tertiary consumers the demersal benthivorous fishes composed
the highest proportion of the standing stock, primarily because they included
two of the largest predators in the habitats' fish community, the kelp
greenling (Hexagrammos decagrammus) and the lingcod (Ophiodon elongatus).
Epibenthic planktivorous fishes, though composing a more diverse element of
the community, accounted for less than one-half of the standing stock of the
demersal fishes; yellowtail rockfish (Sebastes flavidus), black rockfish
(S. melanops) and copper rockfish (_S. caurinus) were the prominent species in
this group.
The added dimension of the intertidal and shallow subtidal substrate
also contributed to a greater diversity of birds foraging in these habitats.
The benthivorous species, primarily the Surf Scoter, White-winged Scoters,
and Glaucous-winged Gull, completely dominated this group.
The most important marine mammals to utilize prey resources within these
habitats included the killer whale and Pacific harbor seal, though they
likely forage primarily in nearshore and offshore waters. Both are
opportunistic fish-eaters.
In general, this food web is broadly based upon a variety of carbon
sources including detritus, although a greater proportion of the detritus
45
-------
generated by the extensive macroalgae production in these habitats is
probably exported into other, more protected habitats. The major transfer of
trophic energy, at least in terms of maintenance of standing stock of
consumer organisms, however, is through macroalgae herbivores and suspension
feeders.
IV. A. 3. b. (3) Exposed unconsolidated habitats.
The high exposure to waves and the unconsolidated character of coarse
sediments typifying these habitats generally do not allow benthic vegetation
to attach or persist to any degree. Thus, the majority of the autotrophic
production from within the habitats is from phytoplankton production. The
food web, however, is characteristically based upon detritus (Figure 9). It
appears that spits, pocket beaches, and headlands exposed to heavy current
and wave transport receive a relatively high biomass of detached macroalgae
and other organic detritus from adjacent habitats. In these high-energy
systems the large detritus particles are quickly broken down into smaller
particles by the grinding action of the coarse sediments and are made
available to the assortment of detritivores which are able to persist in the
unconsolidated sediments. Among these detritus and general deposit feeders,
the gammarid amphipods (especially Paramoera mohri and Paraphoxus spp.)
comprised the highest proportion (83%) of the standing stock; echinoderms
(Dendraster excentricus), polychaetes (especially Scoloplos pugettensis) and
oligochaetes constituted most of the remaining standing stock.
Comparing standing stock, however, suspension-feeding bivalves
(including Mysella tumida and Psephidia lordi) were the more predominant of
the primary consumers at this trophic level. Because the weight of bivalves
included that of their shells and these animals are long-lived, their
dominance may have been overestimated when calculated from standing stock
data. Despite a relatively high average standing stock of macroalgae,
herbivores that consume attached plants were sparse and limited to gastropods
and amphipods.
Epibenthic omnivorous crustaceans (the mysids Ac an thornysis sculpta,
A. nephrophthalma, and Neomysis mercedis) and an omnivorous fish (the buffalo
sculpin, Enophrys bison) filled the position intermediate between the primary
and secondary consumers in their ability to utilize both living and detrital
food sources.
Secondary consumers in the food web representing exposed unconsolidated
intertidal/subtidal habitats were more diverse and abundant than in any of
the food webs discussed previously. Carnivorous nemerteans and polychaetes
(primarily Onuphis sp.) and epibenthic planktivorous fishes (12 common
species, including redtail surfperch, Amphistichus rhodoterus; juvenile
English sole, Parophrys vetulus; and juvenile Pacific tomcod, Microgadus
proximus) prey upon the diverse array of epibenthic animals, the majority of
which are detritivores. Carnivorous gastropods (including Natica clausa and
Nucella sp.) and demersal benthos-eating fishes (8 species, including
juvenile starry flounder, Platichthys stellatus; juvenile sand sole,
Psettichthys melanostictus; and Pacific staghorn sculpin, Leptocottus
armatus) were somewhat less important.
46
-------
INTERTIDAL/SUBTIDAL-EXPOSED UNCONSOLIDATED
PISCIVOROUS
BIRDS
KO.OI)
PISCIVOROUS
MARINE
MAMMALS
BENTHIVOROUS
BIROS
(0.00
EPIBENTHIC
PLANKTIVOROUS
FISHES
(4.01)
CARNIVOROUS
POLYCHAETES
(4.81)
CARNIVOROUS
GASTROPODS
1.90) '
DEMERSAL
BENTHIVOROUS
FISHES
(1.50)
OMNIVOROUS
FISH
(0.11)
OMNIVOROUS
MYSIDS
0.03)
HERBI-
VOROUS
GASTRO-
PODS
(0.15)
DETRITI-
VOROUS
OLIGO-
CHAETES
(2.67)
DETRITI- DETRIT1-
VOROUS VOROUS
HARPAC-
TICOID
DEPOSIT
FEEDING
POLY-
CHAETES
(3.63
DETRITI- DETRITI-
VOROUS VOROUS
CUMACEANS
HERBI-
VOROUS
AMPHI-
PODS
(0.02)
SUSPENSION
FEEDING
TANAIDS
(0.74)
SUSPENSION
FEEDING
BIVALVES
(156.73)
AMPHI-
PODS
(56.71)
OSTRA-
CODS
KO.OI)
^COPEPODS
(0.01)
MACROALGAE
(81.19)
PHYTOPLANKTON
BENTHIC
MICROALGAE
DEPOSIT
FEEDING
ECHINO-
DERMS
(S.30)
Figure 9. Characterization of exposed unconsolidated intertidal/subtidal
habitat food web. Average1biomass of major taxa represented
in parentheses(grans/m2 or grams/m3).
47
-------
Benthos-eating birds, including the Glaucous-winged Gull (71% of the
standing stock), Surf Scoter (9%), and the California Gull (7%) dominated the
standing stock of tertiary consumers, which also included fish-eating birds
(i.e., Great Blue Heron) and marine mammals (the harbor seal).
The standing stock of primary producers was relatively low in these
habitats. However, the food web was also highly dependent upon detritus
processing. It included many secondary consumers. It also included a high
biomass of suspension feeding bivalves. Biomass data for bivalves may be
overestimated because they include the dense shells. Nevertheless, these
bivalves represent an interesting carbon sink in this food web in that they
are not preyed upon by very many species. Thus, standing stock of these
molluscs, though comparatively high, is generally not effectively
incorporated into the community's food web at higher consumer levels and may
have been disproportionally allocated to respiration. Accordingly, most of
the turnover of trophic energy within these habitats must be assumed to be
regulated and limited by the import of detritus and by the rate of physical
and microbial processing of the detritus particles. We have no information
on these various processes and their rates. They would appear to be very
seasonal in nature due to the seasonal growth and die-off of algae and other
plant material, the magnitude of wave action which controls mechanical
disintegration, and the temperature and nutrient regimes which regulate
microbial decomposition of the detritus.
IV. A. 3. b. (4) Protected unconsolidated habitat.
The influence of topographic protection from winds and currents was
evident in the food webs characterizing protected habitats and can be
directly related to the structure and stability of the sediments which
accumulate there. The most notable effect of protection was a marked
increase in the overall diversity (number of nodes) of the food web
(Figure 10). High diversity was due to the biomass of benthic infauna, which
are restricted in their ability to populate the exposed unconsolidated
sediment habitats, and the greater in-situ production of plants and the
accumulation and retention of detritus produced elsewhere.
While the apparent input of detritus particles in other habitats
originates from outside sources, it would appear that the protected-soft/
intertidal-subtidal habitats generate high standing stocks of macroalgae and
plant material which, if not consumed by herbivores, eventually contributes
to the detritus pool within the habitat. Macroalgae common to the habitat
included Enteromorpha spp., Rhizoclonium sp., and Fucus distichus in the
intertidal zone and Laminaria saccharina and Gracilariopsis sjoestedtii in
the subtidal zone; eelgrass was predominantly Zostera marina; saltmarsh
plants included a diverse assortment of vascular plants, represented by
Scirpus (sedges).
Detritus was consumed or processed primarily by deposit-feeding
polychaetes (primarily Lumbrineris sp., Owenia fusiformis and Tharyx
multifilis) and bivalves (primarily Macoma nasuta), which together formed 94%
of the estimated total standing stock of detritivores. By contrast, true
suspension-feeders were dominated by a diverse group of bivalves, including
48
-------
INTERTI DAL/SUBTIDAL- PROTECTED SOFT
O
BENTHIVOROUS
BIROS
(0,22)
CARNIVOROUS CARNIVOROUS
NEMERTEAN DECAPOD
(3.81) _•*. (0.46)
O
HERBI-
VOROUS
BIRDS
(O.06)
EELGRASS /BALTMARSH
(2036.51) /VASCULAR
PLANTS
(5225.3)
Figure 10. Characterization of protected unoonsolidated intertidal/subtidal habitat food web,
Average biomass of major taxa represented in parentheses(grams/m2 or grams/m3).
-------
Protothaca staminea, Transennella tantilia, Tresus spp., Clinoeardium
nuttallii. Tapes japonica, Mytilus edulis, and Psephidia lordi.
Of the consumers forming the second trophic level in the food web, 88%
were carnivorous polychaetes such as Dorvillea spp., Eteone sp., and Exogone
sp. which prey principally upon other polychaetes and meiofaunal crustaceans.
Gastropods (primarily Nassarius mendicus and Aglaja diomedea) were also
conspicuous predators upon the high biomass of deposit-feeding and
suspension-feeding bivalves.
Epibenthic plankton-eating fishes (primarily shiner perch, Cymatogaster
aggregata, tidepool sculpin, Oligocottus maculosus, juvenile English sole,
Parophrys yetulus, and rock sole, Lej>idopsetta bilineata) composed a standing
stock of higher carnivores more than twice that of the demersal
benthos-eating fishes (primarily Pacific staghorn sculpin and starry
flounder). Benthos-eating birds (Glaucous-winged Gull) preyed upon the
abundant bivalves in the first consumer level.
*
The prominence of eelgrass had the functional effect of magnifying both
the diversity and standing stock of the food web. Although the diversity of
epibenthic zooplankton did not appear to increase within the eelgrass beds,
the density and standing crop of these organisms, especially harpacticoid
copepods, were orders of magnitude higher than in the areas of these habitats
which did not have any eelgrass (Simenstad et al., 1980). And, while the
nearshore fish sampling conducted in this region was not designed to separate
such microhabitat-associated fish assemblages, there were indications that
certain species of nearshore fishes, including bay pipefish (Syngnathus
griseolineatus), shiner perch (Cymatogaster aggregata), silverspotted sculpin
(Blepsias cirrhosus), penpoint gunnel (Apodichthys flavidus), crescent gunnel
(Pholis laeta), and padded sculpin (Artedius fenestralis), were uniquely
associated with the eelgrass. Thus, 46% of the epibenthic-feeding fish
species in the secondary consumer level of the food web could be attributed
directly to the presence of the eelgrass. At this point, however, we cannot
verify whether this association was a function of trophic linkages to the
epibenthic prey organisms associated with the eelgrass beds or of the struc-
tural aspects of the eelgrass beds as hiding places from predators.
Eelgrass also acts to enhance the accumulation of detritus particles by
creating low energy zones where suspended matter can settle. Although there
is little information on the effect of eelgrass upon the rates of detritus
accumulation and decomposition, we can validly assume that the majority of
the processing of the detritus particles in these habitats is biochemical
rather than physical and that entrapment and retention is conducive to the
microbial breakdown of the detritus particles into a form utilized as food by
detritivores. The association between detritivorous epibenthic crustaceans
and eelgrass also suggests that these animals are probably playing an
important role in processing the detritus entrained by the eelgrass plants
and whose populations are consequently enhanced. The fact that the majority
of detritus processing is a function of biochemical activity suggests that
the rate of detritus production available for detritivores would be much
slower in these habitats than in physically-controlled habitats but also
spread out over a longer time period, e.g., prone to less seasonal variation.
50
-------
The third role of eelgrass is obvious, for it seasonally supports high
densities of herbivorous birds, specifically the Black Brant and American
Wigeon, which forage directly upon the intertidal plants during winter and
spring in these habitats.
IV. A. 3. b. (5) Summary.
Although the dramatic differences in productivity at different levels of
the food web practically negated our ability to compare the characteristic
food webs from differing habitats, the comparison of the food web diversity,
in terms of the number of feeding groups and standing stock within feeding
groups deserves some attention. Table 3 illustrates the proportions of
biomass among the trophic groups in the five habitat types represented in the
study area. In terms of standing stock of organisms, the rock-cobble
intertidal/subtidal habitats had the highest biomass at all levels except the
deposit-feeder/detritivores. Suspension-feeders in the exposed
unconsolidated/intertidal-subtidal habitats had a higher standing stock than
those in the protected soft/intertidal-subtidal habitats, reflecting the
influence of dense-shelled bivalves, particularly in subtidal Guemes
Island-south area.
From this synthesis it is apparent that diverse communities of organisms
have evolved to utilize the divergent sources of plant-produced carbon and
detritus available in the region's marine habitats. The rate of flow and
distribution of this trophic energy through the food web also varies between
communities and appears to be a function of 1) amount and rate of utilizable
carbon (detritus, macroalgae, phytoplankton) entering the habitat or
generated within it; 2) the stability and spatial heterogeneity of the
habitat, and 3) the effect of upper trophic level predators in structuring
the lower trophic levels of the communities.
IV. A. 3. c. Species richness, abundance and biomass.
Summaries of the quantitative data collected for each category of
organisms are presented in this section. Average values have been calculated
for each of the eight habitat types (each habitat usually represented by
several specific sampling sites) on a seasonal basis. These data were used
to identify major differences between habitats on a seasonal basis. Plants
were not included due to the difficulties involved in quantifying them.
IV. A. 3. c. (1) Species richness.
Our present understanding of the distribution of marine mammals
precludes any attempts to relate their occurrence to any particular subtidal/
intertidal habitat type. However, a few general statements based upon
presumed or known behaviors of some species can be made. Harbor seals were
most often observed hauled out on protected rock and exposed unconsolidated
habitats. Sea lions generally hauled out on protected rock. These
occurrences only reflected resting behavior and, in the case of harbor seals,
pupping and nursing activities as well. Foraging activities, a critical
portion of the time budget of these species, were generally conducted in the
nearshore habitats (harbor seals) and offshore habitats (sea lions).
51
-------
ro
Table 3. Number of feeding groups (in parentheses) and mean annual standing crop (g/m2 or g/m3)'
in marine habitats of northern Puget Sound and the Strait of Juan de Fuca.
Habitat Types
Protected
Unconsolidated
Intertidal/
Subtidal
Exposed Uncon-
solidated
Intertidal/
Subtidal
Rock-Cobble
Intertidal/
Subtidal
Nearshore
Neritic
Offshore
Neritic
Primary Deposit-feeders
Producers and detritivores
(4)
7635.49
(3)
81.19
(4)
7842.87
(1)
0.40
(1)
< 0.10
(10)
451.36
(8)
68.35
(10)
160.45
(0)
< 0.01
(0)
< 0.01
Micro- and
Macroalgae
Herbivores
(3)
13.43
(2)
0.18
(5)
741.40
(0)
0.00
(0)
0.00
Suspension-
feeders
(5)
72.12
(2)
160.48
(5)
647.57
(1)
- 0.20
(1)
- 0.50
Carnivores
(8)
25.42
(7)
15.53
(10)
118.35
(6)
0.27
(6)
0.09
Omnivores
(2)
1.76
(2)
0.14
(1)
42.81
(1)
< 0.01?
(0)
< 0.01?
"Standing crop is expressed as g/m2 in intertidal/subtidal habitats; g/m3 in
offshore and nearshore habitats.
-------
Depending upon the occurrence of sea lions (two species), harbor seals, or
river otters, species richness for marine mammals rarely exceeded two at any
site.
The mean total species richness values for the other biotic groups are
shown in Figures 11-14 for each season. The values reflect the averages of
many observations made throughout the study area.
The largest number of bird species, either annually or seasonally,
occurred at the protected mud habitat. These data illustrate the importance
of areas like Padilla Bay, a protected muddy site, to marine birds. Other
habitats having a relatively large number of species throughout the year were
the protected mud-sand and mud-gravel habitats along with the exposed mixed
coarse habitat. In the fall and winter the cobble habitat also supported a
large number of bird species. Year-round, the lowest numbers generally
occurred at exposed and protected rock sites. Clearly the lowest number of
bird species at nearly all of the intertidal/subtidal habitats were found in
the summer.
On an annual or seasonal basis, the number of species of fish was
highest at the protected mud gravel habitat; but otherwise the number of
species was fairly similar (note that the rock/cobble collections are
incomplete). Generally, the lowest numbers occurred at protected rock and
exposed sand sites. Seasonally, the tendency was for the lowest number of
species in the winter and spring, and the most in the summer and fall.
No seasonal summations of intertidal/subtidal species richness data are
available for invertebrates due to unresolvable problems with the data sets.
However, species richness was generally highest at exposed rock sites (e.g.,
Pillar Point, Tongue Point), followed by cobble and protected rock sites.
For example, mean annual species richness for rock and cobble sites along the
Strait varied from 38 to 169 at the +3 foot tidal elevation; whereas that for
other habitats was typically lower (1.5 to 45.3). Species richness was
usually lowest at exposed sand and exposed mixed coarse sites.
IV. A. 3. c. (2) Abundance of organisms.
No habitat-related trends in abundance are apparent for marine mammals.
Though Table 2 above shows that many of the major harbor seal haul-out areas
are rock, their popularity is probably mainly related to isolation from human
disturbance rather than the type of substrate.
Total mean abundance of the other biotic groups per habitat type is
shown in Figures 15-18 per season. The reader should note that the abundance
of invertebrates is about 10* times greater than that of fish or birds as is
indicated on the vertical axis label of Figures 15-18. Also, the abundance
values for tidepool fishes at rock and cobble habitats have not been included
because they were not obtained in a comparable manner to other nearshore
fishes.
Bird abundance was quite seasonal but one habitat, the protected
mud-sand habitat such as found at Jamestown, had relatively high numbers
53
-------
"40-
o
w
OS
w
!20-
a.
£40-
i—i
CJ
w
Pu
en
PH
O
Pi
S20-
PROTECTED
MUD
PROTECTED
MUD-SAND
PROTECTED
MUD-GRAVEL
b.
£40-
w
P-.
en
o
120-
EXPOSED
SAND
EXPOSED
;XED COARSE
c.
COBBLE
PROTECTED EXPOSED
ROCK ROCK
Figure 11. Numbers of species of intertidal/subtidal fish(shaded bars) and
birds(hatchad bars) in the winter at (a) protected habitats,
(b)exposed habitats, and (c) rock and cobble habitats.
54
-------
40-
w
04
C/3
O
e*
w
20-
u
120-
PROTECTED
MUD
PROTECTED
MUD-SAND
PROTECTED
MUD-GRAVEL
340-
M
O
w
OH
en
O
S
20H
EXPOSED
SAND
EXPOSED
MIXED COARSE
PROTECTED
ROCK
EXPOSED
ROCK
COBBLE
Figure 12. Numbers of species ot intertidal/subtidal fisMshaded bars) anc
birds(hatched bars) in the spring at (a) protected habitats,
(b) exposed habitats, and (c) rock and cobble habitats.
55
-------
£40-
H
g
GO
PH
o
S20-
1
a.
u
fa
o
120
PROTECTED
MUD
PROTECTED
MUD-SAND
PROTECTED
MUD-GRAVEL
b.
O
I 20^
EXPOSED
SAND
EXPOSED
MIXED COARSE
c.
PROTECTED
ROCK
EXPOSED
ROCK
COBBLE
Figure 13. Numbers of species of intertidal/subtidal fish(shaded bars) and
fish(hatched bars) in the summer at (a) protected habitats,
(b) exposed habitats, and (c) rock and cobble habitats.
56
-------
u
w
ex
Crt
ffc
o
Pi
w
20-
PROTECTED
MUD
PROTECTED
MUD-SAND
PROTECTED
MUD-GRAVEL
b.
40-
u
w
PM
1/3
P-
EXPOSED
SAND
EXPOSED
MIXED COARSE
c.
PROTECTED
ROCK
EXPOSED
ROCK
COBBLE
Figure 14, Numbers of species of intertidal/subtidal fish(shaded bars) and
birds(hatched bars) in the fall at (a) protected habitats,
(b) exposed habitats, and (c) rock and cobble habitats.
57
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a.
CNI
o
X
CM
-o
•H
-D
'c
.c
en
S -H
C/3 U-l
en
100-
50-
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MUD-SAND
PROTECTED
MUD-GRAVEL
b.
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Pi )-l
o m
fi
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O 3
W CM
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55 X
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EXPOSED
SAND
EXPOSED
MIXED COARSE
c.
u_i
O
100-
50-
PROTECTED
ROCK
EXPOSED
ROCK
COBBLE
Figure 15. Abundance of intertidal invertebrates(open bars) subtidal inverte-
bratesdined bars), fish(shaded bars) and birds(hatched bars) in
the winter at (a) protected, (b) exposed and (c) rock and cobbl<
habitats,
58
-------
X
en
•a
(-1
-a
c
03
100-
50-
PROTECTED
MUD
PROTECTED
MUD-SAND
PROTECTED
MUD-GRAVEL
b.
100-
f*
o
W CM
O I
3
C
X
CD
0)
'01
>
a
z;
50-
EXPOSED
SAND
EXPOSED
MIXED COARSE
c.
100-
50-
COBBLE
PROTECTED EXPOSED
ROCK ROCK
Figure 16, Abundance of intertidal invertebrates(open bars), subtidal inverte-
bratesdined bars), fish(shaded bars) and birds (hatched bars) In
the spring at (a) protected, (b) exposed and (c) rock and cobble
habitats. 59
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throughout the year. In the winter, relatively high abundances of birds were
also found at the other protected habitats. Very high numbers occurred in
the spring at the cobble habitat associated with herring spawning, and in the
fall fairly high numbers were found at the exposed sand habitat.
Fish abundance was characterized by consistently high numbers of fish
throughout the year at the protected mud-gravel habitat such as found at
Beckett Point. Other habitats where numbers of fish were relatively high on
a seasonal basis were the protected mud and exposed sand habitats in the
winter, the protected mud/mud-sand and exposed sand/mixed coarse habitats in
the summer, and the protected mud-sand and exposed mixed coarse habitats in
the fall.
Invertebrates, both in intertidal and subtidal zones, stand out as being
particularly abundant at the cobble habitat throughout the year, illustrating
the dense biota at sites like Cherry Point and Morse Creek. Intertidal
invertebrates were also abundant throughout the year at the other rock
habitats (protected and exposed) and the protected unconsolidated habitats.
With the exception of some exposed mixed coarse habitat sites in the summer,
intertidal invertebrate abundance was lowest at the exposed unconsolidated
sites. Subtidal invertebrates appeared to be most abundant at protected
mud-sand sites.
IV. A. 3. c. (3) Biomass of organisms.
Our understanding of the role of marine mammals in the aquatic ecosystem
is not clear enough to allow for an accurate assessment of biomass by season
by habitat type. The fact that harbor seals may haul out on protected rock
habitats in greatest numbers in the fall does not necessarily imply that the
sum of their biomass is of any special importance to that habitat. As marine
mammals relate to the ecosystem, their biomass plays a significant role only
in the nearshore and offshore habitats. A minimum estimate of the number of
harbor seals in the study area is 1,900 (Everitt et al., 1980), and
individual animals may reach 110 kg. Sea lions occur in smaller numbers with
California sea lions numbering to 300 individuals (primarily males which can
weigh up to 275 kg) and northern sea lions numbering to 260 individuals (with
potential weights to 1,000 kg).
The reader should note that the biomass values of invertebrates are on
the order of 102 times larger than for fish, and 10 times larger than for
birds—as indicated in the vertical axis of Figures 19-22. Also, biomass
values for tidepool fishes at rock and cobble habitats have not been included
because they were not obtained in a comparable manner to other nearshore
fishes.
Bird biomass was consistently high at the protected mud-sand habitat
throughout the year. On a seasonal basis, relatively high biomass was seen
at the protected mud/mud-gravel habitats in the winter and at the cobble
habitat in the spring.
Fish biomass, besides being very high at the protected rock habitat
throughout the year, was also relatively high at the protected mud-gravel
62
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100-
50-
CM
O
•H
XI
PROTECTED
MUD
PROTECTED
MUD-SAND
PROTECTED
MUD-GRAVEL
X
CM
Z J
-------
CN
o
tn
-a
XI
o"
-H
X
00 Cxi
s e
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o
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e
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o
en
en
S CM
o e
en
0)
M
-Q
OJ
100-
50-
a.
00-
50-
PROTECTED
MUD
PROTECTED
MUD-SAND
PROTECTED
MUD-GRAVEL
b.
100-
o
50H
217
EXPOSED
SAND
EXPOSED
MIXED COARSE
PROTECTED
ROCK-
EXPOSED
ROCK
COBBLE*
Figure 21
Biomass of intertidal invertebrates(open bars), subtidal inverte-
brates(lined bars), fish(shaded bars) and birds(hatched bars) in
the summer at (a) protected, (b)exposed and (c) rock and cobble
*Does not include tidepool fishes.
65
habitats.
-------
100-
50-
e
en
j2
O
W
S CM
OS M-I
O
fn
O
100-
X
50-
O og
en
0)
,0
01
s
c
PROTECTED
MUD
PROTECTED
MUD-SAND
PROTECTED
MUD-GRAVEL
b.
100-
150 EXPOSED
SAND
EXPOSED
MIXED COARSE
Figure 22.
PROTECTED EXPOSED COBBLE*
ROCK* ROCK
Biomass of intertidal invertebrates(open bars), subtidal inverte-
brates(lined bars), fish(shaded bars) and birds(hatched bars) in
the fall at (a) protected, (b) exposed mud and (c) rock and cobble
habitats. *Does not include tidepool fishes.
66
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habitat throughout the year. Seasonal highs for fish biomass were seen at
the protected mud and exposed sand habitats in the summer and at the exposed
mixed coarse habitat in the fall.
The most obvious feature of the graphed biomass data is that biomass for
most groups was highest at either protected unconsolidated habitats or rock
habitats. Both invertebrates and fishes had very high values at the
protected rock habitat during all seasons. The high biomass values for
invertebrates were due to the occurrence of many large and/or dense-shelled
invertebrates. Because of these same biotic groups, invertebrate biomass was
also relatively high during all seasons in the cobble habitat. In the
spring, the subtidal invertebrate biomass was high in the exposed mixed
coarse habitat.
IV. A. 3. d. Migrants.
IV. A. 3. d. (1) Rock/cobble.
Marine mammals: Sea lions are the only migratory marine mammals that
utilize rock habitats primarily for resting. Sea lions move into the study
area from breeding grounds further north and south and are most abundant in
the winter. Total combined counts of over 300 animals have been recorded
during winter surveys. Neither the seals nor the sea lions apparently use
the cobble habitat in the study area for hauling out.
Birds; Census data did not permit differentiation between exposed and
protected rock types. The seabird censuses were not focused closely enough
on shoreline intertidal/subtidal habitat types to include only migratory
species associated directly with rock substrate. The censuses at Fidalgo
Head, for example, included diving ducks foraging off nearby Shannon Point (a
different substrate); thus, the data in Appendix Table III-B do not
characterize Fidalgo Head itself. Of the very large numbers of migratory
birds which may be observed nearby, only a very few use rock substrate
habitats for foraging.
Yearly peak numbers of migratory birds were much lower than those in
other habitats, but migrants occurred in fall through spring. They included
Harlequin Ducks and small numbers of "rock" shorebird species: Black
Turnstones, Surfbirds, a few Rock Sandpipers, Ruddy Turnstones, and Wandering
Tattlers. Gulls included resident Glaucous-winged Gulls, but also migrant
and wintering species like California, Mew, Bonaparte's, and Heermann's
Gulls. Migrant gulls were observed foraging in rocky intertidal areas, but
often used rocks above tidal influence for resting and waiting for feeding
opportunities in tidal fronts offshore. Black Oystercatchers are a resident
species, but form flocks in winter (up to 40 birds) which appeared to move
about among rock habitats of the study area.
Seabird data for cobble substrates were obtained at the Cherry Point
area. Populations there were characterized by great seasonal variations.
The lowest numbers were found during the summer months. Large numbers of
migratory diving ducks often appear in the fall and spend the winter along
this shoreline. The density of birds and the seasonal range in abundance
67
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were usually lower in cobble habitats where Pacific herring do not spawn.
The most abundant species (Appendix Table II-B) included Greater Scaup,
Common Goldeneye, Bufflehead, Harlequin Duck, White-winged and Surf Scoters.
In addition to resident Glaucous-winged Gulls, wintering Mew Gulls and spring
and fall migrant Bonaparte's Gulls used the cobble habitat. Along the Strait
of Juan de Fuca, Heermann's Gull was a common migrant and summer resident.
Shorebirds did not occur in appreciable numbers in cobble habitats, though
some species like Black Turnstones may forage there on occasion during
migration. The presence of Sanderlings on Appendix Table II-B represents
occurrence in an adjacent habitat, not in cobble itself.
Fish; The single most obvious seasonal feature of the cobble habitat
type involving migratory fish is the Pacific herring spawn in late
winter-spring. Along the eastern Georgia Strait this phenomenon represents
the end result of a large migration of this species in nearshore waters, with
herring eggs deposited on intertidal/subtidal vegetation, rocks, and pilings.
The cobble areas and adjacent exposed unconsolidated habitats are one of the
most important marine spawning habitats in the study area. The herring
spawning activity, in turn, attracts very large numbers of birds described
above. In eastern Georgia Strait, it takes place when marine birds are
moving northward in the spring; and for some populations this phenomenon may
represent an important staging/feeding concentration during migration.
IV. A. 3. d. (2) Exposed unconsolidated.
Marine mammals; The only species of marine mammal utilizing the exposed
unconsolidated habitat to any significant degree is the nonmigratory harbor
seal. The migratory sea lions apparently do not use this habitat type for
hauling out, though they may forage in the subtidal zones.
Birds; Birds of the two exposed unconsolidated habitats—mixed coarse
and sand—had similar species and seasonal characteristics (Appendix Tables
III-D and III-E). Patterns of migration involved essentially a passage of
several gull species and Common Terns through the area during the fall; an
influx of large numbers of diving ducks in the fall for the overwintering;
and a subsequent emigration of these ducks in the spring.
Bald Eagles, found in small numbers on most shorelines of the study
area, were observed more frequently along the shorelines of the San Juan
Islands. They migrated into the area during the winter. As in other
shoreline habitats, a large proportion of the fall gull populations were
using the shorelines for resting between foraging flights offshore.
Exposed unconsolidated habitats generally support few shorebirds,
although these are characteristic habitats for Sanderlings. This species,
while common on the outer coast of Washington, occurs in small numbers as a
spring and fall migrant and as a winter visitor in the study area.
Fish; Important movements of a number of fish species are known to take
place in or adjacent to exposed unconsolidated habitats. These include
juveniles of important commercial species, especially pink and chum salmon,
and including Chinook and coho salmon. Pacific herring accounted for 76% of
68
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total numbers of fish and 75% ^of total biomass in samples taken in our
studies. Long-finned smelt and sand lance were also taken, though in smaller
numbers. Maxima in species richness and standing stocks in summer and minima
in winter apparently reflect large migrations of herring.
IV. A. 3. d. (3) Protected unconsolidated.
Marine mammals; Similar to what was observed at exposed unconsolidated
habitats, migratory marine mammals apparently do not use this habitat type to
haul out, though they may forage in subtidal zones.
Birds; Seasonal migration patterns for the three types of protected
soft habitats were found to be similar and magnitudes of movements were
large. Very large numbers of diving ducks (Appendix Tables III-F-H) moved
into the protected unconsolidated areas in the fall and remained through
spring. Where eelgrass was present, species like Black Brant and American
Wigeon also occurred in large flocks. The Black Brant had a somewhat
atypical migration pattern, with very large numbers occurring in most
habitats only during northward spring migration. Only a small number of
protected eelgrass emabyments had wintering brant populations, though the
species was widespread from March into May. The significant migrations of
the two primary eelgrass-associated species in and out of most bays were not
duplicated in Westcott Bay, where neither species was recorded in 1978-1979.
Sizable migrations of dabbling ducks and several species of gulls also
took place to and from protected unconsolidated habitats. A number of these
species also wintered in the area, from about September through April.
Because these habitats supported many species during the year and Appendix
Table II-B gives only the 10 most frequently occurring species, there were
many other species that occurred in sizable numbers that were omitted from
the tables.
Protected habitats were the most important areas for Great Blue Heronsj
with highest populations in summer and early fall, and with most birds
apparently moving out of the area during the winter. These were also the
primary habitats for shorebirds, such as Killdeer, Sanderling, and Black
Turnstone. These habitats have been reduced by human activities in the study
area, but still support considerable migrant populations of species like
Semipalmated Plover, Whimbrel, Greater Yellowlegs, Short-billed Dowitcher,
and Western Sandpiper. Dunlins arrived in late fall and winter in the study
area in large numbers, and flocks of Black-bellied Plovers wintered locally.
Fish: Pacific herring often spawn in protected soft habitats in eastern
Georgia Strait, through this migration/spawning is of a much lesser scale
than nearby exposed cobble and unconsolidated habitats. There appears to be
movement of Pacific herring larvae into protected habitats after hatching.
Frequently, there are also movements of salmonids, particularly juvenile chum
salmon, in and out of these areas.
69
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IV. A. 3. e. Variability between and within habitat types.
IV. A. 3. e. (1) Introduction.
The division of the nearshore region into physically defined habitat
types rests upon the assumption that biological communities are closely
related to general substrate profiles and exposure. Within habitat types,
similarity in species richness, biomass, and abundance might be expected.
Reasonably similar distribution of species with season and, where
appropriate, with tidal elevation might also occur.
Thus far, mean abundances of species per unit area have been presented
without particular comment on the variation associated with those means.
Variation in species abundance has been reported in various ways by the
individual investigators. For benthos and dominant bird species, means and
standard deviations were available. Webber (1980) reported the percent of
species whose coefficients of variation, as s/X x 100, were greater than
100%. Miller et al. (1980) calculated the power of the test for detecting
hypothetical decreases in fish numbers or biomass. Variability in fish prey
spectra was described by calculating an Index of Affinity, which is a
pairwise coefficient of similarity for Index of Relative Importance (I.R.I.)
values. For marine mammals, probable factors in observed variation in
numbers were discussed in the text, but no statistical analyses were
performed (Everitt et al., 1980). In general, the variation observed
probably arises from several interacting factors; and under the sampling
programs used it is usually not possible to tell which factors had major
effects.
The first section of this discussion focuses on sources of variation in
sample means which can be demonstrated in the data, and the second section
describes briefly the overall magnitude of variation in the major habitat
types. In some cases it is possible to postulate causes for major variation,
but most of the variation could be due to a number of different and not
necessarily mutually exclusive causes.
IV. A. 3. e. (2) Sources of variation.
Main sources of variation in sample means for MESA/WDOE survey data can
be divided into variation arising from sampling design, and that arising from
natural unpredictability of population abundance within habitats.
Aspects of sampling design that affect measures of variation are:
1) habitat definition, 2) control of variable factors within habitats,
3) reasonable levels of replication and appropriate sample area, and
4) quality control. In all surveys, efforts were made to ensure that
reasonable confidence could be placed in the results, given the constraints
of available time and funding. However, the efficacy of the designs in
estimating species richness and abundance was not thoroughly investigated.
Some elements of habitat definition for all the surveys were substrate
type and extent of the defined habitat type. For fish and bird surveys,
water depth formed another element of habitat type. Substrate type was
70
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consistently described, although standard grain size analyses with adequate
replication were not always performed. For mobile species, such as birds,
mammals, and fishes, considerable movements over boundaries of substrate type
were qualitatively described. Individual bird census tracks could not always
be broken down by substrate type, nor was it considered appropriate to do so.
The benthic survey sites were chosen based partly on substrate specificity,
but the definition of substrate type was largely descriptive, rather than
quantitative. As a result, habitats defined as equivalent exhibit some
degree of difference in patterns of species occurrence and abundance.
Exposed mixed coarse sites are a case in point. Mean water depth was at
least estimated for fish and bird habitats. Especially strong increases of
bird species richness and abundance in shallow water versus deeper water
supports the use of water depth in defining habitat for these censuses.
The effect of habitat extent on the abundance, occurrence, and
preditability of species holds promise for future study for all the animal
groups, but was not specifically investigated in the baseline program. One
example of the effect was described by Miller et al. (1980). Fish species
are more numerous at the pocket gravel beaches on San Juan Island (Eagle
Cove, Deadman Bay) than at gravel beaches with longer extent, such as South
Beach and Dungeness. This trend occurred because demersal fish species from
nearby rock, kelp, or eelgrass habitats probably regularly forage in the
gravel area. Local levels of abundance of birds and also of benthic species
could be influenced by habitat extent as well. For instance, Osman (1978)
showed that species richness of benthic species colonizing submerged plates
increased as the area of the plate increased. A relative increase in
immigration was hypothesized to account for this increase. This effect may
only be seen where the habitats are substantially heterogeneous, since
species immigration in habitats of large extent might be reduced.
Variation in physical factors within habitat types probably influences
both mobile and sessile species. Some of these factors are at least related
to season, elevation above Mean Low Low Water (MLLW), hydrographic
conditions, weather, tide stage, and both chronic and catastrophic
disturbance.
For benthos, variables that were consistently present were thought to be
the most important. Seasonal and elevation differences were investigated at
each habitat, and fairly undisturbed sampling sites were chosen. Subtidal
sampling took place at the same tide stage in each season, to minimize this
possible source of variation. Local weather and hydrographic conditions were
not recorded continuously, so observed year-to-year variation in benthic
species abundance is difficult to relate to these variables. A massive die
off of limpets has been reported during the simultaneous occurrence of low
tides and hot weather in California (Wolcott, 1973). In the study area,
mortality caused by depressed salinity during heavy runoff could also occur.
Differences in the magnitude of salinity and temperature fluctuations could
make the difference between normal mortality or catastrophic mortality,
especially if juvenile forms suffered high mortality in one year but not in
another. In the MESA/WDOE baseline surveys, distinctions between year
classes were not routinely attempted. Even when massive recruitments were
seen, it was impossible to tell whether physical conditions were a major
71
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One major contributor to this variation is the nonrandom distribution of
individuals within a treatment group. A treatment group consists, for
instance, of samples from one elevation in one season, or from one type of
sampling gear in one season. None of the surveys included designs which
tested for nonrandom spatial distribution. Nevertheless, nonrandomness was
obviously common. It is easiest to see this in mobile species which form
flocks or schools, but benthic species may exhibit aggregation as well. The
high variation in tow net catches probably was largely due to schooling
species, such as Pacific herring. Often, Cither a large number was caught
when schools were encountered, or none (or few) were present. For benthic
species, the degree of aggregation or patch size was not measured for even
the most abundant species, as it was outside the scope of basic survey work.
It is, therefore, impossible to tell if variation was due to patchiness or to
low replicate number. For some abundant species, the coefficient of
variation was less for individual strata than for all strata combined. This
trend could be taken as an indication that within homogeneous conditions,
variance is lowered. Interpretations should be made cautiously, however.
Another factor, especially in the estimation of year-to-year variation,
is the breeding or recruitment success of the species under consideration.
In the benthic data there are indications that in some years, some species
had much better reproductive success than in other years. This observation
was not consistent for all species in the same year.
Table 4 shows several examples of mean abundance and variability for
selected benthic species as measured by the coefficient of variation (CV) at
the -1 foot level in summer. These examples illustrate the kinds of
variation to be expected in benthic baseline data. In example 1, mean
numbers of the barnacles, Balanus glandula/crenatus, are shown for several
rock and cobble habitats. Summer samples taken at -1 foot MLLW are used to
aid in comparison. Data are missing for several of the sites, but 1976
appeared to be a particularly successful year for barnacles at .Cherry Point.
While at Tongue Point, an exposed rock habitat, barnacle numbers were much
greater in 1977 than in 1976. Barnacle numbers at Cherry Point were much
lower in 1978 and 1979 than in 1976, indicating that 1976 was an unusually
good year at this site. At Cantilever Pier, a protected rock habitat, many
more barnacles were present in 1977 than in 1978; and the CV was smaller in
1977 than in 1978. Cherry Point had lower numbers and a higher CV for
barnacles in 1978 than in 1979, indicating that conditions for barnacle
survival were poorer in 1978 at this site as well. Partridge Point, which is
another cobble beach, had very few barnacles in any of the summer sampling
periods. Note also that the CV decreases as the means increase within all
the sites, which is a weak indication that barnacles are not aggregated in
spatial distribution.
Example 2 shows that for Fidalgo Head, a protected rock habitat, Balanus
cariosus was quite abundant and was less patchy than Balanus glandula.
JL* glandula was rare at this site in the summer of 1976.
Example 3 shows that the polychaete Cirratulus cirratus had comparable
abundance and CV in 1978 and 1979. The species was less numerous at
74
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Table 4. Examples of mean abundance and coefficients of variation for selected invertebrate
species at several intertidal sites in summer. Means normalized to 0.25 m2.
on
Species
Example 1
Balanus glandula/crenatus
Site
Partridge Point
Cherry Point
Cantilever Pier
Tongue Point
1976 1977
Elev. X CV "X CV
-I1 0
-I1 21210.0 0.3
-1' 976.0 0.9
0' 22.0 4197.5
1978 1979
X CV X CV
0.3 1.2 10.0 0.9
6715.0 0.6 0.2
1.8 1.6
Example 2
Balanus glandula
Balanus cariosus
Example 3
Cirratulus cirratus
Example 4
Scoloplos sp.
Oligochaeta
Fidalgo Head -1'
Fidalgo Head -I1
Partridge Point -1'
Cherry Point -I1
Fidalgo Bay +1.5'
Fidalgo Bay +1.5'
4.0 1.3
1293.0 0.7
48.0 0.7 13.8 1.8
178.5 0.5 113.5 0.5
190.0 0.3 45.5 0.6
3760.0 0.4 9.0 0.9
-------
Partridge Point than at Cherry Point in both years, and was more variable in
numbers in 1979 than in 1978.
Example 4 shows that strong year-to-year variations also occurred in
homogeneous habitat types. At Fidalgo Bay at the +1.5' elevation in summer,
the polychaete Scoloplos sp. showed a mean count in 1978 that was four times
higher than in 1979. The CV in 1978 was half as large as that in 1979.
Oligochaetes were about 400 times more abundant in 1978 relative to 1979, but
the CV was only about half as large in 1978 as in 1979.
Published information on variations in species abundances indicates that
differential settlement as well as differences in successional stage occur in
a range of habitat types. Eagle (1975) observed patchy but stable
communities having different dominant species in subtidal soft substrates in
Liverpool Bay. He hypothesized that these arose from the timing of
catastrophic storms. Species more abundant at the time of a storm as larval
forms differentially colonized patches disturbed at different times.
Differences in successional stage, as described by Lubchenko and Menge (1978)
for rocky intertidal habitats, may also contribute to high variation about
estimated mean abundances when random sampling design is used.
Variation in the abundances of benthic species might be expected to
result in variation of prey spectra of opportunistic bottom-feeding fish.
Miller et al. (1980) showed that the percent prey overlap, as measured by
Sanders' Index of Affinity on I.R.I, values, is not particularly high for
several benthivorous species. For example, at Port Williams in summer,
tidepool sculpins apparently switched from gammarid amphipods as a major prey
item in 1977 to harpacticoid copepods in 1978. The abundance of prey and
their rates of production are unknown for this time period, and preferences
for different prey items in tidepool sculpin are unknown.
Variations in fish species importance in the Strait sites were presented
in several different ways by Miller et al. (1980). The rank order of species
abundance, biomass, and frequency of occurrence of the 10 most common
intertidal fish species show that changes in rank order occurred for all
three parameters. These changes were due to the occasional capture of
schooling species, such as smelt or herring, and also to the capture of large
individuals of such species as spiny dogfish and pink salmon. Yearly
variation in exposed sand sites may also be partly due to a large year class
of speckled sanddab in the Strait of 1978. Some regional variation was noted
as well. The Strait sites had significant numbers of sand sole and redtail
surfperch which were absent from collections in northern Puget Sound.
Schooling species generally ranked higher in.tow net collections in northern
Puget Sound than in the Strait.
The variation of site data was presented by calculating the probability
that specified decreases in population density or biomass would actually be
detected. The probability of detecting a 50% decrease in numbers or biomass
in beach seine samples was rather low in general, but was reasonably high at
Twin Rivers and Morse Creek for some seasons. The probability of detecting a
75% decrease in numbers or biomass was generally high, except in spring. A
90% decrease in biomass could usually be detected with a probability of over
76
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90%, except at Jamestown in the spring, where the probability was still less
than 50%. The probability for detecting such a decrease in numbers was
somewhat higher at this site, however. For tow-net data, even a 90% decrease
in biomass or numbers could not necessarily be detected with a probability of
50% or more. Even a 95% decrease in numbers still resulted in low
probabilities of detection in some cases.
These data indicate a rather high degree of variation in all samples.
The ability to predict decrease in populations is also apparently not as good
as one would hope for. One of the assumptions of the power analysis is that
the variance in the reduced population would be the same as that in the
original population. The variance of baseline data is increased in large
part by the schooling species, and also by the presence of aggregated larvae
and juveniles. A decline in population would likely decrease the variance,
since the degree of aggregation would not be the same.
For bird species, the coefficients of variation ranged from about 0.5
to 4. Values for the most abundant species commonly were in a range of 1
to 2. Problems inherent in habitat definition and sampling design no doubt
played a part in the observed variation. For the currently defined
intertidal/subtidal habitat types, coefficients of variation were generally
lower in the protected mixed fine category than in other habitats. These
areas also harbored the largest mean numbers of individuals. In the case, of
birds, it is important not to discount the validity of data simply because of
high variances. Migrations of large numbers of individuals over relatively
short time spans is one of the major features of shallow water areas. Data
should be examined for patterns which account for the observed variation.
This is also true when examining data on the other taxa.
Since mammal species were not censused using a habitat approach, little
can be said about variation in habitat usage. However, habitat types were
noted at major hauling out sites for pinnipeds. There does seem to be a
clear preference for rocky islands or gravel beaches as haul-out areas, but
this trend may relate more to factors of disturbance and proximity to
abundant prey than to substrate preference. As with birds, total counts of
some mammal species varies widely with time due to their migratory habits.
IV. A. 3. e. (4) Observed variation within and between habitat types.
Rock/cobble habitat; Numbers of benthic species showed a decrease by a
factor of 10 from the -10 m depth to the +6' level for all the sites. Wet
weights of plants and animals at these sites were on the order of 100 to
1000 g/m at the +3' and 0' levels, and on the order of 10 g/m at the +6'
level. Macroalgae and barnacles predominated in terms of biomass at the
rock-cobble sites except for Partridge Point. This site had very low numbers
of barnacles. Cherry Point, another cobble site, consistently had enormous
numbers of barnacles. This difference was probably due to differences in
grain-size profile. The relatively small, uniform cobbles at Cherry Point
may be too unstable for macroalgae or may not provide suitable stable
crevices for barnacle-eating predators to lurk in during low tide. The
subtidal substrate at this site grades to mixed fine sediment rather quickly;
77
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while at Partridge Point, the subtidal substrate is similar to the intertidal
cobble substrate.
Fish species richness in rock and cobble habitats increased with
increasing substrate stability. Tidepools in rock outcrops generally
supported more species than did tidepools in cobble beaches. Variability in
net samples was rather high, but rank order and frequency of fish species
were relatively consistent.
Dominant bird species in rock-cobble habitats included both those
species which are fairly habitat-specific and those that are not. The Black
Oystercatcher and the Harlequin Duck were consistently present in low numbers
in rock habitats. The CV for these species is quite high, which is probably
a result of difficulty of detection as well as patchy use of habitat. Surf
Scoters and Glaucous-winged Gulls were widespread in other habitat types in
addition to the rock-cobble areas. These species used the areas both for
roosting and for occasional feeding. The variation in abundance might relate
both to patchy use of the habitat and to cyclic activity patterns not
accounted for in the sampling design. For example, the presence of offshore
tide rips nearby may make some rocky outcrops or cobble beaches more
attractive as roosting sites than other areas which superficially look
identical.
Exposed unconsolidated habitat; Two main patterns of benthic species
richness, biomass, and density with elevation were observed at the exposed
unconsolidated sites in the study area. Where the subtidal substrate was
relatively stable cobble, as at Ebey's Landing and Guemes Island South,
biomass and abundance were usually higher below +0' than above. However,
during some seasons, even the intertidal elevations had high densities and
biomass, possibly due to seasonal growth of scavenging or detritivorous
species. At Ebey's Landing, amphipods were abundant in spring and summer and
at Guemes South isopods were abundant in summer to fall. At other exposed
sites, the intertidal zones had uniformly low occurrence and abundance of
benthic species. The subtidal substrate graded to mixed sand and pebble in
these locations. While there was an increase in species richness and
abundance at tidal elevations, it was not nearly as great at sites where
cobbles were present in subtidal zones. Subtidal cobble habitat in these
exposed locations may be somewhat less stable than areas with less sediment
transport. For instance, at Ebey's Landing in winter of 1977-1978, one
subtidal elevation was inundated by sand. The species found there were
closely similar to those found at West Beach, a site on Whidbey Island which
had sand in the subtidal area.
Exposed sites were characterized by high variation in fish catches due
to the effects of capturing schooling species. There was substantial
between-year variation in seasonal catches as well. This variation could be
due to differences in year class success, but no conclusive evidence is
available.
Birds in exposed sites were often roosting or migrating, but some
species possibly were also feeding there, especially when migrating or
schooling fish were present. The variation in mean abundance probably
78
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resulted from both feeding and migration, as well as from local weather and
tide conditions. As at all areas in the Puget Sound region, migration
resulted in lower species ricftness in the summer than in other seasons; but
resident breeding species, such as the ""Glaucous-winged Gull, often were
abundant. Variation in density of the resident species prob'ab-ly depended on
proximity to breeding colonies, but the presence of juveniles in nonbreeding
areas may have negated this effect.
Protected unconsolidated habitat; Protected sites with unconsolidafed
sediments showed substantial variation in benthic species richness and
abundance with elevation and season. Species richness decreassed most
strongly above the +3' to +5' level in the intertidal zone at all the sites.
This trend may not reflect actual differences in community organization,
however. Benthic biomass was much lower at the +6' elevation than at lower
elevations, unless rock or gravelly substrates were found at this elevation.
Fidalgo Bay had rock outcrops in the high intertidal zones, which supported
some algae and barnacle growth. At Birch Bay and Dray ton Harbor, the +6'
level had high mean biomass due to the extremely patchy occurrence of
eelgrass. Biomass was generally highly influenced by the occurrence of large
bivalves. Density varied between sites in unpredictable ways. The high
elevations were often dominated by small oligochaetes and polychaetes. Even
at the mid- and low-intertidal elevations, the sites did not show very
similar mean abundances. Polychaetes, oligochaetes, and amphipods were
typically important groups, but the abundances of these groups were not
particularly similar across all protected mixed fine sites. For example, the
low elevation at Jamestown and Birch Bay differed in mean count by a factor
of 10, as did the low elevations at Beckett Point and Webb Camp.
Variability in fish abundance at the protected sites was again largely
due to capture of schooling species. Abundance and species richness were
consistently high in these habitats as compared to most other areas.
Dominant bird species showed relatively small variability within seasons
in the protected habitats. Seasonal variation is large due to migrations.
In the fall, winter, and spring, when seasonally resident species were
numerous, coefficients of variation were relatively low for the dominant
species.
Kammals using mudflats as haul-out areas were less numerous than they
were at other areas. Some sites, such as Padilla Bay, were consistently
used; while others, such as Lumni Bay, were apparently not. Disturbance
could have caused some of these differences, but this factor was not measured
routinely.
IV. A. 3. e. (5) Summary.
This analysis may seem to indicate that much of the baseline data are
unreliable for hypothesis testing. While this conclusion may be true for
data examined on a yearly basis, the data for each season and, for benthos,
data further segregated by specific elevations are generally less variable.
Dominant species, as defined by relatively high biomass or numbers, were also
often less variable in their abundance than the less abundant species.
79
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In assessing the impact of some perturbation on a given location,
careful attention should be given to defining the habitat. Although not
tested experimentally, using appropriate subsets of baseline data as being
representative of sites not sampled might be fairly reliable. However, one
must be particularly wary of interpreting differences in mean abundances
without considering the degree of variation about those means.
IV. B. Nearshore Waters
IV. B. 1. Habitat definitions. The nearshore water habitats include the
water column from the high tide line offshore to the 20 m (*V*60I) depth
contour. This 20 m depth contour was selected as the dividing line between
nearshore waters and offshore waters (Section IV.C) in part because several
of the various investigations used this as an outer boundary for their study,
and also because observations (of birds, for example) very often indicated
species composition and abundance of biota changed at about the 20 m isobath.
Animals and associations described in the following sections are those within
the water column itself, while those more directly associated with the
intertidal and subtidal substrates were discussed under the preceding
section.
While the nearshore water column communities differ among themselves
less than those of their various adjacent intertidal/subtidal communities,
they do not represent one homogeneous type. We, therefore, differentiated
communities, where data permitted, between nearshore waters over rock/cobble,
protected unconsolidated sediments, and exposed unconsolidated substrate
types, as described in Section IV.A.I.
Though the nearshore waters represent a small fraction of the total
water surface area of the study area (see section IV.B.2, below), their use
as spawning, nursery, and feeding areas suggests an importance inverse in
proportion to their limited area or volume. It is likely they also provide a
substantial part of the zooplankton which later inhabit offshore waters and
support communities there.
IV. B. 2. Spatial extent. The extent of the nearshore area is estimated in
Table 5. Much of the shallow water area occurs along the open shorelines and
adjacent embayments of the Strait of Juan de Fuca, eastern Strait of Georgia,
and in the bays of Whatcom and Skagit counties. The narrow shelves along
passages and around islands represent a relatively small part of the total.
IV. B. 3. Major Biological Assemblages.
IV. B. 3. a. Community composition. This section deals with the mammals,
birds, and fish using this neritic area and not directly associated with the
bottom. Most feed exclusively within the water column. Many spend only a
part of their life cycle or a part of each day in this zone.
The birds and mammals are primarily fish-eaters, and include a number of
species which feed on bottom-associated fish as well as mid-water prey.
Thus, many of these predators are partly dependent upon the productivity of
the shallows.
80
-------
Table 5. Extent of nearshore and offshore waters within the study area*
Estimated Area in km^
A. Bays
Discovery Bay
Bays in Whatcom-Skagit Counties
Bays in San Juan Islands
B. Passages
Northern Admiralty Inlet
Bellingham Channel
Haro Strait
Rosario Strait
Northern San Juan Waters
Passages in San Juan Islands
C. Open Waters
Strait of Juan de Fuca
Eastern Strait of Georgia
Western Strait of Georgia
Nearshore
«20 m)
10
155
70
15
5
15
20
5
20
300
140
20
775
(12%)
Offshore
(>20 m)
20
180
30
60
70
550
280
150
130
3,500
420
360
5,750
(88%)
Total
30
335
100
75
75
565
300
155
150
3,800
560
380
6,525
*Boundaries and areas derived from Wahl et al. (1981).
81
-------
A relatively abrupt change in species composition, richness, and numbers
occurs at about the 20 m depth as exemplified by the birds (Table 6).
The nearshore area is the principal foraging habitat of the harbor seal,
which presumably feeds in bays and along shorelines of all types. Those
pinnipeds described previously as hauling out on intertidal rocks and beaches
seek refuge from disturbance and forage for fish in nearshore waters.
The only cetacean that can be considered nearshore is the harbor
porpoise, though they may occur in offshore water also. They appear in
nearshore waters most commonly in spring and summer. Other local cetaceans
are capable of entering the nearshore areas while transiting to other areas
or while foraging or in pursuit of offshore prey, but these movements are
unpredictable. It is reasonable to expect that any of the cetaceans common
to the study area (gray whale, minke whale, killer whale, Dall porpoise, and
harbor porpoise) can on occasion be found in the nearshore areas.
Nearshore waters also support a large proportion of the fish-eating
marine birds which occur seasonally within the study area, including a number
of species of loons, grebes, cormorants, mergansers, gulls, and alcids.
Appendix Tables III-I to III-P list the most frequently occurring bird
species seasonally within the eight nearshore habitats. Allowing for
seasonal differences, these lists are remarkably similar. Twelve of the 21
species occurred (as one of the 10 seasonally most-frequently observed
species) in all eight habitats, and five more species occurred in at least
six habitats. These species are all either obligate fish-eaters (loons,
grebes, cormorants, mergansers, Common Tern, and nearshore alcids) or gulls
which eat many things including fish. While other species occurred
seasonally within these water-column habitats, numbers were relatively small.
Most of the obligate fish-eaters in the nearshore group occurred almost
strictly within the nearshore waters. Mergansers, for example, seldom were
observed feeding in water of greater than 20 m depth.
The most common birds varied seasonally at exposed habitats and from
place to place, though the gulls were always abundant. In the protected
habitats grebes were abundant in nearshore waters over mud-gravel habitats
and Pigeon Guillemots occurred consistently at mud-sand habitats. Large
numbers of Double-crested Cormorants at protected mud habitats reflected the
observations of many of these birds commuting daily to forage in the shallows
of Padilla, Samish, and Fidalgo Bays. Marbled Murrelets occurred
consistently in low densities at exposed rock; Pigeon Guillemots in large
numbers foragad off exposed rocks in the summer. Protected rock habitat was
important to Pigeon Guillemots and Marbled Murrelets year-round, Common
Murres in the fall, and Pelagic Cormorants in the summer.
Birds found in these nearshore habitats showed greater mobility than
bottom- or benthic-feeding species which foraged on shellfish or eelgrass,
for example, and which normally show relatively stable seasonal distribution
patterns. On the other hand, the neritic fish-eaters appear to show more
consistent patterns of distribution than their counterparts in the offshore
waters (Section IV.C).
82
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Table 6. Predominant distribution of commonly occurring bird species
feeding within nearshore and offshore water columns (maximum
seasonal densities from Appendix Tables III-I thru III-P)
Nearshore
«20 m)
Offshore
O20 m)
Common Loon
Red-throated Loon
Arctic Loon
Red-necked Grebe
Horned Grebe
Western Grebe
Double-crested Cormorant
Pelagic Cormorant
Brandt's Cormorant
1
Red-breasted Merganser
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet 3
Common Murre
Ancient Murrelet'
Tufted Puffin I
1 Did not occur (as one of 10 most-frequently occurring species) in
nearshore habitats.
2 Did not occur in offshore habitats.
^ Highest nearshore densities due to feeding flocks along shorelines
adjacent to offshore area—often more widespread offshore.
83
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Both the MESA and WDOE nearshore (tow nets) fish sampling schemes were
patterned on the intertidal habitat classification; i.e., sampling sites were
at the various exposed, protected, unconsolidated, and rock substrates as
observed at low tide. The original idea was to investigate whether the
nearshore pelagic fish assemblage reflected a dependency on the intertidal
habitat communities. However, in both the Strait of Juan de Fuca and
northern Puget Sound, no strong correlation was found between the defined
intertidal habitats and the composition of the nearshore pelagic fish
community. Consequently, the decision to consider the nearshore water as a
single distinct habitat appears appropriate and useful in the case of fishes.
Although the method of sampling neritic fishes was highly variable, the
general results were quite consistent for both the Strait of Juan de Fuca and
northern Puget Sound (Table 7). Pacific herring larvae and juveniles were
the single most important species in terms of percent occurrence, abundance,
and biomass. Other important neritic species (but clearly of secondary
importance to herring) were surf smelt (all life history stages); longfin
smelt (juvenile and adults); Pacific sand lance (all life history stages);
juvenile chum, pink, coho, and chinook salmon; juvenile tomcod and walleye
pollock; and tadpole sculpin (all life history stages). The one obvious
difference between northern Puget Sound and the Strait of Juan de Fuca was
the absence of three-spine sticklebacks from the Strait samples. Those
species (except herring) that often ranked highly in percent occurrence
usually ranked highly in abundance also, but low in biomass (e.g., surf
smelt). Conversely, some species such as spiny dogfish ranked second or
third in biomass but relatively low in occurrence and abundance. Some 29
species from the Strait were included in this ranking scheme, while only 17
were included for the northern area.
Although there was no association with specific intertidal habitats,
longfin smelt, and threespine stickleback were most abundant in areas of
freshwater inflow which presumably were also spawning sites for these
freshwater spawning species. Of course, salmon are also freshwater spawners
and when they first come out of the rivers and streams to the saltwater, they
are concentrated in those areas; but since they migrate to the open ocean
there are juvenile salmon throughout northern Puget Sound and the Strait of
Juan de Fuca. In addition, the studies of nearshore fishes indicated that
protected embayment areas harbored larger quantities of these fishes which
stayed longer through the year (i.e., they appeared sooner in the spring and
left later in the fall).
Pronounced seasonal changes were evident from all data collected on
nearshore species (species composition, abundance, biomass, and length
frequency). By winter almost the entire neritic fish assemblage had moved
away from the shoreline, presumably to deeper water, except in the case of
salmon, at least some of which may have made it to the open ocean. Pacific
herring larvae predominated in spring, herring juveniles predominated in the
summer, but by fall herring juveniles had left the nearshore waters.
In summary, although the diversity of fish species in the nearshore
habitats was low, the habitats appeared to be critically important as nursery
84
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Table 7. The 10 most common nerltlc fishes of northern Puget Sound and the Strait of Juan de Fuca
ranked according to occurrence, abundance, and biomass, 1974-1979.
CO
en
Occurrence
Northern Puget Sound
Species
Pacific herring
Threespine stickleback
Pacific sand larice
Surf smelt
Pacific staghorn sculpin
Chinook salmon
Tadpole sculpin
Longfin smelt
Chum salmon
Soft sculpin
Shiner perch
Pacific tomcod
Spiny dogfish
Starry flounder
Coho salmon
Northern anchovy
Snake prickleback
1974-1975
1
2
3
4
5
6
7
8
9
10
1975-1976
1
2
3
4
6
7
10
5
9
8
Abundance
1974-1975
1
2
3
5
7
10
4
9
6
8
1975-1976
1
3
2
5
9
7
4
10
8
6
Biomass
1974-1975
1
3
8
9
5
7
6
2
4
10
1975-1976
1
8
3
5
6
7
2
4
9
10
Continued
-------
Table 7. (Contd.)
CO
cr>
Occurrence
Strait of Juan de Fuca
Species
Pacific herring
Surf smelt
Tadpole sculpin
Crescent gunnel
Pacific sand lance
Walleye pollock
Long fin smelt
Tubesnout
English sole
Shiner perch
Pink salmon
Northern anchovy
Manacled sculpin
Pacific tomcod
Spiny dogfish
Starry flounder
Coho salmon
Pile perch
Striped perch
Chinook salmon
Pacific staghorn sculpin
Wolf eel
Kelp greenling
Threespine stickleback
Sailfln sculpin
Widow rockfish
Chum salmon
Bay pipefish
Pacific sandfish
76-77
1
2
3
4
5.5
5.5
7
8
9
11.5
11.5
11.5
11.5
77-78
1
5
3.5
11
2
5.5
5.5
7.5
7.5
3.5
11
11
9-
78-79
1
3
5
5.5
2
5.5
4
9
9
6.5
9
6.5
Abundance
76-77
1
5
7
8
4
2
9
10
3
6
77-78
1
4
9
10
3
8
2
5
7
6
9.5
78-79
1
3
5
2
6
8.5
4
9.5
7
8.5
76-77
1
9
4
2
7
3
5
6
8
10
Biomass
77-78
1
7
5
2
6
4
10.5
3
8
9
10.5
78-79
1
5
8
2
4
10
3
7
6
9
-------
areas for some economically and ecologically very important fishes—i.e.,
salmon, herring, smelt, sand lance, and cod fishes.
IV. B. 3. b. Trophic organization. The problems concerning a lack of
trophic structure data as outlined above for the intertidal/subtidal habitats
also apply to the nearshore habitats. Very little is known of energy flow in
nearshore habitats. Some information exists for adjacent habitats in the
southern Strait of Georgia and the Puget Sound central basin. For example,
Parsons et al. (1969a and b) provided phytoplankton information for the water
masses under the Fraser River plume in the Strait of Georgia between February
and May 1967. It was used to approximate the nearshore situation because of
the mixing and nutrient characteristics. Complementary data on chlorophyll _a
in that region were also surveyed (Stephens, 1968) and transformed to a total
organic weight value by a C/Chl £ ratio of 30 (Strickland, 1960) and a carbon
proportion of 50% of total weight. These values were also compared with
Parsons et al. (1970) and Stockner et al. (1979) in their summary of plankton
production in that region. Offshore standing stock of phytoplankton was
estimated from Chester et al. (1980) and Mackas et al. (1980) in the same
manner for chlorophyll a^ measurements in the middle of the Strait of Juan de
Fuca.
Herbivorous (suspension-feeding) and carnivorous zooplankton of offshore
and nearshore neritic habitats have also been poorly documented. Similar to
the primary production estimates, data on zooplankton within the Fraser River
plume (Parsons et al., 1969a, 1970) were used as an estimate of the nearshore
standing stock and data from the center of the Strait of Juan de Fuca
(Chester et al., 1980; Mackas et al., 1980) were used, in conjunction with
data from selected stations in the southern Strait of Georgia (Robinson
et al., 1968a and b; Barraclough and Fulton, 1967, 1968; Barraclough et al.,
1968; Barraclough, 1967a and b; Robinson, 1969) to estimate zooplankton
standing stock for offshore habitats.
The trophic organization of the nearshore zones did not appear to be
habitat-specific. All the organisms were swimmning or floating. The majority
were highly mobile and were not closely associated with underlying benthic
habitat types. Therefore, the following discussion applies broadly to all
nearshore areas; and because much of the data were available only from
offshore (>20 m) waters, it also applies somewhat to offshore habitats
discussed in further detail in Section IV.C. below.
The food web structure characterizing the neritic zone adjacent to the
shore (Figure 23) was basically a condensed version of the offshore habitat
group. Nearshora habitats supported biological communities similarly based
upon phytoplankton production, suspension-feeding hervivorous zooplankton,
carnivorous zooplankton, planktivorous fishes and birds, and piscivorous
fish, birds, and marine mammals. Production, at least in terms of standing
stock, appeared to be measurably higher than in offshore waters.
The taxa dominating these food web nodes also tended to be the same as
those offshore but with some exceptions. Deep water herbivorous calanoid
copepods (i.e., Calanus) which were important offshore did not appear in
equal density nearshore. Epibenthic forms, such as omnivorous mysids,
87
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entered the community from the adjacent epibenthic communities and
contributed to the diet of neritic zooplanktivorous fishes. The schooling
neritic fishes, particularly Pacific herring and Pacific sand lance, also
were more common in these habitats and, consequently, constituted major prey
resources for the piscivorous fishes and birds in the community. As in the
offshore habitats, loons and grebes, particularly the Western Grebe and
Arctic Loon, were the dominant piscivores; but the Common Murre also often
comprised a large proportion of the total standing stock of piscivorous
birds.
The role of piscivorous marine mammals in energy flow is poorly
understood and has not been quantified in the area. Killer whales, however,
have been known to consume pinnipeds, flatfish, cod fishes, salmon, and
squid. Harbor porpoise apparently eat schooling fishes, such as herring.
Harbor seals are known to consume a wide variety of fish, including cod
fishes, osmerids, and sea perch. They occasionally eat octopus also.
Whiting (hake) and various bottomfishes apparently are important prey for sea
lions.
Although structurally similar to the offshore food web, the nearshore
food web supports a higher standing stock of organisms at most trophic levels
and may reflect actual differences in production considering that the
functional groups are essentially the same as in the offshore food web.
There are a number of possible explanations for this apparent difference.
First, unlike in the offshore habitats, surf ace-to-bottom mixing and
estuarine plumes are typical of the nearshore habitats, especially in the
vicinity of headlands (Pingree et al., 1978) which are common features of the
region's shoreline. Second, adjacent shorelands and rivers provide immediate
sources of nutrients which are mixed into the nearshore neritic water.
Third, spawning populations of animals with pelagic larvae, whether
nearshore, shallow subtidal or intertidal, release their progeny directly
into the nearshore water column. A certain proportion of these migrate or
are transported into offshore habitats; but the majority appear to feed,
grow, and develop in the nearshore habitats where they form important prey
and predator populations during that time. Two examples of such animals
include the Pacific herring and Dungeness crab. Pacific herring spawn their
demersal eggs in shallow subtidal habitats. Upon hatching the larvae soon
begin schooling in neritic waters and typically aggregate in contained
embayments through much of their larval and early juvenile life; during these
stages they form high density congregations that feed upon small herbivorous
copepods. They are, in turn, fed upon heavily by neritic fish-eating fishes
and nearshore birds. During this period (April-July), the role of Pacific
herring in the nearshore food web is pervasive.
Dungeness crab also release their pelagic larvae into nearshore waters,
especially in contained embayments and estuaries, where they develop through
the various larval stages. As zoea they are fed upon extensively by juvenile
salmonids and other neritic zooplankton-eating fishes and are themselves
carnivorous upon smaller zooplankton. In both cases, it would appear that a
highly advantageous life history strategy is to release progeny into
nearshore waters where primary and secondary production is measurably greater
and less heterogeneously distributed than in offshore habitats.
-------
PISCIVOROUS
MARINE
MAMMALS
NEARSHORE
PISCIVOROUS
FISHES
O 0,1-1
o < i
PISCIVOROUS
BIRDS
ZOOPLANKTIVOROUS
FISHES
(0.23)
CARNIVOROUS
ZOOPLANKTON
ZOOPLANKTIVOROUS
BIRDS
OMNIVOROUS
ZOOPLANKTON
HERBIVOROUS
ZOOPLANKTON
«0,20)
PHYTOPLANKTON
«0,4)
Figure 13. Characterization of nearshore habitat food web. Average biomass
of major taxa represented in parentneses(.grams/m2 or grams/m2).
89
-------
IV. B. 3. c. Density, biomass, species richness. The emphasis in the marine
mammal studies was on the most observable species that could be quantified.
Thus, primarily the hauled-out pinnipeds were counted. Equivalent data for
nearshore areas are not available.
Seasonal densities of birds assumed to be associated with the water
column (i.e., fish- and plankton-eating species, as opposed to those feeding
on bottom organisms) are given in Appendix Tables III-I through III-P,
listing the seasonally most common species which may be defined as the
predominent species.
For all eight habitats, average densities ranged from about 13 to 396
birds/km2 for all species during the year. If gulls, which also forage on
intertidal/subtidal habitats, were removed, this range becomes about 2 to
102/km2. These ranges compare with equivalent densities for corresponding
intertidal/subtidal habitat types of 8 to 1280/km2 for all species and 1 to
1142/km2 for species other than gulls (Appendix Tables III-A through H).
Densities of intertidal/subtidal and nearshore water habitats were more
similar in the relatively low-density exposed unconsolidated and rock
habitats and generally differed more in high-density protected habitats.
This situation was most evident in the fall, winter, and spring seasons, when
large populations of waterfowl resulted in protected intertidal/subtidal
densities up to 20 times greater than those in adjacent nearshore waters.
Densities were more nearly equal in exposed habitats where large numbers of
fish-eating species were present in nearshore waters and subtidal/intertidal
habitats had low numbers of bottom-feeding or grazing birds. The particular
exception to this was cobble habitats where herring spawned. Scoters feeding
on spawn in the intertidal/subtidal habitat resulted in densities of 10 to 20
times those of the nearshore waters.
Summations of total species richness, density, and biomass for each
season are shown in Appendix Tables III-Q through III-T. During the spring,
most bird groups were very similar; exposed sand and rock were lowest for all
three parameters. Exposed mixed coarse and protected rock had highest
densities and biomass in summer. Exposed rock was clearly lowest in density
and biomass in the fall. Protected rock and protected mud-gravel were
highest in density and biomass in winter.
Fish species richness for tow net catches in nearshore zones of the
study area were surprisingly similar from site to site (Figure 24). Mean
species richness ranged from 2.7 at Deadman Bay to 9.8 at Lummi Bay. Most
mean values were in the 4- to 6-species range. The mean of the means for
rocky, exposed, and protected habitats were 6.3, 5.7, and 7.4, respectively.
The maximum number of species occurred in the spring at most sites, or
in summer at some sites, followed by a reduction in the fall and a minimum in
winter. High values in the spring and summer reflect the influx of larvae
and juveniles into nearshore surface waters. Sites sampled in the San Juan
Islands had the fewest species relative to the other regions sampled.
Samples collected at the eastern Strait sites were often more species-rich
than those in the more exposed western Strait sites.
90
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-------
Mean fish densities in tow net catches varied between less than 0.01 to
0.52 fish/m among the 24 sites that were sampled (Figure 25). Mean of means
for rocky, exposed, and protected habitats were 0.13, 0.05, and 0.06 fish/m ,
respectively. The higher value for the rocky habitat reflects the large
catches made at Morse Creek, a cobble site. The mean of means for the sites
in the San Juan Islands, Cherry Point/Lummi Bay area, Anacortes area, and
Strait of Juan de Fuca were 0.09, 0.10, 0.03, and 0.15, respectively. Again,
high values at Morse Creek influenced the high mean densities (due to an
unusually large catch of juvenile Pacific herring in the summer of 1977).
Seasonal density trends generally followed those of species richness;
maxima often occurred in the spring and minima in the winter. The schooling
tendencies and patchy distribution of the species (Pacific herring, smelts,
sand lance, etc.) most often caught in tow nets resulted in highly variable
catch statistics, especially densities and biomass. Trends were difficult to
define very clearly.
Mean fish biomass for tow net samples (Figure 26) ranged from less than
0.01 to 1.04 g/m ; the unusually high value at Morse Creek reflected a
uniquely massive catch in the summer of 1977. Disregarding the Morse Creek
summer 1977 sample, the range was 0.01 to 0.69. The mean of the means for
rocky, exposed, and protected habitats was 0.08, 1.10, and 0.25 g/m , again
disregarding the Morse Creek summer 1977 sample. Mean biomass values were
highest in the Cherry Point/Lummi Bay area; while those for the San Juan
Islands, Anacortes area, and Strait of Juan de Fuca were slighly lower, but
similar to each other.
Mean biomass was often greatest in summer catches, lowest in the winter.
Some tendency toward highest biomass in protected habitats was apparent, but
this trend was not consistent as reflected by low biomass at Jamestown/Port
Williams and Guemes Island East. Many of the lowest values occurred at the
exposed sites. High variability in biomass data usually was a result of the
occasional capture of large species such as spiny dogfish, various sea perch,
flounder, and sculpin. The extremely high value for summer 1977 at Morse
Creek reflects the capture of 120,000 juvenile Pacific herring weighing
300 kg.
IV. B. 3. d. Migrants. In describing typical movements in and out of
nearshore waters, the term migrant may be somewhat misleading since it
usually implies movements over long distances. In the nearshore waters,
movements of animals in and out of this habitat may actually be quite
restricted and involve animals moving into the water column during certain
times of the day or season. A discussion of larger scale migrations as
observed through offshore waters is described in Section IV.C.3.d. below.
Migratory marine mammals are generally not important components of the
nearshore communities. During their northward migration, a few gray whales
have been observed in the inside waters, often pausing to feed. This feeding
activity usually takes place in the nearshore habitats, normally in
mud-gravel areas and mud-sand areas. Typical feeding behavior for this
species includes passing over the bottom on its side and scooping and sifting
sediment through baleen plates to recover benthic organisms. Killer whales
92
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-------
may occasionally frequent nearshore areas utilized by harbor seals.
Presumably killer whales entering these areas forage upon pinnipeds and fish.
Both California and northern sea lions, which are migrants, pass through
nearshore areas as they enter a haul-out area, but they are not considered to
be important components of the nearshore community. They are primarily
offshore and deep-water feeders.
Seabirds in the nearshore area exhibited movements that were similar to
those found in offshore waters. Major movements of birds took place to and
from inland nesting sites (occupied in the spring and summer) to wintering
areas in the nearshore bays (e.g., Western Grebes). Other loons, grebes,
cormorants, alcids, and mergansers also followed this pattern. Large flocks
of gulls passed through the nearshore waters during migration seasons; and
two species, Mew and Thayer's Gulls, were important nearshore residents.
Smaller scale movements of locally nesting birds, like the Common
Merganser, to saltwater and the dispersal of species, like the cormorants,
Pigeon Guillemots and Marbled Murrelets, to and from breeding areas occurred
throughout the nearshore regions. Movements of the latter species were from
breeding areas nearshore to foraging areas, often offshore. Glaucous-winged
Gulls, the most abundant gull in the study area, also dispersed from areas
around colonies to nearshore wintering habitats in August-September. Adults
began to return to nesting colonies and establish territories as early as
January or February, though most juveniles remained away from the colony all
year.
Based on density information from Appendix Tables III-I through III-P,
the greatest densities of birds were observed in the spring and fall with
fewer large densities recorded in the winter and summer. These data nay
demonstrate a seasonal influx into the nearshore areas following summer
breeding seasons (for the fall) and again just prior to the onset of a new
breeding period in the spring. Many species found in the nearshore areas
during these periods would be expected to be in transit either to or from
inland areas.
Generally, many species of fish demonstrate the yearly (or seasonal)
spawning migrations into the nearshore habitat. Some spawning activity may
be occurring at virtually every season of the year. Many other species, on
the other hand, make much smaller scale (local) movements on a seasonal or
diel basis. Seasonal movement usually consists primarily of species leaving
the nearshore area for the deeper waters during the winter when conditions in
that habitat are the poorest. Dogfish, ratfish, and some cod fishes and
rockfish move from deeper, offshore waters into the nearshore waters at night
for foraging purposes.
Juvenile salmon usually move through the nearshora habitats as wall as
offshore waters as they migrate to sea in the winter and spring. Adults of
these species move into the study area through tha offshore waters in the
summer and fall.
95
-------
Adult herring usually move from offshore waters into the nearshore areas
for spawning purposes from December through June; the timing is dependent
upon the location of the spawning grounds. Juvenile herring remain
associated with these nearshore waters until the late fall when they move
into deeper water.
Surf smelt swim into nearshore waters for spawning. Spawning on
intertidal beaches can occur during any month but is usually site specific.
Other than the fact that movements into nearshore waters for spawning occur,
as with longfin smelt which spawn in streams, the extent or duration of surf
smelt movements is unknown.
Cod fishes usually move into nearshore waters during spawning migrations
in the winter months and become dispersed offshore during the rest of the
year. Juvenile cod, however, often remain in the nearshore area until they
are one year old before moving out into deeper waters.
IV. 3. B. e. Variability. The nearshore water was perhaps the most
consistently monitored area (for fish, birds, and mammals) during the MESA
program. Thus, one expects that any natural variability would have been
adequately documented. However, the difficulties of sampling far-ranging
study sites using a variety of methods has generated some uncertainty as to
the adequacy of the data. Some variability in biologic data observed in the
nearshore zones may be entirely related to methodology.
Harbor seals were the dominant mammals of nearshore waters, though many
other species were also observed. Censusing methods concentrated on haul-out
areas, thus data for nearshore and offshore waters are minimal. Difficulties
in observing mammals which haul out are magnified when the animals are in the
water. Glare, waves, wide dispersal and submergence of the animals, distur-
bance by aircraft, and formation of pods are factors directly affecting
estimates of population sizes.
Generally, recent collection of data on marine mammals in the study
area, while providing a basic inventory, are not of the quality to detect
subtle variations.
While there was considerable variation in bird species composition in
the intertidal/subtidal habitat types, there was remarkable similarity in the
species foraging in nearshore waters overlying the various substrate types.
The seasonal lists of the most frequently observed species (Appendix Tables
III-I through III-P) were comprised of a relatively few species, each
occurring in a number of nearshore habitats.
The sources of variability in bird data included site-specific
short-term phenomena, such as herring spawning and tidal turbulence, observer
vision, glare,. waves, and other weather-related factors, disturbance caused
by the censusing vehicle (boat or plane), taxonomic ability, submergence of
diving birds, and diurnal movement patterns of some species. "Normal"
seasonal variations related to migrations, breeding, nesting, etc. add
further sources of variability. The two-year study period provided
insufficient data for documenting annual variations in bird populations using
96
-------
nearshore waters. Substantial variations are probable. These relate to the
success of the previous breeding season and to variations in productivity of
the marine systems.
A major source of sampling error for nearshore fishes was likely related
to gear selectivity. Each gear type used would tend to selectively sample
any given area and direct comparison of catches "from different gear types
could be misleading. However, in most cases data from similar gear types
were comparable. Other uncontrollable variation was a result of bottom
topography, weather conditions, sea conditions, etc.
A decrease in total number of fish species collected was observed in
beach seine catches as the MESA study progressed, due largely to an unusual
appearance of rare species in the first year's catch. The presence or
absence of these locally rare species (rock greenling, Pacific sandfish,
plainfin midshipman, and kelp perch) was not considered significant.
The rank order of the most abundant species caught in tow net samples
was generally consistent from year to year (Table 7) and suggests that for
some species habitat occupation is fairly constant. Differences between
years may be a result of the random occurrence of unusually large numbers of
individuals of a species. Variation in age class abundance could also affect
the rankings. For example, few speckled sanddabs were collected early in the
MESA study; abundance of this species increased markedly during later years.
Pacific herring and other schooling fish often dominated the tow net
catches. Pacific herring are most abundant in the spring and summer as
larvae and juveniles. Few herring were caught in the fall and winter as this
species moved into the offshore waters. A difficulty in assessing the
habitat preference of herring was encountered and was attributed to the
schooling nature and, thus, patchy distribution of this species. Most smelt
were collected in the western Strait of Juan de Fuca in the summer and fall
months corresponding to spawning activities in the nearshore areas.
Between-year and between-season variability in tow net catches (as shown in
the Strait data in Figures 27, 28, 29) often resulted from influxes of
schooling fish, such as the clupeids and osmerids. While species richness
remained fairly constant, abundance and biomass occasionally varied widely.
For example, the summer 1977 sample at Morse Creek was highly unusual for a
site that normally had low-density, low-biomass catches.
Species richness of nearshore fishes was greatest during summer and fall
and diminished in the winter and spring. This trend may generally reflect an
influx of larvae and juveniles into nearshore waters during these seasons.
Densities of fishes caught followed a similar pattern.
IV. C. Offshore Waters
IV. C. 1. Habitat definitions. Offshore areas with water depths of 20 m
(60f) or greater comprised a set of habitats which differed in many respects
from the shallower areas. These areas were characterized as parts of the
MESA plankton, bird, and mammal studies.
97
-------
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Twin Morse Dungeness Jamestown Beckett Pt.
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Williams
1977-78 1978-79
—
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West Alexander's
Beach Beach
Figure 27. Number of species of fish caught per season(winter/sprinq/suiiitiicr/fa11)
at nine nearshore sites along the Strait of Juan de Fuca, 1976-1979
(from Miller et al., 1980).
-------
$/////
1976-77 1977-78 1978-79
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Kydaka Pillar Pt. Twin Morse Dungeness Jamestown Beckett Pt. West
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=1
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Alexander's
Beach
Figure 28. Dens1ty(no./m3) of fish caught per season(winter/sprin(]/sunimer/fall) at
nine nearshore sites along the Strait of Juan de Fuca, 1976-1979ffrom
Miller et al., 1980).
-------
W/
W
1976-77 1977-78
2.29
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Alexander's
Beach
Figure 29. Biomass(granis/ni3j of fish caught per season(winter/spriiK]/suM»iier/fd] 1) at
nine nearshore sites along the Strait of Juan do Fuca, 1976-1979(fro;«
Miller et al., 1980).
-------
These deep water areas have been classified here as three types: the
deeper portions of several embayments in the study area; passages; and the
extensive open water areas of large bodies like the Strait of Juan de Fuca.
Note that these habitat types are not "pelagic" in the oceanic sense, though
processes may be similar in many respects.
IV. C. 1. a. Bays. Several embayments in the study area have deep offshore
areas that showed pronounced species differences from immediately adjacent
nearshore waters. Discovery Bay and Bellingham Bay had sizable offshore
components. Padilla Bay was largely composed of shallow eelgrass beds; but
its outer portion was deep and, like Discovery and Bellingham Bays, the
marine bird species composition changed abruptly at about the 20 m depth
contour.
IV. C. 1. b. Narrow passages. Deep narrow passages between land masses in
the study area featured strong tidal currents and turbulence along tidal
fronts. Areas such as Speiden and San Juan Cnannels were included in this
habitat type. Areas of extremely strong tidal exchange like southern San
Juan Channel near" Cattle Point and Active Pass in Canadian waters were also
included. Tidal fronts were more common in passages than in deep bays or
open waters.
IV. C. 1. c. Open waters and broad passages. A large proportion of the
offshore waters were within the Strait of Juan de Fuca and southern Strait of
Georgia. These contained very deep, open waters; and while tidal fronts were
noticeable, they often had lower current velocity and less tidal turbulence
than narrow passages. We have included Haro Strait, Rosario Strait,
Admiralty Inlet, and Bellingham and Presidents Channels in the broad passage
habitat type.
IV. C. 2. Spatial extent. About 88% of the water surface in the study area
covers depths greater than 20 m (Table 5). About 4% of these offshore waters
are components of large bays like Discovery Bay and the
Bellingham-Samish-Padilla Bays complex and small bays within the San Juan
Islands. The deep passages make up about 21%. The Strait of Juan de Fuca
waters comprise about 61% of the total deep waters of the study area, and the
study area portion of the southern Strait of Georgia makes up 14%.
The offshore waters include a very high proportion of the total water
volume of the study area. Assuming average nearshore depth as 10 m, and
average offshore depth as 100 m, about 99% of the volume of the Strait of
Juan de Fuca would be in the offshore waterf;.
IV. C. 3. Major Biological Assemblages
IV. C. 3. a. Community description. The four offshore habitats resemble
each other in a number of ways; and some of the variation between habitat
types probably represents conditions at arbitrarily selected points on a
scale grading from narrow, turbulent passages like San Juan Channel at Cattle
Point to apparently featureless waters in the middle of the Strait of Juan
de Fuca.
101
-------
One of the most characteristic features of the offshore community as
presented here is that some of the predominant and most visible species are
usually not directly associated with the bottom community. These species
function primarily at the surface and in upper and middle levels of the water
column. Plankton and fish along with the marine birds and mammals which, in
turn, prey mostly on plankton and fish, comprise the community.
Animals usually appear to have a "patchy" or "clumped" distribution,
presumably reflecting concentrations of their prey items. Major proportions
of marine bird populations observed in the offshore waters were in areas of
fronts between water masses: tide rips, convergence and downwelling zones,
etc.
Thus, the discussion below will focus on interspecific, primarily
feeding, relationships and on important phenomena such as the tidal fronts.
We stress, again, that few data are available for offshore mid-water
organisms and even less is known of offshore bottom waters.
At least 21 species of marine mammals have been reported in the offshore
waters of the study area. They primarily use these waters for feeding and
migrations. The gray whale, minke whale, killer whale, harbor porpoise, and
Ball porpoise were the most common cetaceans. The harbor seal, though
primarily a nearshore inhabitant, was the most common pinniped.
Four species of fish-eating birds were most common in offshore waters:
the Common Murre, Brandt's Cormorant, Western Grebe, and Arctic Loon.
Although variable in their feeding habits over the spectrum of pelagic fishes
available to them, these birds occurred in relatively predictable periods and
concentrations as a function of breeding, roosting, and migration. The
mobile, gregarious birds foraging in offshore waters functioned sometimes in
pure flocks of one species, and often in multispecies assemblages. They were
capable of taking advantage of feeding opportunities which existed for a very
brief time when schools of fish were near the surface or during periods when
prey concentrations were found in tidal fronts.
A composite of the 10 most frequently observed bird species per season
within the four offshore habitats (Appendix Tables III-U through III-X)
indicates 28 species utilize offshore habitats. One species (Hooded
Merganser) is considered incidental in the offshore habitats. Of the
remaining species, 16 can be considered obligate piscivores, three can be
considered obligate planktivores (Fort-tailed Storm Petrel, Northern
Phalarope, and Cassin's Auklet), two are gulls which specialize on large
plankton and small fish (Bonaparte's and Mew Gulls), one is a kleptoparasite
while in the study area (Parasitic Jaeger), and the remaining species are
omnivores (large gulls).
The offshore bird population is composed of large numbers of a
relatively few species when compared to nearshore habitats. As an example,
Table 8 shows characteristic winter bird species composition and percent of
total estimated population for winter in offshore waters of some regions.
102
-------
o
CO
Table 8. Percentage of estimated total winter populations of major marine birds
by species or species groups for selected offshore regions and total
densities per region, 1978-1979.
Western
Strait of
ijuan de Fuca
Diving birds
Loons 2
Grebes 3
Cormorants
Common Murre
Other alcids
Other species
Ducks
Gulls
Total estimated
birds
Birds /km 2
< 1
< 1
< 1
68
1
< 1
30
37,000
19.6
Eastern
Strait of Admiralty
Juan de Fuca Inlet
< 1
1
4
28
3
9
56
36,000
22.1
1
7
1
26
7
4
53
3,000
50.8
Western Eastern Southern
Strait of Strait of Rosario
Georgia Georgia Strait
2
2
1
36
5
3
49
1,300
3.5
6
6
2
39
7
19 "*
23
22,000
76.6
4
< 1
10
59
2
1
24
9,500
84.8
Offshore
Active Bellingham
Pass Bay
21
< 1
40
6
< 1
3
29
4,000
385.5
3
.62
2
9
2
10
11
32,000
258.7
* Gulls may be overstated: some data from ferry - no allowance for ship following here.
Almost all Arctic Loons.
3 Almost all Western Grebes.
Mostly Oldsquaws.
Source: unpublished MESA data.
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Species and groups of species of birds and mammals differ in their use
of the offshore areas, relating to needs to come ashore diurnally or
seasonally during their presence in the study area. Several species have no
direct ties with nearshore habitats while they are present within the study
area. The cetaceans do not come ashore at all under normal circumstances.
The murres, with a fall-winter population likely in the hundreds of
thousands, form one of the major components of the offshore system and are
almost exclusively dependent upon it (Table 9).
Table 9. Percentage of selected major wintering bird species occurring
in offshore waters in the study area.
Number estimated Percent in
in study area offshore waters
Arctic Loon 4,800 82
Western Grebe 72,000 77
Brandt's Cormorant* 3,700 58
Common Murre 81,000 96
*Some censused at roosts onshore; numbers using offshore waters
understated. Source: Unpublished MESA data.
Other species use the offshore waters to a large extent for foraging but
spend a proportion of their lives ashore. These include Brandt's Cormorants,
which roost ashore. The Rhinoceros Auklet spends all its nonnesting season
on the water, otherwise coming ashore nightly during its spring-summer
nesting season. For these highly specialized diving animals, the foraging
opportunities of the offshore areas are essential. In the case of a species
like the Rhinoceros Auklet, breeding within the study area and foraging
offshore, reproductive success and maintenance of adult populations may
depend on localized food resources of the offshore area.
For fishes there has been little effort to identify the offshore water
assemblages in the Strait of Juan de Fuca or northern Puget Sound. Neverthe-
less, it is reasonable to separate the offshore fishes into surface organisms
(upper few meters of the water column), mid-water (from a few meters below
the surface to a few meters above the bottom), and demersal (on the bottom
and a few meters above it).
The offshore surface waters were particularly notable during the winter
and spring months for large quantities of pelagic fish eggs and larvae. The
most common eggs were those of flatfish species (which all have pelagic eggs
except rock sole); but there were also eggs of the cod fishes, pollock, hake,
and probably tomcod (but not Pacific cod which have demersal eggs). The
variety of larvae found in the offshore surface water was great (Chester
et al., 1977), including smelts, cod fishes, sculpin, and flatfishes. They
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were dominated by the greenlings (including the lingcod), mostly one or more
species of Hexagrammos (white-spotted-, kelp-, or rock-greenlings). There
were also some juvenile and adult fishes seen in offshore surface waters, but
quantitative data are lacking. Juvenile and adult herring may congregate
right at the surface (herring balls) at most any time of the year or time of
day, although the youngest juveniles are known to school at the surface at
dusk (Hart, 1973). Many marine birds were attracted to these herring balls.
At times juvenile salmon were seen migrating at the surface across open water
(such as the Strait of Georgia), and even adult salmon (and other fishes)
were occasionally found right at the surface. The nature and predictability
of these surface aggregations has not been determined.
This apparent unpredictability fits into the well-known foraging pattern
of gulls over the water surface. Feeding assemblages of birds are apparently
unpredictable in time and space. Enough study has not been done to determine
if the gulls are the nuclear species, the species that starts feeding
assemblages. But the foraging pattern of gulls is such that it allows for
the finding of unpredictable food sources. Once an individual finds a food
source, its behavior communicates to other gulls and other bird species the
presence of food. Fishermen have learned to read these feeding activities as
'well. There is some thought that the Rhinoceros Auklet may drive prey items,
schooling fish, to the surface and make them available to a variety of
surface foragers.
Offshore mid-water also apparently supports sizable aggregation? of
fish, but standardized survey data are again generally lacking. It is not
likely that many pelagic fish eggs occur in offshore mid-water (although it
should be noted that many pelagic fish eggs eventually sink from the surface
waters). Chester et al. (1977) indicated from the oblique bongo net tows
they made in the upper 50 m offshore stations, that a fairly diverse
assemblage of larvae was present including the more abundant Pacific herring,
in addition to smelts, Pacific sand lance, cod fishes, sculpins, pricklebacks
(blennies), rockfish, English sole, rock sole, and other flatfish. There has
been no systematic offshore mid-water survey of juvenile and adult fishes in
the Strait of Juan de Fuca and northern Puget Sound, but clearly such waters
are the primary or secondary habitat of most adult and many juvenile pelagic
fish species. Many species are fished commercially and recreationally in the
offshore mid-water, such as spiny dogfish, Pacific herring, salmon (all five
species), cut-throat trout, steelhead trout, surf smelt, Pacific cod, hake,
tomcod, pollock, Pacific sand lance, and several species of pelagic rockfish.
Some of these fishes occur in the offshore mid-water during one season (e.g.,
herring adults, chinook salmon adults) or during a particular life history
stage (e.g., juvenile herring and salmon), while other species occur through-
out all seasons and life history stages (e.g., tomcod and pollock). Various
combinations may also occur.
The offshore bottom waters have had little or no sampling for fish eggs
and larvae. Major offshore demersal spawning may occur in deep water. For
example, while there is direct evidence for lingcod spawning in the subtidal
depths (i.e.,<20m) and indirect evidence for Pacific cod spawning there
also, many fisheries biologists believe both the lingcod and Pacific cod also
have deep offshore spawning grounds where their demersal eggs are deposited.
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The evidence is also beginning to mount that there are demersal fish larvae
that spend all or part of their larval life on or near (perhaps even in) the
bottom. Unfortunately, the supporting evidence for the previous statements
about eggs and larvae in offshore bottom waters is entirely circumstantial.
Deep offshore bottom waters are important for commercial and
recreational fishing in the area. Such economically valuable demersal fishes
include the demersal rockfishes (several species), sablefish juveniles,
whitespotted greenling, lingcod, and flatfish (several species including the
Pacific halibut). Other abundant demersal species in the offshore bottom
waters which are important ecologically as forage organisms, predators,
scavengers, etc. include skates (two species), ratfish, midshipman, eelpouts
(two or three species), snake prickleback, bay goby, sculpins (two species),
and poachers (two species).
It is worth pointing out that demersal species have been found to group
primarily on the basis of depth and only secondarily by geographic locality.
In central and southern Puget Sound, the demersal fishes caught in trawl
collections were found to form distinct groups associated with depths of less
than 30 m, 30-70 m, and greater than 70 m.
The herbivorous zooplankton included copepods such as Pseudocalanus and
Calanus. Plankton carnivores included ctenophores such as Beroe and
Pleurobrachia; chaetognaths such as Sagitta and Eukrohnia; and crustaceans
such as Parathemisto (hyperiid amphipod), Pasiphaea (shrimp), and Podon and
Evading, (cladocerans). Nektonic carnivores are primarily larval and juvenile
fishes, including Pacific herring, Pacific sand lance, smelts, Pacific
salmon, and greenlings. Piscivorous fishes are assumed to include maturing
or resident Pacific salmon, Pacific hake, and walleye pollock.
There were some apparent differences in species' habitat preferences
among offshore communities occurring in the bays, passages, and open waters
of the study area, particularly as far as birds are concerned.
IV. C. 3. a. (1) Bays. Marine mammals were less frequently observed in
deeper waters of -the large bays than in nearshore waters. Harbor seals were
the most abundant mammal in this habitat.
While the four major offshore bird species occurred in all the deeper
bays, the predominant fish-eating species in Bellingham Bay, one of the major
deep bays in the study area, was the Western Grebe (Appendix Table III-U);
the other species were relatively less abundant.
IV. C. 3. a. (2) Narrow passages. Northern and California sea lions were
observed in the narrow passages of Active Pass and San Juan Channel more
frequently than in many other foraging habitats. Harbor seals were also seen
in this habitat, though rarely.
The composition of bird populations in narrow passages differed from
that in deep bays. Brandt's Cormorants and Arctic Loons occurred in greatest
densities in passages (e.g., Active Pass, Appendix Table III-V). Bonaparte's
Gull also occurred in high densities in narrow passages (Active Pass), though
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they also occurred in a patchy distribution throughout the offshore habitats,'
especially in tidal fronts where plankton was concentrated. Quantities of
pelagic fish eggs and larvae occurred particularly in winter and spring; and,
indeed, relatively high densities of Bonaparte's Gulls were offshore at these
times (Appendix Tables III-U through III-X). Fish-eating species (Arctic
Loons, Brandt's Cormorants) also occurred in peak numbers at locations and
habitats where concentrations of eggs and larvae presumably attract fish.
These may also relate to proximity to nesting sites, roosts, and haul-out
areas (in the cases of birds and pinnipeds), or variations in oceanographic
features like salinity and turbidity.
IV. C. 3. a. (3) Broad passages. Unlike birds, pinnipeds and cetaceans do
not appear to be as obviously keyed on "fronts." However, killer whales
travel in pods, occasionally totalling among all pods over 75 animals in the
study area, and foraging within concentrations of prey (e.g., salmonids)
would seem essential to even small groups. Minke whales were most often
observed in broad passages or along steep shorelines with tidal convergence
action where plankton and small fish prey were concentrated. While cetaceans
were infrequently encountered, seabirds were occasionally observed following
large marine mammals as they do in other areas.
As in narrow passages, major feeding functions of birds in broad
passages resulted from concentrations of prey species in tidal fronts and
eddies. This phenomenon is transitory but it is consistent and birds may, as
a result, become concentrated. Prey would seem less likely to be in schools,
but rather simply concentrated by currents, and cooperation between
individual predators would seem less advantageous here. Gulls serve less as
catalysts, and diving birds often forage independently. Both surface-feeding
and underwater-feeding species usually fly up-current, and feed while
drifting down-current to a presumed point where feeding becomes less
efficient then they repeat the procedure.
This activity was patchy, with observed densities of animals varying
greatly during censuses over the offshore waters of broad passages. As an
example, density of all species in most of southern Rosario Strait was 19/km
in the fall, while the densities of birds on a census transect from Shannon
Point to Bird Rocks were as high as 907 and 2171/km2. The predator species
involved were generally highly mobile and gregarious.
Relative abundance of bird species shifted from the patterns of bays and
narrow passages in this habitat. The Common Murre was the dominant species
among the fish-eating species during the fall and winter seasons, while
Rhinoceros Auklets were present in summer (Appendix Table III-W).
IV. C. 3. a. (4) Open waters. Cetaceans were most frequently observed in
the open waters of the study area, particularly the Strait of Juan de Fuca.
Minke whales and Dall porpoise were found mostly in open waters. Killer
whales and harbor porpoise were also found there, but were occasionally found
in nearshore waters also.
The avian community composition of open waters resembled that of broad
passages. Common Murres dominated the fish-eating species for the fall and
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winter period, while Rhinoceros Auklets were the abundant species in summer
(Appendix Table III-X).
During .aerial censuses, herring balls were observed in open waters of
the Strait of Juan de Fuca being preyed upon from the surface by gulls and
Rhinoceros Auklets feeding from below the surface. Gulls often find a school
while foraging from the air; and, since these birds are highly visible, their
feeding behavior attracts other gulls and divers, which in our study area
will often be Arctic Loons, Brandt's Cormorants, Common Murres, and
Rhinoceros Auklets. Additionally, jaegers steal food from diving birds and
gulls. The complementary attacks on prey from the surface by gulls and from
below by divers may maximize exploitation of the opportunity by tending to
keep schools of prey species "rounded up." However, these feeding activities
are temporary and birds attracted from long distances may arrive after prey
is dispersed.
Another type of feeding is likely very important but poorly understood
for the study area. This activity is related to availability of zooplankton
which ascends to surface waters during hours of darkness. Many seabirds feed
at night. Zooplankton availability may explain the movements of Common
Murres from the Strait of Juan de Fuca into Rosario Strait in the daytime;
the murres may forage on plankton and plankton-associated fish at night in
the Strait, and on prey in tidal fronts in Rosario Strait during the day.
In addition, phalaropes, which are essentially fall migrants, are known
to feed directly on concentrations of planktonic organisms on the surface.
From mid-July to September, Northern Phalaropes were seen in drift or rip
lines in open waters and passages. This activity increases with proximity to
the ocean.
IV. C. 3. b. Trophic organization. The structure of the offshore food web
(Figure 30) resembles the classic autotrophically-based pelagic community
characterized by a phytoplankton-herbivorous zooplankton-carnivorous
zooplankton-planktivorous fishes energy flow (Hardy, 1924); although it is in
all probability a more complex and interlinked system (Gushing, 1970; Petipa
et al., 1970).
The major forms of phytoplankton included diatoms, dinoflagellates,
coccolithophorids, and various microflagellates. Microflagellates were
dominant in the Strait during late fall and winter. Diatoms were dominant
during spring and early summer, and occasionally during a fall bloom.
Dinoflagellates reached their maximum 'abundance during late summer and early
fall. Variability in community composition was very high spatially and
between replicates.
The grouping of producer and consumer organisms into feeding categories
has masked the considerable temporal and spatial variation in the taxonomic
and size composition of the organisms within these groups. The herbivorous
zooplankton, for instance, included both the relatively small (1-2 mm long)
calanoid copepod Pseudocalanus minutus, which was found in surface waters at
high densities, and large (2-4 mm long) Calanus spp. (principally £.
plumchrus. and a complex of C. pacificus/C. marshallae) which resided
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OFFSHORE
O o.i-1
PISCIVOROUS
MARINE
MAMMALS
PISCIVOROUS
FISHES
PISCIVOROUS
BIRDS
ZOOPLANKTIVOROUS
FISHES,,
C?)
ZOOPLANKTIVOROUS
BIRDS
CARNIVOROUS
ZOOPLANKTON
HERBIVOROUS
ZOOPLANKTON
(1.0)
PHYTOPLANKTON
Figure 30. Characterization of offshore habitat food web. Average biomass
of major taxa represented in parentheses (grains /m or grams/m3).
1 09
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principally in deep water as adults, though migrating into surface waters at
night. Not only are the requisite food (phytoplankton) particle sizes
different for these calanoids, their relative production rate in terms of
generation times are also divergent (1 per year for Pseudocalanus vs. 6 to 9
per year for Calanus) (Mackas et al., 1980).
The carnivorous zooplankton and zooplanktivorous fishes varied even more
dramatically over time and space. Considering the kinds of sizes and
morphological features associated with feeding by these animals, the single
trophic link shown between them and their prey is not representative of the
complex, variable flow of energy between primary and secondary carnivores.
Despite the tremendous potential productivity of the lower trophic level
organisms in this food web, the standing stock of consumers does not appear
to be high. The rapid turnover in organic matter through predation and
population regeneration, however, belie the actually dynamic flow of energy
through this food web. The spatial and temporal distributions of prey
resources for various consumer groups are, on the other hand, highly variable
and patchy due to the influences of the complex oceanographic characteristics
of the study area. Strong advection and tidal mixing, wind-driven (Ekman)
upwelling, and the influences of estuarine circulation contribute to
large-scale patchiness in the standing stock and productivity of zooplankton
(Mackas et al., 1980 ; Bowman and Esaias, 1978). These frontal processes
dominate the habitat only in narrow passages such as Admiralty Inlet. Thus,
secondary and tertiary consumers are limited in their ability to utilize
these prey resources by the predictability, frequency of occurrence, and
spatial coverage of these optimal foraging zones. So, while production and
the rate of energy flow through the offshore (pelagic) food web may be high,
it is typically concentrated in localized zones and is not representative of
the habitat as a whole.
IV. C. 3. c. Density, biomass, species richness. The research design
utilized to describe local marine mammal concentrations focused on the more
easily observed pinnipeds which haul out throughout the study area.
Consequently, there is little quantitative information available for the
offshore areas. Essentially, all of the 21 species of marine mammals
documented in the study area could occur in offshore areas, although some
species (notably river otters) probably rarely, if ever, leave nearshore
waters. Cetaceans were an important component of this area and appeared to
be most abundant with the influx of spring and summer migrants. Sea lions
forage in this habitat- as well, and were most abundant in the study area
during winter months. While some harbor seals undoubtedly forage in the
offshore areas, the extent that these habitats are used by the population as
a whole is unknown.
Offshore habitats are generally characterized by low numbers of bird
species, low density, and low biomass. This pattern becomes especially
apparent when comparing the measurements for open waters with
intertidal/subtidal habitats (Appendix Tables III-A through III-H and III-U
through III-X). This effect is, in part, explained by the lack of
appropriate habitat for foraging for many species. In the deep offshore
habitats, diving species are unable to reach the bottom to feed. Thus,
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species that are present must be able to feed on the surface or in the
near-surface waters, or be able to dive into the mid-water column to feed or
feed elsewhere. These restrictions immediately eliminate many species that
are adapted to feed in shallow water areas or onshore. Additionally, many
species are not capable of sustained presences in offshore habitats. This is
due to a poor swimming capability, their inability to float on the water for
long periods of time, or their inability to stay airborne for long periods of
time. The species commonly found in offshore waters are loons, grebes,
jaegers, gulls, cormorants, and alcids. These species are either strong
fliers, or can stay on the open waters for indefinite periods of time; and
all are specialized as surface feeders or divers.
The number of species on the offshore waters is generally low, but the
total number of individuals is often high because the amount of offshore
habitat in the study area is vast compared to other habitats. Thus, Common
Murres in the late summer often start to invade the study area from the outer
coast and peak in numbers in the late fall at which time the density may
reach as high as 30 to 80 birds per km2 in certain areas. When the total
counts are projected, their numbers approach a quarter million birds in the
study area, far outnumbering any other species count in any other habitat.
The offshore habitats showed seasonal patterns of abundance, with
numbers generally at the lowest level during the summer months. At that time
densities as low as eight birds per km2 were common. Peak seasonal densities
usually did not equal those seen in other habitats, especially the
intertidal/subtidal habitats. The highest density level seen for offshore
habitats was 229 birds per km in narrow passages. The density levels for
the intertidal/subtidal habitats reached several times this level.
Deep-water bays usually have the lowest numbers of species of all the
offshore habitats. Bays, like all other habitats, show seasonal variations
with peak numbers of species, density, and biomass during the winter months.
The highest seasonal density and biomass levels of the offshore habitats were
recorded in narrow passages where flocks of birds foraged. Even including
populations associated with adjacent breeding colonies, the summer values for
number of species, density, and biomass were the lowest recorded in the
offshore habitats. The fall and winter numbers were only a fraction of the
previous habitat values.
The open waters of the study area are the single largest habitat.
Except for the summer, the values of bird density and biomass in this
habitat were the lowest recorded in the study area. The summer values were
only slightly larger than in other areas. However, though the values of
density and biomass were low, the number of species observed was relatively
high in comparison to the other habitats, perhaps due to the passage of birds
between other nearshore or intertidal/subtidal habitats.
Many of the stations sampled by surface trawl in the Strait of Georgia
by Robinson et al. (1968a and b), Barraclough and Fulton (1967 and 1968),
Barraclough et al. (1968), Robinson (1969), and Barraclough (1967a and b)
included offshore, broad passage habitats. Species richness of fish averaged
9-10 during these spring and summer (April-July) collections. And although
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there was no quantification of the area or volume sampled, the consistent
sampling methodology allows comparisons of species density. Depending upon
time of season and influence of the Fraser River plume, the typically
prominent fishes included larval and postlarval Pacific herring and Pacific
sand lance, larval walleye pollock and rockfish, juvenile Pacific salmon, and
juvenile greenling (Hexagrammidae). Other species which were only
infrequently captured in abundance included postlarval eulachon (Thaleichthys
pacificus), larval starry flounder, ronquils (Bathymasteridae), river
lampreys (Lampetra ayresii), and threespine sticklebacks (Gasterosteus
aculeatus).
Offshore phytoplankton, zooplankton, and ichthyoplankton data were
collected at nine sites in the Strait at several depths with a variety of
methods. The data were reported in several documents (Chester et al., 1977;
Chester, 1978; Chester et al., 1980).
Phytoplankton biomass. as measured as chlorophyll £, ranged from about
10 mg/n? to over 500 mg/m^ in the upper 50 m of the water column. Most
measurements were in the 10-75 mg/m2 range. However, a distinct spring bloom
was recorded in June of 1976 in which about 500 mg chl a/m were observed.
Diatoms contributed to much of the biomass, especially in the spring. Most
samples had 1,000 to 10,000 diatoms per liter, some had up to 100,000 per
liter, and those collected during the spring of 1976 bloom exceeded 1 million
per liter in the upper 1 m of water. Over the two-year study, 93 species in
32 genera were identified. During the same period, 23 species of
dinoflagellates in 11 genera were identified. They were less abundant than
diatoms. Most samples had 100 to 1,000 dinoflagellates per liter, while
those collected during the spring of 1976 bloom had 100,000 per liter in the
upper 1m of water. Coccolithophorids occurred sporadically, usually
associated with oceanic intrusions of surface water.
Zooplankton settled volumes were used as an index of biomass. Most
samples taken in oblique (50-0 m) tows with 333 y m mesh size nets captured
less than 1 ml/m3, often less than 0.5 ml/m3 in the fall and winter. Some
samples taken in the spring had up to 2 ml/m . Finer-mesh (211 pm)
vertically towed nets often captured 1 to 2 ml/m 3 in the upper 100 m with a
maximum of 16.6 ml/m3 during the spring of 1976 bloom. More than 100 species
of zooplankton were identified, 60 of which were copepods. Four species of
euphausiids and 'four of chaetognaths were found. During the spring of 1976
bloom, 80% of the numbers of zooplankton collected were of a single copepod
type (Pseudocalanus spp.).
Ichthyoplankton densities in oblique tows (333 ym) from 50 to 0 m depth
ranged from less than 0.1 to 0.7 eggs/n? and from less than 0.1 to 0.7
larvae/m3. Pleuston net (333ym) samples ranged in densities from less than
1 to more than 10 eggs/m3 and less than 1 to over 100 larvae/m3.
Ichthyoplankton were clearly most concentrated near the surface, as indicated
by the pleuston net samples. They also were most concentrated in the spring
and summer months (April through June). Numbers of taxa ranged from 1 in
winter (November) to up to 20 in late winter (March) in oblique tows and 1 in
late summer (August-September) to 13 in late winter-early spring (March-
April) in pleuston nets. Biomass data were not collected.
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IV. C. 3. d. Migrants. Generally, migrations can be considered as falling
into two categories. The first involves local populations which typically
perform small-scale or short movements from one local area to another. The
second category includes large-scale movements performed by large numbers of
animals (generally belonging to one species) moving through the study area to
the extremes of their ranges. Often these movements can cover many thousands
of miles.
Movements of marine mammals were difficult to assess with the survey
methodologies used in the study. Cetaceans were generally more abundant in
the spring and summer months presumably in response to increasing
productivity in the study area. However, survey efforts in the fall and
winter have been so low that lack of any species in an area during this
period may simply imply no data. As an example, the Dall porpoise was
usually seen in our surveys in low numbers during the fall and winter.
However, this species was regularly observed throughout the Strait of Juan
de Fuca from recent surveys conducted aboard the NOAA ship John Cobb in the
fall and winter of 1979-1980.
Certainly one of the most unique movements of marine mammals in the
study area is the long migration of the California gray whale from its
breeding grounds in Baja California to its foraging areas in the Bering and
Chukchi Seas. During the late winter-early spring, this species moves
northward through Washington's coastal waters, passing through the far
western Strait of Juan de Fuca between Tatoosh Island and Pachena Point.
Occasionally, individuals penetrate deep into the inland waters. The
majority of the gray whale population also pass through to Washington waters
during their southbound migration in the late fall.
The most notable movements of pinnipeds are made by California and
northern sea lions, described above as foraging in offshore and nearshore
waters and hauling out on rocks. Both species were observed to enter the
inland waters in the late fall, peak in abundance in the winter, and decrease
through spring. By summer both species were essentially absent from the
study area. Presumably, these movements are timed with the onset of breeding
activities (outside of Washington) in the spring.
The effects of migrations were reflected clearly in the seasonal rise
and fall of bird densities at the various census points in the study area.
Typically, many species are highly migratory and can be expected in the study
area only during certain times of the year. The most dramatic example of a
large-scale movement through the study area was that of the Common Murre.
This species was observed to enter the study area in large numbers in the
early fall (August to September). By late winter-early spring, a movement to
breeding areas along the outer coast south to the Farallon Islands and north
to Alaska occurred.
Another example of migratory seabirds in the study area is Rhinoceros
Auklet which were absent from the area in the late fall and winter, spending
those seasons along the outer coast south to southern California and
returning to breeding islands (primarily Protection Island) in the spring and
r summer. Other species that usually come up the coast included the Heermann's
Gull, which entered the Strait of Juan de Fuca in the late summer.
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Generally, bird movements through this area follow the pattern
demonstrated by the Common Murre—abundant during the nonbreeding fall and
winter and virtually absent during the breeding periods (spring and summer).
Included in this scenario are Western Grebes which typically leave in the
spring for breeding sites inland; Arctic Loons which arrive in the winter
from northern nesting grounds; and Brandt's Cormorants entering from coastal
areas. Large numbers of gulls (Bonaparte's, California, Mew and Thayer's)
pass through the study area during fall migrations and spend a large portion
of their time foraging in tide rips and other productive areas (often in
nearshore waters). The only offshore "ducks" in this area are several
thousand Oldsquaw which usually appear in late fall and remain through
spring. They are often particularly abundant in the eastern Strait of
Georgia and deep bays (e.g., Discovery Bay).
Smaller-scale movements of birds are less easily understood but small
numbers of phalaropes, storm-petrels, Sooty Shearwaters, and Tufted Puffins
migrate through the study area in the spring and fall. They often remain
into summer or winter, respectively. Many of the species leave breeding
areas within the study area during winter months to forage in offshore water.
The offshore waters in the study area are used extensively by fishes in
their migrations. Most notable are the adult salmon migrations (all species)
in the summer and fall when the salmon move through the Strait of Juan de
Fuca, Hood Canal, Puget Sound, and north through and around the San Juan
Islands and Georgia Strait to the Fraser River and other smaller rivers and
streams. Juvenile salmon reverse the migrations to the open ocean. Although
pink and chum salmon appear to use both the nearshore and offshore waters as
they migrate to sea, juvenile sockeye, Chinook, and coho appear to primarily
utilize the offshore waters. Steelhead trout also utilize the offshore
waters for migration purposes in much the same manner as salmon do.
Adult herring make large offshore spawning migrations from the ocean to
their major spawning grounds along the shoreline from Sandy Point to Birch
Bay in the Georgia Strait. They also move to other spawning areas along the
Strait of Juan de Fuca, among the San Juan Islands, in Hood Canal, and in the
Puget Sound central basin. Spawning and, presumably, most of the migrations
occur from about December to June with generally the earlier spawning in
southern areas and later spawning in the more northern areas. Although
juvenile herring are initially clearly associated with nearshore waters, they
usually move to deeper offshore waters in the winter as they continue their
migration to the ocean.
Surf smelt migrations are not well-understood. Spawning occurs in most
months of the year on saltwater beaches, although specific time varies among
sites. The later larvae, juveniles, and adults occur in the offshore waters;
but it is not known whether extensive migrations are made or just local
movements in the general vicinity of spawning grounds. Longfin smelt spawn
in the fall in freshwater streams, and adults are often caught near the
bottom in offshore waters. As with surf smelt, it is not clear what the
pattern or extent of migrations or movements are between the nearshore and
offshore waters other than the fact that there is movement.
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Among the cod fishes, Pacific cod spawning migrations are
well-documented. Cod migrate through the Strait of Juan de Fuca to spawn in
the nearshore waters of Protection Island, Port Townsend Bay, and elsewhere
during the winter and then disperse into the offshore waters of the Strait to
feed for the remainder of the year. Juvenile Pacific cod appear to move out
of nearshore areas to the offshore water of the Strait of Juan de Fuca by the
time they are one year old.
Lingcod make spawning migrations in the winter and spring from offshore
bottom waters to nearshore waters for the purpose of depositing eggs in a
nest on rocky substrates. While female lingcod then return to deeper waters,
male lingcod precede the female from offshore waters to nearshore waters and
remain to guard the nests for several weeks following spawning. However, it
has not been established what percentage of lingcod spawning is also done on
offshore bottom reefs rather than on nearshore reefs. Thus, it is unknown
what percentage of females or males remain in the offshore bottom waters.
Finally, there is a true migration different than the usual once-a-year
seasonal spawning migrations. This migration is part of the life cycle of
the sablefish and yellowtail rockfish, and perhaps other species. Based on
the indirect evidence that the larvae and early juveniles of these species
have not been caught in the extensive nearshore sampling, this migration
probably occurs primarily in the offshore waters. Only juvenile (i.e.,
sexually immature) specimens of sablefish and yellowtail rockfish have been
caught in Puget Sound, Hood Canal, the San Juan Islands, and the eastern half
of the Strait of Juan de Fuca. Several age groups of both species have been
caught. When they become adults (sexually mature), they migrate out to the
open ocean where spawning occurs—this pattern has been demonstrated to a
very limited degree by tagging, but the evidence is primarily circumstantial,
based on research samples and commercial and sportfishing catches. The
adults do not migrate back to inland waters after spawning, but remain in or
near the open ocean. However, the larvae and/or juveniles migrate back into
Puget Sound and the San Juan Islands area. As stated earlier, the term
"migration" is used in this report to include both passive (larval drift) and
active transport (swimming).
Many species show local, small-scale movements on a seasonal and/or
day-night basis that are correlated with physical factors such as
temperature, protection from predators, and amount of light, or biological
factors such as feeding activity. Seasonal movement between the offshore and
nearshore waters seems to be primarily a matter of nearshore species moving
into offshore waters in the winter when the nearshore hydrographic conditions
and, perhaps, food supply are poor, rather than seasonal movement by offshore
species into the nearshore. An exception is migrations involving spawning;
it appears that offshore species spawning in the nearshore areas stop feeding
enroute to the spawning area. Examples of nearshore species moving into the
offshore waters in the winter include black rockfish, juvenile yellowtail
rockfish, surfperches, herring, and smelt. It is also known that day-night
movements of fish take place, consisting primarily of nocturnal feeding
forays of offshore fishes into the nearshore waters. Dogfish, ratfish, cod
fishes, and some rockfish are examples of fishes exhibiting this behavior.
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IV. C. 3. e. Variability. The limited data base presently available for
cetaceans in the study area precludes any assessment of variability at this
time. Since offshore whales usually occur in small numbers or in pods, their
occurrence at any location at any time is totally unpredictable. However,
the general migratory patterns of killer whales in and adjacent to the study
area are fairly well known. Thus, it is likely to find these animals in the
southern Strait of Georgia in the summer in search of Fraser River salmon.
For both California and northern sea lions, arrival and departure dates were
comparable for both years of the study. However, total numbers of animals
varied from year to year for California sea lions.
For seabirds, offshore species richness varies by season with a greater
number of species occurring in descending order in the fall, spring, winter,
and summer. Total abundance of all species does not follow this trend;
largest numbers occur in the fall and decline through the winter and spring,
and reach a minimum in summer.
Absolute arrival and departure dates for some migratory seabirds may
vary somewhat from one year to the next. For example, two species that are a
large component of the offshore winter population—Western Grebes and Common
Murres—arrived at different times over the two-year study period, and were
about two weeks later in 1979 than in 1978.
Considerable variability in species composition among offshore regions
was observed. The reasons for these differences (see section IV.C.S.a) are
not understood but may relate to prey availability. The standard deviations
calculated for offshore abundance data (Appendix Tables III-U through III-X)
demonstrate that variability among sites representing a single habitat type
is often very high.
Diurnal variability differs with the season. In nonbreeding seasons,
seabird numbers in offshore waters are similar during all hours except that
cormorants and gulls which feed in offshore waters come ashore at night to
roost. During the spring and summer breeding months, apparently few seabirds
remain offshore at night. Although some may continue to feed at night, most
nesting cormorants, gulls, and Rhinoceros Auklets are usually onshore.
The MESA data demonstrate considerable unexplained variability in bird
usage of offshore regions in the course of the two-year study. The projected
abundance estimates for many areas differed in 1978 and 1979. It is possible
that much of this variability may relate to yearly differences in the
location of prey species or to sampling frequency or to the location of the
boundaries of artificial census subregions.
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V. IDENTIFICATION OF AREAS OF BIOLOGICAL IMPORTANCE
V. A. The Need for Identifying Areas of Importance
In this chapter the focus is on those particular characteristics that
for one reason or another make a particular habitat important. Factors that
we have selected which can be used to evaluate the importance of a habitat
include: algal/eelgrass biomass; benthic faunal biomass; occurrence of
detritus; the use of a habitat for foraging by fish, birds, or mammals; the
use for reproduction, rearing, migration, or resting; and the human uses of
harvesting (both commercial and recreational), recreation, etc.
Sites representing various habitats for which data on one or another
importance factors are available will be discussed. It might be expected
that other unstudied sites will also have these important functions and uses.
For resource managers concerned with the impact of human use on the
marine environment, these importance factors identify those characteristics
of a habitat that should be carefully evaluated. These importance factors
and their criteria can be of value in estimating the relative biological
importance of unstudied areas of known physical characteristics. Although
one should not conclude that a particular importance factor will always be
found or applicable at an unstudied site, past experience indicates that, in
the study area, there is a strong possibility it will be found when studied.
V. B. Importance Factors and Descriptions of Examples
V. B. 1. Rationale for approach. The synthesis team that prepared this
report was unable to determine what specific sites or subregions in the study
area were, overall, highly important, though each had identified sites that
appeared to be important to the respective taxonomic group(s) they studied.
The data base was incomplete geographically and topically. Research emphasis
was not applied uniformly and continuously to all areas, thus all parts of
the study area could not be treated equally.
The approach taken in this chapter was selected to allow the readers a
framework for making their own decisions regarding the relative biological
importance of specific sites. This approach assumes the reader is physically
and technically able to determine the physical characteristics (e.g.,
exposure and habitat type) of the sites or subregions of interest. Following
that step, the reader can refer to Table 10 to determine which factors are to
be considered in evaluating the site of interest. The accompanying text
provides a brief description of each importance factor and how it applies to
each of the habitat types of the study area.
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Table 10. Importance factor/habitat matrix and sites exemplifying
each habitat type.
Habitat Type
INTERTIDAL-SUBTIDAL
NEARSHORE
OFFSHORE
1. Mixed coarse
2. Sand
3. Mud-gravel
4. Mud- sand
5. Mud
6. Exposed rock
7. Protected rock
8. Cobble
9. Mixed coarse
10. Sand
11. Mud-gravel
12. Mud- sand :
13. Mud
14. Exposed rock
15. Protected rock
16. Cobble
17. Broad passages
18. Narrow passages
19. Bays
20. Open water
Importance Factors
Nonharvesting
X
X
X
X
X
X
X
X
X
X
Harvesting
X
X
X
X
X
X
X
X
X
X
X
X
X
Roosting
X
X
X
x
X
X
X
X
X
X
X
X
X
X
Migration
X
X
X
X
X
X
X
X
X
X
X
X
Rearing
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Reproduction
X
X
X
X
X
Foraging
X
X
X
X
x
X
X
X
X
X
X
X
X
X
X
X
X
X
Detritus
X
X
X
Benthic Faunal Biomass
X
X
X
X
X
Plant Biomass
X
X
X
X
X
X
X
X
Example (s)
Dungeness Spit
Ebey's Landing
West Beach
Eagle Cove
Beckett Point
Birch Bay
Jamestown
Padilla Bay
Westcott Bay
Tongue Point
Point George
Fidalgo Head
Cherry Point
Morse Creek
Dungeness Spit
West Beach
Beckett Point
Jamestown
Padilla Bay
Pillar Point
Point George
Cherry Point
Admiralty Inlet
Active Pass.
Speiden Channel
Bellingham Bay
Western Strait
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V. B. 2. Description of Importance factors and criteria.
V. B. 2. a. Recreational and educational use (nonharvesting). One important
use of intertidal and nearshore habitats is for nonharvesting recreational
uses, such as use of habitats for photography,, beachcombing, education, tide
pool observing, shell collecting, scuba diving, and bird-watching. The bays
are important for photography and boating (Table 10). This list is not
exhaustive, but, instead, is illustrative of the kinds of uses humans make of
these habitats.
Some of these human uses are compatible with the ecological function of
the habitats. Some have a detrimental impact, while others depend on
biological components. Beachcombing, sunbathing, and swimming are not
dependent upon and have little impact on biological resources. Educational
field trips, tide pooling, and scuba diving are dependent upon the biological
resources; and, as long as collection is not permitted, damage to biological
resources is minimal. Shell collection which takes live specimens from the
intertidal and shallow subtidal zones is destructive to the biological
communities. -
The areas that are important are those put to multiple use, those used
year-round or repeatedly each season, or those that require indigenous
biological resources or high esthetic quality to be put to use for
recreation.
V. B. 2. b. Harvesting. Harvesting, or the consumptive use of biological
resources, is an important consideration when any modification of the
environment is proposed. One goal of wildlife and fisheries management is to
allow local harvests in designated seasons, often necessitating closure of
the area to harvests in other periods in an effort to maximize harvest and
avoid overharvest.
Commercial fisheries exist for salmon, bottomfish, oysters, clams, crab,
shrimp, and sea urchins. Use of the area by hunters and fishermen is often
quite important to local communities in terms of recreation or vacation
dollars spent. Some areas lend themselves more to one type of harvesting
than another. Nearshore waters near Sequim and open waters throughout the
area support large skiff and charter boat fishing activities during major
salmon runs. The waters near Dungeness Spit are important for Dungeness crab
harvest, while Discovery Bay is more important for bottomfish and clam
digging. Intertidal harvesting of invertebrates (e.g., clams) is important
in all protected unconsolidated and rocky habitats. Recreational fisheries
are important off rocky shores. A substantial harvest of salmon, crab, and
herring dominates the commercial fishery off the cobble shore at Cherry
Point.
It is difficult to set a standard for assessing the importance of
harvesting in a localized area. Perhaps the best approach is to list all
known recreational and commercial uses of the area in question, the estimated
value of those activities (in terms of dockside value for commercial
fisheries and recreational dollars for noncommercial harvests), and an
estimate of the effect the proposed action might have on these harvest
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activities. It remains a subjective judgment of local planners whether the
risks to harvestable resources justifies the proposed action. Washington
State resource agencies have promulgated various criteria for evaluating the
relative importance of areas to clam dredging, aquaculture, and similar
activities.
V. B. 2. c. Roosting, resting, hauling out. Many marine animals,
particularly pinnipeds and various bird species, require locations for
hauling-out or roosting. Availability of these sites is limited, yet they
are critical to maintenance of populations. These areas appear to be
selected on bases of security or isolation from predation and disturbance,
and, perhaps secondarily, for protection from weather and proximity to
feeding areas. Many intertidal/subtidal beaches and rock islets are
important hauling-out sites for seals and sea lions. Birds roost in
nearshore waters, bays, and open water; many rest or roost on beaches near
the shoreline. While there may be some flexibility or opportunism shown in
site selection, there is apparently considerable tradition involved in site
preference and populations or local groups may be critically dependent on
availability of specific locations. Only a small group of bird
species—loons, grebes, diving ducks, and alcids—appear to be able to, or
prefer to, remain on open waters offshore during all resting cycles. While
many other birds (dabbling ducks, for example) appear to rest on water
surfaces, they also come ashore regularly as do seals and sea lions.
Cormorants require both night roosts (often available only at considerable
distances from foraging areas) and day roosts near foraging areas for use
while drying and preening. Gulls spend much time on-shore betweeen foraging
periods, as do the pinnipeds.
Criteria for measuring importance of resting sites are difficult to
establish because precise population sizes and location of some nighttime
roosts are unknown, and because of the difficulty in comparing the importance
of one species with another. In the study area, however, sites used by >25
harbor seals, >10 sea lions, or >500 birds are noteworthy.
V. B. 2. d. Rearing, nursery. Many habitats are important for the rearing
and feeding of juveniles (Table 10). Intertidal beaches of the area are used
by many species of fish, particularly in the estuaries. Osmerids,
embiotocids, and salmonids, for example, rear juveniles in saltmarshes,
eelgrass beds, and along protected beaches. These same beaches, as well as
the bays, are used by marine birds. Open water is important to rearing some
birds and mammals; however, harbor seals in the study area are primarily
raised on rock islets and gravel beaches. Invertebrate larvae are ubiquitous
and no specific habitat is more important than any other; however, juvenile
crabs and shrimps are often very abundant in protected mud/eelgrass habitats.
The following types of sites are important: sites where reproductive
activity takes place year-round; sites used year after year by specific
populations (e.g., harbor seals); sites where the most sensitive life cycle
stages occur in abundance; and sites where a reproductive product (e.g., fish
larvae) is important prey for other animals.
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v- B' 2- e- Migration. All the intertidal/subtidal habitat types are used
by migrants, especially marine birds which use them for resting, feeding, or
breeding (Table 10). Sea lions use rock islets as a result of migrations
into the area. Juvenile salmonids are common in nearshore waters off mixed
coarse beaches in their spring outmigrations. Open waters are important to
migrating whales, marine birds, and adult salmon.
The importance of any given geographic area, such as a marsh, bay, or
passage, is judged by the importance of the area to the species being
considered at the time. The importance of the area tc the species is also
judged by whether it is unique; that is, if it is lost can the individuals
under consideration easily find another suitable area that is not already
used to the limit of its carrying capacity?
Important sites for migrants are those that are irreplaceable in the
survival of a population, or provide a critical feeding, breeding, resting,
or molting area that, if lost, would jeopardize a population. Important
sites are those that are used by many individuals representing numerous
species or a major portion of the population of a single species. Each
species must be looked at individually at each site in question and, then,
the species must be considered in total. Total species populations must be
kept in mind at all times; the maximum annual total of all individuals that
utilize the area must be considered, not just the individuals present at any
given time.
V. B. 2. f. Reproduction. Reproduction among the generally sedentary array
of benthic organisms occurs wherever the adults happen to be distributed.
However, among the marine birds, mammals, and fish, reproduction is often
•limited to a much narrower habitat when compared to the distribution of
adults. The critical habitat characteristic for river otters, harbor seals,
and marine birds is the absence of human and other mammal disturbance,
usually found on small islands. Many marine fish show a high degree of
habitat specificity. The floating eggs of flatfish and larvae of greenling
:(Hexagrammos spp.) are restricted to the near-surface plankton. Herring
spawning is confined in this region to a few, exposed cobble and gravel
beaches, while other species such as ling cod spawn at specific subtidal rock
nest sites.
The importance of exposed unconsolidated rock and cobble intertidal/
shallow subtidal habitats for reproduction is illustrated in Table 10. Sites
representing these habitat types which are important are those which have a
demonstrable association with specific groups or species reproductive
activities; for example, rock beaches and recurring seal pupping (55 pups
per year); bird nesting on upper intertidal and associated uplands of gravel
beaches and spits (- 50 pairs per year); cobble and other beaches and major
herring spawning activities.
V. B. 2. g. Foraging and predator-prey interactions. One of the most
important factors determining the extent and structure of the faunal
communities of a habitat is the amount of organic material or energy passing
'through the food web. The critical process in the passage of such trophic
energy is, of course, that of feeding or foraging by one organism upon
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another. Consumer organisms tend to aggregate where the abundance and type
(size, shape, mobility) of food organisms are sufficient to guarantee the
consumer enough energy for maintenance, growth, and reproduction. Thus, the
important habitats and locations are those that support dense and
sought-after prey populations and active consumers.
This factor is important at all but two habitats. We have designated
habitats as important to foraging based upon both the relative abundance and
use by prey and predators rather than upon the basis of the production of
food organisms alone, because both are important indicators of trophic energy
flow in the area. The principal criteria determining habitat importance thus
include habitats which: (1) are characterized by high densities of feeding
consumers, (2) possess unique concentrations of prey organisms which are
uncommon in other habitats, or (3) have populations of organisms which,
through reproduction or immigration, are principally responsible for the
recruitment of prey organisms important in adjacent habitats. Examples of
the first criteria include habitats which support large flocks of feeding
Western Grebes or dense schools of postlarval and juvenile Pacific herring.
One example of the second criteria would be a habitat which supports a high
standing stock of eelgrass, which is fed upon extensively by herbivorous
waterfowl such as Black Brant. An example of the third criteria would be a
habitat in which Dungeness crab spawn extensively and provide an abundance of
larvae which are transported into neritic waters where they are consumed by
planktivorous fishes such as juvenile Pacific salmon.
V. B. 2. h. Detritus production, accumulation, and recycling. As Simenstad
et al. (1979) and this volume have illustrated, virtually all of the food
webs associated with intertidal/subtidal habitats in northern Puget Sound and
the Strait of Juan de Fuca are based primarily upon detrital carbon. While
we have little empirical data on the sources of the detritus which enters or
becomes available in these habitats, it probably originates from benthic
macroalgae, eelgrass, saltmarsh plants, and river-borne terrestrial plants.
The fact that the community structure and production of the biota of the
region are so dependent upon these detritus sources, and upon the processes
which make the detritus available for detritivores, dictates that the
habitats involved are of primary importance.
The criteria determining relative importance to overall detritus
production include habitats which: (1) produce significant amounts of algal
or plant biomass which contribute to the detritus pool (shown in Table 10 as
important for plant biomass), (2) are primarily responsible for the physical
(mechanical) and biological (microbial/chemical) reduction of large particles
to the sizes utilizable by detritivores, (3) accumulate detritus, making it
available for accelerated processing, and (4) are characterized by high
densities of detritivores or other detritus-processing fauna. As shown in
Table 10, the protected habitats having a major mud component are
instrumental in detritus cycling.
V. B. 2. i. Benthic faunal biomass. Although for the region as a whole the
biomass of marine mammals, birds, and fish is substantial, when expressed per
square meter it is very small for all three faunal groups. However, in some
habitats the biomass or standing stock of benthic animals can be very high.
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In mud, mud-gravel, rock, and cobble habitats (Table 10), the benthic faunal
biomass can exceed 1 or 2 kg/m2. The animals responsible for this high
biomass are primarily infaunal clams and epifaunal mussels and barnacles, all
animals with heavy shells. Mussel beds can create thick multispecies
assemblages on rock and cobble habitats, thus adding a three-dimensional
component to communities at these habitats. Sties with frequently observed
(several years, each season) faunal biomass values in excess of 500 g wet
weight per square meter should be considered as important.
V. B. 2. j. Biomass of plants. As shown in Table 10 plants are primarily
important in evaluating rock, cobble, and protected unconsolidated habitats.
In benthic communities macroalgae can be important at rock and cobble sites
and eelgrass important in protected unsolidated sites. First, they modify
the character of the habitat in several important ways. Stands of algae and
eelgrass reduce wave and current shock felt by the animal species residing in
them. In eelgrass beds, the release of oxygen during photosynthesis may
moderate local conditions of low oxygen. Also, intertidal algae retain
moisture during low tides, moderating fluctuations in salinity and
temperature which occur on bare substrates. The presence of algae adds a
.third dimension to rock surfaces, which invariably results in a large
increase in species richness .
Macroalgae and eelgrass provide a major source of organic carbon to the
marine system. This carbon is used directly by macroalgal grazers, and also
indirectly, as detritus, by scavengers and detritivorous species.
Few local data on productivity per se are available, either for
rmacroalgae or eelgrass, though Webber (1981) provided growth rate data for
two species. Therefore, standing stock of plants is taken here as a very
rough indicator of production. Mean yearly values of plant standing stock
ranged from less than 1 g/m 2 to over 30 kg/m2 at the MESA study sites.
:Values on the order of 1 to 10 kg/m2 were typical of the low intertidal zones
jof rock and cobble substrata, where algal cover is at least seasonally high.
Subtidal sites with appreciable macroalgal or eelgrass stands also had values
in that range. Wet weight of about 1 kg/m 2or greater can be used as a rough
Criterion of importance, but factors such as patchiness, seasonal patterns of
abundance, and distribution of plants with elevation should also be consid-
;,V. B. 3. Factors important in evaluating each habitat type.
V. B. 3. a. Intertidal/subtidal zone.
V. B. 3. a. (1) Intertidal/subtidal: exposed mixed coarse. This habitat
;can be important for foraging, reproduction, rearing, roosting, use by
migrant species, and for nonharvesting recreational use (Table 10). This
habitat type is characterized by high wave and/or current action, which often
^results in large movements of sediments.
s.. °
r Dungeness Spit on the Olympic Peninsula exemplifies many of the
^important features of his habitat. Both phytoplankton and detritus form the
iase of the food web at this site. Macrobenthos standing stock at Dungeness
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Spit was among the lowest at any of the study sites (Nyblade, 1979a), but
epibenthic zooplankton densities were not among the lowest compared to other
sites (Simenstad et al. 1980). Macrobenthos at other exposed mixed coarse
sites may occasionally be dense. At Ebey's Landing, for instance, the
intertidal region supported a phenomenal explosion of Paramoera sp., a
gammarid amphipod, in late spring and early summer, when numbers reached
100,000/m2.
Large populations of migrating fish in nearshore waters feed upon
zooplankton associated with subtidal sediments. The availability of food in
proximity to relatively undisturbed shoreline makes Dungeness Spit an
attractive roosting site for birds during all seasons, with large numbers of
migrants like California and Heerman's Gulls included in the fall. Harbor
seals often find this habitat suitable for hauling out, due to the minimum
amount of disturbance and proximity to prey. The mixed coarse exposed
beaches of Protection Island and Smith-Minor Islands are often important to
seals as hauling-out and pupping sites.
Recreational use is important year-round at Dungeness Spit.
Beachcombing, bird-watching, photography, and educational activities are all
important.
V. B. 3. a. (2) Intertidal/subtidal; sand. Importance factors identified
at this habitat include nonharvesting recreation, migration, rearing, and
reproduction (Table 10). Sites identified as showing these importance
factors include West Beach and Eagle Cove.
The use of the sites by migratory birds is similar to other habitats;
that is, there is usually an increase in numbers of species in fall and
winter seasons. Shorebirds, gulls, and ducks (including Goldeneyes,
Buffleheads, Oldsquaw, and Harlequins) are important migratory species.
Other migratory birds include the Common Tern and the White-winged Scoter.
Seals and some birds may use this habitat type for reproduction.
The sand type of the exposed unconsolidated habitat is important for
recreational uses at some sites. Although bird diversity (and, consequently,
bird-watching) is lower than at other habitats, the use of sand beaches for
recreation is extremely important. The frequent occurrence of backshore
dunes and the relative uniformity of the sand substrate through the
intertidal and shallow subtidal zones makes this habitat attractive for
sunbathing, swimming, wading, and beach walking.
V. B. 3. a. (3) Intertidal/subtidal; mud-gravel. Of the importance factors
found in this type of habitat, perhaps the most noteworthy are the benthic
animal biomass and sport and commercial harvesting. Hard shell clams are
responsible for both of these importance factors. Clam biomasses of over
8,000 g/m have been reported for Webb Camp on Westcott Bay (Nyblade, 1977).
Mud-gravel beaches are the hard shell clam beaches throughout the region.
Sport and commercial harvests represent a multimillion dollar industry in the
region.
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Other factors important in this habitat are high plant biomass (chiefly
Zostera marina in subtidal zones), high detritus accumulation and recycling
(Simenstad et al., 1979), high levels of foraging and rearing of young, and
high use by migrants. The food webs of mud-gravel habitats are based on
phytoplankton and especially detritus. The detritus supports a large
community of epibenthic and planktonic crustaceans (Simenstad et al., 1980),
which, in turn, are critical food sources for larval fish. These habitats
can be crucial nursery areas for a large number of fish species, including
several species of flatfish, sculpin, and salmon. The eelgrass of these
habitats is a vital food resource of the Black Brant and Wigeon. In
addition, the calm waters of the embayments where these habitats are found
are very important stopover points for migratory marine birds.
V. B. 3. a. (4) Intertidal/subtidal; mud-sand. Numerous factors of
importance are associated with the mud-sand habitat, most notably rearing,
foraging, and detritus accumulation; only reproduction and benthic faunal
biomass are relatively unimportant compared to the other intertidal/subtidal
habitats. Benthic infauna may be abundant, but, due to their small size,
they often do not account for high biomass values. Epibenthic organisms can
be quite prominent, especially in association with eelgrass (Zostera spp.)
beds which are often dense in the more protected areas of the habitat.
Perhaps as a result^ of the linkages to epibenthic crustaceans, there is a
coincident abundance of predatory juvenile flatfish, cottids, and various
shorebirds, characterizing the middle trophic level consumer organisms.
Herbivorous birds (Black Brant, Wigeon) are also commonly associated with the
eelgrass beds during periods of their migration through the region or during
overwintering.
Several locations exemplify the intertidal/subtidal mud-sand habitats,
including Birch Bay and Jamestown. These two sites represent the extremes of
this habitat. Birch Bay is the more exposed with coarse sand sediments in
many places, sand waves, and sparse eelgrass beds, while Jamestown has
sediments with more fines and some extensive, dense eelgrass beds.
Simenstad et al. (1980) illustrated that the Jamestown/Port Williams
site had the highest number of taxa, density, and standing crop of epibenthic
zooplankton at seven habitats sampled along the Strait of Juan de Fuca in
August 1978. Harpacticoid copepods, which are the principal prey of many
juvenile fishes rearing in this habitat, were the epibenthic crustacean which
dominated the composition of this community. These organisms were associated
with the dense eelgrass beds and macroalgae found at this site.
Demersal fish communities are typically of intermediate diversity and
standing stock between more exposed habitats and the more protected mud
habitat. But, like the mud habitat, juvenile forms of many species,
including English sole, sand sole, salmon, and staghorn sculpin, can form
much of the demersal fish community in this habitat during the late spring
and summer. The apparent association between these juvenile fishes and the
eelgrass beds and their abundant epibenthic zooplankton communities is
considered to be a function of the accumulations of detritus, abundant prey
resources, and refuge from predation.
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Bird communities, composed primarily of Glaucous-winged Gulls, American
Wigeon, Black Brant, and Bufflehead Ducks, were typically the largest of any
habitat, especially in fall and winter months when migrant and overwintering
waterfowl foraged and roosted there. Black Brant represent the extreme
example; at their peak residency in April over 1,500 brant were observed in
the Jamestown area in 1978-1979.
Commercial and recreational harvesting of infaunal bivalves and mobile
macroinvertebrates such as Dungeness crab and shrimp is common in this
habitat as is the recreational hunting of Black Brant and other waterfowl
during the fall months. Nonharvesting uses are typically restricted to
bird-watching and beachcombing.
V. B. 3. a. (5) Intertidal/subtidal: mud. Factors that are important
include high levels of plant biomass production (particularly of eelgrass),
benthic faunal biomass, detritus accumulation, foraging activities, rearing
of young marine organisms, migrants, roosting, and harvesting.
Interrelationships of factors like these, particularly detritus, eelgrass,
and benthic organisms, are often reflected in high species richness and
seasonal standing stock levels among many biotic groups. Bottom-feeding and
grazing species of birds like Black Brant and American Wigeon are often
abundant. This is one of the principal habitats for shorebirds, and at some
sites it supports the study area's highest densities of Great Blue Herons
which feed upon fish. The protected mud habitats are important for foraging
by migrating birds, and are often used by birds for roosting and by harbor
seals for hauling out. Harvesting of crabs and bivalves can be important
here.
Padilla Bay is an example of this habitat type. Eelgrass beds there are
among the most extensive on the Pacific Coast, and this floral biomass, in
turn, often attracts up to 50,000 Black Brant during spring migration.
Likewise, wintering flocks of American Wigeon are among the largest in the
northwest Washington-southwest British Columbia region. Large quantities of
detritus accumulate within the habitat, and areas like Padilla Bay may also
supply nutrients to adjacent areas through eelgrass detritus drift. In
addition to grazers, large numbers of dabbling ducks—scaup, Common
Goldeneyes, Buffleheads and scoters—winter in Padilla Bay. Seasonal
densities and biomass ,of birds are usually greatest in winter, though spring
biomass is relatively high due to the major movement of Black Brant through
this habitat. Glaucous-winged Gulls, which nest on dredge-spoil islands west
of the Swinomish Channel, and large numbers of migrant Bonaparte's, Mew,
Ring-billed and California Gulls forage on exposed intertidal areas, as do
seasonally large flocks of shorebirds, primarily Black-bellied Plovers,
Western Sandpipers, and Dunlins. Concentrations of up to 300 Great Blue
Herons observed foraging in Padilla Bay (Manuwal et al., 1979) were among the
highest counts recorded in the study area.
Padilla Bay serves as a rearing area for invertebrate species. While
fish species like salmon inhabit the nearshore water column, the productivity
of the subtidal-intertidal zone is reflected in the concentrations of
epibenthic-feeding juvenile chum salmon in Padilla Bay.
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Large numbers of birds roost on the exposed intertidal areas and on the
water surface of Padilla Bay. Harbor seals haul out at low tidal stages on
banks of channels at several locations in Padilla Bay, where Everitt et al.
(1970) observed a maximum of about 70. The area is used for pupping also.
Harvesting of Dungeness crabs and bivalves is conducted on an important
scale, and sport-hunting of waterfowl is a major recreational harvesting
activity at Padilla Bay.
Many features of Padilla Bay are duplicated, on a smaller scale, at
similar habitats at Samish Bay, Lummi Bay, Birch Bay, Drayton Harbor, and
other locations. There are some differences evident in this intertidal/
subtidal type at other locations like the Nooksack Delta in Bellingham Bay,
or at the Skagit Delta (south of Padilla Bay and outside the study area),
where large river inflows lower the salinity of the bays and predominent
vegetation shifts from eelgrass to brackish marsh plants like bulrushes
(Scirpus). sedges (Carex), and arrowgrass (Triglochin). There is also some
shift in faunal species related to vegetation. While Padilla Bay supports
one of the largest Black Brant concentrations in North America during the
spring migration, very few Snow Geese or swans are observed foraging here.
The Skagit Delta is a major wintering ground for Snow Geese and Whistling
Swans.
V. B. 3. a. (6) Intertidal/subtidal; exposed rock. Nearly all of the
importance factors described for the study area are important to this habitat
type with the exception of detritus buildup and use of the habitat as a
rearing or nursery area. These two factors are eliminated by the exposure of
this habitat to full tidal, wave, and swell forces which effectively remove
any detritus materials and make the area unsuitable for fragile juveniles.
Dominant organisms in this habitat include large, dense attached algae and
invertebrates. This habitat can be important for roosting and breeding by
birds and hauling out by harbor seals and migratory sea lions at some sites.
Little harbor seal reproduction is associated with this habitat, but
invertebrates and fish often reproduce there. Harvesting of mussels,
urchins, and fish can be important; and photography, sightseeing, and tide-
pooling are common recreational activities.
Tongue Point is an example of an exposed rock habitat for which data
were collected during the MESA program. The benthos of this area was
composed primarily of macroalgae, gastropods, barnacles, and mussels. The
occurrence of these organisms was extremely patchy, though there was little
variation from season to season. Marine birds occurred in low nubmers,
dominated by Glaucous-winged Gulls. No recent fish data are available from
this site and no marine mammals were observed that could be directly
associated with this site. Race Rocks are very important to harbor seals and
sea lions for hauling out and, in the case of harbor seals, for pup rearing.
The Tongue Point area is important as a foraging area for top carnivores
in the study area, including river otters, seals, cormorants; reproduction of
benthic epifauna is also important. Many of the birds reported from this
area were seasonal migrants. Aerial shoreline censuses in the rock area
between Tongue Point and Observatory Point recorded relatively low densities
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of birds, though large numbers of gulls were occasionally observed during
migrations and winter.
Harvesting by recreationalists is limited to collection of mussels,
though some surf and spear fishing may occur. Tongue Point is attractive to
nonconsumptive users who may find the wild coastline and dramatic surf
appealing. Beachcombing, photography, tidepool observing, and bird-watching
can provide satisfactory diversions to the vacationer.
V. B. 3. a. (7) Intertidal/gubtidal! protected rock. All of the factors
that make exposed rock sites important also apply to protected rock.
Rearing, in addition, can be important as harbor seals and some birds use
protected rocks in the San Juan Islands for the rearing of young. Macroalgae
and dense, shelled invertebrates contribute to a high algal and benthic
faunal biomass at important areas. Foraging by nearshore fishes,
reproduction and rearing by harbor seals and some birds, hauling out by
harbor seals and migratory sea lions, harvesting of invertebrates and fishes,
and recreation can be important.
Point George and Fidalgo Head are examples of this habitat type.
Numerous molluscs (mainly gastropods), crabs, and echinoderms were found on
subtidal rock at Point George, which is a biological research preserve. The
kelps Alaria and Nereocystis were common there, as were intertidal fishes.
Harbor seal pupping activity may result in 10 to 30% of a population
consisting of pups on protected rocks. Northern sea lions are often found on
protected rocks in the San Juan Islands; they are among the most important
migrants to use this habitat. Various ducks, scoters, alcids, and gulls
frequent important protected rock habitats during their migrations and
foraging activities.
Harvesting of kelp bed fishes, mussels, and urchins occurs where these
resources are dense. Recreational activities such as sightseeing,
photography, and educational field trips are common.
V. B. 3. a. (8) Intertidal/subtidal; cobble. This habitat at some sites is
important to harvesting and nonharvesting activities, roosting, migration,
rearing, foraging, and reproduction of benthic faunal biomass and algal
biomass. The cobble nature of the bottom allows for the attachment of many
organisms which, in turn, provide habitat and living space for other
organisms.
Cobble beaches are at times utilized by birds, especially gulls, for
roosting. Harbor seals also utilize this habitat for hauling out. During
their migrations, gulls and ducks use this habitat for short stays to feed
and roost.
At the Cherry Point site, annual spawning of Pacific herring attracts
commercial harvesting operations in adjacent nearshore waters in the spring.
This spawn, a very large one, also attracts large numbers of birds that feed
upon the eggs. Fish are also attracted to the large volume of food
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available. Birds attracted to the spawn include large numbers of scoters and
gulls.
The algal and invertebrate benthic biomass measured at Morse Creek was
consistently among the highest of any of the sites. Nyblade (1979a) observed
up to 15,000 organisms/m*- and over 3,000 g/nr at the 0' tidal elevation.
Barnacles, molluscs, and macroalgae were dominant. Intertidal fish density,
species richness, and abundance among the Morse Creek cobbles were comparable
to those of other sites (Miller et al., 1980). Harvesting of intertidal
invertebrates and fishes takes place at Morse Creek and Cherry Point.
Subtidal commercial crabbing occurs at Cherry Point. Educational field trips
and recreation are common due, in part, to the abundance of marine organisms.
V. B. 3. b. Nearshore.
V. B. 3. b. (1) Nearshore; exposed mixed coarse. Migration and roosting
are important uses of this habitat for many fish and bird species,
respectively. Substantial seasonal migrations of both adult and juvenile
salmonids occur. Large concentrations of Pacific herring and sand lance are
common. Fish densities at Dungeness Spit, for example, were among the
highest found at any of the sites.
Many bird species migrate through this habitat in large numbers.
California, Bonaparte's, and Heermann's Gulls, Bufflehead, Surf Scoters,
Rhinoceros Auklet, Common Murres, various loons, and cormorants all use the
area during migration. The alcids, loons, and cormorants may spend more time
in deeper water offshore during migration. Gulls and alcids roost on the
water in this habitat, although alcids may prefer deeper water, and the gulls
may roost on nearby exposed beaches much of the time.
V. B. 3. b. (2) Nearshore: sand. Importance factors recognized for this
habitat include migration and foraging (Table 10). West Beach is one site
having these characteristics.
As with other habitats, bird species are important migrants. Some
species (i.e., the Mew and Thayer's Gulls) are only commonly found in spring
and fall during their northerly and southerly migrations. Other species are
commonly found during fall and winter and move north or inland in spring and
summer. Species having this type of migration include Western Grebes, loons,
cormorants, alcids, and mergansers.
Fish species are also important migrants. Juvenile pink and chum salmon
are found in the nearshore waters of the sand habitat during spring and
summer. Adult Pacific herring are found from December to June preparing for
reproduction. Juvenile herring are common in the summer and move offshore
during the fall.
The use of this habitat for foraging has been noted for birds, mammals,
and fish. Both harbor porpoises and killer whales can be expected to use
this habitat for feeding. Birds seasonally foraging include the Horned
Grebe, Arctic Loon, and Common Murre. Juvenile Pacific cod may be found
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feeding during their first year. Adult spiny dogfish, ratfish, and some cod
may move into this habitat at night to feed.
Two important juvenile fish seasonally forage off Eagle Cove (Miller
et al., 1978). Pink salmon are abundant from June to August, feeding
primarily on calanoid copepods, harpacticoid copepods, and gammrid amphipods.
Silver salmon may be found commonly from April to October feeding primarily
on drift insects, although zooplankton (i.e., zoea and megalops) and
epibenthos (i.e., gammarid amphipods) are also used for food.
V. B. 3. b. (3) Nearshore: mud-gravel. Mud-gravel habitats are typically
found along the sides of large embayraents, such as at Beckett Point in
Discovery Bay and in small embayments, such as Webb Camp in Westcott Bay on
San Juan Island. The nearshore area of these mud-gravel habitats may be
important for roosting, rearing, and foraging (Table 10). The water column
is a rich foraging area for nearshore fish, seabirds, and mammals.
The high primary productivity of these embayments may support high
secondary production of nearshore zooplankton in important sites. This
community, in turn, serves as the food resource for rearing postlarval sand
lance, surf smelt, and herring. Fish-eating birds (grebes, guillemots,
cormorants, loons) and harbor seals are supported by rich secondary produc-
tion.
Some large embayments such as Discovery Bay serve as very important
roosting areas for a variety and high density of migratory and resident
marine birds. Manuwal et al. (1979) found up to 9,000 birds roosting in
Discovery Bay.
V. B. 3. b. (4) Nearshore; mud-sand. Important characterisics of the
nearshore waters at the mud-sand habitat include roosting, rearing, and
foraging. As described for the intertidal/subtidal habitats, the nearshore
waters associated with mud-sand habitats characteristically occur in
semiprotected regions of embayments. The importance of this nearshore
habitat is associated with characteristics common to all embayments. Due to
the usually increased water stability and nutrient sources entering such
embayments, the water column primary productivity tends to be higher and
occur earlier in the year than in colder, more mixed water masses. Detritus
sources in the mar£h, riverine, and eelgrass habitats common to embayments
also tend to contribute to this increased productivity through the generation
of dissolved organics and other nutrients important to phytoplankton
production. This increased primary production is directly linked to the
secondary production of neritic zooplankton, which, in turn, support high
standing stocks of consumers during certain times of the year. This linkage
results in a distinctive association of zooplankton-eating fishes and
fish-eating seabirds which forage and rear their young in this habitat from
winter through late spring and early summer. Postlarval and juvenile Pacific
herring, surf smelt, and Pacific sand lance constitute the principal
zooplankton-eating fishes which are observed to aggregate in these habitats,
especially when they are in proximity to the intertidal/subtidal mud-sand and
eelgrass habitats where reproduction of these species occurs. Fish-eating
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birds common to this habitat include Western and Horned Grebes, Pigeon
Guillemot, Pelagic Cormorant, and Common Loon.
The neritic waters adjacent to the Jamestown site provide an example of
the nearshore mud-sand habitat. Catches of postlarval Pacific herring, surf
smelt, and Pacific sand lance as high as 0.65, 0.09, and 0.05 fish/m3,
respectively, were documented in spring tow net collections at Port Williams
(Miller et al., 1980). The most prevalent fish-eaters in the Jamestown
region during spring were Western Grebes and Red-breasted Mergansers. Bird
densities of 1,000 to 2,000 birds/km2 and projected total counts of up to
46,000 birds roosting or swimming in the Jamestown subregion were recorded in
winter (Wahl et al., 1981). In early summer, Pigeon Guillemots occurred
prominently in the region and may be directly associated with the habitat
through their foraging upon sand lance migrating through the neritic waters
adjacent to the intertidal/subtidal eelgrass beds. Foraging by seals on fish
was important at Jamestown.
V. B. 3. b. (5) Nearshore; mud. Important characteristics of the nearshore
waters of protected, mud habitats include foraging by many species, rearing
of young fish, and use by birds for roosting. Many of the processes and
activities taking place in the water column relate both to the relatively
protected nature of embayments and the productivity of underlying subtidal
and intertidal habitats.
This mud-eelgrass-detritus trophic base supports abundant plankton which
are prey for a wide range of small fish, including many resident and migrant
species, particularly juvenile chum salmon. This trophic base may, in turn,
support sizable populations of fish-eating harbor seals and birds such as
loons, cormorants, mergansers, .and opportunistic gulls in important areas.
Water-column plankton include larvae of many benthic forms, and concentra-
tions of drifting larval forms of fish, barnacles, and other organisms.
Padilla Bay exemplifies this habitat type in the study area. In
addition to large populations of resident fish species, its nearshore waters
serve as rearing habitats for juvenile salmonids, Pacific herring, and sand
lance, and as winter foraging habitat for large numbers of Common and
Red-throated Loons, Red-necked, Horned and Western Grebes, Double-crested
Cormorants, and Red-breasted Mergansers. The winter average of about 300
Double-crested Cormorants (Manuwal et al., 1979) represents one of the
largest foraging concentrations of the species in the study area. Groups of
up to 70 harbor seals (Everitt et al., 1980) observed hauled out at low tidal
stages in Padilla Bay presumably also forage at least part of the time in the
water column here.
The nearshore habitat is important as a roosting area for the birds
discussed above, and also for thousands of ducks and geese which are resident
from fall through spring. Average winter flocks of about 80,000 waterfowl
which forage in intertidal/subtidal habitats also rest on the surface of the
bay. Because seasonal averages understate presence of species showing abrupt
occurrence peaks, the spring season estimate given in Manuwal et al. (1979)
does not truly reflect the importance of Padilla Bay in this season when up
to 50,000 Black Brant may be present at one time. Padilla Bay thus serves as
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an important roost both for birds using the nearshore wawter column and for
birds using intertidal/shallow subtidal foraging habitats. This roosting
activity is likely due to the high degree of protection offered in the
embayment from effects of weather, security from predation, and minimal human
disturbance (likely due in part to shallow water depths).
V. B. 3. b. (6) Nearshore; exposed rock. Because of the limited
information on this habitat, only a few important factors were identified as
being significant in this habitat. They include: foraging, harvesting, and
nonharvesting (nonconsumptive use).
An example of nearshore exposed rock for which recent biological
information has been collected is Pillar Point. This area has limited value
as a roosting area and bird densities are quite low. Manuwal et al. (1979)
reported densities for all species of less than 200 birds/km2 for the sub-
region along the coast that includes Pillar Point. Foraging nearshore fishes
were abundant in tow net catches, dominated by Pacific herring. Fish
densities were greatest in summer months (1.66/m3) (Miller et al., 1980).
This abundance and diversity of fishes may make sites such as this important
foraging areas for marine mammals. However, few marine mammals records are
available for this site.
Recreational sport fishing undoubtedly constitutes the most important
human use of this habitat though diving and surf fishing may also occur.
Nonconsumptive uses include photography and bird-watching. This portion of
the Olympic Peninsula attracts many vacationers.
V. B. 3. b. (7) Nearshore; protected rock. The nearshore protected rock
habitat may be important for the same factors at exposed rock: foraging,
harvesting, and recreational activities. These factors are related to the
rock/kelp bed physical structure and to the relatively low wave and current
action.
Point George is a site representative of this habitat type. Miller
et al. (1978) showed that fish densities there were relatively high (mean of
0.29 fish/m3) in tow net catches. Mean standing crop values were relatively
high also, but were lower than those at protected mud-eelgrass habitats,
reflecting the small size of the dominant species at Point George. Foraging
by sand lance, Pacific herring, and kelp bed fishes appears to be important
at this site.
Harvesting of kelp bed fishes such as sea perch and greenlings by
hook-and-line and diver can be important at protected rock sites such as
Point George. Many of the species found at this habitat type avoid tow nets
and thus do not appear in catch statistics. Nevertheless, they are
attractive to fishermen. Nonharvesting recreational activities such as
sightseeing, diving, and photography may be important at sites having this
habitat type.
V. B. 3. b. (8) Nearshore; cobble. This habitat is important for
harvesting and nonharvesting activities, roosting, rearing, and foraging. An
example of this habitat type is Cherry Point.
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As for the intertidal/subtidal cobble example, the annual herring spawn
is of significance at some sites having this habitat. Part of this spawn is
harvested in nearshore waters by commercial fishermen, while the bulk is left
to develop or to be eaten by various predators, including fish, scoters, and
gulls. Other diving birds are often associated with the feeding activities.
These include, especially in the winter, loons, grebes, alcids, and cormor-
ants. Gulls are always found in the area, but are confined to the surface
layer of the water column in their feeding activities.
The nearshore waters of cobble beaches are foraged by seals and often
used for roosting by various diving ducks, gulls, and other diving birds.
These birds often spend the night on the water.
The foraging activities of nearshore fishes such as herring were
reflected in the relatively high tow net catches at Cherry Point. Though
highly variable and seasonal, tow net catches there averaged 0.05 fish/m and
0.13 g/m3 with some catches exceeding 2.6 fish/m and 5.6 g/m in summer
(Miller et al., 1978). The dominant species was Pacific herring.
Rearing of the herring that hatched nearby constitutes an important
activity in some sites, including Cherry Point. The major harvesting
activities are related to the herring and salmon populations at this site,
while recreational activities include boating and sightseeing.
V. B. 3. c. Offshore
V. B. 3. c. (1) Offshore; broad passages. Activities that can be important
in this habitat are foraging, migration, rearing, and harvesting. Since
emphasis in the MESA and WDOE studies was on the intertidal/subtidal and
nearshore habitats, little data exist for this habitat.
Admiralty Inlet exemplifies the broad passage habitat. Admiralty Inlet
is a broad passage and it marks the water exchange area between central Puget
Sound and the Strait of Juan de Fuca, It is often marked by strong tidal
currents and convergences with obvious turbulence.
Commercial harvesting and sport harvesting of salmon is a common
activity in the passage area. Summer run king salmon are captured by gill
net and purse seine. Blackmouth (resident chinook salmon) and coho salmon
are also pursued by sports fishermen.
Because this is the passage between two major water systems, it is the
scene of migrations within the study area and between other Washington
waters. Birds commonly fly up and down the passage as they change areas of
foraging activity. During the summer months Rhinoceros Auklets are seen
flying daily through the passage. Marine mammals such as harbor seal, Ball's
porpoise, and killer whale utilize the area for passage to and from the Puget
Sound central basin. On a larger scale, birds passing through the study area
on migration are noted in the passage seasonally.
Foraging by birds commonly is observed in the passage, especially by
large feeding flocks consisting of alcids, gulls, and cormorants, which are
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often seen associated with the tidal fronts. The activity of these birds is
constantly changing as the currents ebb and flow in the passage. Foraging
activity by migratory salmon and predatory mammals such as killer whales is
important in this area.
Some larval stages of fish which occupy intertidal and nearshors
habitats as adults are reared in these waters as members of the near-surface
ichthyoplankton. Some marine mammal juveniles can be abundant there.
V. B. 3. c. (2) Offshore; narrow passages. Karrow passage habitats often
feature very strong tidal currents, and factors cf importance relate to
concentrations of plankton borne by currents and on nekton. Plant (phyto-
plankton) biomass, foraging, migration, and harvesting can be important.
Some of the highest observed densities of foraging birds within the study
area were recorded in this habitat, though it is dramatically apparent that
foraging activity varies greatly, depending on tidal stage and season.
Densities and estimated populations given in Manuwal et al. (1979) are mean
seasonal averages and do not represent peak usage which may be 100-200%
greater. In addition, concentrations of sea lions are often observed in this
habitat type.
Because of their biological features, narrow passages are important to
migrating fish, mammals, and birds, in addition to resident animal popula-
tions. The concentrations of many species are related to tidal stage and.,
thus, are recurring features; and they consistently attract predator species
which migrate through the study area or winter there. The narrow passages
are also notably important for one popular form of harvesting recreation—
sport-fishing for salmon. Food webs are structured around phytoplankton and
productivity may be very high in these passages; advection of prey animals by
tidal contents may also be responsible for pelagic plankton-eating concentra-
tions in this habitat.
Speiden Channel and Active Pass illustrate the biological importance
features of narrow passage habitats and also variations between these pas-
sages. Speiden Channel's offshore waters (>20 m depth) had highest bird
densities in fall (89.0/km2) when migrating small gulls and terns represented
most birds present, and in winter (84.8/knr) when loons, cormorants, gulls,
and alcids accounted for foraging populations. Many birds observed in fall
(Bonaparte's Gulls and Common Terns) primarily eat small fish or plankton.
while abundant wintering species like Arctic Leon, cormorants, Mew Gulls, and
Common Murres are larger in size and presumably feed on larger-sized prey.
Active Pass is narrower and its strong tidal currents attract very large-
foraging flocks of birds. Average densities in spring 1978 were 674.8/km",
and the winter average was 383.8/km2. These included censuses during "slack-
water," periods when bird activity was low. While Bonaparte's and Mew Gulls,
which feed upon zooplankton, often were present in large numbers, the great
proportion of the biomass consisted of birds of two piscivorous species, the
Arctic Loon and Brandt's Cormorant. The spring and winter concentrations of
these two species in Active Pass were relatively consistent and were among
the highest recorded in the study area. Herds of up to 30 Stellar*s or
California sea lions were also consistently found in Active Pass in the
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winter-spring seasons, and killer whales are regularly observed there.
Active Pass is also well-known as one of the most productive salmon
sport-fishing locations in the region due to the use of this passage by
migratory salmon.
Similar situations and importance factors, with variations in magnitude
and species, are found at other narrow passages in the study area, in
particular, southern San Juan Channel near Cattle Point and Deception Pass
and, on a lesser scale, Thatcher Pass and Obstruction/Peavine Passes.
V. B. 3. c. (3) Offshore; bays. This habitat type encompasses the deep
(>20 m) water of bays. Available biological information for offshore
habitats is limited to bird and mammal data. Phytoplankton production and
biomass can be important in this habitat, since the contribution of attached
plants to total production is minimal. Conditions such as water column
stability, insolation, and nutrient inputs are optimal for phytoplankton.
This habitat can be important as a foraging, rearing, or nursery area for
some species; a roosting area for birds; and for use by both nonharvesters
and harvesters.
An example of an offshore bay habitat is Bellingham Bay.. This bay is
quite large and has a sizable offshore component. This area is notable for
the large percentage of Western Grebes found there, which is by far the most
abundant bird species drawn to forage upon the rich fish fauna. This and
other common species which roost on the open waters are loons, grebes, gulls,
and Common Murres. Bird densities exceeded 258/km? in our surveys, and total
abundance has been estimated at 32,000 birds (Wahl et al., 1981).
Everitt et al. (1980) reported harbor seals in Bellingham Bay on a few
occasions but in small numbers. The difficulty in counting seals from the
air in an area of high human disturbance may have accounted for these low
numbers since several haul-out sites known to local residents were never
observed with seals during aerial surveys. Balcomb et al. (1979) speculated
that local pods of killer whales can be expected in this area during fall
salmon runs. Other cetaceans observed in Bellingham Bay include gray whales
(rarely), minke whales, and harbor porpoises.
Bellingham Bay is undoubtedly important as a rearing area for juvenile
salmon, though no data were collected in this study to verify this assertion.
Nonconsumptive users can be found in Bellingham Bay engaged in a variety of
recreational pursuits, probably the most obvious of which is sail and motor
boating. The bay provides a valuable commercial fishery and is heavily
fished by local salmon gill-netters during peak runs. An active sport
fishery also occurs; greatest activity is often found on the outer reaches of
the bay.
V. B. 3. c. (4) Offshore: open. Open water represents a very large
component in the study area. However, little biological data were collected
there. Factors of importance to this habitat include foraging, rearing,
migration, and roosting by many species and harvesting by commercial and
sport fisheries.
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The Western Strait of Juan de Fuca is an example of this habitat. The
major foragers and migrants through the area are mammals, birds, and salmon.
Marine bird densities in this area were quite low during most of the year.
Common Murres roosting on open waters comprised the largest component of bird
fauna for any season with greatest densities observed in the fall when a
total of up to 140,000 were observed. Fall is the season when densities of
all species of birds were the greatest, exceeding 89 birds/km2; in the spring
as few as 4 birds/km2 were observed (Manuwal et al., 1979). Cetaceans
utilize the open water areas exclusively and may be more abundant in the
western Strait than any other location in the study area (Everitt et al.,
1980). Essentially,* the entire population of gray whales migrates through
the offshore waters at the mouth of the Strait during north and south move-
ments. Ball's porpoise may also occur here frequently. Few harbor seals are
found in this area, but sea lions (northern and California) must pass through
this area during the postbreeding season (fall and winter) movements into
Fuget Sound.
This area is important for rearing many fish species, as indicated by
the abundance of fish eggs and larvae in plankton samples. Chester et al.
(1980) found 49 taxa of eggs, larvae, and juveniles in ichthyoplankton
samples, 15 of which were of commercial value (e.g., salmon, sole, smelt,
greenling, herring, cod, and ling cod). Greatest densities were recorded in
late winter and early spring. The authors estimated as many as 100 million
fish eggs may occur in the Strait at any one time.
Sport fisheries are active in this area keying in on migrating salmonids
and assorted bottom fishes. Commercial fisheries, primarily for salmon, are
equally important.
V. C. Ecological Relationships.
V. C. 1. Habitat-to-habitat relationships. Although this report considers
habitats to be separate and identifiable entities, it is important to note
that they all belong to a single ecological system and that there are many
functional linkages between habitats. Also, many human activities often
affect more than one habitat either directly or indirectly. Perhaps the best
example of this is the flow of biological energy through habitats. Rock and
cobble habitats, as well as those protected unconsolidated habitats that have
eelgrass beds, are energy exporters. That is, algae and plankton tissue is
dislodged by natural die-off and wave action and is carried by currents to
other areas. As this plant tissue is mechanically broken and degraded into
detritus, it is an important source of food to organisms in other habitats.
Although this detritus does not accumulate on exposed gravel and sand
beaches, sites having these habitats may support large amphipod populations
such as those seen at Ebey's Landing and Deadman Bay. Detritus tends to
accumulate in protected unconsolidated habitats where it is an important
source of energy to the total faunal community. The intertidal/subtidal food
web at the protected Jamestown site, for example, is detritus-based; and the
sources of detritus are located both nearby and far away.
Reproduction of many species bridges the boundaries between habitats.
Many species of benthic invertebrates have planktonic larvae that spend some
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time as pelagic forms in the nearshore and offshore habitats. Some fish
species move from deep to shallow water to spawn. The eggs and larvae of
cod, ling cod, greenlings, sole, herring, and smelts occur in abundance in
j>pen water but may either spawn or live as adults in nearshore or subtidal
habitats. Salmon use the offshore habitats for adult migration and the
intertidal and shallow subtidal zones for feeding and protection of the
juveniles. Birds (i.e., the Glaucous-winged Gull) nest only on undisturbed
^areas but may feed at many different habitats. Rhinoceros Auklets nesting on
Protection Island fan out to the Puget Sound central basin, Admiralty Inlet,
;and elsewhere daily to feed. Similar movements of harbor seals through a
variety of habitats for feeding, hauling out, and reproduction have been
observed.
Though many of the sites sampled in the MESA and WDOE studies were
clearly representative of one habitat type, some showed the influence of
other nearby habitat types. Point George (rock) was near a bay; the Morse
Creek beach seine site (gravel) was near cobble; Twin Rivers (gravel) was
near two streams and protected offshore by a cobble/kelp reef. Thus,
biological data collected at these sites represented inputs from more than
one habitat type.
The ecological linkages among species and the patterns of utilization of
various habitats are complex. Any consideration of the structure and
function of a single habitat must include linkages with other habitats.
V. C. 2. Importance of each habitat to total system. Habitats in this
report were defined primarily on a physical basis. The definitions of
habitats are directly relevant only to those species which are directly
dependent upon the physical characteristics, and indirectly relevant to those
species which are present as a function (result) of the presence of other
species of plants and animals.
Each habitat type means something different to each species. For one
species a habitat may be important as a source of food, while to another it
is a breeding or roosting site, and so on. The matrix of habitats and life
support activities (e.g., foraging, reproduction, rearing of young) for each
species differs among species. It can differ in terms of the number of
habitats that are used in each activity and in the relative importance of
each habitat. Some species may conduct all of their life support activities
at only one habitat, while others may conduct each activity at several
habitats. These former species would be considered to have narrow ecological
relationships, while the latter species would be said to have broad ecologi-
cal relationships.
The collection of physical habitats and processes and the species
loosely or closely associated with each make up the ecosystem of the study
area. Because some species have very specific or physical requirements,
their abundance and distribution in the . area are a direct function of the
abundance and distribution of their required habitat. Thus, a species of
narrow requirements with only limited habitat available will be necessarily
rare or common only where the appropriate habitat requirements are met. The
'habitats that support the greatest number of species, greatest biomass, and
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greatest energy flow are often the most important. Further, one can look at
the importance of a habitat from its contribution to the maintenance of
species in other habitats; i.e., it is a net exporter of reproductive pro-
ducts, material, and/or energy.
From the discussion above it is apparent that the biological components
of the ecosystem are dependent upon all habitats. No community associated
with a habitat type functions in a vacuum entirely dependent on just one site
representing a single habitat type. It follows, then, that the loss of any
area would not only affect those biota at that site, but possibly those
associated with other habitats at other sites.
The importance factors and examples discussed above address each habitat
type individually as if they were not interrelated. Of course, this asser-
tion is not true. The reader must appreciate that while the nature of the
interrelationships may be poorly understood or nonquantified, these
relationships do exist and are often important.
V. C. 3. Importance of study area to Northeast Pacific. The importance of
the study area to the biota of the northeast Pacific and adjacent provinces
became apparent during many of the studies. Though no studies were performed
to specifically characterize the relationship of the study area to adjacent
or larger systems, several examples are noteworthy.
The relatively protected nature of the study area lends itself to
providing important habitats for juveniles and breeding adults of many
species. These waters are situated near (between) the boundaries of
boreal/sub-Arctic and subtropical waters, and as such its fauna is rich,
including species of both areas. For many species of fish, birds, and
mammals, these waters provide a place to pause during northward or southward
migrations.
Five species of salmon move through these waters during two phases of
their life cycles. Adults move into the protected waters from the open ocean
enroute to spawning streams and large runs occur at all seasons of the year.
After spawning and hatching, smolts move into the study area and eventually
enter open ocean waters. The contribution of Puget Sound salmon to the North
Pacific pool is large. Adult herring also move in and out of the study area
from northeast Pacific waters for spawning purposes. It is unknown what1
contribution this spawning population makes to the oceanic herring stock.
The inland waters of Washington provide a rearing area for larval and/or
juvenile forms of sablefish, yellowtail rockfish, and, perhaps, other related
species. Adults of these species move into oceanic waters before becoming
sexually mature, and all spawning takes place in the ocean. The adults
remain offshore, but juvenile forms enter the Puget Sound region until they
too approach sexual maturity.
The study area is important as a wintering area for migratory marine
birds that nest in other coastal or inland areas. An example is the Common
Murre which is abundant in the inside waters of the Strait in fall and winter
and which return to breeding areas along the open coast from California to
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Alaska in spring and summer. Other species exhibiting similar use of the
study area include Western Grebes, Arctic Loons, Brandt's Cormorant,
Oldsquaw, and Mew and Thayer's Gulls.
Manuwal et al. (1979) identified the Rhinoceros Auklet as comprising
approximately 60% of all breeding birds in the study area. Of the nearly
18,000 pairs of Rhinoceros Auklets, most breed on Protection Island. This
large breeding concentration represents a significant proportion of the
entire northeast Pacific population of Rhinoceros Auklets.
The importance of the study area to northeast Pacific- populations of
most cetaceans is unclear. Most species occur here rarely or accidentally.
Of the common species only the gray whale and killer whale occur in
appreciable numbers. Essentially, the entire population of gray whales
passes through the extreme western reaches of the study area during its
northward migration in the late winter and spring and southward migration in
the fall. This endangered species is the largest remaining population of
baleen whales in the northeast Pacific.
California sea lions migrate into the area in the late fall and winter
from California and adjacent areas. Nearly 300 animals have been observed in
November in the study area. Northern sea lions also migrate into the area
during late fall and winter, though usually in lower numbers than the
California sea lion. Northern sea lions breed in coastal locations of
California, Oregon, British Columbia, and north to the Bering Sea.
California sea lions breed along the coast of California and Baja.
No benthic invertebrates or plants are endemic to the study area. The
inland protected habitats provide a contribution to the total gene pool of
the coastal northeast Pacific waters. Many soft bottom infauna and rocky
intertidal epifauna common in the area are also found along the coast and in
other inland areas north into Alaska and south at least to Point Concepcion.
Open ocean zooplankton have been observed entering the Strait during
strong onshore winds associated with storms. These organisms, while not
normally excluded from the Strait, become very concentrated during these
events. Their entry into the Puget Sound central basin has not been
documented.
V. C. 4. Unique features. During the studies that were performed under the
MESA and WDOE programs, the investigators observed biological features of the
study area that were unique and noteworthy. These are listed and briefly
discussed below. This list is not comprehensive. It is not explicitly meant
as a list of important features (biologically, socially, or politically),
though this conclusion is implicit. Such an explicit evaluation of relative
importance for all biota is not possible, since the data base is neither
complete topically nor geographically. The list has not been formulated in
any particular order.
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V. C. 4. a. Protection Island. Over 19,000 of 30,000 pairs of breeding
birds in the study area were found there. Total counts of over 8,000 birds
were recorded along the shoreline. Eagle nests were found on the island.
Average monthly counts of nearly 150 harbor seals were recorded; a maximum of
223 were observed at one time. The second largest breeding population of
harbor seals was found there. Nearby Dallas Bank supports an important kelp
bed and foraging area for predators.
V. C. 4. b. Smith-Minor Islands. A maximum of 44 harbor seal pups was
observed there, making this the most important pupping site in the study
area. Monthly counts of harbor seals averaged about 150; a maximum of 257
were observed at one time. About 850 pairs of breeding birds were recorded.
V. C. 4. c. Race Rocks. Combined counts of over 300 California and northern
sea lions were made for this rocky isle in the winter. Monthly counts of
harbor seals in a coastal area of Vancouver Island that included Race Rocks
averaged about 200; a maximum of 504 were counted in August.
V. C. 4. d. Dungeness Bay/Dungeness Spit/Jamestown. Dungeness Spit is a
National Wildlife Refuge. A maximum of nearly 5,000 birds occurred along the
shoreline of the spit. Another 200 birds were observed breeding in the
Dungeness Bay/Jamestown area. Nearly 55,000 birds have been observed along
the shoreline in the latter area, the largest concentration of marine birds
recorded along the shorelines of the study area. The highest Bird-Oil Index
values were calculated for the Jamestown subregion, indicative of the density
of birds and their sensitivity to oil. Monthly counts of harbor seals
averaged about 50; a maximum of 119 were observed in August. Over 50,000
infaunal organisms/nr were found at Jamestown. Beach seine collections were
species-rich and high in biomass. Epibenthic zooplankton samples taken in
eelgrass at Jamestown exceeded those taken elsewhere in biomass by at least
an order of magnitude. Juvenile salmon were abundant in beach seine samples
taken on the exposed side of Dungeness Spit and at the Jamestown site.
V. C. 4. e. Padilla Bay. This bay has been designated as a National
Estuarine Sanctuary. The broad mudflats support dense infaunal benthos and
eelgrass. Projected total estimates of up to 90,000 birds along the
shoreline and in the water have been calculated for the bay, the majority
being found in the water. As many as 95 harbor seals have been observed
hauled out on mudflats at low tide; the area is important for pupping.
Samish Bay and the undeveloped portion of Bellingham Bay share many of the
same characteristics as Padilla Bay.
V. C. 4. f. Slip Point to Pillar Point. Mean total biomass for intertidal
epibenthos was very high along this rock bench. At the 0' tidal elevation,
over 11,000 g/m2 were recorded, the highest value observed along the Strait.
Species richness was also high (over 120 species) among epibenthos sampling
sites.
V. C. 4. g. Admiralty Inlet. Average projected estimates of over 7,000
birds were calculated for this area; many species are known to be susceptible
to the effects of oil. Killer whales, minke whales, northern elephant seals,
and harbor seals transit the inlet to and from Puget Sound and probably
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forage there. Salmon migrating to and from Western Washington streams
transit the area also. Foraging by over 12,000 birds in the turbulent waters
at one time in this area has been observed.
V. C. 4. h. Cherry Point. The highly important herring spawn activity in
February/March is reflected in a considerable commercial fishery, high-
density tow net catches, and a seasonal influx of marine birds. Up to 24,000
birds, 22,000 of which were scoters, were observed in the spring.
V. C. 4. i. Western Strait of Juan de Fuca. Total estimates of Common
Murres of up to 140,000 in the fall have been calculated for these open
waters; exceptionally high Bird-Oil Index values accompany these counts.
Cetaceans such as gray, minke, and killer whales occur there periodically, as
do Ball's porpoise.
V. C. 4. j. Discovery Bay. A high species richness of birds and projected
total counts of up to 18,000 birds have been recorded. Mean species richness
values of up to 30 species of fish were observed for beach seine samples
taken at Beckett Point, the highest recorded for the Strait. Fish abundance
and biomass were consistently very high. Epibenthic zooplankton abundance
and biomass were exceeded only by those data from Jamestown. A major commer-
cial clam bed exists along the shoreline of Discovery Bay. Mean total
abundance of benthos at the 0' tidal elevation equalled nearly 60,000
organisms/m2, rivalled only by that of the Jamestown site. Species richness
and biomass were also relatively high.
V. C. 4. k. Southern Lopez Island and vicinity. Projected total estimates
of up to 11,000 marine birds were recorded. Nearly 2,000 pairs of breeding
birds were observed in the area. Up to 32 harbor seals were seen on Mummy
Rock near Lopez Island. Northern sea lions were also seen there and in
Middle Channel. Considerable epibenthos were associated with the exposed
rock habitat. Killer whale migratory routes through the San Juan Islands and
the eastern Strait converge in the area immediately south of Lopez Island.
V. C. 4. 1. Tatoosh Island. Nearly 2,200 breeding pairs of marine birds
were seen on this island, the second most important breeding colony in the
study area. Projected total estimates of up to 17,000 birds were made for
the area along the shoreline and on the island. Some harbor seals and as
many as 55 northern sea lions have been seen on Tatoosh Island. Epibenthos
on this exposed rock is probably abundant and dense.
Other areas having unique features outside or bordering the study area
have not been listed, though the large salmon runs into the Fraser River and
bird populations throughout the Canadian Gulf Islands and in Boundary Bay,
Skagit Bay, Port Susan, and Penn Cove are well-known.
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VI. POTENTIAL INTERACTIONS OF HABITAT TYPES AND
KNOWN OR PROPOSED TYPES OF PERTURBATIONS
VI. A. Summary of Present Pollution Status
The study area has been and remains relatively free of pollution. The
majority of the shorelines bordering the study area are unpopulated or
sparsely populated. Except for isolated areas near Seattle and Tacoma in the
adjacent Puget Sound basin, the assimilative capacity of the marine
ecosystems generally has not been exceeded (Goldberg, 1979). Urbanization
and industrialization have primarily occurred near estuaries and embayments
(e.g., Port Angeles, Friday Harbor, Bellingham, Anacortes). Some local
historical, existing, and/or potential problems have been identified,
however, and are discussed briefly below.
A large variety of pollutional stresses conceivably could take place in
the study area. The categories addressed below are those considered by the
authors to be most important .in the study area relative to their historical,
existing, or potential impacts.
VI. A. 1. Oil spills and other industrial accidents. Two large spills have
occurred in the study area. One, a spill of 5,000 gallons of crude oil off
the ARCO dock at Cherry Point in 1973, was not studied, and its effects on
the marine environment are not known. The second was a 200,000 gallon diesel
fuel spill from the Texaco dock at Anacortes in April 1971. The initial
mortality from this spill was evaluated, primarily west and north of the
spill site. Localized areas showed extensive mortality of surface
invertebrates, algae, and infauna. Some nemerteans, polychaetes, clams,
snails, barnacles, limpets, and sea cucumbers suffered substantial
mortalities;.some recovery was observed six months later in gravel and cobble
beaches (Woodin et al., 1972). No studies of impacts on fish, plankton, or
birds were conducted, nor was any long-term damage assessment made. Effects
from a small but persistent spill of Navy Special Fuel Oil residue upon
intertidal biota near Cape Flattery were restricted to a small area and
included loss of some species and pathological problems in sea urchins (Clark
et al., 1975). Other small spills have occurred in the area, primarily in
maritime harbors, but their effects have not been studied. Existing levels
of petroleum hydrocarbons in the study area were found to be very low at
sites distant from harbors and refineries (Brown et al., 1979).
Spills of other hazardous substances have not been documented in the
study area. However, a major PCB (polychlorinated biphenyl) spill occurred
in the Duwamish River in Seattle south of the study area in 1974. Approxi-
mately 1,300 kg of Aroclor 1242, a PCB mixture, were spilled when a
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transformer was dropped. Some of the material was removed by dredging, but
up to 2 ppm in sediments were recorded in the immediate area following the
spill (Pavlou and Horn, 1979; Pavlou et al., 1977).
VI. A. 2. Oil refineries and transshipment facilities. Four oil refineries
are located within the study area. Their total refining capacity is about
336,500 barrels per day. Despite the considerable efforts on the part of
these industries to remove pollutants from wastewaters, chronic inputs of
B.O.D. materials and oil and grease occur. A range of 10.2 to 29.5 mg/1
B.O.D. and 3.7 to 11.9 mg/1 oil and grease were measured in 1972 over a
two-month period. Maximum pulses of 1,074 mg/1 and 426 mg/1, respectively,
were measured in 1974. Though the total oil removal efficiencies of the
refinery wastewater treatment facilities ranged from 95 to 99.99%, these
facilities were found to be relatively ineffective at removing soluble
aromatic fractions (Pizzo et al., 1978). Consequently, petroleum
hydrocarbon levels in sediments and mussel tissues collected near these
refineries were often higher than in samples collected elsewhere in the study
area (Brown et al., 1979).
No consistent indications of lethality among oyster larvae, and juvenile
coho and chinook salmon exposed to undiluted refinery effluents and receiving
water were recorded by the Washington Department of Fisheries (Pizzo et al.,
1978). No studies on the effect of refinery operations on the benthos are
available.
No crude oil or refined products pipelines traverse the study area at
this time. Refinery products are currently transported to the Seattle area
and other Northwest markets by truck, barge, overland pipeline, and ship.
Puget Sound refineries shipped about 36 million barrels of products in 1974,
40% of which was transported by marine traffic (Pizzo et al., 1978).
Several proposed tanker-to-pipeline crude oil transportation facilities
are under consideration for the area and/or nearby Canadian locations. If
constructed, a throughput volume of 700,000 to 933,000 barrels per day would
be expected in at least one of the proposed facilities, involving from 300 to
395 tanker port calls per year. Oil spills as a result of tanker collision
or grounding and operational mistakes or equipment (e.g., pipeline) failure
could occur (U.S. Bureau of Land Management, 1979). The processes that may
determine the fate of oil spills resulting from the operation of one proposed
facility and the biological communities that may be affected have been
summarized (Long, 1980).
VI. A. 3. Habitat modification. The irreversible losses of habitat
associated with dredging and construction of piers, marinas, jetties,
bulkheads, etc. occur periodically in the study area. Loss of habitats can
occur through removal of sediments, filling, burial, modification of
nearshore currents, or removal of marsh or other vegetation.
The study area as a whole has been minimally impacted by projects that
cause loss of habitat due, in part, to the low human population density.
Those projects which have been implemented often were intended to either
stabilize shorelines or protect and accommodate ships or boats. Habitat
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modifications which have occurred in the past include breakwater construction
at Neah Bay; stabilization of Ediz Hook with rip-rap; construction of piers
at Cherry Point, March Point, Dungeness and Port Angeles; construction of
marinas at Sandy Point, Orcas Island, Friday Harbor, Port Angeles, Neah Bay,
Birch Bay, Anacortes, and Bellingham; dredge-and-fill operatios at Semiahmoo
Spit and Bellingham; and construction of structures and docks at Anacortes,
Port Angeles, San Juan, Orcas, Shaw, and Lopez Islands.
VI. A. 4. Upland modification. Upland activities such as agriculture,
construction, and logging ultimately affect marine habitats. Excessive
nutrient inputs from fertilizer runoff, excessive suspended solids inputs
from erosion and runoff of pesticides can reach the bays and estuaries of the
study area and cause deleterious biological effects.
Upland modification activities are greatest along the Olympia Peninsula,
in the Skagit River basin, and in areas surrounding Bellingham. Suspended
solids loads from the Fraser River system to the north represent the single
largest input to the study area. Stockner et al. (1979) observed trends in
phytoplankton productivity and biomass apparently related to characteristics
of the plume,
VI. A. 5. Forest products. Four major pulp mills are located in the study
area (Bellingham, Anacortes, two in Port Angeles). Pollution problems from
these mills have been documented and are of two types: First, the deposition
of settleable solids in bays and harbors creates anaerobic conditions in the
sediments and tends to eliminate many macrobenthos species. Second, the
effluent, because of oxygen-demanding and toxic materials, can cause water
quality problems. Lethal conditions to juvenile salmon, benthos (including
oysters), and bivalve larvae have been documented (FWPCA, 1967).
Rafted logs are stored in water in a number of locations in the study
area. Although no studies of the impact of log rafting are available for the
study area, Waldichuk (1979) described some impacts in parts of British
Columbia under conditions similar to those of the study area. Detrimental
impacts of log rafting include compacting of sediments and smothering of
benthos at intertidal log storage areas; production of organic leachate toxic
to juvenile salmon; accumulation of oxygen-demanding bark and wood debris
under log rafts, causing anaerobic conditions unsuitable for many benthic
species including prey for juvenile salmon; and abrasion by shifting logs
disrupting benthic fauna and rooted vegetation such as eelgrass.
VI. A. 6. Domestic wastes. Domestic wastes discharged from urban areas into
marine waters, in most cases, only receive primary treatment. Although
detrimental effects to the environment have not been documented in the study
area, potential pollution effects from B.O.D. material, nutrients, and/or
toxic substances (metals, organics) exist.
The largest metropolitan areas (Bellingham, Anacortes, Port Townsend,
Friday Harbor, Port Angeles, Sequim) produce the greatest volumes of
municipal sewage and, thus, potentially pose the greatest environmental
problems. Permitted discharge volumes (millions of gallons per day) for the
largest municipal waste treatment plants in the area were documented in 1975
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as follows: Port Angeles, 2.3 mgd; Anacortes, 2.2 mgd; Bellingham, 1.56 mgd;
Sequim, 0.57 mgd; Friday Harbor, 0.5 mgd. Smaller municipalities, such as
Skyline (near Anacortes) and Ferndale, discharge considerably less than
500,000 gallons per day (National Commission on Water Quality, 1975).
VI. A. 7. Commercial and sports fisheries. Fisheries harvesting represents
a major portion of the economy of the Pacific Northwest. Both anadromous and
resident fish are caught along with shellfish. Gill nets, purse seines,
trawls, and trolling gear are used to capture fish. Traps and pots are used
to collect crab and shrimp. Both diver-operated and boat-operated hydraulic
gear are used to collect subtidal bivalves, while rakes and shovels are used
for intertidal bivalves.
Salmonid fishing activity within the study area is most intense in the
Strait of Juan de Fuca, Rosario and Haro Straits, while bottomfish are
collected most often in the embayments, such as Discovery Bay. Shrimp and
crab are caught throughout the area and in the adjacent Hood Canal. Bivalve
fisheries are restricted to the embayments, such as Dungeness and Discovery
Bays.
The environmental implications of commercial harvesting of subtidal
hardshell clams with a hydraulic escalator harvester have been observed in
field experiments and summarized (WDOF/WDNR, 1978). Disturbance of the
bottom results in furrows, redistribution of sediments, some burial of
organisms, and temporarily increased suspended particle concentrations.
Dislodged, nonharvested clams and other species may be vulnerable to
predation. Some individuals may die due to shell breakage. The numbers of
associated benthic species in areas affected by harvesters is reduced, but
the abundance and biomass per unit area appear to remain unchanged. Marine
eelgrass and algae beds can be lost due to removal; however, harvesters
cannot operate in dense eelgrass mats. Thus far, very little of this
activity occurs in the study area, but various parts of the Strait of Juan de
Fuca support potentially harvestable clam beds.
VI. A. 8. Mariculture. Mariculture operations are largely restricted to
salmonids and bivalves in the study area, often in suspended or floating pens
or racks. The technology to raise marine algae is currently being develolped
nearby, but is not yet operational. Salmonids have been raised in floating
pens at one time or other at Lopez and Orcas Islands. Oyster raising
operations have occurred in Dungeness Bay, Sequim Bay, Padilla Bay, Samish
Bay, and Westcott Bay. Currently, plans for siting experimental algae
mariculture apparatus focus upon embayments.
VI. A. 9. Recreation, educational activities, scientific collection. A wide
variety of activities lumped together here can have detrimental biological
.effects, though usually unintentional. These activities are often greatest
in biologically important areas as the biota are the attraction to many of
the people causing the perturbation. Activities included here are: recrea-
tional boating near or among marine mammals and birds; recreational and
commercial aviation near marine birds; beachcombing, walking, motorcycle
riding, horseback riding, other recreational activities and dogs near or
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among nesting bird colonies; educational field trips; and collection and
removal of organisms for educational and research purposes.
Areas where significant disturbance and/or removal of organisms has
occurred include: Dungeness Spit; Protection Island; Smith Island; Sucia,
Patos and Matia Islands; Tongue Point; Slip Point; Padilla, Bay; and numerous
bird nesting sites in the San Juan Islands.
Everitt et al. (1980) documented disturbance of harbor seals on
Protection Island and Smith-Minor Islands. Groups of seals on Protection
Island were disturbed (enough to flee to the adjacent water) most often by
approaching boats and to a lesser degree by airplanes, beach walkers, and
helicopters. Disturbance was greatest on weekends and usually at mid-day.
The period of time involved for seals to return to haul-out sites following
removal of the disturbance was not measured, but appeared to take from
several hours to several days.
VI. B. General Perturbation Effects on Biological Communities
As described earlier in this report a wide variety of marine communities
are found in this region. In the nonperturbed or "healthy" state, they vary
greatly in the following community parameters: species components and
organization, species richness and diversity, abundance, and biomass. No
single measure would differentiate a healthy community from a possibly
perturbed community. However, perturbations have general biological effects.
An understanding of these plus careful study may allow assessment of perturba-
tion impact at a given site.
Perturbations may be placed into three broad categories. The first is
habitat alteration. Many perturbations involve a change in the physical
characteristics at a site. For example, the construction of a breakwater may
involve replacing a soft sediment habitat with a rock habitat. This results
in the wholesale replacement of one community by another in response to
destruction of one type of habitat and replacement by another. Community
parameter measures would change to match those of the "new" community. There
would be new species components and possibly organization. The parameters of
species richness and diversity, abundance, and biomass may increase or
decrease. Habitat alteration effects are generally dramatic and, given our
general understanding of regional marine communities, the effects may be to
some extent predictable.
A second category of the biological effects of perturbations is the
nonselective destruction or enrichment of a community. Examples of nonselec-
tive destruction are often dramatic. An example is a crude oil spill. In
the rocky intertidal the primary effect is suffocation of the entire
community. Other toxicants may kill the entire community. Less acute
nonselective pollutants may depress the community parameter measurements of
species richness and diversity, abundance, and biomass compared to prestress
values. Once the toxicant is removed, community values return in time to
normal. Examples of nonselective enrichment are rare. In a hypothetical
example, a slight nutrient addition might result in nonselective enrichment
146
-------
of an entire community where primary production is nutrient limited. Biologi-
cal effects of nonselective perturbations may to some degree be predictable.
The perturbation category with the most complex and least predictable
biological effects is a selective destruction or enrichment. Many or most
perturbations affect community species members differently. Species specific
responses are due to the differing physiological tolerances of organisms,
differing feeding habits, microhabitats, life cycle sensitivity, or general
life styles (sessile, motile, flyer, swimmer, etc.).
The community level result of species specific responses is potentially
very complex and unpredictable. Community species components may change due
to selective mortality of sensitive species or the addition of new
opportunistic species resistant to the pollutant involved. Community
organization may be altered. The species-rich marine communities are
structured by complex interactions of predation and competition among its
component species. Selective removal of a key predator or competitor may
dramatically alter the community structure. Community food webs may also be
dramatically altered by selective removal of a key predator or other vital
trophic link. In general, selective perturbations reduce species richness
and diversity. However, selective removal of a competitive dominant species
may actually increase both richness and diversity.
Community productivity as reflected in the parameters of abundance and
biomass may be increased or decreased by a .pollutant. If the pollutant in
nontoxic concentrations can serve as a nutrient substrate, blooms of the
organisms able to utilize it may result in increased community productivity.
However, most pollutants fall into the class of toxicants, which may decrease
community productivity if key producers are sensitive.
From the discussion above it is apparent that the nature of the effect
is highly dependent upon the nature of the cause. Some types of perturba-
tions, for example, may cause an increase in productivity, possibly to the
point where eutrophication occurs, while others may drastically reduce
productivity. Some types may result in the total loss of a population, while
another population may flourish. Some effects occurring over a short time
can be easily observed and quantified. Other effects may be very subtle and
are measurable only after considerable time.
VI. C. Perturbation Types and Their Possible Effects
Table 11 briefly outlines the major perturbation types in the study area
as perceived by the authors; those communities and habitats most sensitive to
each; the potential impacts of each and the biological processes affected;
and environmental questions or concerns that should be examined to lessen or
estimate possible effects. This table is not intended to be exhaustive but,
rather, provides a framework for considering possible environmental reper-
cussions of each type of perturbation.
-VI. C. 1. Oil spills and other industrial accidents. Acute effects of
spills of crude oil, petroleum products, or other toxic substances have
historically been documented among marine birds and benthos. Adult fish and
147
-------
Table 11, Major perturbation types and their possible effects in the study area
Perturbation Types
Especially
Sensitive.
Communities Especially
Directly Sensitive
Affected Habitats
Potential Impacts
Processes Affected
Environmental
Questions
A. Oil Spills and Other
Industrial Accidents
- oil spills
- hazardous substance
spills
- birds
- benthos
- fish
- mammals
00
- open
water
- protected
intertidal
habitats
- protected
bays
direct mortality caused
by toxic effects of
hazardous substances
decrease in bird hatch-
ing success due to
oiling of eggs
mortality, morbidity
of benthos, causing
community and biomass
changes
retention of oil In
protected muddy
habitats, inhibiting
recolonization
death of benthos
larvae, leading to
community changes
tainting of benthos, fish
increased mortality
among pinniped pups;
increased chances of
mother/pup separation;
disturbance during
spill cleanup opera-
tions
changes in population
sizes due to emigration,
mortalities, decreased
hatching success
changes In community
composition and biomass
leads to changes in
food webs and produc-
tivity
decrease in population
size, growth rate,
spatfall success in
commercial bivalves
tainting decreases
marketability of
seafoods
What method and
plans are available
to protect biologi-
cally Important
areas?
Which areas, habi-
tats and seasons are
especially sensi-
tive?
What recovery rates
are to be expected?
How will food webs
be affected by loss
of prey groups?
What economic
impacts are ex-
pected?
What preventative
measures can be
implemented to
decrease spills?
Are species of
critical trophic
importance also
those most sensitive
to effects of oil?
Continued
-------
Table II (Contd.)
Perturbation Types
Especially
Sensitive
Communities
Directly
Affected
Especially
Sensitive
Habitats Potential Impacts Processes Affected
Environmental
Questions
B. Petroleum Refining,
Transshipment and
Utilization
- chronic oil Inputs
in refinery waste-
water
- atmospheric inputs
from refinery
stack emissions
- oil inputs from
bilges, small
dockside spills,
marinas, small
craft, etc.
benthos - bays - chronic inputs of
fish - protected hydrocarbons cause
seabirds intertidal mortalities and
(especially and near- abnormalities among
diving shore larvae of benthos
species) habitats and fish
- chronic inputs of
hydrocarbons lead
to physiologic
stresses, histo-
pathologic
diseases and
behavioral changes
in adult benthos
and fish
- seabirds susceptible
to oil-fouling and
death during small
spills
- changes in benthos and
fish community compo-
sition
- decrease in reproductive
success among benthos
and fish
- histopathologic diseases
cause decreased ability
to compete for food, to
avoid predators, and to
reproduce
- losses of seabirds leads
to community composition
changes and decreased
density
Will decreasing or
stopping chronic
hydrocarbon inputs
minimize or elimi-
nate impacts?
Are there siting
alternatives that
would avoid impacts
upon important
biologic communities
or result in rapid
and considerable
dilution of inputs?
Can effluent/
emission be used to
reduce monitoring
data effects?
Can safeguards
(e.g., booms) or
regulatory actions
be implemented to
decrease impacts?
Continued
-------
Table 11 (Contd.)
Perturbation Types
Especially
Sensitive
Communities-
Directly
Affected
Especially
.Sensitive
Habitats Potential Impacts Processes Affected
Environmental
Questions
in
C. Habitat Modifications
- piers, Jetties,
marinas, bulkheads
- solid and wood
waste fills
- dredging (shell-
fish and
channelization)
and filling
- buildings,
underwater pipe-
lines, bridges,
other structures
infaunal
zoobenthos
shore and
diving
birds
marine
mammals
fish (e.g.,
spawning
herring)
- all
Potential Impacts (contd.)
- possible rerelease
of sediment-bound
toxic chemicals
- removal, loss, burial
or substitution of
habitat/substratum
types, causing changes
in community composi-
tion
- changes in nearshore
circulation, possibly
leading to beach
morphology changes and
further burial or habi-
tat loss, shifts in
sediment characteris-
tics and changes in
replenishment of
nearshore water
masses
- disturbance of birds
and mammals during
construction
- burial or removal of
biota, nests, eggs,
animal burrows,
causing direct mor-
tality
- removal or modifica-
tion of roosting,
resting, haul-out
site habitats
- alteration of water
quality and current
patterns
- decrease in avail-
ability of food
species
- decrease In plant
productivity due to
removal or loss of
suitable substratum
- shift in faunal
community structure
to less desirable
state
- decreased hatching,
nesting, pupping
success
- decreased benthic
blomass
- emigration of seals
and birds, decreas-
ing population size
• Can the proposed
project be modified
to decrease habitat
loss?
• Can construction be
scheduled for a
season in which
disturbance would
be minimal?
Can new habitats be
established to re-
place that which
will be lost?
Will any new habi-
tats be suitable for
biota?
Are there siting
alternatives that
would minimize
impacts?
What is the esti-
mated recolonlzation
period and is
enhancement (e.g.,
bivalve seeding)
feasible?
Continued
-------
Table 11
-------
Table 11 (Contd.)
Perturbation Types
Especially
Sensitive
Communities
Directly
Affected
Especially
Sensitive
Habitats Potential Impacts Processes Affected
Environmental
Questions
E. Forest Products
- pulp and paper
mill effluents
- log-rafting
- chips, debris
- zoobenthos
- fish larvae
- zoobenthos
larvae
- bays/
estuaries
. en
PO
- mill wastewater
discharges, causing
direct mortality
among larval forma
of fish and benthos
- lignins, tanins,
chips and debris
leached or spilled
into water, causing
death or burial of
benthos and modifi-
cation of substratum
characteristics
- logs directly scour
or abrade bottom,
removing or crushing
benthos
- decrease in benthos and
fish population sizes
through death of larvae,
modification of bottom
substrata
- decrease in benthos
bipmaas through toxic
effects of effluents,
leachates, scouring,
or abrasion
- low-oxygen or anoxic
conditions in near-
bottom water caused
by fi.O.D. materials,
leading to physio-
logic stresses
Can potential
impacts be minimized
by siting alterna-
tives If new mills
or other facilities
are built?
Can potential im-
pacts be minimized
by modifying
practices and
implementing
seasonal controls?
Can log-rafting
methods be modified
to minimize or
eliminate impacts?
Continued
-------
Table 11 (Contd.)
Perturbation Types
Especially
Sensitive
Communities
Directed
Affected
Especially
Sensitive
Habitats Potential Impacts Processes Affected
Environmental
Questions
F, Domestic Wastes
- municipal wastes
(sewage)
- urban x'unoff
- nonpoint sources
- phyto- and - poorly
zooplankton flushed
- benthos bays
- fish larvae
01
GJ
— nutrient inputs
raised, leading to
eutrophication
- excessive inputs of
freshwater, suspended
solids may cause mor-
talities due to
changes In water
chemistry
- inputs of toxic
substances may be
taken up by biota
- Inputs of pathogenic
bacteria and/or toxic
substances may con-
taminate seafood
- eutrophication can lead
to anoxia, lethal to
plankton, benthos
- productivity depressed
and composition of
plankton communities
changed
- subtle histopathologlc
diseases caused by
toxic substances
- physiological processes
altered or stressed,
e.g., osmoregulation
- food webs and other
species-species
relationships altered;
some predators may
leave due to lack of
suitable prey
- loss of or decrease
in harvestable
fisheries
Continued
Are there siting
alternatives that
would eliminate or
minimize anoxia
conditions?
Will eliminating or
diminishing pollu-
tant inputs alle-
viate physiologic
stresses?
Will eliminating or
decreasing toxics
and bacterial Inputs
alleviate human
health problems?
What are the eco-
logic repercussions
of altering food
webs?
Are there alterna-
tives to waste water
discharge?
How can effects of
discharges be
monitored?
What is the carrying
capacity of receiv-
ing waters to
accommodate pollu-
tant inputs?
-------
Table LI (Contd.)
Perturbation Types
Especially
Sensitive -
Communities
Directly
Affected
Especially
Sensitive
Habitat Potential Impacts Processes Affected
Environmental
Questions
G. Commercial and
Sports Fisheries
- finfish
- shellfish
- fish
- diving
birds
- marine
mammals
- subtidal
zoobenthos
- open
straits
- nearshore
(all)
en
•£•
excessive selective
removal of target
species
incidental drowning
of diving birds, seals;
Incidental removal of
nontarget species
loss or disruption of
sediments by shellfish-
gathering machinery
disturbance of marine
birds, mammals
significant removal of
important prey
resources
selective removal of
predators, affecting
food webs, predator
pressure and overall
community structure
decrease in standing
stock of target
species, species
accidentally killed
and predators
decrease in benthos
species richness and
standing stock due
to removal or loss
of substratum
emigration of species
intolerant of distur-
bance, affecting
density and community
composition
Can fishery be
implemented so as to
decrease or
eliminate incidental
deaths?
Can fishing pressure
be timed or regu-
lated to minimize
effects of loss of
target species?
What is expected
recovery time of
incidentally
affected communities
if fishery were
stopped?
What is maximum
fishing pressure
target species and
nontarget species
can tolerate?
Are there shellfish
harvesting tech-
niques which mini-
mize sediment
disturbance?
Continued
-------
Table 11 (Contd.)
Perturbation Types
Especially
Sensitive
Communities
Directly
Affected
Especially
Sensitive
Habitat
Potential Impacts
Processes Affected
Environmental
Questions
H, Mariculture
- shellfish
- finfish pens
- benthos
- certain
marine
birds
- protected
bays
01
en
fecal wastes cause
substratum modifica-
tion, increases in
B.O.D., burial and
smothering of adjacent
or underlying benthos,
increases in sedimen-
tation rates
pens, floats, other
equipment attract
some bird species
and disturb others
production or utili-
zation (depending on
type of operation)
of nutrients may
lead to nutrient
level changes in
water
-increased oxygen demand
near sediment-water
Interface can cause
community composition,
biomass changes among
benthos
- changes in marine bird
communities can occur
due to emigration of
some species and
immigration of others,
possibly including
nuisance species
- plankton communities
may change due to
nutrient level
changes
Continued
- Are siting alterna-
tives or pen rota-
tion schemes
available to de-
crease potential
impacts?
- Can benthos commu-
nity changes, if
any, be monitored?
- What means are there
to minimize distur-
bance of marine
birds?
- What is the physi-
cal/chemical fate of
fecal wastes?
- What is the assimi-
lative capacity of
of the local eco-
system relative to
the magnitude of the
facility?
- What are the bio-
logical effects of
predator control
practices?
- What means are
available to avoid
attracting predator?
-------
Table 11 (Contd.)
Perturbation Types
Especially
Sensitive .
Communities
Directly
Affected
Especially
Sensitive
Habitats Potential Impacts Processes Affected
Environmental
Questions
cn
I. Recreation, Educational
Activities, Scientific
Collection
- boating - epibenthoa
- aviation - marine
- beachcombing birds
- educational field - marine
trips mammals
rock and
cobble
(especially
with tide-
pools)
protected
embayments
Isolated
rocks,
islets,
sand spits
selective removal,
trampling, and mor-
tality of rock/
cobble community
species
disruption or dis-
turbance of nesting,
hatching, pupping or
rearing activities
changes in benthos
community structure
and density
decrease in bird and
mammal population size
due to emigration and
impaired reproductive
success
decrease in predator
pressure, possibly
leading to prey
community changes
Can recreation and
educational activi-
ties be conducted
without causing
biologic impacts?
Can these activi-
ties be regulated or
restricted to avoid
nesting or other
sensitive seasons?
Is disturbance a
transient effect?
How long does
recovery take?
Should especially
sensitive areas be
set aside for com-
plete exclusion of
humans ?
-------
mammals are largely able to avoid oil spills, though losses of fish and seal
pups have been documented during oil spills. Fish eggs, larvae, and juve-
niles are more susceptible to the effects of oil spills than adults. Marine
organisms may not escape toxic substances as easily if the substances become
dissolved. Mortality among the plankton undoubtedly occurs during spills,
but it is very difficult to measure. Also, plankton communities have the
capacity to recover very quickly.
Open water habitats (e.g., western Strait of Juan de Fuca) where huge
numbers of marine birds feed and roost would be especially sensitive.
Protected mudflats, eelgrass beds, and bays (e.g., Dungeness Bay, Jamestown,
Fadilla Bay) would also be sensitive because of the density of marine birds
and benthos in those habitats and the possible long-term effects of spilled
substances there. Spilled substances such as crude oil would become trapped
in protected habitats and little physical energy would be available to
facilitate the weathering and/or transport out of the area.
Spilled substances could cause direct mortality to birds coming in
contact with the substance; mortality to benthos due to smothering or
toxicity; loss of larvae, chicks, juveniles, or other offspring due to
toxicity; inhibition of benthos recruitment due to loss of larvae or
unsuitability of the substrate; and tainting of marine biota used as food by
predators and man. These impacts could, in turn, lead to decreased bird
populations; changes in benthos community composition, productivity and
biomass; changes in food web structures; decreases in commercial bivalve
stocks; and decreased (temporarily) marketability of seafood species.
VI. C. 2. Petroleum refining, transshipment and utilization. Chronic
effects of low-level inputs of petroleum hydrocarbons from refineries,
transshipment facilities, and spills and leaks from a wide variety of other
sources can occur among the benthos, fish, and birds. The magnitude of
effects would be greatest in habitats where dilution, through weathering
and/or transport, would be minimal, i.e., in protected bays, mudflats,
eelgrass beds, and marshes (e.g., Padilla and Dungeness Bays).
Low-level inputs of petroleum hydrocarbons would have little biological
impact if the resulting environmental loads were small. That is, if inputs
were dilute, small in volume, or rapidly dispersed, impacts may be minimal.
However, if repeated or continual inputs occurred and dilution was minimal,
sublethal effects may occur as well as death among some species.
The larval and other young stages of benthos and fish are especially
sensitive to low levels of petroleum hydrocarbons. Depending upon the
hydrocarbon concentration, death or a variety of behavioral, physiological,
or histological changes may occur among the adults or young. Seabirds
(especially diving species) may be lost due to direct toxicity and
oil-fouling in highly-concentrated oil slicks. These impacts could, in turn,
lead to changes in community composition, standing stock, and density of
benthos and fish; decreased reproductive success; decreased abilities to
compete for food, space, mates, and to avoid predators and disease; and
altered seabird communities. Marine mammals may be affected by disturbance
during cleanup operations.
157
-------
VI. C. 3. Habitat modifications. A wide variety of activities in the marine
environment result in removal, modification, or substitution of the habi-
tat (s) that certain organisms depend upon. Since these activities are mostly
restricted to nearshore and shoreline areas, the habitats therein are most
often affected.
Infaunal benthie animals are highly sensitive to burial and removal or
substitution of substrate. Many have limited vertical burrowing capabilities
if buried, all are removed if the substrate they are associated with is
removed, and all have low tolerance of substrate substitution. Pacific
herring and other organisms spawn among eelgrass or other vegetation and,
therefore, are sensitive to removal of either the vegetation itself or the
substrate they reside in. Marine birds and mammals are sensitive to distur-
bance, loss of feeding habitat (e.g., Black Brant and eelgrass) and loss of
nesting, roosting, or hauling-out sites.
Impacts commonly associated with habitat loss include: changes in
community composition and/or wholesale loss of benthos; changes in nearshore
or littoral circulation as a result of changes in beach morphology;
disturbance and emigration of birds and mammals; burial or removal of biota
or their nests, eggs, or burrows; removal or modification of habitats at
roosting, resting, and haul-out sites; and possible release of sediment-bound
toxicants. These impacts could, in turn, result in decreased biomass,
density, and productivity of benthos; changed benthic community composition
and prey availability; decreased bird and mammal populations and reproductive
rates; and alterations in current patterns and water quality.
Habitat modification may be mitigated, in part, by creation of new
habitats (e.g., floats, pilings, rip-rap) for marine organisms. However,
species assemblages may differ considerably from those of the original
substrate type.
VI. C. 4. Upland modification. Upland construction activities and other
actions that affect soil management can have both discrete and subtle effects
on marine biota many kilometers away. These effects invariably involve an
intermediary stream; thus, they are most likely to affect an estuary receiv-
ing such a stream. The plankton, benthos, and fish larvae living in
estuaries and,bays are most sensitive.
Potential impacts are induced by excessive runoff of nutrients,
suspended solids, and/or pesticides, and subsequent transport of these
materials to the marine system via streams. Excessive nutrient inputs can
cause rapid plankton blooms and eutrophication, possibly leading to an anoxic
condition that affects all biota. Inputs of pesticides can cause death or
sublethal effects among the plankton, benthos, and mammals. Since most
pesticides are very long-lived, they can be transmitted from prey to predator
causing excessive levels in the tissues of birds and mammals, leading, at
high levels, to decreased ability to survive and reproduce. Inputs of
suspended particles can decrease primary productivity due to shading of
plants; can clog feeding and respiratory organs of plankton, benthic inverte-
brates, and fish; and can bury or smother benthic organisms.
150
-------
Generally, the repercussions of these impacts include decreased biomass,
productivity, density, and diversity of biological communities. Impacts
resulting from pesticide inputs could be long-term due to the stability of
pesticide compounds, whereas those of nutrient or suspended solid inputs
would stop shortly after the sources were cut off.
VI. C. 5. Forest products. A wide variety of environmental problems
associated with the forest products industry, besides those attributed to
logging operations, have been documented. Pulp and paper mill effluents are
lethal to many organisms, especially the larvae of some zoobenthos and fish.
The toxicity of many effluents has decreased in recent years, however, due to
implementation of effluent treatment practices. Log-rafting results in the
release of toxic lignins and tanins into the water. Mill effluents and log
leachates cause greatest problems in confined areas where dilution is mini-
mal; thus, bays and estuaries with poor water exchange are most sensitive.
Also, the young of many species of fish and bivalves are reared in bays and
estuaries.
Log-rafting can also cause severe scouring or abrasion of surrounding or
underlying benthos (discussed above) as the rafts shift back and forth in
response to he tides, winds, currents, and handling. Chips and debris
resulting from sawmill operations and log-rafting often sink and can smother
the underlying benthos, cause anoxia during decomposition, and release
lignins and tanins.
The repercussions of these impacts can, in turn, include decreased
density of benthos and fish populations, including totally abiotic sediments;
decreased benthos biomass; and water quality-related physiologic stresses and
mortality. In the case of mill effluents and log leachates, recovery would
be expected to be relatively quick following a cutoff of the source(s),
assuming toxic materials had not accumulated appreciably on the bottom.
Recovery of benthos in areas impacted with chips and debris would be
relatively slow, since suitable substrate and near-bottom water quality
conditions would not be available until the chips and debris were either
removed or decomposed.
VI. C. 6. Domestic wastes. Municipal sewage, urban (street) runoff, septic
drain fields, and nonpoint source wastes involve environmental problems as a
result of excessive nurtrients, suspended solids, freshwater, toxic sub-
stances, and pathogenic bacteria inputs. These problems are related to
magnitude and concentration; thus, poorly flushed bays or other relatively
confined areas with poor exchange are likely to be the most sensitive.
Nutrient inputs can cause rapid plankton blooms which can lead to
eutrophication and anoxia. Low oxygen levels would affect all biota.
Depressed salinity and increased suspended solids can lead to death,
decreased primary productivity, and emigration of sensitive species among the
plankton, benthos, and fish. Both factors can also cause alterations of
certain physiologic processes, such as osmoregulation and respiration. Toxic
substances such as metals, aromatics, and chlorinated hydrocarbons can cause
a wide variety of concentration-dependent problems, including death,
pathologic diseases, behavioral changes, and interruption of physiologic
159
-------
processes among plankton, benthos, and fish. Pathogenic bacteria and toxic
substances may make certain seafoods unmarketable.
The results of these impacts may include: changes in density, biomass,
and community composition of plankton, benthos, and fish; decreased primary
productivity; long-term subtle physiologic, behavioral, and pathologic
effects, possibly causing decreased ability to compete for available
resources and to reproduce; altered food webs; and loss of revenue from
contaminated seafoods. Nutrient inputs from domestic effluents may serve as
a boon to overall productivity in nutrient-limited systems; but community
changes due to competitive exclusion and toxicity of toxic substances may
also occur.
VI. C. 7. Commercial and sports fisheries. To many people these activities
may not seem to constitute a perturbation. Usually a thriving fishery is
indicative of good water quality and a healthy ecosystem. However, a variety
of stresses are indeed imposed upon some biota as a result of these
activities, not the least of which is excessive selective removal of the
target species. The sensitive biota (Table 11) are those which are sought
and those incidentally killed or injured. The sensitive habitats are those
in which the fishery is usually harvested.
The biological effects of fisheries activities vary greatly with the
type of gear used and the target species. The most obvious impact is
selective removal of large numbers of the target species, a decrease in
density that otherwise would not occur. Direct effects often occur to
predators, many of which are target species of commercial fisheries. If the
target species is an important prey species, as in the case of herring and
shrimp, prey resources for predators would be decreased. Another impact is
death or injury of incidentally-caught nontarget fish and shellfish and
entanglement and drowning of diving birds and marine mammals. Entanglement
and drowning of some birds, such as Western Grebes, may increase if all
fishery seasons are extended into winter. Loss or disruption of bottom
sediments and epifauna by dragging (trawling) and hydraulic equipment can
occur. Hydraulic and hand equipment for digging in the bottom disrupts
sediments, especially in shallow muddy habitats. Disturbance of marine birds
and mammals by passing boats and equipment can cause these animals to flee.
Removal of prey and/or predator species can result in changes in
prey-predator relationships, food web structures, community changes, and
decreased standing stock of target and nontarget species. Decreased benthos
species richness would result from disturbance or removal of substrate.
Emigration of species sensitive to disturbance would occur if the disturbance
was continuous or repeated often, though many may return quickly after the
disturbance is discontinued.
VI. C. 8. Mariculture. This is a relative new industry in the Puget Sound
area and little is known of the effects of mariculture operations upon the
surrounding environment. However, at least three problem areas are apparent:
fecal waste inputs from the population being cultured, attraction of some
birds and disturbance of others, and alteration of nutrient levels.
160
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Fecal waste inputs, which could be sizable and poorly dispersed in
protected bays or inlets, could be expected to impact nearby, or, in the case
of suspended or floating racks or pens, underlying benthos. Modification of
the substrate, increased B.O.D., burial, and smothering of organisms due to
sedimentation of feces and excess .food may occur. The operational equipment
may attract some birds, especially fish-eating species, gulls and crows, and
disturb others. Decomposition of animal wastes and excess food may increase
nutrient levels, while photosynthesis of cultured algae populations may strip
the surrounding water of nutrients.
Overall, changes in benthos, bird, and plankton communities may be
expected. In a worst-case situation, bottom sediments may become abiotic
directly underneath a floating or suspended animal culturing operation.
VI. C. 9. Recreation, educational activities, scientific collection. As
with fisheries (above) these activities are not often considered to be
harmful to the marine environment. In most cases they are not. But when
performed often, or by many people, they can cause severe problems, including
death or disturbance of biota.
Two widely differing impacts are possible. The first, removal, trampling
and death of epibenthos, is often restricted to rock and cobble habitats.
These impacts result from vandalism, running or walking on rocks, and recrea-
tional or scientific collection of intertidal biota. Collection of inter-
tidal biota is restricted in those areas designated as marine preserves.
The second, disturbance, occurs as a result of boating and aviation in
areas, especially bays, where marine birds congregate; boating in areas near
where marine mammals haul out (e.g., isolated rocks, islets, and sand spits);
and beachcombing, horseback riding, motorcycle riding, etc. on beaches where
nesting, roosting, pupping, or rearing activities of birds and mammals occur.
Unintentional disturbance of bird nesting colonies has been known to result
in crows taking eggs from unattended nests. Scuba diving and snorkeling near
colonies, roosts, and haul-out sites, along with sport fishing from boats in
adjacent kelp beds, may keep birds off nests and under stress for extended
periods. As a result, chilled eggs, young stressed by heat or cold, or
predation on eggs or young may occur. Disturbance of foraging cetaceans by
recreational boaters can potentially disrupt feeding patterns or interfere
with mother/calf relationships.
Changes in epibenthos community structure would occur in areas severely
or repeatedly impacted. Decreased bird and mammal population sizes would
occur if adults emigrated to other areas or reproductive success was
impaired. Also if these population sizes decreased, prey communities may
change due to lack of predator pressure.
VI. C. 10. Miscellaneous. Biological impacts could potentially arise from
other human activities in the area. These impacts would vary in magnitude
and type according to the activity.
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Atmospheric fallout of radioisotopes, fly ash, soot, or acid rain are
possible, especially from major industrial activities within or adjacent to
the study area. Acid rain is known to cause pH problems in the northeastern
United States lakes that lead to diminished fish populations there. Atmos-
pheric fallout is not controllable, though source emissions are.
Maritime traffic (nonspill related) can cause bird and mammal
disturbance in open water and the habitat modification problems described
above can result from the construction of port facilities. Oiling of birds
by bilge wastes can occur.
Dissolved and particulate aluminum refinery effluents may decrease
receiving-water quality and smother benthos adjacent to the plants. Overall,
biological effects may be difficult to measure. Power plant effluents may
affect the receiving-water by increasing water temperature, killing plankton
and fish due to entrainment and impingement and inputs of biocides such as
chlorine. Changes in community structure and density, reproductive success,
metabolic rates, and feeding activity may occur.
Toxic chemicals such as metals, petroleum hydrocarbons, and synthetic
chlorinated hydrocarbons may cause biological impacts. These chemicals can
reach the biota either through historical or on-going inputs. They can cause
a wide variety of histopathological diseases, similar to those found nearby
in the waterways near Seattle and Tacoma; changes in benthos communities;
death among plankton and bivalve larvae; and decreased reproductive success
among birds. Elevated levels of toxic chemicals have been found in sediments
collected in Bellingham Bay, Port Angeles harbor, and southern Strait of
Georgia.
Although no large urban areas exist in the study area, the potential
exists for low level chronic stress on water quality there by influxes of
pollutants from adjacent areas. Transport of pollutants from the Fraser
River/southern Strait of Georgia system and from the main basin of Puget
Sound pose the greatest potential threats. Mixing of water masses carrying
chlorinated organics, petroleum hydrocarbons, and trace metals is possible.
VI. D. Potential for cumulative and long-term subtle effects
The perturbation types and associated effects discussed above do not
occur singly or in a vacuum. Antagonistic or synergistic effects can occur
where two or more perturbations have opposite or additive influences,
respectively. In the case of oil spills, an antagonistic perturbation may be
a high-nutrient, high-temperature effluent that results in increased
microbial decomposition of the spilled oil in an area where decomposition
normally is limited by nutrients and temperature. Oil spills may cause
greater effects in areas receiving continual low-level hydrocarbon discharges
than in areas without these additional inputs.
Biological stresses such as molting, along with physical factors such as
weather or freezing, can create synergistic situations among biological
communities. Cumulative effects may result from repeated stresses that,
individually, have little or no effect.
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Visibly dramatic effects, such as a massive fish or bird mortality, from
acutely toxic perturbations, usually are ephemeral in nature. Biologic
systems have evolved to quickly mediate such short-lived insults, even though
they may be extensive in scope. Rapid dispersal, dilution, and biodegrada-
tion of toxicants; recruitment and recolonization by organisms from adjacent,
healthy habitats; and increased population growth of residual organisms will
act to facilitate the recovery of the endemic community. Sublethal or
chronic perturbations which persistently impact a habitat, on the other hand,
have the potential to cause significant changes in the structure and
productivity of the community. The fact that these subtle insults usually go
undetected or take a long time to manifest themselves as an identifiable
problem, attributable to a known perturbation, implies that the long-term
effects are potentially the more deleterious and the recovery of the
community more prolonged. Chronic perturbations in the form of pollutants
can be the result of either continuous introductions of low-level concentra-
tions or the entrapment of a large concentration of pollutant and subsequent
leeching of toxic components from that source.
The potential mechanisms of damage to the community are diverse and
their effects vary according to habitat type (Malins, 1977; Simenstad et al.,
1979). The productivity of the community can be depressed through direct
alteration of growth, metabolism, and reproduction of either producer or
consumer organisms and indirectly through the removal of habitat. The latter
affects primary producers the most, where the reduction of nutrients, light,
or the availability of substrate (in the case of attached plants) can reduce
the amount or rate of carbon fixed. Communities in all habitats are vulner-
able to such effects but those of contained embayments, where restricted
water circulation and fine sediments tend to accumulate pollutants, would
appear to be particularly susceptible. Phytoplankton productivity in the
bays and associated with water over nearshore mud, nearshore mud-sand, and
nearshore mud-gravel habitats and the production of eelgrass in the
intertidal/subtidal mud, mud-sand, and mud-gravel habitats would be most
susceptible to sublethal disruption of water-borne pollutants (especially
oil), as would the associated neritic and epibenthic zooplankton communities
in these habitats.
Changes in food resources, although often involving only qualitative
shifts in community structure, can result in subsequent changes in
populations of consumer organisms. In general, most consumers are adapted to
exploit a restricted portion of the prey community available to them, thus
minimizing the deleterious effects of competition with other organisms and
their vulnerability to predation. Selective reduction of the principal prey
of dominant consumer organisms will thus force the consumers to switch to
"less than optimum" prey and, at a minimum, result in. lower total production
or, at an extreme, cause the exclusion of the species. Neritic and
epibenthic zooplankton-eating fishes, especially larvae and juveniles, would
appear to be extremely sensitive to such a perturbation. These fishes
include juvenile Pacific salmon, herring, and sand lance in nearshore and
offshore habitats. And, consequently, the production of young by Rhinoceros
Auklets, which feed extensively upon these fishes in those habitats adjacent
to Protection Island during nesting season, may also be limited by their
dependence upon this unique food resource.
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Selective effects upon particular components of the community may be
even more far-reaching, as in the case of keystone species. These dominants,
by their selective predation on competitively dominant species at lower
trophic levels or by their own competitive dominance, fill key roles in
structuring the character of the nearshore community. Significant reduction
of such species or inhibition of their predator or competitor functions will
likely drive the community toward a new, different structure which, in
itself, may become ecologically stable. Two habitats would be most
susceptible to such an alteration. The subtidal rock habitat supports
several predacious starfish (Pisaster ochraceus, Leptasterias hexactis,
Pycnopodia helianthoides) and herbivorous sea urchins (Strongylocentrotus
spp.) which constitute keystone species in their maintenance of the community
structure as we know it. Most of these species (at least the nonbrooding
species) are also known to have very intermittent and often low recruitment
such that significant reduction in their abundance or in their reproductive
potential would probably result in a sustained modification of the nearshore
community structure for years or decades. If an impact occurs to the star-
fish only, the sea urchin population may proliferate. Then the production of
macrophytic algae could be reduced dramatically by increased grazing. Also,
a probable secondary consequence may include reduced detritus input to food
webs in the region. In the intertidal/subtidal mud and mud-gravel habitats
predatory gastropods and large infaunal bivalves play similar roles and,
coincidentally, also have low rates of recruitment.
The actual physiological and pathological condition of individual
organisms can also be directly affected by perturbations involving a subtle
decrease in water quality. Increased vulnerability to histopathological
diseases, if not resulting in direct mortality, can increase the suscepti-
bility of the diseased organism to predation or reduce their competitive
advantage such that the population can be measurably affected. Some
pollutants have been implicated as mutagenic agents and, as such, could be
responsible for adverse changes in physiological or morphological character-
istics of future generations or ovigerous organisms influenced by the pollu-
tant. Agents which have been implicated in these effects include chlorinated
hydrocarbons (pesticides), heavy metals, polychlorinated biphenyls, and
aromatic hydrocarbons. Sensitive habitats have included soft-sediment
subtidal regions adjacent to heavy industrial and agricultural runoff. In
the case of the northern Puget Sound-Strait of Juan de Fuca region, epiben-
thic and benthic communities of subtidal protected mud habitats are the most
likely to face such an insult, especially those associated with contained
embayments with low flushing and turnover rates of the water mass within.
Harbors and marinas would be additionally sensitive.
In examining the overall susceptibility of the various habitats in the
region to extended sublethal effects, it is apparent that the soft sediment
habitats are the most vulnerable. They have a tendency to entrain pollutants
within the sediments, often preserving their toxic effects until they are
released at a later date. They can be released either physically (through
erosion) or biologically (via burrowing infauna) and thus made available to
incorporation into the food web. The fact that these habitats tend to be the
most productive in the region and are almost completely based upon the
decomposition of detritus makes them even more susceptible to alteration. As
164
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mentioned previously, the sorption of pollutants upon detrital particles may
constitute one of the most important pathways by which a pollutant may be
transported through food web linkages, potentially causing subtle but long-
term effects upon the organisms at each trophic level.
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VII. DATA EVALUATION, DATA GAPS, RECOMMENDATIONS
VII. A. Evaluation of the MESA/WDOE Data Set
In compiling this synthesis, we have probably tended to overemphasize
the data gaps and unanswered questions resulting from our interpretation of
the voluminous baseline study data. This tendency, however, is the logical
result of both scientific hindsight and the problem of addressing a^
posteriori questions about ecological processes based upon a purely descrip-
tive data base. We believe the basic knowledge gathered during these two
studies is important, for we would not be in the position of projecting the
various processes and impacts discussed above in Chapters V and VI if we had
only the meager, fragmented data on nearshore communities which existed prior
to 1974.
The list of advances achieved during the biological studies is too
lengthy to enumerate in full, but the major accomplishments unique to the
.state of the science in this region should be noted:
1. The first systematic documentation of community (taxonomic)
structure, density, and standing crop in representative (parallel)
intertidal/subtidal and nearshore habitats for a broad spectrum of
the communities, from macroalgae to marine mammals;
2. Characterization of plankton, birds, and mammals in offshore (deep)
waters;
3. Quantitative documentation of seasonal and annual variations in
species abundance and community parameters;
4. A synthesis of trophic structure and prey-predator interactions
among the major organisms on a habitat basis;
5. Distributional and taxonomic clarification or extension of many
groups, especially the crustaceans;
6. Baseline levels of petroleum hydrocarbons that organisms in the
nearshore habitats are now exposed to relative to existing
(potential) sources of chronic release and to locations beyond the
influence of any known sources;
7. The first controlled oil spill experiments on in situ intertidal/
shallow subtidal communities in the region and quantitative
documentation of the community response and recovery rates;
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8. Synthesis of available data collected on biota of the region;
9. The processes and controlling factors of oil degradation by
microorganisms;
10. Identification of relationships between the physical processes that
could disperse and transport oil spills and the important biologi-
cal populations and communities that may be adversely affected;
11. Statistical analyses of baseline data and estimates, based upon the
results of these analyses, of the utility of the data in predicting
or assessing damage caused by a major perturbation such as an oil
spill;
12. Development of a shoreline oil-sensitivity index for habitats of
the region and mapping of the extent of these habitats.
Additional work involving oceanographic processes are summarized in Cannon
(1978) and Holbrook et al. (1980).
While some elements of the biological research had been described for
northern Puget Sound, especially in the region of the University of
Washington's Friday Harbor Laboratories on San Juan Island, essentially
nothing was known about the nearshore or offshore communities and habitats
along most of the Strait of Juan de Fuca. This was completely virgin
territory for the intertidal ecologist as well as the fisheries biologist and
marine mammalogist.
VII. B. Data Gaps
Despite the extensive regional data base developed in the past five or
six years and described above, both topical and geographic data gaps exist.
Only the macrobenthos ( >1 mm) were sampled, except in the case of epibenthic
zooplankton. No quantitative data exists for the meio- or microfauna or the
microflora. Very little quantitative data exist for deep offshore benthos,
so it was omitted entirely in this repott. Except for the one-time collec-
tion of epibenthic zooplankton, no nearshore or intertidal/shallow subtidal
plankton (including ichthyoplankton) data have been collected. No quantita-
tive offshore fish sampling was done. Offshore fish information given in
this report is, therefore, largely qualitative. No research was performed
expressly to learn the ecological relationships of most communities; popula-
tion counts were emphasized. Marine mammal studies emphasized easily
observed pinniped populations; abundance and distribution of cetaceans were
poorly documented. No data were collected for the saltmarsh habitat. Little
work was done on subtidal rocky-reef kelp bed fishes.
Perhaps the most significant topical data gap is production or rate
information. Studies in the region on benthic primary production, general
secondary and tertiary production, and bacterial and fungal degradation are
almost totally lacking. The data accumulated to date addresses only standing
stock, not the rate of energy flow through the biological system.
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Geographic gaps were implied in the introduction. The boundaries of
this report were artificial and did not necessarily follow the natural
boundaries of any system. The northern boundary of the study was the
Canadian border, not the natural northern boundary of this system. Little
work was performed in the southern Strait of Georgia, particularly in the
Canadian portions. The western boundary was Cape Flattery, thus omitting the
outer coast. The west side of Whidbey Island was part of the eastern
boundary thus leaving out the Saratoga Passage/Skagit Bay area. The southern
boundary was Admiralty Inlet omitting all of Puget Sound proper and Hood
Canal. Relatively few intertidal benthos and nearshore fish data were
collected in the interior of the San Juan Islands compared to other regions
within the study area.
VII. C. Recommendations for Further Research
Data needed to more fully understand the biology of the area include:
- productivity estimates and population characteristics of dominant
species;
- statistically-derived sampling designs for benthos;
- distribution and abundance of those biota not yet surveyed -
cetaceans, nearshore plankton, rocky-reef fishes, meiofauna;
- comprehensive survey data for nearby areas not yet studied - Puget
Sound, Hood Canal, areas east of Whidbey Island, outer coast,
adjacent Canadian waters;
- energetics of intertidal/subtidal communities and relative roles of
phytoplankton, attached plants, and benthic diatoms in productiv-
ity;
- relative importance of intertidal/subtidal habitats in reproduction
and rearing of young animals;
- recruitment dynamics of intertidal communities;
- functional relationships between prey and predators;
- systematic monitoring of benthos, marine mammals, and birds at
selected protected areas;
- reliability of and variability in marine bird and mammal census
data;
- quantification of prey uptake by marine birds, fish, and mammals;
- rates of interactions of birds and mammals with fisheries;
- further definition of the relative abundance of epibenthic
zooplankton at major habitat types;
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method for rapidly assessing harbor seal populations in the event
of an oil spill; and
relative importance of roosting/nesting sites and hauling-out sites
for birds and mammals, respectively, and movements of animals to
and from these sites.
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REFERENCES
Abbot, I. and G. Hollenberg. 1976. Marine Algae of California. Stanford
University Press, Stanford, California. 825 pp.
Balcomb, K. C., J. R. Boren, R. W. Osborne, and N. J. Haenel. 1979.
Observations of killer whales (Orcinus orca) in Greater Puget Sound,
State of Washington. A report of field research conducted by the
Moclips Cetalogical Society, Inc. April 1, 1976 through December 31,
1979. 27 pp. and 17 plates.
Barraclough, W. E. and J. D. Fulton. 1968. Data record: Food of larval and
juvenile fish caught with a surface trawl in Saanich Inlet during June
and July 1966. Fish. Res. Bd. Canada, MS Rept. Ser. 1003, Pac. Ocean.
Group, Nanaimo, B.C. 78 pp.
Barraclough, W. E., D. G. Robinson, and J. D. Fulton. 1968. Data record:
Number, size, composition, weight, and food of larval and juvenile fish
caught with a two-boat surface trawl in Saanich Inlet, April 23-July 21,
1968. Fish. Res. Bd. Canada, MS Rept. Ser. 1004, Pac. Ocean. Group,
Nanaimo, B.C. 305 pp.
Barraclough, W. E. and J. D. Fulton. 1967. Data record: Number, size,
composition, and food of larval and juvenile fish caught with a two-boat
surface trawl in the Strait of Georgia, July 4-8, 1966. Fish. Res. Bd.
Canada, MS Rept. Ser. 940, Pac. Ocean. Group, 'Nanaimo, B.C. 82 pp.
Barraclough, W. E. 1967a. Data record: Number, size, and food of larval
and juvenile fish caught with an Isaacs-Kidd trawl in the surface waters
of the Strait of Georgia, April 25-29, 1966. Fish. Res. Bd. Canada, MS
Rept. Ser, 926, Pac. Ocean. Group, Nanaimo, B.C. 79 pp.
Barraclough, W. E. 1967b. Data record: Size, composition, and food of
larval and juvenile fish caught with a two boat surface trawl in the
Strait of Georgia, June 6-8, 1966. Fish. Res. Bd. Canada, MS Rept.
Ser. 928, Pac. Ocean. Group, Nanaimo, B.C. 58 pp.
Bowman, M. J. and W. E. Esaias (Eds.). 1978. Ocean fronts in coastal
processes. Proc. Workshop, Mar. Sci. Res. Center, State Univ. of New
York, Stony Brook, N.Y., May 25-27, 1977. Springer-Verlag, Berlin.
114 pp.
Brown, T. J. and J. R. Sibert. 1977. The food of some benthic harpacticoid
copepods. J. Fish. Res. Bd. Canada. 34:1028-1031.
170
-------
Brown, D. W. and others. 1979. Investigation of petroleum in the marine
environs of the Strait of Juan de Fuca and northern Puget Sound. U.S.
Dept. Comm./EPA Interagency Energy/Environment R&D Program Rept.
No. EPA-600/7-79-164. 107 pp.
Brown, R. F. 1980. Abundance, movements, and feeding habits of the harbor
seal (Phoca vitulina) at Netarts Bay, Oregon. M.S. Thesis, Oregon State
Univ., Corvallis, Oreg. 69 pp.
Cannon, G. A. (Ed.). 1978. Circulation in the Strait of Juan de Fuca. Some
recent oceanographic observations. U.S. Dept. Comm. NOAA Tech. Rept.
ERL 399-PMEL 29. Pac. Mar. Environ. Lab., Seattle, Wash. June 1978.
49 pp.
Chester, A. J., D. M. Damkaer, D. B. Dey, G. A. Heron, and J. D. Larrance.
1980. Plankton of the Strait of Juan de Fuca, 1976-1977. U.S Dept.
Comm./EPA Interagency Energy/Environment R&D Program Rept.
No. EPA-600/7-80-032. 64 pp.
Chester, A. J. 1978. Microzooplankton in the surface waters of the Strait
of Juan de Fuca. NOAA Tech. Rept. ERL 403-PMEL 30, Pac. Mar. Environ.
Lab., Seattle, Wash. 26 pp.
Chester, A. J. , D. M. Damkaer, D. B. Dey, and J. D. Larrance. 1977.
Seasonsl distribuitons of plankton in the Strait of Juan de Fuca. NOAA
Tech. Memo. ERL MESA-24, MESA Prog., Environ. Res. Lab., Boulder, Colo.
71 pp.
Clark, R. C. Jr., J. S. Finley, B. G. Patten, and E. E. DeNike. 1975.
Long-term chemical and biological effects of a persistent oil spill
following the grounding of the General M.C. Meigs. In: Proc. 1975
Conf. on Prevention and Control of Oil Pollution. API/USCG/EPA,
San Francisco, Calif. March 25-27, 1975.
Cross, J. N., K. L. Fresh, B. S. Miller, C. A. Simenstad, S. N. Steinfort,
and J. C. Fegley. 1978. Nearshore fish and macroinvertebrate
assemblages along the Strait of Juan de Fuca including food habits of
the common nearshore fish. NOAA Tech, Memo. ERL MESA-32, MESA Prog.,
Environ. Res. Lab., Boulder, Colo. 188 pp.
Gushing, D. H. 1970. Introduction to Part II. Pelagic Food Chains,
pp. 69-73. In: J. H. Steele (Ed.), Marine Food Chains. Univ. of
Calif. Press, Berkeley. 552 pp.
Dayton, P. 1971. Competition, disturbance, and community organization: the
provision and subsequent allocation of space in a rocky intertidal
community. Ecol. Monogr. 41(4):351-389.
Eagle, R. A. 1975. Natural fluctuations in a soft bottom benthic community.
J. Mar, Blol. Ass. U.K. 55:865-878.
171
-------
Ebbesmeyer, C. C., J. M. Cox, J. M. Helseth, L. R. Hinchley, and D. W.
Thompson. 1979. Dynamics of Port Angeles harbor and approaches,
Washington. U.S. Dept. Comm./EPA Interagency Energy/Environ. R&D
Program Rept. No, EPA-600/7-79-252. Dec. 1979. 107 pp.
Ekman, S. 1953. Zoogeography of the Sea. Sidgwick and Jackson, Ltd.
London. 485 pp.
Everitt, R., R. Beach, A. Geiger, S. Jeffries, and S. Treacy. 1981. Marine
mammal-fishery interactions on the Columbia River and adjacent waters,
1980. Washington Game Dept. Rept., Olympia, Wash. 109 pp.
Everitt, R. D., C. H. Fiscus, and R. L. DeLong. 1979. Marine mammals of
northern Puget Sound and the Strait of Juan de Fuca - a report on
investigations November 1, 1977-October 31, 1978. NOAA Tech. Memo. ERL
MESA-41, MESA Prog., Environ. Res. Lab., Boulder, Colo. 191 pp.
Everitt, R. D., C. H. Fiscus, and R. L. DeLong. 1980. Northern Puget Sound
marine mammals. U.S. Dept. Comm./EPA Interagency Energy/Environ. R&D
Prog. Rept. EPA 600/7-80-139. July 1980. 134 pp.
Federal Water Pollution Control Administration. 1967. Pollutional effects
of pulp and paper mill wastes in Puget Sound. March 1967. U.S. Dept.
Interior, FWPCA, Portland, Oreg. 474 pp.
Gardner, F. 1978. North Puget Sound baseline program, 1974-1977.
Washington Dept. of Ecology Rept., Olympia, Wash., June 1978.
Goldberg, E. D. (Ed.). 1979. Proceedings of a workshop on assimilative
capacity of U.S. coastal waters for pollutants, Crystal Mountain, Wash.,
July 29-Aug. 4, 1979. U.S./NOAA, Environ. Res. Lab., Boulder, Colo.
284 pp.
Hardy, A. C. 1924. The herring in relation to its animate environment.
I. The food and feeding habits of the herring with special reference to
the East Coast of England. Fish. Invest., Univ. of Calif. Press,
Berkeley, Calif. 552 pp.
Hart, J. L. 1973. Pacific fishes of Canada. Fish. Res. Bd. Canada Bull.
180. Ottawa. 740 pp.
Hedgpeth, J. W. 1957. Marine Biogeography. In: Treatist on Marine Ecology
and Paleoecology, vol. 1, Marine Ecology, J. W. Hedpeth (Ed.), Mem.
Geol. Soc. Amer. No. 67:359-382.
Herlinveaux, R. H. and J. P. Tully. 1961. Some oceanographic features of
Juan de Fuca Strait. J. Fish. Rss. Bd. Canada 18:1027-1071.
172
-------
Holbrook, J. R., R. D. Muench, D. G. Kachel, and C. Wright. 1980.
Circulation in the Strait of Juan de Fuca: Recent oceanographic
observations in the eastern basin. U.S. Dept. Com./NOAA Tech. Rept. ERL
412-PMEL 33. April 1980.
Holbrook, J. R. and D. Halpern. 1977. Observations of near-surface
currents, winds, and temperature in the Strait of Juan de Fuca during
November 1976-February 1977. Trans. Ainer. Geophys. Union. 53:1158.
Isaacs, J. D. 1972. Unstructured marine food webs and "pollutant
analogues." Fish. Bull. 70(3):1053-1059.
Isaacs, J. D. 1973. Potential trophic biomasses and trace-substance
concentrations in unstructured marine food webs. Mar. Biol. 22:97-104.
Kimura, D. K. and A. R. Millican. 1977. Assessment of the population of
Pacific hake (Merluccius productus) in Puget Sound, Washington.
Washington Dept. of Fisheries Tech. Rept. pp. 35-46.
Kikuchi, T. and J. M. Peres. 1977. Consumer ecology of seagrass beds. In:
Seagrass Ecosystems: A Scientific Perspective. C. P. McRoy and C.
Herfferich (Eds.). Marcel Dekker, New York. Vol. 5, pp. 147-193.
Lemberg, N. A. 1978. Hydroacoustic assessment of Puget Sound herring,
1972-1978. Washington Dept. of Fisheries Tech. Rept. pp. 41, 43.
Long, E. R. 1980. Physical processes and critical biological areas in the
vicinity of a proposed petroleum transfer facility. Conf. Rec. Oceans
'80, Seattle, Wash., Sept. 8-10, 1980. In: IEEE Pub. No. 80CH1572-7.
Inst. of Electrical and Electronic Engineers, New York. pp. 489-497.
Lubchenko, J. and B. Menge. 1978. Community development and persistence in
a low rocky intertidal zone. Ecol. Monogr. 59:67-94.
Mackas, D. L., G. C. Louttit, and M. J. Austin. 1980. Spatial distribution
of zooplankton and phytoplankton in British Columbian coastal waters.
Can. J. Fish. Aquat. Sci. 37(10):1476-1487.
Malins, D. C. (Ed.). 1977. Effects of petroleum on Arctic and Subarctic
marine environments and organisms. Acad. Press. 2 vols.
Mann, K. H. 1972a. Ecological energetics of the seaweed zone in a marine
bay on the Atlantic coast of Canada. I. Zonation and biomass of
seaweeds. Mar, Biol. 12:1-10.
Mann, K. H. 1972b. Ecological energetics of the seaweed zone in a marine
bay on the Atlantic coast of Canada. II, Productivity of the seaweeds.
Mar. Biol. 14:199-209.
173
-------
Manuwal, D. A., T. R. Wahl, and S. M. Speich. 1979. The seasonal
distribution and abundance of marine bird populations in the Strait of
Juan de Fuca and northern Puget Sound in 1978. NOAA Tech. Memo ERL
MESA-44, MESA Prog., Environ. Res. Lab., Boulder, Colo. 391 pp.
McConnaughey, T. and C. P. McRoy. 1979a. Food web structure and the frac-
tionation of carbon isotopes in the Bering Sea. Mar. Biol. 53:252-262.
13
'McConnaughey, T. and C. P. McRoy. 1979b. C label identifies eelgrass
(Zostera marina) carbon in an Alaskan estuarine food web. Mar. Biol.
53:263-269.
Mclntyre, H. D. 1969. Ecology of marine meiobenthos. Biol. Rev. (camb.)
44:245-290.
McRoy, C. P. 1970. Standing stocks and other features of eelgrass (Zostera
marina) populations on the coast of Alaska. J. Fish. Res. Bd. Canada.
27:1811-1812.
Mercer, R. W., B. D. Krogman, and R. M. Sontag. 1978. Marine mammal data
documentation for the platforms of opportunity project and OCSEAP
program. NWAFC Proc. Rept., U.S. NOAA, Seattle, Wash. April 1978.
Miller, B. S. and others. 1978. Nearshore fish survey. Washington Dept. of
Ecology, Puget Sound Baseline Program. Appendix D. January 1978. .
Miller. B. S., C. A. Simenstad, J. M. Cross, K. L. Fresh, and S. N.
Steinfort, 1980, Nearshore fish and macroinvertebrate assemblages
along the Strait of Juan de Fuca including food habits of the common
nearshore fish. Dept. of Com./EPA Interagency Energy/Environment R&D
Program Report EPA-600/7-80-027. 211 pp.
National Commission on Water Quality. 1975. Puget Sound Regional Assessment
Study. Prep, by Stevens, Thompson, and Runjan, Inc. June 1975.
Appendix, Part 1.
Nyblade, C. F. 1977. North Puget Sound intertidal study (UW). Washington
Dept. of Ecology, Baseline Study Program. Appendix F. April 1, 1977.
Nyblade, C. F. 1978. The intertidal and shallow subtidal benthos of the
Strait of Juan de Fuca, spring 1976-winter 1977. NOAA Tech. Memo. ERL
MESA-26, MESA Prog., Environ. Res. Lab., Boulder, Colo. 156 pp.
Nyblade, C. F. 1979a. The Strait of Juan de Fuca intertidal and subtidal
benthos, second annual report, spring 1977-winter 1978. Dept. of
Comm./EPA Interagency Energy/Environment R&D Program Report
EPA-600/7-79-213. 129 pp.
Nyblade, C. F. 1979b. Five year intertidal community change. San Juan
Islands, 1974-1978. Washington Dept. of Ecology Baseline Study Program,
North Puget Sound. Appendix F (update). August 1979.
174
-------
Osman, R. 1978. The influence of seasonality and stability upon the species
equilibrium. Ecol. 59(2):383-399.
Paine, R. I. 1966. Food web complexity and species diversity. Am. Nat.
100(910):65-75.
Palmer, R. S. 1976. Handbook of North American Birds, Vol. 2, Waterfowl
(part 1). Yale Univ. Press, London. 519 pp.
Parsons, T. R., R. J. LeBrasseur, J. D. Fulton, and 0. D. Kennedy. 1969a.
Production studies in the Strait of Georgia. Part II. Secondary
production under the Fraser River plume, February to May 1967. J. Exp.
Mar. Biol. Ecol. 3:39-50.
Parsons, T. R. , K. Stephens, and R. J. LeBrasseur. 1969b. Production
studies in the Strait of Georgia. Part I. Primary production under the
Fraser River plume, February to May 1967. J. Exp. Mar. Biol. Ecol.
3:27-38.
Parsons, T. R., R. J. LeBrasseur, and W. E. Barraclough. 1970. Levels of
production in the pelagic environment of the Strait of Georgia, British
Columbia: A review. J. Fish. Res. Bd. Canada. 27(7):1251-1264.
Parsons, T. R., L. J. Albright, and J. Parslow. 1980. Is the Strait of
Georgia becoming more eutrophic? Can. J.. Fish. Aquat. Sci. 37(6):1048-
1054.
Pavlou, S. P., R. N. Dexter, and W. Horn. 1977. Polychlorinated biphenyls
(PCB's) in Puget Sound: Physical/chemical aspects and biological
consequences. In: The use, study, and management of Puget Sound.
Proceedings, March 23-25. Univ. of Washington, Seattle, Wash.
pp. 100-133.
Pavlou, S. P. and W. Horn. 1979. PCB removal from the Duwamish River
estuary: Implications to the management alternative for the Hudson
River PCB cleanup. In: Health effects of "halogenated aromatic
hydrocarbons. Annals of the New York Academy of Science, Vol. 320, pp.
651-671.
Petipa, T. S., E. V. Pavlova, and G. N. Midonov. 1970. The food web
structure, utilization, and transport of energy by trophic levels in the
planktonic communities. In: J. H. Steele (Ed.), Marine Food Chains,
Oliver and Boyd, Edinburgh, pp. 142-167.
Phillips, R. C. 1974. Temperate grass plots. In: H. T. Odum, B. J.
Copeland, and E. A. McMahan (Eds.), Coastal Ecological Systems of the
United States, Vol. 2. Conserv. Found., Washington, D. C. pp. 244-299.
175
-------
Pingree, R. D., M; J. Bowman, and W. E. Esaias. 1978. Headland fronts. In:
M.J. Bowman and W. E. Esaias (Eds.), Ocean Fronts in Coastal Processes.
Proc. Workshop, Mar. Sci. Center, State University of New York, Stony
Brook, N.Y., May 25-27, 1977. Springer-Verlag, Berlin, pp. 78-86.
Pitcher, K. and D. Calkins. 1979. Biology of the harbor seal (Phoca
vitulina richardii) in the Gulf of Alaska. Final Kept., RU 229. In:
Environmental Assessment of the Alaskan Shelf. Annual Reports of
Principal Investigators. U.S. Dept. Comm./NOAA, Environ. Res. Lab.,
Boulder, Colo. 72 pp.
Pizzo, J. T., T. L. Johnson, and G. W. Harshman. 1978. Washington State
refineries: Petroleum, petroleum derivatives, and wastewater effluent
characteristics. U.S. Dept. Comm./EPA Interagency Energy/Environment
R&D Program Report No. EPA-600/7-78-040. March 1978. 169 pp.
Rattray, M. Jr. 1967. Some aspects of the dynamics of circulation in
fjords. In: G. H. Lauff (Ed.), Estuaries. AAAS, Washington, D. C.
pp. 52-62.
Robinson, D. G., W. E. Barraclough, and J. D. Fulton. 1968a. Data record:
Number, size, composition, weight, and food of larval and juvenile fish
caught with a two-boat trawl in the Strait of Georgia, May 1-4, 1967.
Fish. Res. Bd. Canada. MS Rept. Ser. 964, Pacific Ocean Group, Nanaimo,
B. C. 105 pp.
Robinson, D. G., W. E. Barraclough, and J. D. Fulton. 1968b. Data record:
Number, size, composition, weight, and food of larval and juvenile fish
caught with a two-boat surface trawl in the Strait of Georgia, June 5-9,
1967. Fish. Res. Bd. Canada. MS Rept. Ser. 972, Pacific Ocean Group,
Nanaimo, B. C. 109 pp.
Robinson, D. G. 1969. Data record: Number, size, composition, weight, and
food of larval and juvenile fish caught with a two-boat surface trawl in
the Strait of Georgia, July 4-6, 1967. Fish. Res, Bd. Canada. MS Rept.
Ser. 1012, Pacific Ocean Group, Nanaimo, B. C. 71 pp.
Rugh, D. J. and H. W. Braham. 1979. California gray whale (Eschrichtius
robustus) fall migration through Unimak Pass, Alaska, 1977. A
preliminary report. Rept. Int. Whale Comm. 29:315-320.
Seki, H. 1966. Role of bacteria as food for plankton. (Review) Inform.
Bull. Planktol. Japan 13:54-62.
Simenstad, C. A., W. J. Kinney, and B. S. Miller, 1980. Epibenthic
zooplankton assemblages at selected sites along the Strait of Juan de
Fuca. NOAA Tech. Memo. ERL MESA-46, MESA Prog., Environ. Res. Lab.,
Boulder, Colo. 73 pp.
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Simenstad, C. A., B. S. Miller, J. N. Cross, K. L. Fresh, S. N. Steinfort,
and J. C. Fegley. 1977. Nearshore fish and macroinvertebrate
assemblages along the Strait of Juan de Fuca including food habits of
nearshore fish. NOAA Tech. Memo. ERL MESA-20, MESA Prog., Environ. Res.
Lab., Boulder, Colo. 144 pp.
Simenstad, C. A., B. S. Miller, C. F. Nyblade, K. Thornburgh, and L. J.
Bledsoe. 1979. Food web relationships of northern Puget Sound and the
Strait of Juan de Fuca. U.S. Dept. Comm./EPA Interagency Energy/
Environment R&D Program Report EPA-600/7-79-259. 335 pp.
Smith, G. F. and H. H. Webber. 1978. A biological sampling of intertidal
habitats of northern Puget Sound. Washington Dept. of Ecology, Baseline
Study Program, North Puget Sound, Appendix K. September 1978.
Smith, G. F. 1979. A quantitative sampling program of benthic communities
in nearshore subtidal areas within the Rosario Strait region of northern
Puget Sound, Washington State, 1976. Washington Dept. of Ecology, Oil
Baseline Program, Appendix L.
Stephens, K. 1968. Surface distribution of chlorophyll £ in the Strait of
Georgia, 1966-1967. Fish. Res. Bd. Canada. MS Rept. Ser. 971, Pacific
Ocean Group, Nanaimo, B. C. 25 pp.
Stockner, J. G., D. D. Cliff, and K.R.S. Shortbreed. 1979. Phytoplankton
ecology of the Strait of Georgia, British Columbia. J. Fish. Res. Bd.
Canada. 36:657-666.
Stockner, J. G., K. S. Shortbreed, and E. A. Maclsaac. 1980. The benevolent
strait: Reply. Can. J. Fish. & Aquat. Sci. 37(6):1048-1054.
Strickland, J.D.H. 1960. Measuring the production of marine phytoplankton.
Fish. Res. Bd. Canada., Bull. 122. 172 pp.
Summers, C. and M. Mountfield. 1975. Counting the common seal. Nat.
253:670-671.
Sverdrup, H. U., M. W. Johnson, and R. H. Fleming. 1942. The oceans: their
physics, chemistry, and general biology. Prentice-Hall, Inc., Englewood
Cliffs, N.J. 1087 pp.
U.S. Bureau of Land Management. 1979. Final environment statement. Crude
oil transportation systems. 4 volumes.
Wahl, T. R., S. M. Speich, D. M. Manuwal, K. V. Hirsch, and C. Miller. 1981.
Marine bird populations of the Strait of Juan de Fuca, Strait of Georgia
and adjacent waters in 1978 and 1979. U.S. Dept. Comm./EPA Interagency
Energy/Environment R&D Program Report EPA-600/7-81-156. 789 pp.
Waldichuk, M. 1979. Ecological impact of logs. Mar. Poll. Bull. 10(2):33-
34.
177
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Washington Department of Fisheries/Washington Department of Natural
Resources. 1978. Final environment impact statement for the commercial
harvesting of subtidal hardshell clams with a hydraulic escalator
shellfish harvester. April 1978.
Webber, H. H. 1980. Whidbey Island intertidal and shallow subtidal benthos.
U.S. Dept. Comm./EPA Interagency Energy/Environment R&D Program Report
EPA-600/7-80-167. 91 pp.
Webber, H. H. 1981. Growth rates of benthic algae and invertebrates in
Puget Sound. I. Literature Review, and II. Field studies on Laminaria
hereocystis NOAA Tech. Memo OMPA-4, Office of Marine Pollution
Assessment, Boulder, Colo. 45 pp.
Wiens, J. A., D. Heinemann, and W. Hoffman. 1978. Community structure,
distribution, and interrelationships of marine birds in the Gulf of
Alaska. OCSEAP Final Rept. RU 108, Phase I.
Winter, D. F., K. Banse, and G. C. Anderson. 1975. The dyanamics of
phytoplankton blooms in Puget Sound, a fjord in the northwestern United
States. Mar. Biol. 29:139-176.
Wolcott, T. G. 1973. Physiological ecology and intertidal zonation in
limpets (Acmaea). A critical look at limiting factors. Biol. Bull.
145:422- .
Woodin, S. A., C. F. Nyblade, F. Chia. 1972. Effect of diesel oil spill on
invertebrates. Mar. Poll. Bull. 3(9):139-143.
178
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APPENDIX I
AVAILABILITY AND ACCESSIBILITY OF DATA SETS
1. Data Formats
As new biological data are generated, they are reported in tabular
form in reports and simultaneously entered onto computer tapes. Both
the MESA and WDOE data listed in Table I-B are, or will soon be, avail-
able in report form. The reports contain narrative descriptive informa-
tion about the data, tabularized raw data, plots, and histograms. In
addition, most of these data are also available on magnetic tape, where
they were archived on standardized formats (refer to the next section on
data acquisition).
2. Data Acquisition and What to Expect
a. Reports
MESA and OMPA Technical Reports and DOC/EPA Interagency
reports found in Table I-A may be obtained from the Office of
Marine Pollution Assessment, Pacific Office, RD/MPF25, 7600 Sand
Point Way N.E., Bin C15700, Seattle, WA 98115 (206-527-6341; FTS
8-446-6341). Washington Department of Ecology (WDOE) reports are
available from Mr. Fred Gardner, State of Washington, Department of
Ecology, Olympia, WA 98504 (206-753-0577).
b. Magnetic Tapes
Most of the data identified in Table I-B are available on
magnetic tape or diskette in one of two forms: (1) data received
at the data centers that have undergone only preliminary editing
and (2) data that have been subjected to some degree of editing and
quality control and are considered final-processed. Most of the
data sets can be retrieved as a specific file type, which is
defined as a format for coding, processing, and exchanging a
specific category of ecological and environmental data. Please
refer to Table I-C for specific file type categories.
c. Tape Contents
Magnetic tape outputs can be obtained in one of two forms. The
first (that most all file types may be obtained in) is the raw data
retrieval, which consists of a format of coded information. The
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coded records contain file and station header information that
indicate the unique file type, file identifier, cruise or field
period dates, geographic location, etc. The physical or biological
records contain the coded sampling methods, taxonomy, weights,
counts, station physical parameters (water temp, sea state, tide
information), or other information pertinent to a biological
specimen's condition (external or internal). Further information
on specific file types, copies of formats for specific files,
programs for checking routines, and documentation may be obtained
by contacting the Environmental Data and Information Service, or
locally, the EDIS Pacific Northwest Liaison Office, Seattle, WA
98115 (206-527-6263; FTS 8-446-6263).
In addition, special products such as nonformatted listings or
simple formatted tables have been developed for retrieval of Marine
Birds (FT041), Marine Mammals (FT027), and the Intertidal/Shallow
Subtidal Benthos (FT100) data sets. In these outputs data listings
are arranged hierarchically and typically show the file type,
investigator (FT100), tape track, site, location, dates sampled,
sample elevation, gear type, biological name (taxonomy), counts,
weights, and possibly some simple calculations such as biomass or
abundance, or behavior as in the Marine Mammals (FT027).
Further inquiries as to data availability and how to order
tapes or listings should be made by contacting:
U.S. Dept. of Commerce/NOAA
Environmental Data and Information Service
National Oceanographic Data Center
2001 Wisconsin Ave., N.W.
Washington, D. C. 20235
(202-634-7441; FTS 8-634-7441)
or locally the EDIS Pacific Northwest Liaison Office.
Additional information regarding MESA data sets, special
products, costs for products, and file type summaries is found in
the Data Catalog for the Marine Ecosystems Analysis Puget Sound
Project, Distribution and Summarization of Digital Data (May 1980
ed.). Copies of this document are available from the OMPA Pacific
Office or the EDIS Pacific Northwest Liaison Office.
Benthos, fish, plankton, bird, and mammal data were collected
at the locations shown in Figures I-A through I-D and Table I-C.
3. Data Set Error Identification and Correction
Data sets received by the MESA Project from contractors are entered
on cards or tape in the formats described above. They are initially
checked for gross errors such as missing items, parity errors, and
agreement with survey dates and locations. Some research groups
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performed their own data checks (see Mercer et al., 1978 for marine
mammal data checking program).
Subsequent checking is performed with a series of programs
implemented by machine. These checks are performed to ensure that the
taxonomic codes are reasonable; that blank spaces are correct and do not
represent omissions; that counts and weights are reasonable and within a
preestablished valid range; that the biological measurements data match
the field collection conditions data and vice versa; and that the codes
used for sampling stations, gear types, sampling conditions, etc., are
reasonable. Any questionable data sets or errors are resolved with the
principal investigator and corrections are made to the data tapes by
appropriate editing.
4. Data Management Recommendations
A number of things have been learned through trial and error
regarding data management that may be of interest to managers of
subsequent projects similar to this one. This assumes, though, that
management elects to archive the data collected. Given the amount of
time and difficulty experienced in this project in managing and archiv-
ing data, it may not be cost effective or worthwhile. If the data are
to be manipulated sometime in the future or as a part of the reporting
requirement; if the project is large and multidisciplinary; if computer
facilities are readily available; and if the data are collected with
standardized quantitative methods, then a data management/archival
program is recommended.
a. Formats
Establish the framework for each data format very early in the
project, based on the known kinds of data which will be collected.
Finalize the details of the format (s) with the concurrence of the
investigator(s). Keep the formats simple, as cluttered, detailed
formats are difficult to use.
b. Investigators
Select the investigators, in part, on their ability to
professionally meet data management requirements. Those with
minimal previous experience, limited access to computer facilities,
minimal interest in data archival, and little understanding of the
resources required to properly manage data should be avoided.
c. Proposed plan
Review the investigator's data management plan to ensure that
it meets the project requirements. Insist that the data management
activities be an integral part of the overall investigator's
management plan. Insist that data products (e.g, tapes) be pro-
vided on a regularly scheduled basis along with reports, meetings,
etc. If necessary, provide in the contractual agreements that
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invoice payments will be predicated upon receipt of deliverables,
including data products.
d. Quality control
Require early delivery of quality controlled digital data
sets, ensuring that the investigator has checked his own data for
accuracy and completeness.
e. Data checking
Either establish a data checking program or acquire an
existing one for checking delivered data sets. Also devise a plan
for getting corrections, if needed, from the investigators. It is
critical to have sufficient time allowed in the contract(s) to
review and check data sets, request corrections, receive and edit
in corrections. Establish rigorous standards for required fields,
codes, content, range checks, etc.
f. Availability
Provide equipment or facilities for manipulation of data sets,
following their final editing. Further problems with data sets
often become apparent when the data are actually used to solve a
problem. For example, development of formatted tabular listing
programs may turn up a problem with data completeness that escaped
previous checks.
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Table I-A. Publications resulting from NOAA/MESA and WDOE biological studies
MESA
Chester, A. J., 1978. Microzooplankton in the surface waters of the Strait
of Juan de Fuca. NOAA Technical Report ERL 403-PMEL 30, Pacific Marine
Environmental Laboratory, Seattle, Washington, 26 pp. (NTIS PB-297233)
Chester, A. J., D. M. Damkaer, D. B. Dey, G. A. Heron, J. D. Larrance, 1980.
Plankton of the Strait of Juan de Fuca, 1976-1977. DOC/EPA Interagency
Energy/Environment R&D Program Report EPA-600/7-80-032, U.S.
Environmental Protection Agency, Washington, D. C., 64 pp. (NTIS
PB80-190036)
Chester. A. J., D. M. Damkaer, D. B. Dey, and J. D. Larrance, 1977. Seasonal
distributions of plankton in the Strait of Juan de Fuca. NOAA Technical
Memorandum ERL MESA-24, Marine Ecosystems Analysis Program, Enviromental
Research Laboratories, Boulder, Colorado, 71 pp. (NTIS PB-281833)
Cross, J. N., K. L. Fresh, B. S. Miller, C. A. Simenstad, S. N. Steinfort,
and J. C. Fegley, 1978. Nearshore fish and macroinvertebrate assem-
blages along the STrait of Juan de Fuca including food habits of the
common nearshore fish. NOAA Technical Memorandum ERL MESA-32, Marine
Ecosystems Analysis Program, Environmental Research Laboratories,
Boulder, Colorado, 188 pp. (NTIS PB-292261)
Everitt, R. D., C. H. Fiscus, and R. L. DeLong, 1979. Marine mammals of
northern Puget Sound and the Strait of Juan de Fuca - a report on
investigations November 1, 1977-October 31, 1978. NOAA Technical
Memorandum ERL MESA-41, Marine Ecosystems Analysis Program,
Environmental Research Laboratories, Boulder, Colorado, 191 pp. (NTIS
PB-299287)
Everitt, R. D., C. H. Fiscus, and R. L. DeLong, 1980. Northern Puget Sound
marine mammals. DOC/EPA Interagency Energy/Environment R&D Program
Report EPA-600/7-80-139, U.S. Environmental Protection Agency,
Washington, D. C., 134 pp. (NTIS PB81-127516)
Gundlach, E. R., C. D. Getter, M. 0. Hayes, 1980. Sensitivity of coastal
environments to spilled oil, Strait of Juan de Fuca and northern Puget
Sound. Informal Report. MESA Puget Sound Project, NOAA, Seattle,
Washington, 76 pp.
Long, E. R., 1980. Physical processes and critical biological areas in the
vicinity of a proposed petroleum transfer facility. Conference Record
Oceans '80: Ocean Engineering in the '80s. Seattle, Washington,
Sept. 9-10, 1980. IEEE Pub. No, 80CH1572-7, pp. 489-497, Institute of
Electrical and Electronic Engineers, New York.
103
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Table I-A (Contd.)
Manuwal, D. A., T. R. Wahl, and S. M. Speich, 1979. The seasonal
distribution and abundance of marine bird populations in the Strait of
Juan de Fuca and northern Puget Sound in 1978. NOAA Technical
Memorandum ERL MESA-44, Marine Ecosystems Analysis Program,
Environmental Research Laboratories, Boulder, Colorado, 391 pp. (NTIS
PB80-130859)
Miller, B. S., C. A. Simenstad, J. N. Cross, K. L. Fresh, and S. N.
Steinfort, 1980. Nearshore fish and macroinvertebrate assemblages along
the Strait of Juan de Fuca including food habits of the common nearshore
fish. DOC/EPA Interagency Energy/Environment R&D Program Report
EPA-600/7-80-027, U.S. Environmental Protection Agency, Washington,
D. C., 211 pp. (NTIS PB81-155435, All)
Nyblade, C. F., 1978. The intertidal and shallow subtidal benthos of the
Strait of Juan de Fuca, spring 1976-winter 1977. NOAA Technical
Memorandum ERL MESA-26, Marine Ecosystems Analysis Program,
Environmental Research Laboratories, Boulder, Colorado, 156 pp. (NTIS
PB-285703)
Nyblade, C. F., 1979. The Strait of Juan de Fuca intertidal and subtidal
benthos, second annual report, spring 1977-winter 1978. DOC/EPA
Interagency Energy/Environment R&D Program Report EPA-600/7-79-213, U.S.
Environmental Protection Agency, Washington, D. C., 129 pp. (NTIS
PB80-142136)
Schoener, A. and F. B. DeWalle, 1982. Effects of petroleum on selected
uniform substrates: a feasibility study. NOAA Technical Memorandum
OMPA-18, Office of Marine Pollution Assessment, Boulder, Colorado,
44 pp. (NTIS PB82-232927)
Simenstad, C. A., W. J. Kinney, B. S. Miller, 1980. Epibenthic zooplankton
assemblages at selected sites along the Strait of Juan de Fuca. NOAA
Technical Memorandum ERL MESA-46, Marine Ecosystems Analysis Program,
Environmental Research Laboratories, Boulder, Colorado, 73 pp. (NTIS
PB80-209596)
Simenstad, C. A., B. S. Miller, J. N. Cross, K. L. Fresh, S. N. Steinfort,
and J. C. Fegley, 1977. Nearshore fish and macroinvertebrate assem-
blages along the Strait of Juan de Fuca including food habits of
nearshore fish. NOAA Technical Memorandum ERL MESA-20, Marine
Ecosystems Analysis Program, Environmental Research Laboratories,
Boulder, Colorado, 144 pp. (NTIS PB-297406)
Simenstad, C. A., B. S. Miller, C. F. Nyblade, K. Thornburgh, and L. J.
Bledsoe, 1979. Food web relationships of northern Puget Sound and the
Strait of Juan de Fuca. DOC/EPA Interagency Energy/Environment R&D
Program Report EPA-600/7-79-259, U.S. Environmental Protection Agency,
Washington, D. C., 335 pp. (NTIS PB80-169592)
1 <"M
los-
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Table I-A (Contd.)
Vanderhorst, J. R. , J. W. Blaylock, P. Wilkinson, 1979. Research to
investigate effects from Prudhoe Bay crude oil on intertidal infauna of
the Strait of Juan de Fuca, first annual report. NOAA Technical
Memorandum ERL MESA-45, Marine Ecosystems Analysis Program,
Environmental Research Laboratories, Boulder, Colorado, 38 pp. (NTIS
PB80-160955)
Vanderhorst, J. R., J. W. Blaylock, P. Wilkinson, M. Wilkinson, and G.
Fellingham, 1980. Recovery of Strait of Juan de Fuca intertidal habitat
following experimental contamination with oil (second annual report fall
1979-winter 1980). DOC/EPA Interagency Energy/Environment R&D Program
Report EPA-600/7-80-140, U.S. Environmental Protection Agency,
Washington, D. C., 73 pp. (NTIS PB81-112518)
Vanderhorst, J. R., J. W. Blaylock, P. Wilkinson, M. Wilkinson, and G.
Fellingham, 1981. Effects of experimental oiling on recovery of Strait
of Juan de Fuca intertidal habitats. DOC/EPA Interagency Energy/
Environment R&D Program Report EPA-600/7-81-088, U.S. Environmental
Protection Agency, Washington, D. C., 129 pp. (NTIS PB81-247165, A07)
Wahl, T. R., S. M. Speich, D. A. Manuwal, K. V. Hirsch, and C. Miller,. 1981.
Marine bird populations in the Strait of Juan de Fuca, Strait of Georgia
and adjacent waters in 1978 and 1979. DOC/EPA Interagency Energy/
Environment R&D Program Report EPA-600/7-81-156, U.S. Environmental
Protection Agency, Washington, D. C., 789 pp. (including 514 pp. micro-
fiche Appendices).
Webber, H. H., 1979. The intertidal and shallow subtidal benthos of the west
coast of Whidbey Island, spring 1977 to winter 1978, first year report.
NOAA Technical Memorandum ERL MESA-37, Marine Ecosystems Analysis
Program, Environmental Research Laboratories, Boulder, Colorado, 108 pp.
(NTIS PB-295815)
Webber, H. H., 1980. Whidbey Island intertidal and shallow subtidal benthos.
DOC/EPA Interagency Energy/Environment R&D Program Report EPA-600/7-80-
167, U.S. Environmental Protection Agency, Washington, D. C., (91 pp. +
microfiche Appendix. (NTIS PB81-151441)
Webber, H. H., 1981. Growth rates of benthic algae and invertebrates in
Puget Sound: I. Literature review, and II. Field studies on Laminaria
and Nereocystis. NOAA Technical Memorandum OMPA-4, Office of Marine
Pollution Assessment, Boulder, Colorado, 45 pp. (NTIS PB81-223760)
Zeh J. E., J. P. Houghton, and D. C. Lees, 1981. Evaluation of existing
marine intertidal and shallow subtidal biologic data. DOC/EPA
Interagency Energy/Environment R&D Program Report EPA-600/7-81-036, U.S.
Environmental Protection Agency, Washington, D. C., 262 pp. + microfiche
Appendices. (NTIS PB82-134065)
185
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Table I-A (Contd.)
WDOE
If NTIS number Is not given, publication is available through DOE, State
Library.
Beak Consultants, 1975. Biological oil impact literature review: Oil
pollution and the significant biological resources of Puget Sound,
Vol. I, Final Report, October 1975.
Beak Consultants, 1975. Biological oil impact literature review: Oil
pollution and the significant biological resources of Puget Sound,
Vol. II Bibliography, Final Report, October 1975.
Brittell, J. D., J. M. Brown, and R. L. Eaton (Eds.), 1976. Marine shoreline
fauna of Washington, Vol. II. Washington State Department of Game,
December 1976. (NTIS PB-265-978)
Eaton, R. L., 1975. Marine shoreline fauna of Washington, Vol. I.
Washington State Department of Game, December 1975. (NTIS PB-254-294)
English, T. S., 1976. Oil pollution and the significant biological resources
of Puget Sound, Open water study. University of Washington, Department
of Oceanography, March 1976.
Gardner, F. (Ed.), 1977. ,North Puget Sound Baseline Study Main Report.
1974-1977 Washington State Department of Ecology.
Isakson, J. S. (Ed.), 1977. Washington coastal areas of major biological
significance. Mathematical Sciences Northwest, Inc., November 1977.
Miller, B. S., 1978. Nearshore fishes, Puget Sound Baseline Program:
Nearshore fish survey, University of Washington, College of Fisheries,
January 1978.
Nyblade, C., 1977. Oil pollution and the significant biological resources of
Puget Sound, North Puget Sound Intertidal Study, April 1977. University
of Washington, Department of Zoology.
Salo, L. J., 1975. A baseline survey of significant marine birds in
Washington State. Washington State Department of Game, September 1975.
(NTIS PB-254-293)
WDOE, 1978. Five year intertidal community change San Juan Islands 1974-78
and the intertidal benthos of north Puget Sound, summer 1978.
Webber, B., 1978. W.W.U. Intertidal Report, September 1978. Huxley College,
Western Washington University.
186
-------
Table I-B. Biological synthesis report: Data sets
Type of Data
Years
of Completion
Study Date Investigator (s)
Form of Data
Data
File
Type
03
MESA
Strait intertidal
Whidbey intertidal
Strait fish
Whidbey fish
Marine birds
Marine mammals
Strait plankton
2 Nov. 79 Nyblade
May 80 Webber
3 May 80 Miller/Simenstad
1 Dec. 78 Miller/Simenstad
2 July 80 Manuwal/Wahl/Speich
2 May 80 Everitt/Fiscus/DeLong
2 Mar. 80 Chester
Food webs 1 Sep. 79 Simenstad/Miller
Oil effects, recovery 2 Sep. 80 Vanderhorst
Epibenthic plankton 1 Apr. 80 Simenstad
Continued
Tape; MESA Report-26;
EPA Report 7-79-213
Tape; MESA Report-37;
EPA Report 7-80-167
Tapes; MESA Report-20;
MESA Report-32;
EPA Report 7-80-027;
Cross thesis
Tape; MESA Report-32;
Tapes; MESA Report-44;
EPA Report 7-81-156
Tapes; MESA Report-41;
EPA Report 7-80-139
Tapes; MESA Report-24;
EPA Report 7-80-032
EPA Report 7-79-259
MESA Report-45; EPA
Reports 7-80-140 & 81-088
MESA Report-46
100
100
100
041
027
024,
028,
029
-------
Table I-B. (Contd.)
Type of Data
Years
of Completion
Study Date Investigator(s)
Data
File
Form of Data
CO
CO
WDOE
NFS plankton, larvae 1 Mar. 76 English
San Juan Island
intertidal
NFS intertidal
NFS subtidal
NFS fish
Fish data analyses
NFS baseline study
NFS fish
GPS fish
7 June 81 Nyblade
2 Sep. 78 Webber
2 Mar. 79 Smith
2 Jan. 78 Miller/Simenstad
2 Jan. 79 Miller/students
3 June 78 Gardner
Jan. 79 Miller/Simenstad
Feb. 79 Wingert/Terry/
Miller
WDOE report
WDOE reports: Oct. 75,
Apr. 77 (tape), Aug. 79,
Feb. 81, June 81
WDOE report: App. K,
Sep. 78; tape
WDOE report: App. L,
Mar. 79; tape
WDOE reports: Feb. 76,
Jan. 79; tape
Moulton thesis;
Wingert thesis
WDOE report: June 78
WDOE final report #78070
FRI-UW 7901
WDOE final report #78062
FRI-UW 7903
100
100
100
-------
Table I-C. NODC file type formats for biological data collected
in MESA studies.
File Type 024 Zooplankton
File Type 027 Marine Mammal Sighting 1
File Type 028 Phytoplankton Species
File Type 029 Primary Productivity
File Type 041 Marine Bird Survey
File Type 100 Intertidal/Subtidal
189
-------
Table I-D. Sampling site names for Appendix Figure I-A.
INTERT IDAL/ SUBTIDAL
Mixed Coarse
1. Legoe Bay
2. Guemes Island S.
3. Ebey's Landing
4. Twin Rivers
5. Dungeness Spit
6. South Beach
7. Deadman Bay
Sand
8. Eagle Cove
9. West Beach
10. North Beach
11. Kydaka Beach
12. Alexander's Beach
Mud-Gravel
13. Webb Camp
14. Beckett Point
Mud-Sand
15. Birch Bay
16 . Jamestown/
Port Williams
Mud
17. Westcott Bay
18. Dray ton Harbor
19. Padilla Bay
20. Fidalgo Bay
Exposed Rock
21. Pillar Point
22. Tongue Point
Protected Rock
23. Point Migley
24. Fidalgo Head
25. Cantilever Pier
26. Barnes Island
27. Point George
28. Allan Island
Cobble
29. Cherry Point
30. Shannon Point
31. Point Partridge
32. North Beach
33. Morse Creek
A. Neah Bay
B. Slip Point
C. Observatory Point
NEARSHORE
Exposed
34. Kydaka Beach
35. Twin Rivers
36. Morse Creek
37. Dungeness Spit
38. Jamestown/
Port Williams
39. Beckett Point
40. West Beach
41. Alexander's Beach
42. South Beach
43. Deadman Bay
44. Eagle Cove
45 . Burrows Island
Protected
46. Birch Bay
47. Cherry Point
48. Lummi Bay
49. Point Migley
50. Legoe Bay
51. Guemes Island E.
52. Padilla Bay
53. Guemes Island S.
54. Shannon Point
55. Point George
56. Westcott Bay
OFFSHORE PLANKTON
Stations 1-9
190
-------
.,
INTERTIDAL / SUBTIDAL BENTHOS
NEARSHORE FISH, AND
PLANKTON SAMPLING STATIONS
Figure I-A.
Locations of plankton-collection sites(l-9) and intertidal/subtidal/nearshore sampling
sites for benthos imc! f ish(l-56) .
-------
I Boundary Boy
'•
49°-
50'-
40'-
48°
30'
20-
AIRCRAFT, FERRY AND
SMALL VESSEL SURVEY TRANSECTS
USED IN MARINE BIRD SURVEYS
Airplane-
Ferry -
Small Vessel
HI
Figure I-B,
Location of marine bird survey transects. Note: in some areas where duplicate
methods were used, only one is shown for clarity.
census
-------
'.•
SHORE CENSUS AREAS
USFD IN MARINE BIRD SURVEYS
40 20' 124°
Figure I-C. Locations of marine bird shore census sites(darkened areas).
-------
I Boundery Boy
MAJOR POINT CENSUS AREAS (Aerial),
AERIAL TRANSECTS, BOAT TRANSECTS
AND LAND OBSERVATION SITES
USED IN MARINE MAMMAL SURVEYS
F'oint Census (aerial) •
Point Census ( land)
Transect Data (aerial) i— -
Transect Data (boat) i
VANCOUVER
ISLAND
WASHINGTON STATE
Figure
20' 124° 40' 2O'
I-D. Locations of marine mammal survey sites and transects.
20'
-------
APPENDIX II
DOMINANT SPECIES PER INTERTIDAL/SUBTIDAL HABITAT TYPE
AND REPRESENTATIVE DATA FROM SPECIFIC SAMPLING SITES
Mammals data are shown as highest single counts made during a two-year
study period at selected sites.
Birds data are shown as mean numbers and biomass per square kilometer
calculated seasonally over a two-year study period for selected survey areas
for the 10 most common (by percent occurrence) species. If fewer than 10
species were observed, density and biomass are shown for the number of
species observed.
Fish data are shown as present (X) or absent for most common species at
selected sites.
Benthos data are shown as mean wet weight (in grams/m ) for plants; and
mean counts/m2 (above) and mean wet weight (grams/m2) (below) for inverte-
brates. Dominants were subjectively selected from lists of species that
comprised at least 10% of the total weight or counts at each site. Abbrevia-
tions of pre (predator), sus (suspension feeder), her (herbivore), sea
(scavenger), dep (deposit feeder) are included for those taxa whose feeding
habits are known.
195
-------
Table II-A. Dominant species of marine mammals
Rock/cobble
Sucia Patos Tatoosh
Island Race Rocks Island Island
Harbor seal
(Phoca vitulina)
Northern sea lion
(Eumetopias jubatus)
California sea lion
(Zalophus califo rnianus)
124
32
135
212
296
X*
10
20
*present, but unquantifled.
Exposed unconsolidated
Protected unconsolidated
Dungeness Smith-Minor Protection
Spit Islands Island
Harbor seal
Northern sea lion
California sea lion
87
0
0
257
0
0
223
0
0
Padilla Bay Samish Bay Dungeness Bay
Harbor seal
Northern sea lion
California sea lion
93
0
0
71
0
0
107
0
0
NOTE: Numbers observed - highest single count.
196
-------
Table II-B. Dominant species of marine birds
Rock/cobble
Greater Scaup
Common Goldenaye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Glaucous-winged Gull
Mew Gull
Bonaparte's Gull
Great Blue Heron
Harlequin Duck
White-winged Scoter
Surf Scoter
Sanderling
Glaucous-winged Gull
California Gull
Maw Gull
Bonaparte's Gull
Hearmann's Gull
Spring
No. /km
12
<1
2
6
3
27
1,090
30
19
89
Fall
No. /km
< 1
2
< 1
8
< 1
9
1
1
7
6
(n = 49)
2 g/km2
11
<1
<1
5
2
38
1,036
40
8
16
(n = 65)
2 g/km*
< 1
< 1
1
8
< 1
12
< 1
< 1
1
2
Great Blue Heron
Mallard
Harlequin Duck
White-winged Scoter
Surf Scoter
Killdeer
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Glaucous-winged Gull
Mew Gull
Bonaparte's Gull
Summer
No. /km
< 1
< 1
3
1
9
< 1
13
< 1
< 1
< 1
Winter
No. /km
10
3
8
2
1
1
25
9
2
< 1
(n = 16)
2 g/km2
< 1
< 1
2
1
9
0
17
< 1
< 1
< 1
(n = 54)
2 g/km2
9
2
3
2
< 1
1
24
11
1
< 1
NOTE: Mean No./km2 and mean g/km2 for 10 most-frequently occurring species.
Continued
197
-------
Table II-B. (Contd.)
Exposed unconsolidated
Spring (n = 4)
Common Goldeneye
Bufflehead
White-winged Scoter
Surf Scoter
Bald Eagle
Glaucous-winged Gull
Mew Gull
Bonaparte's Gull
Great Blue Heron
White-winged Scoter
Surf Scoter
Bald Eagle
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Common Tern
No . /km 2
3
5
2
6
< 1
15
< 1
20
Fall (n
No. /km2
<1
1
17
<1
103
10
68
44
27
50
g/km*
3
2
3
6
4
19
< 1
4.
= 10)
g/km2
<1
2
16
1
134
8
29
8
12
5
Bald Eagle
Killdeer
Glaucous-winged Gull
California Gull
Summer (n • 3)
No. /km2
< 1
< 1
44
< 1
fi/km2
4
< 1
58
< 1
Winter (n - 7)
Great Blue Heron
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Glaucous-winged Gull
Mew Gull
Bonaparte's Gull
No . /km 2
1
< 1
16
2
8
<1
8
26
7
3
g/km2
3
<1
6
2
5
<1
8
34
3
<1
2 2
NOTE: Mean No./km and mean g/km for 10 most-frequently occurring species.
Continued
198
-------
Table II-B. (Contd.)
Mixed coarse
Great Scaup
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Black Scoter
Glaucous-winged Gull
Mew Gull
Great Blue Keron
Harlequin Duck
White-winged Scoter
Surf Scoter
Glaucous-winged Gull
Western Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann ' s Gull
Spring (n
No . /km2
2
2
15
< 1
< 1
2
13
2
58
5
Fall (n
No. /km2
< 1
< 1
3
10
56
< i_
48
14
21
13
= 49)
g/km2
2
2
6
< 1
< 1
3
13
2
75
2
= 81)
g/km2
2
< 1
11
10
72
< 1
37
6
4
6
Summer (n = 15)
Great Blue Heron
Greater Scaup
Harlequin Duck
White-winged Scoter
Surf Scoter
Bald Eagle
Killdeer
Glaucous-winged Gull
California Gull
Bonaparte's Gull
No . /km2
1
< 1
2
< 1
7
< 1
< 1
33
< 1
2
Winter (n
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Black Scoter
Glaucous-winged Gull
Mew Gull
No. /km2
7
12
37
17
3
3
17
3
112
47
g/km2
3
< 1
1
1
6
< 1
0
43
< 1
< 1
= 87)
g/km
6
10
15
13
2
5
16
3
146
20
NOTE: Mean No./krf and mean g/knf for 10 inost-frequently occurring species,
Continued
199
-------
Table II-B. (Contd.)
Protected unconsolidated (mud-sand)
Black Brant
American Wigeon
Greater Scaup
Common Goldeneye
Bufflehead
White-winged Scoter
Surf Scoter
Black Bellied Plover
Glaucous-winged Gull
Mew Gull
Great Blue Heron
American Wigeon
White-winged Scoter
Surf Scoter
Killdeer
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Spring (n
No. /km2
276
32
13
11
58
15
22
4
142
26
Fall (n
No. /km2
4
752
11
29
< 1
109
84
7
19
2
= 14)
g/km2
345
25
12
9
23
21
21
1
184
11
= 20)
g/km2
12
602
15
27
< 1
141
65
3
3
1
Summer (n = 2)
Great Blue Heron
Killdeer
Black Turnstone
Glaucous-winged Gull
No. /km2
4
1
22
354
Winter (n
Black Brant
American Wigeon
Greater Scaup
Common Goldeneye
Bufflehead
Harlequin Duck
White-winged Scoter
Surf Scoter
Glaucous-winged Gull
Mew Gull
No. /km2
122
411
43
23
244
1
15
76
37
22
g/km2
13
< 1
3
461
- 27)
g/km2
153
329
38
20
98
< 1
20
73
48
9
NOTE: Mean No./km and mean g/km2 for 10 most-frequently occurring species,
Continued
200
-------
Table II-B. (Contd.)
Protected unconsolidated (mud)
Great Blue Heron
Black Brant
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
White-winged Scoter
Surf Scoter
Glaucous-winged Gull
Mew Gull
Great Blue Heron
Greater Scaup
White-winged Scoter
Surf Scoter
Kllldeer
Glaucous-winged Gull
California Gull
Ring-billed Gull
Mew Gull
Bonaparta's Gull
Spring (n
No. /kin 2
2
147
65
2
23
< 1
6
74
22
7
Fall (n
No . /km2
5
47
10
19
< 1
20
3
5
7
30
= 43)
g/km2
5
184
59
1
9
< 1
9
70
29
3
= 72)
g/km2
15
43
14
18
< 1
26
2
3
3
5
Summer (n
Great Blue Heron
Mallard
Greater Scaup
White-winged Scoter
Surf Scoter
Bald Eagle
Killdeer
Glaucous-winged Gull
Ring-billed Gull
Bonaparte's Gull
No . /km2
7
< 1
3
1
2
< 1
< 1
42
< 1
9
Winter (n
Common Pintail
American Wigeon
Greater Scaup
Common Goldeneye
Bufflehead
White-winged Scoter
Surf Scoter
Dunlin
Glaucous-winged Gull
Mew Gull
No . /km2
49
65
68
8
60
10
20
93
15
8
" 17)
g/km2
20
< 1
3
2
2
< 1
< 1
54
< 1
2
= 82)
g/km2
47
52
61
7
24
14
19
6
19
3
NOTE: Mean No./km2 and mean g/km2 for 10 most-frequently occurring species,
Continued
201
-------
Table II-B. (Contd.)
Protected unconsolidated (mud-gravel)
Spring (n
Great Blue Heron
Black Brant
Greater Scaup
Common Goldeneye
Bufflehead
White-winged Scoter
Surf Scoter
Black Brant
Glaucous-winged Gull
Mew Gull
Great Blue Heron
American Wigeon
White-winged Scoter
Surf Scoter
Western Sandpiper
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
No./km2
< 1
12
34
< 1
21
43
122
2
37
1
Fall (n
No. /km2
< 1
1
13
9
< 1
29
4
< 1
8
< 1
- 11)
g/km2
1
15
30
< 1
9
60
116
2
48
< 1
= 9)
fi/km2
3
1
18
9
< 1
33
3
< 1
1
< 1
Summer (n = 2)
Great Blue Heron
Harlequin Duck
White-winged Scoter
Surf Scoter
Glaucous-winged Gull
Bonaparte's Gull
No. /km2
2
< 1
< 1
< 1
14
< 1
Winter (n
Common Pintail
American Wigeon
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
White-winged Scoter
Surf Scoter
Glaucous-winged Gull
Mew Gull
No. /km2
1
12
172
58
101
63
53
141
32
14
R/km2
4
< 1
< 1
< 1
19
< 1
- 12)
g/km2
2
10
154
50
40
49
73
134
42
6
NOTE: Mean No./km2 and mean g/km2 for 10 most-frequently occurring species,
202
-------
Table II-C. Dominant species of fish
Exposed sand
Eagle Alexander's West Kydaka
Cove Beach Beach Beach
Microgadus proximus (Pacific tomcod-juv.) X
Amphisticus rhodoterus (redtail surfperch)
Cymatogaster aggregata (shiner perch) X
Blepsias cirrhosus (silverspotted sculpin)
Leptocottus armatus (Pacific staghorn
sculpin) X
Agonus acipenserinus (sturgeon poacher)
Citharichthys stigmaeus (speckled sanddab)
Lepidopsetta bilineata (rock sole)
Platichthys stellatus (starry flounder) X
Parophrys vetulus (English sole-juv.) X
Psettichthys melanostictus (sand sole) X
X
X
X
X
X
X
X
X
X
X
X
X X
X
X
X
X
X X
X
NOTE: Sites at which dominant species were present,
Continued
203
-------
Table II-C. (Contd.)
Exposed mixed coarse
Cherry Legoe Guemes Deadman South Dungeness Twin
Point Bay Island Bay Beach Spit Rivers
Microgadus proximus
(Pacific tomcod-juv.) XX XX
Theragra chalcogramma
(walleye poliock-juv.) X X
Aulorhynchus flavidus
(tubesnout) X X
Syngnathus leptonhynehus
(bay pipefish) X X
Amphisticus rhodoterus
(redtail surfperch) x
Cymatogaster aggregata
(shiner perch) X X X X X
Embiotoca lateralis
(striped seaperch) X X
Rhacochilus^ vacca
(pile perch) X X
Apodichthys flavidus
(penpoint gunnel) XXX X
Pholis laeta
(crescent gunnel) XXX X
_P. ornata
(saddleback gunnel) X X
Hexagrammos stelleri
(whitespotted greenling) X X X X
Sebastes caurinus
(copper rockfish-juv.) X
Artedius fenestralis
(padded sculpin) X X X X X X
_A. lateralis
(smoothhead sculpin) X
Ascelichthys rhodorus
(rosylip sculpin) X
Blepsias cirrhosus
(silverspotted sculpin) XXX X
Clinocottus acuticeps
(sharpnose sculpin) XX X
Enophrys bison
(buffalo sculpin) X X X X X X
Leptocottus armatus
(Pacific staghorn
sculpin) X X X X X X X
Continued
204
-------
Table II-C. (Contd.)
Exposed mixed coarse
Cherry Legoe Guemes Deadman South Dungeness Twin
Point Bay Island Bay Beach Spit Rivers
X
X
X
Myoxocephalus polyacan-
thocephalus (great
sculpin) X' X XX
Oligocottus maculosus
(tidepool sculpin) XX X
Scorpaenichthys marmoratus
(cabezon-juv.) XXX
Synchirus gilli
(manacled sculpin) X
Euinicrotreinis orbis
(spiny lumpsucker) X
Liparis callyodon
(spotted snailfish) X X
_L. florae
(tidepool snailfish) X
_L_. rutteri
(ringtail snailfish) X
Agonus acipenserinus
(sturgeon poacher) X X
Pallasina barbata
(tubenose poacher) X X X X
Citharichthys sordidus
(Pacific sanddab) X
Lepidopsetta bilineata
(rock sole) X
Parophrys vetulus
(English sole-juv.) X X
Platichthys stellatus
(starry flounder) X X
Psettichthys malanostictus
(sand sole)
X
X
X
X
X
X
X
X
X
X
X
X
NOTE: Sites at which dominant species were present.
205
-------
Table II-C. (Contd.)
Exposed rock/cobble
Neah Slip Observatory Morse Twin North
Bay Point Point Creek Rivers Beach
Anoplarchus purpurescens
(high cockscomb) X X
Clinoccottus embryum
(calico sculpin) X
C. globiceps
(mosshead sculpin) X
Oligocottus maculosus
(tidepool sculpin) X X
Gobiesox maeandricus
(northern clingfish) X X
Xiphister atropurpureus
(black prickleback) X
NOTE: Sites at which dominant species were
Rocky kelp bed(subtidal)
X X
X
X
X XXX
X XXX
present .
Barnes Allan Point
Island Island George
Embiotoca lateralis (striped seaperch)
Sebastes caurinus (copper rockfish)
S. emphaeus (Puget Sound rockfish)
S. flavidus (yellowtail rockfish)
S. maliger (quillback rockfish)
S. melanops (black rockfish)
Hexagraromos decagrammus (kelp greenling)
Ophiodon elongatus (lingcod)
Artedius harringtoni (scalyhead sculpin)
Hemilepidotus hemilepidotus (red Irish lord)
Jordania zonope (longfin sculpin)
Coryphopterus nicholsi (blackeye goby)
X X
XXX
X
X
X X
X X
XXX
X X
X
X
XXX
X X
NOTE: Sites at which dominant species were present.
206
-------
Table II-C. (Contd.)
Protected unconslidated (mud/gravel)
Birch Fidalgo Westcott Beckett Jamestown/Port
Bay Island Bay Point Williams
'Microgadus proxiinus
(Pacific tomcod-juv.)
Aulorhytichus flavidus
(tube-snout)
Syngnathus leptonhynehus
(bay pipefish)
Cymatogaster aggregata
(shiner perch)
Embiotoca lateralis
(striped seaperch)
Rhacochilus vacca
(pile perch)
Apodichthys flavidus
(penpoint gunnel)
Lumpenus sagitta
(snake prickleback)
Pholis laeta
(crescent gunnel)
Pholis ornata
(saddleback gunnel)
Hexagraminos stelleri
(whitespotted greenling)
Artedius fenestralis
(padded sculpin)
Blepsias cirrhosus
(silvsrspotted sculpin)
Chitonotis pugetensis
(roughback sculpin)
Clinocottus acuticeps
(sharpnose sculpin)
Enorphrys bison
(buffalo sculpin)
Leptccottus armatus
(Pacific staghorn
sculpin)
Myoxocephalus polyacan-
thocephalus
(great sculpin)
Oligocottus^ maculosus
(tidepool sculpin)
Scorpaenichthys marmoratus
(cabeson)
Continued
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
207
-------
Table II-D. (Contd.) a. Intertidal rock
Nemertea spp. pre.
Nematoda spp. dep.
Oligochaeta dep.
Polychaeta
Arenicolidae spp. dep.
Cirratulidae
Cirratulus sp. dep.
Lumbrineridae
Lumbrineris spp . dep .
Nereidae
Nereis spp. her.
Sabellidae- spp . sus .
Serpulidae
Spirorbia sp. sus.
Spionidae spp. dep.
Syllidae
Terebellidae spp. dep.
4J
C
.^4
o
IV
PM
O Q>
00 -} >>
iH i-l
-------
Table II-D. (Contd.) a. Intertidal rock
Mollusca - Amphineura
Cyanoplax dentiens her.
Katherina tunicata her.
Mopalia spp. her.
Tonicella lineata her.
Mollusca Gastropoda
Collisella digitalis her.
Collisella pelta her.
Collisella strigitella her.
Lacuna variegata her.
Littorina scutulata her.
Littorina sitkana her.
Notoacmea persona her.
Notoacmea scutum her.
Nucalla spp . pre .
Searlesia dira
Tongue Point
24.2
2.5
4.4
23.4
6.7
4.9
100.8
19.0
25.0
19.3
49.2
4.1
18.3
3.3
1159.2
6.7
6.7
1.2
7.5
3.8
Pillar Point
0.5
0.2
6.3
98.3
8.3
0.2
40.0
13.7
6.7
3.3
70.0
0.2
363.3
6.7
6.7
6.7
"O
«
0)
BC
o
00
iH
at
T3
•H
ft,
22.7
129.2
10.0
94.7
0.8
1.0
0.7
2.1
20.7
4.4
54.0
10.2
1.3
0.2
1132.3
5.6
79.0
8.7
46.0
4.5
24.7
7.5
20.0
11.5
12.4
7.3
17.1
20.9
Cantilever Pier
1.9
2.1
0.4
1.1
51.1
278.1
213.9
81.2
829.3
178.0
2.7
12.0
4.8
4->
a
•H
O
04
^
Q>
rH
60
•rl
S
12.0
0.7
0.7
2.8
0.2
90.4
11.8
109.7
5.3
26.4
0.5
84.2
1.3
1304.7
43.0
135.0
6.0
108.3
3.3
6.3
0.7
1.2
0.2
0.2
0.1
Continued
211
-------
Table II-D. (Contd.) a. Intertidal rock
Mollusca - Bivalvia
Hiatella spp. sus.
Musculus pygmaeus sus.
Mytilus edulis sus.
Mytilus spp. sus.
Crustacea - Tanaidacea
Anatanais normani dep.
Leptochelia dubia dep.
Pancolus californiensis
dep.
Crustacea Cirripedia
Balanus cariosus sus.
Balanus crenatus /Balanus
glandula sus.
Balanus spp . sus .
Cthamalus dalli sus.
Crustacea - Amphipods
Caprellidea sp.
Tongue Point
11.7
10225.8
80.8
497.5
6.7
669.2
6.7
48.3
66.9
2633.0
161.0
1180.0
24.8
Pillar Point
13.3
40.8
13.3
3.3
720.0
0.3
590.0
23.3
140.5
284.8
2486.7
63.3
100.0
.6.7
•o
CO
0)
o
00
i-H
RJ
•a
•H
fe
46.7
0.9
1.9
1.5
1710.8
1357.2
176.2
17.4
32.9
1.1
30.5
0.3
M
a>
i
^i
p4 4J
c
H -H
a) o
> Py
.
>H OJ
4J rH
C 00
Cfl -H
u S
0.2
137.0 1911.8
157.5
0.3
230.2 56.0
73.3
505.0 4081.8
451.5
612.6 3603.1
154.8
522.3 2041.9
63.0
Continued
212
-------
Table II-D. (Contd.) a. Intertidal rock
4J
c
i-l
O
PL,
Q)
a
60
C
O
H
Crustacea - Amphipods (Contd.)
Gananaridea spp. dep./her. 2760.0
(Ampithoe sp . )
(Hyale sp . )
(Parallorchestes ochotensis)
(jPontogeneia sp . )
Crustacea - Isopoda
Dynamenella sheareri sea.
Exosphaeroma spp. sea.
Gnorimosphaeroma oregonensis
sea.
Idotea spp. sea.
Limnoria algarum her.
Munna chromatocephala dep.
Crustacea - Decapoda
Cancer oregonensis pre.
Pagurus spp. dep.
Pugattia gracilis her .
22.8
991.7
9.2
10.0
1.5
28.3
3.3
3.3
8.3
5.8
1.0
140.0
5.0
Pillar Point
226.7
7.3
183.3
3.3
87.2
7.3
263.3
3.3
0.8
0.5
3.3
4.3
K
*
0)
r-\
00
•H
s
350.6
4.0
52.7
0.6
117.6
1.3
3.5
0.1
17.2
1.7
51.5
2.3
4.7
0.7
Continued
213
-------
Table II-D. (Contd.) a. Intertidal rock
Insecta
Diptera larvae spp.
dep.
Echinodermata - Asteroidea
Leptasterias hexactis pre.
Echinodermata - Holothuroidea
Cucumaria pseudocurata sus.
4-J
ti
Tt
O
O-t
9)
a
00
g
O
H
709.2
10.0
10.0
5.8
1503.3
42.5
4J
e
•H
O
CL.
M
QJ
r^
.-1
•H
04
100.0
6.7
03
0)
O
00
05
•O
h
55.5
0.1
5.4
1.9
0)
^
0)
V
iH
•H
4J
S
0)
CJ>
144.3
3.1
4J
c
•H
O
CU
^.^
Q|
rH
HO
_-i
2
18.8
0.7
15.0
2.9
Continued
2H
-------
Table II-D. (Contd.) b. Intertidal cobble
^ X
0
Platyhelminthes
Turbellaria pre. 157.5
Partridge Point
7.9
.5.3
4.6
19.4
241.9
11.3
39.9
78.1
31.8
1.7
8.0
50.9
0.1
43.4
34.0
23.7
Shannon Point
157.2
20.3
9.4
173.6
194.2
305.4
45.8
10.6
97.7
1.2
0.3
444.5
54.4
5.3
3.9
13.0
10.3
Cherry Point
280.3
42.7
17.9
472.6
.3.6
13.4
123.7
1.3
14.5
2.9
4.5
0.6
20.4
1.1
4.9
50.2
7.5
n.i
Continued
215
-------
Table II-D. (Contd.) b. Intertidal cobble
Nemertea spp. pre.
Nematoda spp. dep.
Oligochaeta spp. dep.
Polychaeta
Arenicolidae spp. sus./dep.
Capitellidae
Capitella capitata dep .
Mediomastus sp. dep.
Notomastus tenuis dep.
Dorvilleidae
Protodorvillea gracilis
pre.
Glyceridae
Hemipodus borealis pre.
Goniadidae
Glycinde picta pre.
Lumbrineridae
Lumbrineris sp. dep.
•u
a
•r^
o
^ J3 PM
01 O
oj ta oj
H 0) W>
o « *o
•H
(0 *J 4-1
H M H
O O «
218.8 129.7
5.6 1.3
126.7 485.1
4.0 0.3
6.3 180.7 1797.6
0.7 4.7 0.4
71.6
1.8
682.2 19.9
4.2 0.2
7.6
9.3
0.6
739.0
0.2
40.0
0.7
0.3
57.0
8.9
1 1
Shannon Poini
29.5
1.2
8.2
0.1
195.4
1.5
4.4
7.4
114.2
6.2
17.4
1.9
22.6
0.7
32.1
3.2
4J
a
0
a,
n
0)
80.1
1.2
31.5
0.1
756.1
1.5
0.1
4.5
36.4
0.1
139.4
4.3
0.2
32.7
1.8
29.2
0.3
9.0
1.4
Continued
216
-------
Table II-D. (Contd.) b. Intertidal cobble
^
0)
0)
^4
o
0)
to
^|
o
Polychaeta (Contd.)
Nereidae
Nereis sp. her. 143.8
14.0
Platynereis bicanaliculata
her.
Onuphidae
Onuphis spp. sea.
Opheliidae
Armandia brevis dep. 30.4
1.6
Sabellidae spp. sus. 2145.3
18.0
Spionidae
Malacoceros sp. dep. 521.7
2.3
Polydora spp . dep .
Syllidae pre.
Terebellidae spp. dep. /sus.
Thelepus crispus dep .
Mollusca - Amphineura
Amphineura spp. her.
Cyanoplax dentiens her.
-c
u
cfl
00
•H
M
4-1
(4
td
Cu
26.3
6.7
117.7
1.7
552.3
4.7
6.1
7.4
1.4
412.9
0.7
107.4
5.2
300.8
85.0
5.4
5.7
2.3
c
•H
0
a
o
c
c
f^
CO
26.7
4.3
1.9
.1
44.2
0.9
16.1
0.3
3.2
0.3
8.6
6.5
0.1
22.6
1.4
17.5
12.0
67.9
70.3
0.4
0.2
4.7
0.6
4J
a
•H
o
cu
s^
Vi
0)
0
36.1
16.3
3.4
.1
79.8
1.0
0.8
0.1
0.6
20.2
0.3
10.6
0.6
0.2
0.9
0.2
2.1
0.1
Continued
217
-------
Table II-D. (Contd.) b. Intertidal cobble
Mollusca - Gastropoda
Collisella pelta her.
Collisella spp. her.
Lacuna variegata her.
Littorina scutulata her.
Littorina sitkana her.
Notoacmaea sp.
Notoacmea persona her.
Notoacmea scutum her.
Nucella lamellosa pre.
Nucella spp. pre.
Mollusca - Bivalvia
Mysella tumida sus.
Mytilus edulis sus.
Protothaca staminea sus.
Saxidomus giganteus sus.
.w
-------
Table II-D. (Contd.) b. Intertidal cobble
Mollusca - Bivalvia (Contd.)
Tresus capax sus.
Crustacea - Tanaidacea
Leptochelia dubia dep.
Crustacea - Cirripedia
Balanus cariosus sus.
Balanus crenatus /Balanus
glandula sus.
Balanus spp. sus.
Chthamalus dalli sus.
Crustacea - Amphipoda
Gammaridea spp. dep.
(Ampithoe sp. her.,
Corophium spp. sus. /dep.,
Hyale sp . dep . , Paramoera
mohri dep.)
Crustacea - Isopoda
Exosphaeroma spp. sea.
Gnorimosphaeroma
oregonensis sea.
Idotea spp. sea.
Morse Creek
5.1
12.9
9.6
2.9
984.8
110.3
1589.2
44.0
2502.2
33.4
37.7
0.7
17.3
4.9
J2
u
cd
a)
PQ
,e
4-1
VJ
o
!5
3.3
3.3
106.7
6.0
42.0
4.7
107.8
1.3
311.0
7.7
126.7
0.7
395.3
0.2
Partridge Point
1.1
33.2
1.4
990.9
27.6
264.6
3.6
3505.5
17.4
195.1
1.0
135.7
1.3
440.9
14.9
Shannon Point
0.4
0.1
203.0
0.3
91.9
293.1
162.7
10.7
1.8
0.3
157.0
2.7
180.6
3.2
42.3
0.8
74.7
2.7
61.4
9.9
4J
c
•rt
0
Pt
>>
t-t
!-i
-------
Table II-D. (Contd.) b. intertidal cobble
Crustacea - Decapoda
Hemigrapsus nudus sea.
Hemigrapsus oregonensis
sea.
Hemigrapsus spp. sea.
Pagurus spp. dep.
Pinnixa sp. pre.
4-1
C
-,1
•n
0
^ J= 0,
a) o
01 co o
u pa -o
•H
Oi J3 i-i
CO 4J 4J
^ H M
O O «
S !S . PH
3.3 35.0
7.7 99.7
3.7
27.8
39.4
33.2
38.7 42.6
6.1 . 3.4
1.1
c
•H
O
PL,
C
O
C
C
tfl
w
96.8
54.5
55.6
14.9
42.1
5.0
101.1
8.6
27.9
0.9
w
rt
-H
O
^"»
M
t.
0)
0
202.6
77.6
80.9
14.8
11.3
0.9
98.3
2.2
7.4
0.3
Insecta
Diptera larvae spp. dep.
Echinodermata
Leptasterias hexactis pre.
1988.0
3.8
6.7
3.3
4.4
20.5
7.2
1.1
1.6
2.3
13.1
42.9
30.4
Continued
220
-------
Table II-D. (Contd.) c. Subtidal rock and cobble
Chlorophyta
Enteromorpha linza
Monostroma spp.
Phaeophyta
Alaria spp .
Costaria costata
Desmarestia spp.
Egregia menziesii
Laminaria sp . /
Laminaria
saccharina
Nereocystis luet-
keana
Pterygophora
californica
Rhodophyta
Botryoglossum
farlowianum
Calliarthron
tuberculosum
Callophyllus
flabellulata
Gigartina spp.
jtollenbergia sp.
Hymenena sp.
Iridaea spp.
Laurencia
spectabilis
*J TJ 0)
C a so ^4 ,£
•rl tO K >
H
>^ H
0)
-------
Table II-D. (Contd.) c. Subtidal rock and cobble
4J
fi
i-l
O
FM
0)
00
B
0
H
Rhodophyta (Contd.)
Microcladia
borealis
Odonthalia
floccosa
Odonthalia
washingtoniensis
Opuntiella
californica
Plocamium tenue
P. coccineum
Polyneura
latissima
Pterosiphonia sp.
Rhodomella larix
Rhodoptilum
plumps'™
Angiosperms
Phyllospadix
scouleri
Zostera marina
Nematoda spp. dep.
Oligochaeta spp. dep.
Archiannelida
Polygordius sp.
Fidalgo Head
Point George
Morse Creek
21.2
0.3
3.2
5.6
0.3
49.0
1.8
0.8
3.7
0.1
0.8
4.2
4J
C to
•H C
0 i-(
X . PLi T3
U C
cd tt) «J
0) 00 J
PQ -O
•H CO
J= H
*J 4J f^,
MM 0
OR) J3
Z FL, tq
.03
0.6 0.6
0.1 0.1
3.5 .001 .003
0.1 0.1
0.1 .05
.004 0.2
0.1
0.002
0.8 .002
0.3
295.0 278.5 58.5
1.5 0.2 Q.I
712.5 1014.1 187.5
<1.5 0.3
6.7 4.5
4J
C
•H
o
P-.
>v
M
M
(U
U
0.5
3.8
39.7
8.3
Continued
222
-------
Table II-D. (Contd.) c. Subtidal rock and cobble
•M *O
d nj
i-l X JS PL,
M
-------
Table II-D. (Contd.) c. Subtidal rock and cobble
4-1 »O
C oj
•H 0)
0 SC
PU
O
4) 60
00 A
C T»
0 -H
H b
Polychaeta (Contd.)
Onuphidae
Onuphis sp. sea.
Oweniidae
Owenia fusiformis 1.7
dep.
Phyllodocidae
Hesionura coineaui
pre.
Serpulidae
Spirorbis spp. 32.6 15.8
sus . 0.4
Sigalionidae
Pholoe minuta pre. 10.2
Spionidae
Polydora hamata/ 1.0
P. pygidialis
dep.
Prionospio 108.3
steenstrupi dep. 0.1
Spio filicornis dep.
Spiophanes bombyx 0.8
dep.
Syllidae
Typosyllis sp. pre.. 1.2
a
•H
4J
•H h M H
o o o td
PLI S Z Oi
147.5 382.7
1.5 2.4
3.0
100.0
0.1
12.0
347.5 0.3
1.0
106.0 80.0 13.6
2.0 1.5 0.1
180.0 85.8
1.5 0.5
37.3
0.2
416.0 291.9
2.0 0.5
bO
C
•H
*O
a
cjj
H"4
CO
^^
a>
«
12.4
0.1
92.6
1.9
5.2
0.8
1.5
13.2
67.1
0.8
55.1
0.3
124.2
0.7
45.8
0.1
4-1
C
•rH
o
(X,
£
h
-------
Table II-D. (Contd.) c. Subtidal rock and cobble
Terebellidae
Thelepus crispus
dep.
Mollusca - Amphineura
Lepidozona spp.
her.
Tonicella lineata
her.
Molusca - Gastropoda
Acmaea mitra her.
Alvinia sp. sea./
det.
Amphissa colum-
biana sea. /det.
Calliostoma
ligatum her./
pre.
Ceratostoma
foliatum pre.
Fusitriton
oregonensis
pra.
Granulina
margaritula
Haliotis
kamschatkana her.
Lacuna variegata
her.
•U
•H
O
p-l
o o
4J 0)
C to
•H M
O O
PM S
26.7
23.5
3.5
5.2
9.8 250.0
7.6 16.0
14.2
12.6
0.2
9.1
0.3
5.5
0.1
4J
fi
•rH
o
JS P-.
(0 0)
% U
W 6
3.6
0.3
0.2 0.7
0.4 0.5
0.1
0.4
20.7 340.8
1.0
14.3
0.6
0.2
304.7 746.0
2.7 2.8
Continued
225
-------
Table II-D. (Contd.) c. Subtidal rock and cobble
Mollusca - Gastropoda
(Contd.)
Lirularia
lirulata her.
Margaritas
pupillus her.
Oceanebra
lurida pre.
Trichotropis
cancellata sus.
Mollusca - Bivalvia
Astarte
alaskensis sus.
Axinopsida sp. sus.
Clinocardium spp.
sus.
Crenella decussata
sus.
Glycymeris
subobsoleta sus.
Macoma spp. sus./
dep .
Modiolus rectus
sus .
Mysella tumida
dep . /sus .
Protothaca
staminea sus.
Psephidia lordi
sus.
Continued
w -a 0 Hi pj 03
c -a -H vi
O -H O O
H fn Pn S
79.6 4.5
0.6 0.2
114.00 21.3 30.2
10.00 1.1 9.5
26.6 0.6
3.8 5.5
2.5 10.2
0.3 9.3
4.2
5.0
26.5
6.0
2.0
65.8 86.0
2.3
2.5
0.7
8.3 396.0
2.0
12.8
59.5
North Beach
60.0
0.5
702.5
0.5
330.5
1.5
5.0
1.0
50.0
0.5
75.5
0.5
Partridge Point
57.6
0.8
59.4
1.1
26.4
5.8
0.5
0.1
3.3
1.1
683.1
7.9
8.5
0.6
3.6
1.3
44.0
0.1
1.5
0.3
124.7
1.2
Ebey's Landing
14.6
0.2
91.3
2.0
1.0
0.1
4.4
18.4
65.5
0.2
32.7
3.3
5.2
40.5
50.4
0.1
1.9
3.7
273.9
1.3
4J
C
«H
0
fX,
>.
M
M
0)
J3
O
7.5
0.2
2.2
0.1
210.0
2.0
45.0
141.1
50.8
25.0
1.0
684.2
2.8
21.7
1.0
1009.2
11.6
226
-------
Table II-D. (Contd.) c. Subtidal rock and cobble
Mollusca - Bivalvia
(Contd.)
Saxidomus
giganteus sus.
Crustacea - Tanaidacea
Leptochelia spp.
dep.
Crustacea - Amphipoda
4-J
e
•H
0
P-.
(U
3
00
C
o
H
Gammaridae spp. 4734.0
dep.
(Melita sp. dep.)
Crustacea - Isopoda
Exosphaeroma spp.
sea.
laniropsis spp.
dep.
Crustacea - Decapoda
Cancer
oregonensls
pre.
Heptacarpus spp.
pre.
Pagurus spp. dep.
Pinnixa
occidentalis
pre.
Pugettia spp . her .
7.0
192.2
0.2
14.0
9.2
214. &
7.8
482.0
19.2
-U
cd
0)
EC
0
00
rH
CO
•o
•rl
fa
5.0
164.1
119.7
1.0
12.2
1.1
26.7
0.4
7.2
0.3
7.2
14.0
0 X J3
H .
1-1
^
0)
6
111.7
0.1
99.7
0.3
0.3
3.3
0.2
1.0
19.7
0.7
168.5
0.5
Continued
227
-------
Table II-D. (Contd.) d. Intertidal exposed unconsolidated
ro
ro
CO
Platyhelminthes
Turbellaria spp. pre.
Nemertea spp. pre.
Oligochaeta spp. dep.
Polychaeta
Arenicolidae
Abarenicola claparedil
sus./dep.
Capitellidae
Capitella capitata
dep.
Mediomastus sp. dep.
*J 60
•H a
(X -H
CO W *O
M C
cu to (d
> co »4
•H >
3 £3 _O
HP w
42.7
102.0
0.1
20.0 1.7 86.4
1.3 0.5
56.0 4.6
0.7 0.3
fi
jj
o
en
CO
Q)
I
3
3
O
3.1
2.2
0.1
5.7
0.1
m
&*t
cd
(Q
0
3
0
•0
Q
2128.0
246.0
276.0
2.9
1.7
^r*
U
cd
>•> 0)
Qj pQ
P4
cd
0) ^«J
o cd
00 T3
4) >-,
*1 14
57.8
0.5
8.2
0.5
18.0 8.0
0,4 0.7
0.8
r*
U 43
-l CO
O 0)
a s
2.7
4.0 52.2
0.5
5.0 29.3
0.5
8.0
0.7
0.2
0.1
Q>
O
0)
tH
00
cd
8.0
10.0
12.0
6.4
Continued
-------
Table II-D. (Contd.) d. Intertldal exposed unconsolidated
ro
ro
•H
P.
CD C/3
^
CD
•H 0)
f£ C
cu
£ bO
•rl C
Polychaeta (Contd.)
Opheliidae
Armandia brevis dep.
Orbiniidae
Scoloplos sp. dep.
Paraonidae
Paranella platybranchia
dep.
Spionidae
Malacoceros sp. dep. 220.0
0.7
Scolelepis sp. dep.
Syllidae
Syllis sp. pre.
Ebey's Landing
Guemes South
3.4 5.9
0.1
0.4
1.1 0.3
0.3
CO CO 0 ,C i 0) cO O >
CO pq 0) (0 O
c CQ PQ « "
§ct) PP
0) Al rC <"
rQ 0 CO *-" W H
(fl CO T3 H CO W)
(U O
-------
Table II-D. (Contd.) d. Intertidal exposed unconsolidated
ro
CO
o
Mollusca - Gastropoda
Lacuna variegata her.
Crustacea - Mysidacea
Archaeomysis grebnitzkii
dep .
Crustacea - Amphipoda
Gammaridea spp . dep .
(Accedomoera vagor dep . ,
Anisogammarus puget ten-
sis her., Eohaustorius
spp . dep . , Paramoera
mohri dep . , Paraphoxus
spp. dep.)
4-1 00
•f-4 r*
Tl p
M tfl 1-4 C/5
•H S -03 CU
Ho W U p
38.0 16.1
0.2 0.2
354.7 161.7 13118.9 49.2 8838.0
2.0 1.5 81.1 0.6
jg
u
cd
>-, 0)
pQ
cd
OJ ^d
o cd
t>0 X)
iJ W
8.2
0.8
23.0
0.8
1723.3 41.3
12.6 1.5
fi
0 J3 0>
cd o >
-------
Table II-D. ( Contd.) e. Subtidal exposed unconsolidated
Dungeness Spit Guemes South West Beach
Chlorophyta
Ulva spp. 1.2
Rhodophyta
Gracilariopsis sjoestedtii 0.6
Neogardhiella baileyi 0.6
Nemertea spp. pre. 62.5 21.7
1.3 0.2
Polychaeta
Capitellidae
Mediomastus sp. dep. 915.0 139.2 33.8
1.0 0.7 0.1
Dorvilleidae
Onuphis sp. sea. 47.3
11.8
Protodorvillea gracilis pre. 228.0
1.0
Hesionidae
Micropodarke dubia dep. 110.0 19.2 5.3
1.0 0.1
Orbiniidae
Scoloplos pugettensis dep. 102.7
3.3
Spionidae
Prionospio steenstrupi dep. 73.0 7.5 2.0
1.0 0.1
Syllidae
Exogone spp. pre. 254.0 32.5 1.5
1.0 0.1
Molluscs - Bivalvia
Mysella tumida sus. 50.0 56.7 160.7
2.0 0.3 0.5
Protothaca staminea 17.5
280.5
Continued
231
-------
Table II-D. ( Contd.) e. Subtidal exposed unconsolidated
Molluscs - Bivalvia (Contd.)
Psephidia lord! sus.
Saxidomus giganteus sus.
Molluscs - Gastropoda
Natica clausa pre.
Nucella lamellosa pre.
Crustacea - Tanaeidacea
Leptochelia sp. dep.
Crustacea - Cirripedia
Balanus glandula sus.
Crustacea - Amphipoda
Gammaridea spp. dep.
Echinodermata
Dendraster excentricus dep.
Dungeness Spit Guemes South
25.0
2.0
5.0
172.2
0.8
3.7
2.5
1.8
123.0 93.3
2.0 0.1
323.7
9.0
470.0 467.3
2.0 5.7
West Beach
1574.8
12.7
0.2
0.2
155.3
0.1
1414.7
3.5
0.2
15.9
Continued
232
-------
Table II-D. (Contd.) f. Intertidal protected unconsolidated
Chlorophyta
Enteromorpha spp.
Phaeophyta
Fucus distichus
ro Rhodophyta
CO
Rhizoclonium sp.
4J
•H t^
o n)
Cu FM ej ?>•> PQ
B is to
CO i-i O PQ O
U 4J 4J 00
(U W ,C iH
,£) Jrf
cd cd
PQ PQ
CO W
rH 4-1
iH 0
•H O
T3 CD
CO (U
^ s
2.4
14.0 *
o
.0
M
Rj
P^
f-J
o
4-J
^i
(0
M
Q
2568.0
76.0
Angiosperms
Zostera marina
Nemertea spp. pre.
Nematoda spp. det.
Oligochaeta spp. det.
Polychaeta
Arenicolidae
Abarenicola sp./
A., pacifica dep.
74
120
248
2
.0
.2
.9
.0
222.
1.
1092.
2.
360.
3.
0
7
5
3
7
5
25
1
150
3
24460
2
827
14
300.0
.2 5.6
.2
.1 2.0
.3
.7 2.8
.0
.8
.0
5.2 944
48.4 31
1.2 1
36
140.4 14
26
4
.0
.2 131.5
.2
.0 3334.6
.0 8783.7
.8 209.1
.0
736.0
20.0
2.0
13.6
Continued
*present, but not quantified
-------
Table II-D. (Contd.) f. Intertidal protected unconsolidated
CO
Polychaeta (Contd.)
Capitellidae
Capitella capitata dep.
Mediomastus sp. dep.
Notomastus tenuis dep.
Cirratulidae spp. dep.
Chaetozone sp.,
Tharyx multifilis)
Dorvilleidae
Dorvillea spp. pre.
Glyceridae
Hemipodus borealis pre.
Goniadidae
Glycinde picta pre.
g.
5
o
,0
ft
0)
Gc
458.0
2620.0
38.0
924.0
546.9
1,7
40.5
4J
rt
•H
Q
PH
4J
4J
>
rt rt nJ
>•> PQ M «
M 0 n) +J
00 iH -M
J2 rH «H O
0 C8 -rt 0
)_l nQ T3 CO
•H -H nj 0)
pq PH PM 3=
48.8 39.6 52.8 1472.8
0.7
10.0 4470.6
2.8 17.6 31.4 13.7
0.8 1.6
7397.5
3.6 1233.7
0.8 0.3
13.6 26.8 4.0
0.8 1.2
M
O
^
H
cd
EC
C
O
•p
>1
cd
M
O
19.6
0.4
52.0
2.0
92.0
4.4
16.0
0.6
26.4
7r>
.2
135.6
3.6
Continued
-------
Table II-D. (Contd.) f. Intertidal protected unconsolidated
no
OJ
en
a
cd
u
^o
ff)
01
Polychaeta (Contd.)
Lumbrineridae
Lumbrineris spp. dep. 571.2
Maldanidae spp. dep. 167.5
Nephtyidae
Nephtys spp. pre. 0.6
Nereidae
Platynereis bicanaliculata 816.2
her.
Opheliidae
Annaridia brevis dep. 456.4
4-1
a
•H
O
PH
4-1
4-1
01
&
O
P
CO
^
461.5
6.8
444.5
0.8
96.8
0.5
50.2
1.2
J>^
CO
>% pq
a]
W O
00
_r*j f— f
u n)
)-< -O
•H -H
pQ pM
0.8
16.0 2.0
1.6 0.4
2.0
17.2 6.4
2.8
>, >.
CO CO
pq pq
(0 4->
rH 4-1
r-l O
•H O
T3 CO
CO Q)
PH &
26.2
305.0
0.3
2446.9
4.0 2783.7
M
O
J3
M
tfl
PC
(3
0
4J
^
<0
}-i
0
1.6
0.8
1.2
22.8
0.8
Continued
-------
Table II-D. (Contd.) f. Intertidal protected unconsolidated
r\>
oo
!
CJ
» *
CD CQ co
FP ' PQ }rj
cs w a
iH 4J O
rH O 4J
•H 0 >,
*o TO a>
CO 0) M
(^ S Q
0.3
1.2 16.6
39.7 2.0
5.6 335.6 1.2
159.7
268.7
sus./dep.
Continued
-------
JiaDJie LL-U. (.Contd.; ±. Intertidal protected unconsolidated
IND
CO
Polychaeta (Contd.)
Spionidae spp. dep.
Malacoceros glutaeus dep.
Polydora spp. dep.
Pygospio elegans sus. dep.
Streblospio benedicti dep.
Syllidae
Exogone spp. pre.
Terebellidae
Pista spp. dep.
Polycirrus spp. dep.
c
•H
CX CM
CO 4-)
CJ 4J
01
JQ ^4
& CJ
QJ 0)
S PQ
16.9 1644.1
7.5
44.8
446.9
74.1 115.7
0.7
2142.0 1195.3
2.0
437.9 158.7
2.0
g
0
4-1
CO
0)
1
8845.7
3.7
3291.3
1.7
431.0
0.8
4754.3
1.2
1366.0
1.3
s $ $ S
PQ O cO 4J
60 iH 4J
•C rH rH O
cJ cd -H cj
M *O *T3 CO
•H "H CO CO
W F^ PH 3
14.0 6.0 0.3
0.8 27.2
11.2 1.4 27.2 1070.0
8.0 9.6 47.8
50.8
2319.4
47.2
14
0
,0
W
o
4->
Q
1.2
24.0
0.8
90.0
2.4
Continued
-------
Table II-D. (Contd.) f. Intertidal protected unconsolidated
IN3
CO
oo
Polychaeta (Contd.)
Mollusca - Bivalvia
Clinocardium nuttallii
sus.
Cryptomya calif ornica sus.
Macoma nasuta dep./sus.
Macoma spp. dep./sus.
Mya arenaria sus./dep.
Mysella tumida sus.
Mytilus edulis sus.
Protothaca staminea sus.
Tapes japonica sus.
Continued
CX PM
00 4J
U 4J
0)
J2 X
-D U
OJ a)
5.6 145.3
9.5
95.6
23.4 28.7
5.5
19.7
0.6 3624.2
8.0
10.9 812.8
2.3
54.4 94.2
6.7
0.7
5 to
4-1
(D JS
5 -H
<-} «
7.6
5.6
2.0
13.7 0.8
60.3 8.0
32.0 23.6
2.8 4.8
12.0
1.2
36.0
7.6
1.2
«
0
bO
rH
01
'O
•H
6.0
4.8
21.6
144.4
6.4
2.8
7.6
12.4
1.2
1.6
Padilla Bay
6.8
40.0
6.8
3.2
13.6
18.4
1.2
10.8
Wescott Bay
Drayton Harbor
2.5
130.4
6.4
149.4 10.0
8.0
33.7 44.0
9.6
14.1 8.0
6.4
1.2
0.9 30.4
30.4
22.2 0.4
1.6
8.0
23.2
-------
Table II-D. (Contd.) f. Intertidal protected unconsolidated
ro
CO
1
1
Mollusca - Bivalvia (Contd.)
Transennella tantilla sus. 1196.2
Tresus spp. sus. 0.6
Molluscs - Gastropoda
Aglaja diomedea pre. 16,6
Eubranchus olivaceous pre.
Haminoea vesicula pre.
Lacuna varie^ata her.
Littorina scutulata her. 0.6
Littorina sitkana her. 22.2
Nassarius mendicus pre.
Beckett Point
242.8
2.3
76.8
41.5
348.3
2.2
5.8
2.8
fr & %
CO co Co
g f*. W rt Pd
o FP o o) 4J
4J 00 »H *J
CO J3 H H O
ci; o n) -H o
0 >-l T3 "O W
CO -H -H OJ 0)
1-3 pq fn P^ ts
1666.2 6.0 1052.8
6.0
1.2 13.6 2.0 52.5
0.4
17.6
3.2 7.2 0.6
0.4
120.0
.04
22.8
2.4
Drayton Harbor
3.6
0.8
0.8
0.1
22.8
1.6
30.4
0.4
Continued
-------
Table II-D. (Contd.) f. Intertidal protected unconsolidated
ro
-p»
o
P.
1
Phoronida
Phoronopsis harmeri sus.
Crustacea - Tanaidacea
Leptochelia dubia sus. 1779.2
Crustacea - Cirripedia
Balanus glandula sus. 12.6
Crustacea - Amphipoda
Caprella sp. dep. 190.3
Gammaridea sp. 908.4
(Corophium sp. sus. /dep.,
Eohaustorius dep.,
Anisogammarus sp. her.,
Orchestia traskiana sea.,
Parophoxus sp. dep.)
Crustacea - Isopoda
Exosphaeroma sp. sea. 5.2
Beckett Point
6372.7
3.5
676.3
612.0
690.5
4.7
420.5
4.0
cd cd cd
a >•> PQ w w
3 Cd
o PQ o cd 4-1
*J 00 r-t *-"
CO ,C rH i-H O
a> u cd T( o
§M "O IO TO
•H JH «d «
<-> pq N 0* 3
12.0 97.6
1.6
670.3 8.4 1.6 1010.0
2.3
20.0 28.0 0.3
1.2 1.1
1.2 435.9
553.0 445,6 302 290.0 6395.9
6.8 2.4
Dray ton Harbor
194.0
2.0
180.0
0.8
378.0
66.8
6.0
0.4
316.0
2.8
Continued
-------
Table II-D. (Contd.) f. Intertidal protected unconsolidated
ro
1
Crustacea - Isopoda (Contd.)
Gnorimosphaeroma oregonensis 74.3
sea.
Crustacea - Decapoda
Hemigrapsus oregpn.ensis sea. 1.1
Pagurus spp . dep. 1.9
Pinnixa sp. pre. 26.8
Upogebia pugettensis
sus . /dep.
Insecta - Dipteraii larvae 2.5
spp. her. /dep.
Echinodermata
Dendraster excentricus dep.
Leptosynapta clarki dep.
•u
C
o cd td at
O« (3 >• PQ PP W
3 ctj
w o m o cd 4J
4J 4-1 00 rH 4-*
QJ CO JS H iH O
^i CO O Cd -H O
O fi P T) T3 CD
0) «j -H -H W 0)
« >-3 PQ fe flj tS
0.4 0.4
7.6 1.2 12.4
4.0 0.4 1.6
4.3 0.4 0,3
0.3
22.2 20.3
1.0
112.7 0.6 5.2
34.3 2.8
4.0 122.8
264.8
9.5
44.5 57.2 0.4 0.4
1.5 2.0
Drayton Harbor
12.4
6.4
12.8
0.4
1.0
Continued
-------
Table II-D. (Contd.) g. Subtidal protected unconsolidated
Beckett
Point
James town
Birch Fidalgo
Bay Bay
Phaeophyta
Laminaria saccharina
Khodophyta
Gracilariopsis sjoestedti
Neogardhiella baileyi
Angiosperms
Zostera marina
Nemertea spp. pre.
Nematoda spp. dep.
Oligochaeta spp. det.
Polychaeta
Ampharetidae
Ampharete arctica dep.
Capitellidae
Mediomastus sp. dep.
Chaetopteridae
Mesochaetopterus taylori
sus./dep.
Phyllochaetopterus
prolifica sus./dep.
Spiochaetp_p_terus_ costarum
sus./dep.
Cirratulidae
Tharyx multifilis dep.
Dorvilleidae
Protodorvillea gracilis
pre.
Continued
330.0
2.0
260.0
< 2.0
158.0
< 2.0
413.0
< 1.0
135.0
< 2.0
133.0
2.0
881.0
< 2.0
445.0
< 2.0
120.0
1.0
611.0
2.0
180.0
2.0
131.0
2.0
146.0
2.0
996.7
4945.0
64.2
1.7
428.0
0.1
165.0
1.3
1.7
175.0
390.0
1036.7
27.5
1.5
44.3
0.4
242
-------
Table II-D. (Contd.) g. Subtidal protected unconsolidated
Beckett
Point
Polychaeta (Contd.)
Goniadidae
Glycinde picta pre.
Hesionidae
Micropodarke dubia dep. 758.0
2.0
Lumbrineridae
Lumbrineris spp. dep.
Maldanidae
Maldane glebiflex dep.
Nicoinache personata dep .
Nereidae
Platynereis bicanaliculata 1728.0
her. 1.0
Opheliidae
Annandia brevis dep.
Oweniidae
Owenia fusifonnis dep. 68.0
2.0
Phyllodocidae
Eulalia sanguinea pre. 203.0
Z.U
Phyllodoce spp. pre. 517.0
— 2.0
Polynoidae
Hartnothoe imbricata pre.
Sabellidaa
Sabella media sus .
Birch Fidalgo
Jamestown Bay Bay
67.5 92.5
1.1 1.1
521.0 3.3
2.0
34.2 88.3
2.2 2.7
127.5 4.2
3.1 0.2
220.0
2.0
251.0 17.8
2.0 0.1
247.5 50.2
0.5 0.2
90.0 3555.8 241.0
1.5 28.0 2.7
1.7
22.5 4.2
0.2
308.0 24.3 2.5
2.0 0.4 0.2
135.0
i n
Continued
243
-------
Table II-D. (Contd.) g. Subtidal protected unconsolidated
Beckett Birch Fidalgo
Point Jamestown Bay Bay
Polychaeta (Contd.)
Scalibregmidae
Scalibregma inflatum dep. 259.2
5.8
Spionidae
Polydora spp. dep. 578.0 36.0 50.8 362.5
2.0 2.0 0.8 1.0
Prionspio steenstrupi dep. 1180.0 156.0 30.0 8.3
2.0 2.0 0.2
Sternaspidae
Sternaspis scutata dep. 68.3 25.0
8.2 0.8
Syllidae
Exogone sp. pre. 1383.0
2.0
Mollusca - Gastropoda
Alvinia sp. sea./dep. 328.0 218.0 74.5 4.2
4.0 2.0 0.2
Margarites spp. her. 211.0 12.7
2.0 0.1
Mollusca - Bivalvia
Axinopsida serricata sus. ou.u LI^.L
0.3 1.4
Clinocardium nuttalj^ sus. 115.0 284.2 7.5
2.0 1.8
Crenella decussata sus. 726.0
2.0
Macoma spp. sus./dep. 203.0 289.0 167.5 77.5
3.0 19.0 26.5 40.9
Mysella tumida sus./dep. 2183.0 865.0 1480.0 160.8
3.0 2.0 7.5 0.6
Nucula tenuis dep. 106.7 54.2
1.5 0.8
Continued
244
-------
Table II-D. (Contd.) g. Subtidal protected unconsolidated
Beckett
Point
Mollusca - Bivalvia
Psephidia lordi sus.
Tellina spp. sus./dep. 261.0
11.0
Crustacea - Tanaidacea
Leptochelia dubia dep. 788.0
2.0
Crustacea - Amphipoda
Gammaridea spp. dep. 3001.0
4.0
Crustacea - Decapoda
Pagurus spp. dep. 158.0
2.0
Pinnixa occidentalis pre.
Pugettla gracilis her.
Echinodenns
Leptosynapta clarki dep.
Birch
Jamestown Bay
183.0 410.8
2.0 4.7
68.3
0.8
2008.0 7.5
2.0
1598.0 746.2
3.0 4.1
6.7
0.2
830.0
10.4
88.0
2.0
95.8
Fidalgo
Bay
817.2
6.8
7.5
0.6
50.8
705.5
3.1
0.8
158.3
1.7
0.8
1.7
245
-------
APPENDIX III
PERCENT OCCURRENCE, MEAN DENSITY (No./knf )
AND STANDARD DEVIATION FOR COMMON BIRD SPECIES
IN INTERTIDAL/SUBTIDAL, NEARSHORE, AND OFFSHORE HABITAT TYPES
247
-------
Table III-A. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in intertidal/subtidal,
rock (exposed rock) habitat
Species
SPRING (n=21)
Mean
% Density S.D.
SUMMER (n=6)
Mean
Density S.D.
Great Blue Heron
Common Goldeneye
Bufflehead
Harlequin Duck
White-winged Scoter
Surf Scoter
Black Scoter
Bald Eagle
Spotted Sandpiper
Glaucous-winged Gull
Western Gull
Herring Gull
Thayer's Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Common Tern
19
14
19
19
5
19
5
90
1.09
0.21
0.14
1.76
0.03
0.24
0.03
10.65
4.13
0.61
0.31
4.20
0.13
0.60
0.13
17.45
5
29
0.02
12.54
0.12
36.04
17
17
100
0.10
0.22
0.24
7.87
0.53
6.41
248
-------
%
10
10
90
10
7
33
17
73
23
17
FALL
Mean
Density
0.31
0.04
17.54
12.12
0.10
16.35
0.42
124.87
1.39
3.52
(n-30)
S.D.
1.04
0.13
34.18
63.31
0.46
54.68
1.41
231.72
5.02
9.66
WINTER (n=31)
Mean
% Density S.D.
6 0.14 0.54
19 0.30 0.76
32 1.76 5.42
16 0.23 0.80
23 1.65 3.49
32 0.50 1.04
100 16.85 23.31
19 0.40 0.97
61 10.88 25.01
26 2.85 6.66
Species
Great Blue Heron
Common Goldeneye
Bufflehead
Harlequin Duck
White-winged Scoter
Surf Scoter
Black Scoter
Bald Eagle
Spotted Sandpiper
Glaucous-winged Gull
Western Gull
Herring Gull
Thayer's Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Common Tern
249
-------
Table III-B. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in intertidal/subtidal
rock (protected rock) habitat
Species
SPRING (n=27)
Mean
Density S.D.
SUMMER (n=7)
Mean
Density S.D.
Great Blue Heron
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Bald Eagle
Killdeer
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Common Tern
4
15
30
18
15
41
15
100
7
18
0.15
0.34
2.33
0.68
0.66
12.44
0.22
22.37
0.28
27.52
0.79
0.94
5.12
1.84
1.60
47.67
0.54
11.73 100 34.86 51.23
14 0.12 0.29
1.26
119.53
250
-------
%
28
22
6
3
97
22
9
87
31
12
FALL
Mean
Density
0.68
2.71
0.09
0.16
42.80
0.42
0.13
229.12
29.80
0.25
(n-30)
S.D.
1.39
8.04
0.36
0.87
98.49
0.93
0.47
457.33
101.24
0.79
WINTER (n=31)
Mean
% Density S.D.
15
44
82
26
32
62
26
100
65
32
0.36 1.15
1.78 3.02
16.16 28.21
1.10 2.79
1.28 3.09
4.62 6.39
0.45 0.95
17.45 15.42
7.69 17.19
35.96 153.73
Species
Great Blue Heron
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Bald Eagle
Killdeer
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heenaann's Gull
Common Tern
251
-------
Table III-C. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in intertidal/subtidal
rock (cobble) habitat
Species
Great Blue Heron
Mallard
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Killdeer
Sanderling
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
SPRING (n=49) SUMMER (n=L6)
Mean Mean
% Density S.D. % Density S.D.
6 0.05 0.18
6 0.16 0.63
22 11.85 48.21
26 0.61 1.64
22 2.29 7.83
31 5.95 24.86
33 3.34 14.10 19 2.93 7.64
41 27.42 168.24 19 0.76 1.69
80 1090.17 2966.04 37 9.02 27.92
13 0.04 0.12
80 30.44 56.78 100 13.42 11.93
13 0.53 1.71
35 18.53 72.19 6 0.03 0.12
59 89.38 322.67 6 0.06 0.24
252
-------
%
12
43
37
57
12
100
32
25
78
34
FALL
Mean
Density
0.05
1.58
0.76
8.08
0.85
9.09
1.23
0.76
6.60
5.54
(n=65)
S.D.
0.16
3.44
1.58
14.14
2.92
11.85
6.02
2.71
11.69
17.21
WINTER (n=54)
Mean
% Density S.D.
67 9.60 22.28
70 2.61 3.87
74 7.58 19.56
59 2.29 3.39
50 1.17 1.83
48 1.06 2.07
100 25.14 40.64
93 8.57 10.36
46 2.45 6.49
18 0.67 1.93
Species
Great Blue Heron
Mallard
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Killdeer
Sander ling
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
253
-------
Table III-D. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in intertidal/subtidal,
exposed unconsolidated (mixed coarse) habitat
SPRING (n=49) SUMMER (n=15)
Mean Mean
Species % Density - S.D. % Density S.D.
Great Blue Heron
Greater Scaup 24
Common Goldeneye 41
Bufflehead 51
Oldsquaw 16
Harlequin Duck 33
White-winged Scoter 63
Surf Scoter 84
Black Scoter 26
Bald Eagle
Killdeer
Glaucous-winged Gull 86
Western Gull
California Gull
Mew Gull 35
Bonaparte's Gull
Heermann's Gull
47 1.02 2.45
1.65 4.60 7 0.03 0.12
1.91 4.31
15.22 39.29
0.24 0.65
0.67 2.12 13 1.95 5.25
2.46 4.02 20 0.90 2.35
13.20 21.42 40 7.27 20.38
1.50 5.28
7 0.11 0.39
7 0.02 0.08
57.54 91.37 73 33.39 54.76
13 0.81 2.86
4.69 17.02
13 1.92 6.24
254
-------
%
33
17
47
65
73
11
58
33
57
47
FALL
Mean
Density
0.59
0.85
7.56
10.15
53.73
0.63
47.75
14.35
20.75
12.87
(n=81)
S.D.
1.30
2.83
16.99
17.93
104.33
3.74
165.69
110.82
61.00
36.87
WINTER (n=87)
Mean
% Density S.D.
54 6.18 11.62
85 11.64 14.59
86 36.84 70.33
57 16.97 128.85
40 3.14 6.79
60 3.28 6.69
90 16.62 18.50
65 2.75 4.32
76 112.12 387.31
68 47.01 225.14
Species
Great Blue Heron
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Black Scoter
Bald Eagle
Killdeer
Glaucous-winged Gull
Western Gull
California Gull
Mew Gull
Bonaparte's Gull
Heennann's Gull
255
-------
Table III-E. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in intertidal/subtidal,
exposed unconsolidated (sand) habitat
SPRING (n=4) SUMMER (n=3)
Mean Mean
Species % Density S.D. % Density S.D.
Great Blue Heron
Common Goldeneye 25
Bufflehead 25
Oldsquaw
Harlequin Duck
White-winged Scoter 25
Surf Scoter 75
Bald Eagle 50
Killdeer
Glaucous-winged Gull 100
California Gull
Mew Gull 25
Bonaparte's Gull 25
Heermann's Gull
Common Tern
3.18 5.51
4.55 7.87
1.98 3.43
6.13 3.93
0.68 0.75 67 0.72 0.53
33 0.14 0.20
14.72 7.54 100 44.36 19.80
67 0.86 0.68
0.45 0.79 67 0.86 0.68
19.77 34.25
«
256
-------
%
10
20
30
20
100
60
20
60
80
30
FALL
Mean
Density
0.09
1.21
17.11
0.17
103.08
9.76
67.86
44.06
26.69
50.00
(n-10)
S.D.
0.27
2.89
39.19
0.35
131.94
19.07
203.44
98.88
46.59
142.53
WINTER (n=7)
Mean
% Density
29
14
100
71
29
29
86
100
57
43
1.17
0.39
15.83
2.31
8.05
0.31
8.17
25.83
6.75
3.18
S.D.
2.51
0.95
14.63
2.21
13.46
0.50
9.90
35.05
14.34
7.25
Species
Great Blue Heron
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Bald Eagle
Killdeer
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Common Tern
257
-------
Table III-F. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in intertidal/subtidal,
protected unconsolidated (mud-gravel) habitat
Species
Great Blue Heron
Black Brant
Common Pintail
American Wig eon
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Black Scoter
Western Sandpiper
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann * s Gull
SPRING (n=ll)
Mean
% Density S.D.
64 0.38 0.40
64 11.08 13.25
54 30.70 63.28
64 0.54 0.67
73 21.29 32.81
91 43.27 73.64
100 122.03 247.08
91 1.89 2.83
100 36.82 38.90
64 1.42 1.53
SUMMER (n=2)
Mean
% Density S.D.
100 1.45 1.33
. 50 0.24 0.24
50 0.03 0.03
100 0.61 0.50
100 14.33 7.33
50 0.03 0.03
258
-------
FALL (n=9)
Mean.
% Density S.D.
100 0.97 0.72
11 1.47 4.16
78 12.62 18.22
89 9.36 13.93
11 0.80 2.27
100 29.06 32.84
56 4.23 8.48
56 0.49 0.80
78 8.09 12.60
22 0.13 0.29
WINTER (n=12)
Mean
% Density S.D.
50
75
83
100
100
83
92
100
50
100
100
1.61
11.99
171.45
57.82
100.55
62.61
52.59
140.63
0.13
32.29
14.42
2.02
19.58
325.27
111.06
133.77
171.49
70.78
271.15
0.20
62.43
30.61
Species
Great Blue Heron
Black Brant
Common Pintail
American Wigeon
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
Harlequin Duck
White-winged Scoter
Surf Scoter
Black Scoter
Western Sandpiper
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
259
-------
Table III-G. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in intertidal/subtidal,
protected unconsolidated (mud-sand) habitat
Species
Great Blue Heron
Black Brant
American Wigeon
Greater Scaup
Common Goldeneye
Bufflehead
SPRING (n=L7) SUMMER (n=2)
Mean Mean
% Density S.D. % Density S.D.
64
36
57
36
57
276.16
31.79
11.90
10.84
57.80
100 4.28 1.97
402.44
71.89
22.75
32.35
102.58
Harlequin Duck
White-winged Scoter
Surf Scoter
Killdeer
Black-bellied Plover
Black Turnstone
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
79 14.91 34.01
100 22.45 14.67
43
29
4.22
25.94
12.34
100 141.57 144.56
47.62
50
1.25 1.25
50 22.19 22.19
100 354.40 97.48
260
-------
FALL (n=20)
Mean
% Density S.D.
55 4.07 6.66
40 752.20 1695.50
50 11.08 26.06
85 28.54 27.79
30 0.44 0.77
95 108.61 219.59
40 84.43 246.42
65 7.26 14.76
65 18.53 33.35
55 2.38 5.05
WINTER (n=27)
Mean
% Density S.D. Species
Great Blue Heron
67 122.44 314.75 Black Brant
89 411.26 544.59 American Wigeon
63 42.34 93.62 Greater Scaup
70 22.65 30.68 Common Goldeneye
96 274.10 445.80 Bufflehead
33 1.26 2.80 Harlequin Duck
74 14.59 22.67 White-winged Scoter
100 76.38 134.41 Surf Scoter
Killdeer
Black-bellied Plover
Black Turnstone
96 36.78 25.68 . Glaucous-winged Gull
California Gull
70 21.61 63.17 Mew Gull
Bonaparte's Gull
Heermann's Gull
261
-------
Table III-H.
Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in intertidal/subtidal,
protected unconsolidated (mud) habitat
Species
Great Blue Heron
Black Brant
Mallard
Common Pintail
American Wigeon
Greater Scaup
Common Goldeneye
Bufflehead
Oldsquaw
White-winged Scoter
Surf Scoter
Bald Eagle
Killdeer
%
91
77
98
74
79
58
79
95
SPRING (n=43)
Mean
Density
1.73
. 147.25
65.13
1.60
23.25
0.86
6.15
73.71
S.D.
1.85
265.36
127.07
4.90
65.77
2.24
7.88
250.21
SUMMER (n=17)
Mean
% Density
100 6.75
41 0.16
76 3.30
65 1.18
71 2.12
59 0.04
71 0.77
S.D,
5.39
0.36
5.08
1.90
2.95
0.05
1.88
Dunlin
Glaucous-winged Gull 93
California Gull
Ring-billed Gull
Maw Gull 56
Bonaparte's Gull
22.34
19.40
7.49
17.52
100 41.85 37.15
35 0.65 1.58
59 8.99 15.19
262
-------
FALL (n=72)
Mean
% Density S.D.
96 5.24 5.84
72 47.01 145.45
75 9.82 16.17
87 18.99 46.68
75 0.91 1.38
97 20.38 22.09
72 2.64 5.13
82 5.10 7.42
75 7.13 15.55
93 29.73 144.75
WINTER (n=82)
Mean
% Density S.D. Species
Great Blue Heron
Black Brant
Mallard
88 49.32 88.85 Common Pintail
87 64.93 98.63 American Wigeon
99 67.51 66.91 Greater Scaup
95 8.23 15.63 Common Goldeneye
100 59.79 153.38 Bufflehead
Oldsquaw
99 10.38 14.88 White-winged Scoter
96 20.48 31.24 Surf Scoter
Bald Eagle
Killdeer
82 93.35 130.32 Dunlin
100 14.78 16.12 Glaucous-winged Gull
California Gull
Ring-billed Gull
89 7.91 14.62 Mew Gull
Bonaparte's Gull
263
-------
Table III-I. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in nearshore waters (less
than 20 m) exposed unconslidated{mixed coarse) habitat
Species
Common Loon
Red-throated Loon
Red-necked Grebe
Horned Grebe
Western Grebe
Doub le-cres ted
Cormorant
Pelagic Cormorant
Common Merganser
Red-breasted Merganser
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet
SPRING (n=49)
Mean
% Density S.D.
67 1.42 2.12
47 0.72 1.50
55 4.26 6.08
51 2.70 4.60
41 1.37 3.32
92 4.71 4.07
65 8.26 13.43
86 57.54 91.37
35 4.69 17.02
63 2.78 5.02
SUMMER (n=15)
Mean
% Density S
57 0.47 0
20 0.12 0
20 0.10 0
73 2.95 5
13 0.73 2
73 33.39 54
13 1.92 6
80 3.81 3
33 2.13 6
27 5.74 13
.D.
.60
.30
.21
.43
.06
.76
.24
.95
.04
.64
264
-------
%
63
42
41
36
47
73
58
57
47
43
FALL
Mean
Density
1.12
2.43
3.66
2.51
5.85
55.73
47.75
20.75
12.87
1.72
(n=81)
S.D.
1.43
5.30
7.40
5.93
23.21
104.33
165.69
61.00
36.87
3.43
WINTER (n=87)
Mean
% Density S.D.
68 1.32 1.56
46 0.64 1.26
45 1.78 4.10
82 8.14 10.45
75 13.56 33.30
56 3.32 5.71
74 5.82 8.00
72 6.29 9.79
76 112.12 387.31
68 47.01 225.14
Species
Common Loon
Red-throated Loon
Red-necked Grebe
Horned Grebe
Western Grebe
Double-crested
Cormorant
Pelagic Cormorant
Common Merganser
Red-breasted Merganser
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet
265
-------
Table III-J.
Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in nearshore waters (less than
20 m) exposed unconsolidated (sand) habitat
Species
Common Loon
Arctic Loon
Red-necked Grebe
Horned Grebe
Western Grebe
%
25
75
50
50
SPRING (n=4)
Mean
Density
0.23
2.36
0.99
2.77
S.D.
0.39
1.82
1.12
3.40
SUMMER (n=3)
Mean
% Density
33 0.30
S.D.
0.43
Double-crested
Cormorant
Black Brant
Pelagic Cormorant
Red-breasted Merganser
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Common Murre
Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet
33
33
100
100
25
25
25
50
4.68
14.72
0.45
19.77
0.23
0.91
2.69
7.54
0.79
34.25
0.39
1.11
100
67
33
33
33
0.69 0.98
0.14 0.20
100 44.36 19.80
0.86 0.58
0.14 0.20
0.28 0.39
0.56 0.79
266
-------
%
40
40
40
40
100
60
60
80
70
40
FALL
Mean
Density
2.48
0.88
5.63
0.36
103.08
9.76
44.06
26.69
41.88
22.85
(n-10)
S.D.
4.06
1.21
9.63
0.57
131.94
19.07
98.88
46.59
85.76
38.63
WINTER (n=7)
Mean
% Density S.D.
57 11.93 15.86
71 5.90 6.92
100 13.00 9.31
57 7.62 8.04
71 3.30 4.06
100 25.83 35.05
57 6.75 14.34
43 3.18 7.25
86 8.21 8.88
43 0.51 0.66
Species
Common Loon
Arctic Loon
Red-necked Grebe
Horned Grebe
Western Grebe
Double-crested
Cormorant
Black Brant
Pelagic Cormorant
Red-breasted Merganser
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heerraann's Gull
Common Murre
Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet
267
-------
Table III-K.
Percent occurrence, mean density (No./kiO and standard
deviation of common bird species in nearshore waters (less than
20 m) protected unconsolidated (mud-gravel) habitat
SPRING (n=ll) SUMMER (n=2)
Mean Mean
Species % Density S.D. % Density S.D.
Common Loon 91 1.13
Red-throated Loon 64 0.28
Red-necked Grebe 64 0.72
Horned Grebe 82 4.30
Western Grebe 91 21.31
Double-crested
Cormorant
Pelagic Cormorant 82 0.43
Red-breasted Merganser 100 2.58
Glaucous-winged Gull 100 36,82
California Gull
Mew Gull 64 1.42
Bonaparte's Gull
Pigeon Guillemot 91 2.87
Marbled Murrelet
Rhinoceros Auklet
0.89 50 0.03 0.03
0.47
1.15
5.54
30.61
50 0.26 0.26
0.76 50 0.03 0.03
2.29
38.90 100 14.33 7.33
1.53
50 0.03 0.03
4.50 100 1.54 1.24
50 0.28 0.28
50 0.68 0.68
268
-------
FALL (n=9)
Mean
% Density S.D.
67 2.17 3.34
56 5.00 9.37
44 19.27 29.99
44 7.25 9.92
100 29.06 32.84
56 4.23 8.48
56 0.49 0.80
78 8.09 12.60
89 4.73 4.94
56 0.81 1.22
WINTER (n=12)
Mean
% Density S.D. Species
92 1.84 1.96 Common Loon
Red-throated Loon
100 2.65 2.82 Red-necked Grebe
100 14.98 14.63 Horned Grebe
92 44.00 46.00 Western Grebe
83 0.69 0.78 Double-crested
Cormorant
58 0.22 0.22 Pelagic Cormorant
75 8.11 15.15 Red-breasted Merganser
100 32.29 65.43 Glaucous-winged Gull
California Gull
100 14.42 30.61 Mew Gull
Bonaparte's Gull
92 0.95 1.31 Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet
269
-------
Table III-L. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in nearshore waters (less
than 20 m) protected unconsolidated (mud-sand) habitat
Species
SPRING (n=14)
Mean
Density
S.D.
SUMMER (n=2)
Mean
% Density S.D.
Common Loon
Red-throated Loon
Red-necked Grebe
Horned Grebe
Western Grebe
Double-crested
Cormorant
Pelagic Cormorant
Red-breasted Merganser
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Common Tern
Common ,Murre
Pigeon Guillemot
Rhinoceros Auklet
64
29
50
43
57
50
100
29
1.37
0.24
3.25
0.43
2.91
2.39
141.57
25.94
1.44
0.44
4.42
0.55
4.42
4.08
144.56
49.62
64
43
4.69
1.94
6.56
4.57
50
0.38 0.38
100 354.40 97.48
50
4.62 4.62
270
-------
%
60
55
40
95
40
65
65
55
35
60
FALL (n=20)
Mean
Density S.D.
2.15 3.36
9.98 22.09
0.98 1.81
108.61 219.59
84.43 246.42
7.26 14.76
18.53 33.35
2.38 5.05
4.44 8.31
7.57 11.62
WINTER (n=27)
Mean
% Density S.D.
74 2.19 2.51
2.6 0.36 0.73
85 9.19 10.18
41 19.30 50.80
•
30 0.76 1.55
59 7.12 14.82
96 36.78 25.68
70 21.67 63.17
18 2.06 6.50
26 1.12 2.94
Species
Common Loon
Red-throated Loon
Red-necked Grebe
Horned Grebe
Western Grebe
Double-crested
Cormorant
Pelagic Cormorant
Red-breasted Merganser
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Common Tern
Common Murre
Pigeon Guillemot
Rhinoceros Auklet
271
-------
Table I1I-M. Percent occurrence, mean density (No./km 2) and standard
deviation of common bird species in nearshore waters (less
than 20 m) protected unconsolidated (mud) habitat
SPRING (n=43) SUMMER (n=17)
Mean Mean
Species % Density S.D. % Density S.D.
Common Loon 86 1.12
Red-throated Loon 53 0.18
Red-necked Grebe 70 0.62
Horned Grebe 65 1.97
Western Grebe 81 14.28
Double-crested 81 1.71
Cormorant
Pelagic Cormorant
Red-breasted Merganser 84 1.92
Glaucous-winged Gull 93 22.34
California Gull
Ring-billed Gull
Mew Gull 56 7.49
Bonaparte's Gull 46 6.69
Pigeon Guillemot
Marbled Murrelet
1.29 82 0.31 0.34
0.36
0.95
4.61
31.97 47 0.92 2.65
1.92 76 3.00 3.48
2.59
19.40 100 41.85 37.15
23 0.39 1.10
35 0.62 1.58
17.52 23 0.03 0.06
24.30 59 8.99 15.19
47 0.31 0.69
47 0.31 0.73
272
-------
FALL (n=72)
Mean
% Density S.D.
83 1.66 2.52
69 4.19 15.19
65 3.76 7.40
65 20.70 36.20
86 3.91 4.85
97 20.38 22.09
72 2.64 5.13
82 5.10 7.42
75 7.13 15.55
93 29.73 144.75
WINTER (n=82)
Mean
% Density S.D. Species
96 1.32 1.41 Common Loon
74 1.75 5.93 Red-throated Loon
90 1.97 3.28 Red-necked Grebe
96 5.95 23.57 Horned Grebe
91 31.38 51.99 Western Grebe
93 3.16 4.27 Double-crested
Cormorant
52 6.28 52.42 Pelagic Cormorant
96 3.67 8.54 Red-breasted Merganser
100 14.78 16.12 Glaucous-winged Gull
California Gull
Ring-billed Gull
89 7.91 14,62 Mew Gull
Bonaparte's Gull
Pigeon Guillemot
Marbled Murrelet
273
-------
Table III-N. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in nearshore waters (less
than 20 m) protected rock (exposed rock) habitat
Species
Common Loon
Red-necked Grebe
Horned Grebe
Western Grebe
SPRING (n=21) SUMMER (n=6)
Mean Mean
% Density S.D. % Density S.D.
24
24
29
19
0.21
0.59
1.02
1.08
0.41
1.29
2.82
2.59
Double-crested
Cormorant
Pelagic Cormorant
Red-breasted Merganser
Glaucous-winged Gull
California Gull
Mew Gull
Black-legged Kittiwake
Bonaparte's Gull
Heermann's Gull
Common Tern
Common Murre
Pigeon Guillemot
Marbled Murrelet
43 0.73
43 1.81
90 10.65
29
33
14
12.54
0.84
0.90
1.05
3.46
17.45
36.04
2.01
2.60
50
100
17
0.39 0.46
7.87 6.41
0.10 0.23
83 4.18 2.36
17 0.20 0.44
274
-------
FALL (n=30) WINTER (n=31)
Mean Mean
% Density S.D. % Density
23
55
55
19
13 0.26 0.85 29
35
90 17.54 34.18 100
0.37
1.85
9.60
1.08
0.64
3.44
16.85
S.D.
0.86
2.85
28.20
2.71
1.25
7.46
23.31
Species
Common Loon
Red-necked Grebe
Horned Grebe
Western Grebe
Double-crested
Cormorant
Pelagic Cormorant
Red-breasted Merganser
Glaucous-winged Gull
33 16.35 54.68
17 0.42 1.41
73
23
17
23
23
27
124.87
1.39
3.54
1.33
0.61
1.73
231.72
5.02
9.66
3.00
1.41
4.82
61
26
10.88 25.01
2.85
6.66
26
0.63
1.23
California Gull
Mew Gull
Black-legged Kittiwake
Bonaparte's Gull
Heermann's Gull
Common Tern
Common Murre
Pigeon Guillemot
Marbled Murrelet
Z75
-------
Table III-O. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in nearshore waters (less
than 20 m) rock (protected rock) habitat
SPRING (n=27) SUMMER (n=7)
Mean Mean
Species . % Density S.D. % Density S.D.
Common Loon
Arctic Loon
Red-throated Loon 74
Red-necked Grebe 22
Horned Grebe 41
Western Grebe 22
Double-crested
Cormorant
Pelagic Cormorant 30
Red-breasted Merganser 44
Glaucous-winged Gull 100
29 1.07 1.82
14 0.12 0.29
0.70 1.62
1.10 3.16
2.34 4.11
6.77 24.03
14 0.48 1.17
1.03 1.97 29 7.40 17.40
3.13 5.37
22.37 11.73 100 34.86 51.23
California Gull
Mew Gull
Black-legged Kittiwake
Bonaparte's Gull
Heerniann's Gull
Common Murre
Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet
14 0.12 0.29
14
18
27.52
119.53
30
18
1.28
0.68
3.16
1.60
86
14
29
0.18 0.44
5.07 6.86
0.71 1.75
0.71 1.21
276
-------
FALL (n-32)
Mean
% Density S.D.
25 0.52 0.97
19 1.48 5.41
28 9.18 19.68
97 42.80 98.49
22 0.42 0.93
87 229.12 457.33
31 29.80 101.24
44 61,28 261.44
22 1.75 4.95
56 19.98 41.47
WINTER (n=34)
Mean
% Density S.D.
76 2.82 2.54
82 6.31 6.87
79 40.20 53.64
41 1.03 1.91
38 1.24 1.89
71 7.03 7.84
100 17.45 15.42
65 7.69 17.19
38 1.47 8.03
38 3,07 8.26
Species
Common Loon
Arctic Loon
Red-throated Loon
Red-necked Grebe
Horned Grebe
Western Grebe
Double-crested
Cormorant
Pelagic Cormorant
Red-breasted Merganser
Glaucous-winged Gull
California Gull
Mew Gull
Black-legged Kittiwake
Bonaparte's Gull
Heermann's Gull
Common Murre
Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet
277
-------
f\
Table III-P. Percent occurrence, mean density (No./km ) and standard
deviation of common bird species in nearshore waters (less
than 20 m) rock (cobble) habitat
SPRING (n=49) SUMMER (n=16)
Mean Mean
Species % Density S.D. % Density S.D.
Common Loon 47
Arctic Loon 33
Red-throated Loon
Red-necked Grebe 46
Horned Grebe 26
Western Grebe 39
Double-crested
Cormorant
Pelagic Cormorant 33
Red-breasted Merganser 20
Glaucous-winged Gull 90
California Gull
Mew Gull 35
Bonaparte's Gull 39
Heermann's Gull
Common Murre
Pigeon Guillemot 20
Marbled Murrelet
Rhinoceros Auklet
0.76 2.40 38 0.32 0.43
34.52 120.95 12 3.63 13.60
1.22 2.89
0.72 1.88
8.45 42.78 25 0.87 2.19
12 0.12 0.31
0.68 2.84 25 0.26 0.53
0.29 0.79
30.44 56.78 100 13.42 11.93
12 0.53 1.71
18.53 72.19
89.38 322.67
0.29 0.66 56 1.09 1.68
37 1.05 2.13
19 1.26 3.00
278
-------
%
49
32
37
48
100
32
78
34
43
43
FALL (n-65)
Mean
Density S.D.
0.52 0.72
1.08 2.38
4.21 17.37
1.15 3.14
9.09 11.85
1.23 6.02
6.60 11.69
5.54 17.21
1.02 2.04
1.01 1.86
WINTER (n=54)
Mean
% Density S.D. Soecies
72 0.61 0.55 Common Loon
Arctic Loon
43 0.84 1.86 Red-throated Loon
Red-necked Grebe
91 3.72 5.65 Horned Grebe
52 8.09 31.79 Western Grebe
Double-crested
Cormorant
61 1.69 3.32 Pelagic Cormorant
76 1.78 2.14 Red-breasted Merganser
93 8.57 10.36 Glaucous-winged Gull
California Gull
46 2.45 6.49 Mew Gull
Bonaparte's Gull
Heermann's Gull
35 2.34 6.50 Common Murre
Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet
279
-------
Table III-Q.
Number of species, total density (No./km2) and total
biomass for birds occurring in nearshore habitats in
spring 1978 and 1979, combined
Habitat
Number of Total Total
Species Density Biomass
Exposed unconsolidated, mixed coarse
Exposed unconsolidated, sand
Protected unconsolidated, mud-gravel
(mixed fine)
Protected unconsolidated, mud-sand
(Mixed fine)
Protected unconsolidated, mud
Rock, exposed rock
Rock, protected rock
Rock, cobble
16
9
16
A3.88
13.74
36.25
48.53
16.92
54.92
12
17
11
13
15
20.28
22.85
9.80
23.03
54.28
23.33
39.48
11.70
31.22
98.05
280
-------
Table III-R. Number of species, total density (No./km2) and total
biomass for birds occurring in nearshore habitats in
summer 1978 and 1979, combined
Habitat
Number of Total Total
Species Density Biomass
Exposed unconsolidated, mixed coarse
Exposed unconsolidated, sand
Protected unconsolidated, mud-gravel
(mixed sand)
Protected unconsolidated, mud-sand
(mixed fine)
Protected unconsolidated, mud
Rock, exposed rock
Rock, protected rock
Rock, cobble
12
6
20.21
4.81
3.13
19.32
8.80
2.10
2
15
4
8
9
5.38
5.29
4.97
15.92
9.63
3.08
11.16
2.69
20.84
13.65
281
-------
Table III-S. Number of species, total density (No./km2) and total
biomass for birds occurring in nearshore habitats in
fall 1978 and 1979, combined
Habitat
Number of Total Total
Species Density Biomass
Exposed unconsolidated, mixed coarse
Exposed unconsolidated, sand
Protected unconsolidated, mud-gravel
(mixed fine)
Protected unconsolidated, mud-sand
(mixed fine)
Protected unconsolidated, mud
Rock, exposed rock
Rock, protected rock
Rock, cobble
19
14
14
47.17 50.94
99.33 109.97
42.28
41.18
17
18
15
13
16
38.30
37.39
9.84
101.08
30.01
31.91
63.75
10.63
94.30
35.42
282
-------
Table III-T. Number of species, total density (No./km2) and total
biomass for birds occurring in nearshore habitats in
winter 1978 and 1979, combined
Habitat
Number of Total Total
Species Density Biomass
Exposed unconsolidated, mixed coarse
Exposed unconsolidated, sand
Protected unconsolidated, mud-gravel
(mixed fine)
Protected unconsolidated, mud-sand
(mixed fine)
Protected unconsolidated, mud
Rock, exposed rock
Rock, protected rock
Rock, cobble
18
15
18
55.03
62.15
79.82
81.36
77.75
116.18
27
19
15
15
14
47.01
57.97
26.20
83.41
24.27
66.48
95.66
32.94
116.15
34.90
283
-------
Table III-U. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in offshore waters
(greater than 20 m) bays habitat
Species
Common Loon
Arctic Loon
Red-necked Grebe
Horned Grebe
Western Grebe
Pelagic Cormorant
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Common Murre
Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet
SPRING (n=27) SUMMER (n=5)
Mean Mean
% Density S.D. % Density S.D.
18 0.25 0.67
22 0.96 2.64
37 1.31 2.46
22 1.02 2.50
78 70.60 89.99 60 2.17 2.46
18 0.36 0.88
96 6.58 6.13 100 10.86 9.84
20 4 . 00 8 . 00
33 3.80 9.72
22 3.27 10.22 40 0.33 0.42
20 0.09 0.18
284
-------
FALL (n=26) WINTER (n=33)
Mean Mean
_% Density S.D. % Density S.D. Species
Common Loon
11 1.79 7.71 Arctic Loon
58 2.67 3.64 Red-necked Grebe
8 0.26 1.00 36 2.56 8.66 Horned Grebe
35 23.74 81.48 85 123.83 172.31 Western Grebe
27 0.55 1.29 Pelagic Cormorant
92 4.95 7.26 94 11.98 14.67 Glaucous-winged Gull
35 1.16 2.05 California Gull
8 0.06 0.20 67 3.33 6.57 Mew Gull
42 2.97 6.40 39 16.83 58.08 Bonaparte's Gull
50 76.91 256.69 79 40.35 75.86 Common Murre
Pigeon Guillemot
30 3.49 7.21 Marbled Murrelet
11 0.32 1.06 Rhinoceros Auklet
285
-------
Table III-V. Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in offshore waters
(greater than 20 m) narrow passages habitat
Species
Arctic Loon
Red-necked Grebe
Western Grebe
Double-crested
Cormorant
Brandt's Cormorant
Pelagic Cormorant
Hooded Merganser
Glaucous-winged Gull
%
35
21
29
31
37
55
98
SPRING (n=62)
Mean
Density
84.15
0.37
0.59
0.33
85.68
.60
5.52
S.D.
281.11
1.14
1.29
0.83
265.05
1.04
5.99
SUMMER (n=23)
Mean
% Density
22 0.15
4 0.03
17 0.07
4 0.01
96 6.66
S.D.
0.37
0.13
0.20
0.04
6.16
Thayer's Gull
Mew Gull
Bonaparte's Gull
Common Tern
Common Murre
Pigeon Guillemot
Marbled Murrelet
Cassin's Auklet
Rhinoceros Auklet
24 0.41 1.76
33 44.88 153.74
68
2.38
3.49
4
52
22
4
4
0.01
0.60
0.23
0.02
0.01
0.06
0.86
0.53
0.11
0.06
286
-------
FALL (n=83)
Mean
Density S.D.
WINTER (n=112)
Mean
Density S.D.
Species
26
26
23
95
1.49
0.42
6.09
5.14
1.52
6.81 44.42
8.71
46
93
55
31
39
0.78
49.04
5.46
1.13
5.05
1.98
88.43
22.71
6.89
32.62
68
45
28.17
3.89
72.80
7.77
69 48.10 135.27
50 1.27 2.69
96 12.54 25.57
48 1.50 5.24
87 20.48 65.93
79 9.75 26.81
62 2.20 4.60
54 1.69 2.97
25
0.24
0.69
Arctic Loon
Red-necked Grebe
Western Grebe
Double-crested
Cormorant
Brandt's Cormorant
Pelagic Cormorant
Hooded Merganser
Glaucous-winged Gull
Thayer's Gull
Mew Gull
Bonaparte's Gull
Common Tern
Common Murre
Pigeon Guillemot
Marbled Murrelet
Cassin's Auklet
Rhinoceros Auklet
287
-------
Table III-W. Percent occurrence, mean density (No./km^ and standard
deviation of common bird species in offshore waters
(greater than 20 m) broad passages habitat
Species
SPRING (n=48)
Mean
Density S.D.
SUMMER (n=13)
Mean
% Density S.D.
Arctic Loon
Red-throated Loon
Western Grebe
Double-crested
Cormorant
Brandt's Cormorant
Pelagic Cormorant
Glaucous-winged Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Common Murre
Pigeon Guillemot
Marbled Murrelet
Rhinoceros Auklet
17
21
8.59
1.71
44.53
7.65
23
0.25
0.76
25
23
92
17
19
29
44
35
0.18
0.43
4.34
0.22
42.19
1.67
0.63
0.41
0.51
1.80 23
4.61 100
0.77
269.51
6.85 8
0.92 31
8
0.77 31
0.41 1.14
3.24 2.67
0.01 0.03
0.47 1.03
0.01 0.03
3.73 11.94
288
-------
FALL (n=64)
Mean
% Density S.D.
20 2.80 17.77
16 0.15 0.66
92 10.62 17.54
33 0.62 1.76
47 6.17 17.51
42 2.98 9.82
67 42.61 70.38
16 0.16 0.52
25 0.41 1.22
25 0.55 1.92
WINTER (n=76)
Mean
% Density S.D. Species
28 2.20 13.23 Arctic Loon
29 0.29 0.81 Red-throated Loon
Western Grebe
Double-crested
Cormorant
42 8.06 53.19 Brandt's Cormorant
39 0.36 0.64 Pelagic Cormorant
93 10.00 23.86 Glaucous-winged Gull
California Gull
59 9.41 36.68 Mew Gull
21 6.74 38.11 Bonaparte's Gull
Heermann's Gull
92 63.77 146.00 Common Murre
38 0.40 0.83 Pigeon Guillemot
17 0.34 1.28 Marbled Murrelet
Rhinoceros Auklet
289
-------
Table III-X.
Percent occurrence, mean density (No./km2) and standard
deviation of common bird species in offshore waters
(greater than 20 m) open waters habitat
Species
Arctic Loon
Wester Grebe
Fork-tailed Storm
Petrel
Black Brant
Pelagic Cormorant
Northern Phalarope
Parasitic Jaeger
Glaucous -winged Gull
Herring Gull
Thayer's Gull
California Gull
Mew Gull
Bonaparte's Gull
Heermann's Gull
Common Kurre
Pigeon Guillemot
Ancient Murrelet
Rhinoceros Auklet
Tufted Puffin
SPRING (n=16)
Mean
% Density S.D.
25 2.12 7.22
19 0.09 0.30
12 0.64 2.42
25 0.22 0.80
87 0.82 0.70
37 0.27 0.50
44 6.20 22.63
62 0.80 1.98
19 0.03 0.10
56 1.09 1.95
SUMMER (n=9)
Mean
% Density S.D.
11 0.04 0.10
11 0.02 0.05
11 0.01 0.04
44 0.14 0.26
100 3.57 4.36
11 . 1.44 4.06
78 0.77 1.26
22 0.03 0.06
67 2.30 2.63
33 0.04 0.07
290
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%
29
4
100
25
64
33
36
61
89
50
FALL (n=28)
Mean
Density S.D.
0.93 3.07
0.01 0.08
8.94 14.01
0.12 0.34
2.41 6.70
0.22 0.47
2.46 8.83
1.17 3.78
37.36 52.59
1.86 7.08
WINTER (n=36)
Mean
% Density
31 0.12
33 0.06
100 4.94
31 0.18
28 0.13
80 3.00
28 0.89
89 13.96
31 0.97
31 0.09
S.D.
0.30
0.16
5.70
0.67
0.28
8.31
2.18
26.71
2.24
0.20
Species
Arctic Loon
Western Grebe
Fork-tailed Storm
Petrel
Black Brant
Pelagic Cormorant
Northern Phalarope
Parasitic Jaeger
Glaucous-winged Gull
Herring Gull
Thayer's Gull
California Gull
Mew Gull
Bonaparte's Gull
Heennann's Gull
Common Murre
Pigeon Guillemot
Ancient Murrelet
Rhinoceros Auklet
Tufted Puffin
291
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Table III-Y. Number of species, total density (No./km2) and total
biomass for birds occurring in offshore habitats in
spring 1978 and 1979, combined
Number of Total Total
Habitat Species Density Biomass
Bays 21 103.06 164.54
Passages, narrow 29 229.29 407.93
Passages, broad 26 68.48 45.14
Open waters 23 15.62 12.88
292
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Table III-Z. Number of species, total density (No./km2) and total
biomass for birds occurring in offshore habitats in
summer 1978 and 1979, combined
Number of Total Total
Habitat Species Density Biomass
Bays 6 17.65 22.09
Passages, narrow 14 8.29 11.52
Passages, broad 8 8.14 7.08
Open waters 15 12.80 10.32
293
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Table III-AA. Number of species, total density (No./km2) and total
biomass for birds occurring in offshore habitats in
fall 1978 and 1979, combined
Habitat
Bays
Passages , narrow
Passages , broad
Open waters
Number of
Species
15
30
26
30
Total
Density
118.63
84.50
77.25
72. 17
Total
Biomass
137.22
50.79
78.44
65.49
294
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Table III-BB. Number of species, total density (No./km2) and total
biomass for birds occurring in offshore habitats in
winter 1978 and 1979, combined
Number of Total Total
Habitat Species Density Biomass
Bays 30 244.71 375.19
Passages, narrow 40 172.96 268.08
Passages, broad 33 122.77 125.07
Open waters 40 32.80 30.57
295
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