DOC
EPA
United States
Department of
Commerce
National Oceanic and
Atmospheric Administration
Seattle WA 98115
United States
Environmental Protection
Agency
Research and Development
Office of Environmental
Engineering and Technology
Washington DC 20460
EPA-600/7 80-167
October 1 980
Whidbey Island
Intertidal and
Shallow Subtidal
Benthos
Interagency
Energy Environment
R&D Program
Report
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7. Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the INTERAGENCY ENERGY-ENVIRONMENT
RESEARCH AND DEVELOPMENT series. Reports in this series result from the
effort funded under the 17-agency Federal Energy/Environment Research and
Development Program. These studies relate to EPA's mission to protect the public
health and welfare from adverse effects of pollutants associated with energy sys-
tems. The goal of the Program is to assure the rapid development of domestic
energy supplies in an environmentally-compatible manner by providing the nec-
essary environmental data and control technology. Investigations include analy-
ses of the transport of energy-related pollutants and their health and ecological
effects; assessments of. and development of. control technologies for energy
systems; and integrated assessments of a wide range of energy-related environ-
mental issues.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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WHIDBEY ISLAND INTERTIDAL AND
SHALLOW SUBTIDAL BENTHOS
by
H. H. Webber
Huxley College of Environmental Studies
Western Washington University
Bellingham, Washington 98225
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 Federal
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
November 1980
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Completion Report Submitted to
PUGET SOUND ENERGY-RELATED RESEARCH PROJECT
OFFICE OF MARINE POLLUTION ASSESSMENT
NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
by
Huxley College of Environmental Studies
Western Washington University
Bellingham, Washington 98225
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 does not approve,
recommend, or endorse any proprietary product or proprietary material
mentioned in this publication. No reference shall be made to the National
Oceanic and Atmospheric Administration or to this publication in any
advertising or sales promotion which would indicate or imply that the
National Oceanic and Atmospheric Administration approves, recommends, or
endorses any proprietary product or proprietary material mentioned herein,
or which has as its purpose to be used or purchased because of this
publication.
ii
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ABSTRACT
The intertidal and shallow subtidal (+6.01 to -10.0m) benthos of three
representative habitats of the west coast of Whidbey Island were sampled by
stratified random sampling for a two year period. All organisms >1 mm from
a sand (West Beach), gravel (Ebey's Landing) and cobble (Partridge Point)
habitat were identified, counted, weighed wet and preserved.
Species richness at the cobble site was greatest (700) followed by the
gravel (612) and sand site (336). Although values of species richness at
each site were similar for the two years sampling species composition was not.
Similarity indices showed that at each site only around 60% of the species
found in the first year were also found in the second.
At all sites the species richness in the intertidal area was lower than
the subtidal. At the sand and gravel sites intertidal species richness was
low (66-91) compared to the cobble site (around 309). At subtidal areas,
species richness of the gravel site and sand site were similar (401-479)
while that of the sand site was low (around 204).
Species composition in the intertidal areas of the three sites were not
similar (lower than 37%). At subtidal areas species composition at the
gravel and cobble sites were similar (around 65%) while similarity between
cobble and sand and gravel and sand was low (around 40%).
At the sand and gravel sites only a few species (around 25) were found
only in the intertidal area while at the cobble site around 110 species were
found only in the intertidal area.
2
Highest values of numbers of individuals per 0.25m were noted at the
gravel site and were due primarily to the amphipod Paramora mohri. At both
the gravel and cobble sites the greatest number of individuals per 0.25m
were observed in the intertidal area. Highest values of biomass were observed
at the cobble and gravel sites and were a result of algae found at subtidal
strata. There was considerable variation between the two years data.
Species specific data on number of individuals and biomass had high
variability. Coefficients of variation showed the majority of species sampled
had inadequate sample size and/or replicate number. Differences in number of
individuals and/or biomass between seasons and years were not clear. At any
given strata generally less than 5-10 percent of species showed significant
differences with season or year sampled. Most species that showed a signifi-
cant difference in biomass or numbers of individuals had higher values during
summer sampling.
Results on species richness, numbers of individuals and biomass for these
three sites on Whidbey Island agree in general with similar data from studies
conducted in the Strait of Juan de Fuca, the San Juan Islands, and Georgia
Strait.
iii
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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
may 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
report presents the results of the second year of a study of the benthos
of the west coast of Whidbey Island and summarizes both years' data. It
complements reports prepared previously which document the results of
similar research conducted in northern Puget Sound and the Strait of
Juan de Fuca.
iv
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CONTENTS
Page
Abstract iii
.Foreword ....'. iv
Figures vi
Tables vii
Appendices viii
Acknowledgments ix
1. Introduction 1
2. Conclusions 4
3. Recommendations 5
4. Methods 6
Study Areas 6
Sample Schedule 10
Intertidal Field Methods 10
Subtidal Field Methods 12
Laboratory Procedures 12
Taxonomy 13
Data Processing 13
Data Manipulation 14
Dominance 14
Statistical Methods 14
5. Results 16
Habitat Descriptions 16
Species Richness 25
Numbers of Individuals and Biomass 36
Change in Numbers of Individuals and
Biomass with Season 39
Dominant Species 39
Live Sieves 53
Species Diversity Indices 53
Analysis by "t" Test 53
Variability 70
6. Discussion 81
West Coast of Whidbey Island Beach System .... 81
Changes with Time 82
Evaluation of Sample Methods and Errors 83
Comparison to Other Areas 84
References 90
1. Taxonomic References 90
2. Literature Cited 91
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FIGURES
Number Page
1. Whidbey Island Sample Sites 2
2. Site Diagram, West Beach (Sand) 7
3. Site Diagram, Partridge Point (Cobble) 8
4. Site Diagram, Ebey's Landing (Gravel) 9
5. Beach Slope, West Beach (Sand) 17
6. Beach Slope, Partridge Point (Cobble) 23
7. Beach Slope, Ebey's Landing (Gravel) 24
8. Mean Number of Species per Stratum, West Beach 29
9. Mean Number of Species per Stratum, Partridge Point 30
10. Mean Number of Species per Stratum, Ebey's Landing 31
11. Mean Number of Individuals per 0.25 m , West Beach
and Partridge Point 37
12. Mean Number of Individuals per 0.25 m2, Ebey's Landing ... 38
13. Mean Wet Weight Biomass per 0.25 m2, West Beach and
Ebey's Landing 40
14. Mean Wet Weight Biomass per 0.25 m2, Partridge Point .... 41
15. Mean Number of Individuals per Season, West Beach
and Partridge Point 42
16. Mean Number of Individuals per Season, Ebey's Landing .... 43
17. Mean Wet Weight Biomass per Season, West Beach and
Ebey's Landing 44
18. Mean Wet Weight Biomass per Season, Partridge Point 45
vi
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TABLES
Number Pae
1. Number of Replicates and Strata Sampled in Each
of the Two Years Sampling, and Sampling Dates 11
2. Sediment Composition at Sampling Sites 18
3. Surface Temperature (°C) and Salinity (°/oo) for Sites
at Times of Sampling 20
4. Partridge Point Algae Cover , 22
5. Summary of Species Richness and Similarity Index Values 26
6. Species Richness by Season All Sites 33
7. Species Richness in Major Taxonomic Groups 34
8. Summary of Distribution of Dominant Species in Summer
and Winter Sample Periods 46
9. List of Those Species That Were Dominant in Both of the
Years1 Sampling for Summer and Winter 49
10. Partridge Point Live Sieve (0.25m2 by 30 cm deep; 0.5" mesh)
Species Lists, Mean Count and Mean Wet Weight 54
11. Species Diversity Indices (Shannon Index) for Each Site,
Season, Stratum and Year 58
12. Species with Significant Differences (p = 0.05) in Mean
Number and/or Weight Between Summer and Winter Sample
Periods . 60
13. Species with Significant Differences (p = 0.05) in Mean
Number and/or Weight Between the First and Second Year
Sample Periods 71
14. Summary of Coefficient of Variation (sd/mean) 78
15. Comparison of Sand Sites 86
16. Comparison of Cobble Sites 87
17. Comparison of Gravel Sites 89
vii
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APPENDICES
Appendix
2
A list of species found, the mean weight and count per 0.25m , the
standard deviation of weights and counts for each site, season,
stratum and year. Also included in each list are the dominant
species for each year, the total number of individuals and weight
and the species diversity index. Appendix One is available on
microfiche.
viii
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ACKNOWLEDGMENTS
Acknowledgment is due: to Gary Smith for development of underwater
sampling techniques and field collection; to Alice Benedict who was responsi-
ble for general taxonomy and who insured samples moved orderly through lab-
oratory procedures; to Rick Henderson, Wendy Founds and Sue Schonberg who
assisted in the taxonomy of specific groups; and finally to the students of
Huxley College and the Department of Biology whose careful attention to
detail of procedure in field collection and laboratory analysis have contri-
buted to insuring the accuracy of data.
ix
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SECTION 1
INTRODUCTION
Puget Sound is a descriptive term used to describe the inland sea of
northwestern Washington State and southwestern British Columbia (Fig. 1). It
consists of the Strait of Juan de Fuca, the southern portion of the Strait
of Georgia, channels of the San Juan Islands, numerous estuaries, and the
southern inlets that are Puget Sound proper. The increased use of northern
Puget Sound waters and shorelines for the transportation and refining of oil
has increased concern about potential damage to marine resources of the area.
Since 1972 a number of studies have been initiated by industry and state and
federal government to document the components of the ecological systems of
northern Puget Sound. The biological communities of southern Georgia Strait
have been studied by Battelle Northwest (1976) for the Atlantic Richfield Oil
Company. The Washington State Department of Ecology in 1974 initiated a
baseline study of biological resources of Northern Puget Sound (DOE, 1978).
In 1975 the National Oceanic and Atmospheric Administration initiated a MESA
Project (Marine Ecosystem Analysis) in Puget Sound that is designed to pro-
vide a data base on physical, chemical and biological components (MESA, 1978).
An important component of both the DOE baseline program and the NOAA
MESA program is the characterization of the marine plants and animals of the
intertidal and shallow subtidal areas of north Puget Sound. DOE studies have
primarily focused on the geographical area from Anacortes to Blaine (Fig. 1)
with major emphasis on the areas adjacent to oil shipping routes and refining
activity, and similar "control" areas in the San Juan Islands. Results of
these studies are available from the Washington State Department of Ecology
(Nyblade, 1977; Webber, 1978).
NOAA's MESA project on the characterization of the intertidal and
shallow subtidal benthos has focused on habitats of the Strait of Juan de
Fuca (Nyblade, 1978). An important area of Puget Sound that is adjacent to
oil shipping routes and has not had similar characterization studies of inter-
tidal and shallow subtidal flora and fauna is the west coast of Whidbey Island
from Admiralty Head to Deception Pass.
The west coast of Whidbey Island is predominantly unconsolidated material
deposited by glaciation. Moderate wave action has acted on the material to
form a shoreline composed of a series of beaches. At headland areas erosion
has created beaches composed of material that is too heavy for wave action
to transport. These are cobble beaches and are found primarily at the base of
actively eroding bluffs. Material eroded from the bluffs is carried by long-
shore drift to areas where wave action is reduced or some barrier results in
deposition. These areas are accretional and are characterized by sandy beaches
with extensive backshore areas composed of sand dunes. A third type of beach
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STRAIT OF
GEORGIA
VANCOUVER
CANADA
Blain'e
CHERRY POINT
VANCOUVER
ISLAND
I SAN JUAN
VICTORIA
West Beach
STRAIT OF
""*JUAN de FUCA
PORT ANGELES
tWHIDBEY
ISLAND
Partridge Pt
Ebey's
Landing
Figure 1 Whidbey Island
Sample Sites.
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is that where material is not actively eroding or accreting, but is carried
along by longshore drift. These are transport beaches. Transport beaches
are mostly gravel or coarse sand. The southerly portion of the study area
is mostly a series of erosional and transport beaches, while the northerly
portion is primarily an area of accretion.
Three sites were chosen in this study to reflect the predominant beach
types: Partridge Point, an erosional area with a cobble beach; Ebey's Landing,
a transport area with a gravel beach; and West Beach, an accretional area
with a sandy beach.
This study is based on a habitat approach. That is, habitat types
were chosen to reflect the dominant substrate type visible in the inter-
tidal zone. By characterizing in detail the flora and fauna of a typical
habitat type it is assumed that results can be extrapolated to other similar
habitats.
Although the habitat type reflects the dominant substrate visible in the
intertidal area, variability in substrate type exists. Substrate at most
habitats at the +5 foot tide height and above often differs from the dominant
substrate. Cobble beaches usually have a band of gravel at this height; mud
beaches usually have a band of sand or cobbles. Also, the substrate below
the tide line changes from the dominant type. With increasing depth below
the 0.0 tide height wave action decreases and the proportion of silt in the
substrate increases. Except in rocky areas and areas of large tidal current,
substrate type becomes a relatively uniform mud at a depth of 10 m.
The objectives of this study were to quantitatively characterize the
benthos of the intertidal and shallow subtidal areas of three habitats on
the west coast of Whidbey Island. The study area was between +6.0' above mean
low water to -10.0 m below mean low water. Stratified random sampling was
used to select samples. Analysis was to 1 mm in size. This report discusses
results for two years of sampling. Included is an analysis of species rich-
ness, species diversity, community structure, seasonal changes and dominant
forms. Results of the first year sampling were reported in Webber, 1979.
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SECTION 2
CONCLUSIONS
The intertidal areas of the sand (West Beach) and gravel (Ebey's Landing)
habitats are essentially devoid of a distinct community. Only a few species
are found that are not also found in the subtidal, and there is little
similarity in species composition between the intertidal areas of the sand
and gravel habitat. The cobble site (Partridge Point) on the other hand has
a well defined intertidal flora and fauna that is not found in the subtidal.
Subtidal biota are not necessarily related to intertidal biota. The
sand site has a relatively meager subtidal biota probably due to the instabil-
ity of the substrate. The gravel site, although it had an impoverished
intertidal biota, had a rich subtidal biota that was similar to that of the
cobble site.
Species specific data on numbers of individuals and biomass had high
variability. This variability restricts the usefulness of statistical tests
to examine species specific data.
A definition of dominance based on species specific data had little
success in identifying a group of species that characterized the structure
and change with time of the communities of the three habitats.
Field observations indicated that algae that were "canopy" species (i.e.,
Laminaria, Nereocystis) were inadequately sampled.
The distribution of amphipods at the gravel site was restricted to a
relatively narrow region in the intertidal area. Population peaks varied
between the two years and sampling at each foot of tide elevation was
required to describe population distribution.
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SECTION 3
RECOMMENDATIONS
Abundance and biomass data were collected for almost 1,000 species
during the study. The resulting large data set precluded detailed analysis
and this report should be considered as a preliminary analysis. Three areas
warrant continued analysis.
a) Species richness values between sites, seasons, and strata are
relatively consistent. Analysis of species richness with simi-
larity indices that are weighted by abundance or biomass values
should be pursued.
b) The criterion of dominance used in data analysis was of limited
use. Dominance was biased towards algae biomass and was not
sensitive to species with small but stable values of abundance
and/or biomass. Further investigation of the application of
dominance to the data should be made.
Species specific data on numbers of individuals and biomass have high
variability which restricts their use in statistical analysis. The useful-
ness of examining data from species complexes should be investigated.
This study has described the structural characteristics of benthic
communities. In order to evaluate the sensitivity of these biological com-
munities to environmental perturbations, study should be extended to function-
al characteristics. The contribution of littoral communities to primary
productivity; the extent to which photosynthetic energy is utilized by herbi-
vores and the extent to which it contributes to detritus; and the contribution
of energy to higher trophic levels are such characteristics that warrant
study.
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SECTION 4
METHODS
STUDY ABEAS
The sample sites were established on the west coast of Whidbey Island
from Deception Pass to Admiralty Head (Fig. 1). They were, from north to
south, West Beach (sand habitat), Partridge Point (cobble habitat) and Ebey's
Landing (gravel habitat).
West Beach (lat. 48°. 22'1"; long. 123°, 41'3")
The West Beach sample site was approximately one mile west of State High-
way 525 and was reached by travel west on Banta, Murray, and Powell Roads.
The permanent reference marker consists of three spikes driven into the
asphalt parking area. Each spike was located 15.8* above the 0.0' tide height.
The specific location of the sample area is shown in Figure 2.
Partridge Point (lat. 48°. 13'8"; long. 123°. 46'2")
The cobble sample site was reached by traveling approximately three miles
west on Libby Road from its intersection with State Highway 525. This inter-
section was approximately four miles southwest of Oak Harbor. On Libby Road
approximately 200 feet before the public boat launch at Partridge Point, turn
left into Padilla Estates. The sample location was at the foot of the private
access beach road. The permanent reference marker at Partridge Point was the
USGS marker located on the top of a large boulder (Fig. 3). The tide height
of the marker was 12.4* above the 0.0* tide height. The location of the
specific sampling area is shown in Figure 3.
Ebey's Landing (lat. 48°. 11'4"; long. 123°. 42'2")
The gravel site was located at Ebey's Landing. The site was reached by
traveling west on Ebey road from its intersection with State Highway 525
approximately one mile north of Coupeville. The sample site was located
adjacent to the road where it parallels the beach. The permanent reference
marker was three spikes placed in the center of the road surface (Fig. 4).
Each spike was 10.4f above the 0.0' tide height. The specific location of the
sample site is indicated on Figure 4.
Sample Area
At each site the sample area was a 50 m wide strip from the +6' to -1*
tide height. At given strata samples were located along the 50 m line by a
table of random numbers- Adjacent 50 m wide areas were used in each of the
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HOUSE
POWELL
ROAD
+6.0'
50m
1978-79
-IX)1
PARKING
PRM
i
I Distance PRM to +6 tide height, 57m
1 PRM 15.8' above 0.0 tide height
i HIGH TIDE LINE
I
50m
+6.0'
1977-78
-1.0'
Figure 2 Site diagram,West Beach(sand)
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Private beach
access road
USGS tide
marker
HIGH TIDE LINE
PRM (12.4* above 0.0* tide height)
Distance PRM to +6.0 height is
\ 21m at 42° magnetic.
+6.0'
50m
1978-79
-1.0'
50m
6.0'
1977-78
-1.0'
Figure 3 Site diagram. Partridge Point (cobble)
8
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EBEY'S ROAD
PRM (10.41 above 0.0 tide height)
1111111111111 11111 11111 i i 1111111111
HIGH TIDE LINE
+6.0' 50m
50m 6.0'
1978-79
1977-78
-1.01
-1.01
Figure 4 Site diagram, Ebey's Land ing (gravel)
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two years (Figs. 2-4).
Subtidal sample areas were located immediately offshore of the intertidal
sites. Subtidal samples were located on depth contours in haphazard fashion
along a line of approximately 30 m width. Subtidally sample heights were
expressed as depth in meters. Intertidally, because of contract requirements,
sample heights were expressed as feet above the 0.0 tide height.
SAMPLE SCHEDULE
Sample effort varied at site and season. Intertidally one tide height
in each of the upper, mid and lower tide areas was sampled in each of the
four seasons (see Table 1). For Ebey's Landing and West Beach five replicates
were located at each of the three tide heights. During summer and winter
sampling periods each additional tide height between +6 and -1 feet was
sampled with triplicates. For subtidal sampling triplicates were used at all
strata and all seasons. A summary of sampling times and replicate numbers is
given in Table 1.
INTERTIDAL FIELD METHODS
Ebey's Landing (gravel) and West Beach (sand)
2
a. Live Sieves. An area of 0.25m was removed to a depth of 30 cm.
Material was passed through a 0.5 inch2 (1.3 cm) wire mesh and bivalves and
mobile Crustacea retained and preserved in 12% buffered formalin. Live
sieves were taken only at the +6, +3, and 0.0' strata, at each of the repli-
cates.
2
b. Cores. At each replicate a core 0.05m by 15 cm deep was removed
with minimum disruption and placed in a bucket. Twelve percent buffered
formalin was gently worked through the sediment for preservation.
c. Grain Size Sample. Approximately 1 liter of sediment was taken at
+6, +3 and 0.0' strata for grain size analysis.
Partridge Point
a. +6* Stratum. The +6' stratum was sampled as described for West
Beach and Ebey's Landing.
b. Live Sieves. At the +2* and 0.0* strata cobbles were removed from
a 0.25m2 area and mobile invertebrates greater than 1 cm were retained.
Sediment was removed to a depth of 30 cm and passed through a 0.5 inch2
(1.3 cm) wire mesh. Any organism was retained and preserved in 12% buffered
formalin. Live sieves were taken at each replicate.
c. Scrapes. At each replicate a 0.25m2 grid subsectioned into 25 .Olm2
areas was placed on the cobbles. From five subsections (randomly chosen),
all algae and invertebrates greater than 1 mm in size were removed from the
tops, sides and bottoms of the cobbles. Each .Olm2 subsample was separately
preserved in 12% buffered formalin.
10
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TABLE 1
A. NUMBER OF REPLICATES AND STRATA SAMPLED IN EACH OF THE TWO YEARS SAMPLING
+6' to -I1 are tide heights in feet (Port Townsend tide tables). -1.5 m to
-10 m are depths in meters below the O.O1 tide height. PP = Partridge Point,
EL = Ebey's Landing, WB = West Beach.
Height
+61
+51
+4'
+3'
+2'
+11
0'
-1'
-1.5 m
-2.5 m
-5.0 m
-7.5 m
-10.0 m
Spring, Fall
PP4,
not
not
WB5,
PP4
not
PP4,
not
PP3,
not
PP3,
not
PP3,
WB5, ELS
sampled
sampled
ELS
sampled
WB5, ELS
sampled
WB3, EL3
sampled
WB3, EL3
sampled
WB3, EL3
Summer, Winter
PP4,
PP3,
PP3,
PP3,
PP4,
PP3,
PP4,
PP3,
PP3,
PP3,
PP3,
PP3,
PP3,
WB5, ELS
WB3, EL3
WB3, EL3
WB5, ELS
WB3, EL3
WB3, EL3
WB5, ELS
WB3, EL3
WB3, EL3
WB3, ELS
WB3, EL3
WB3, EL3
WB3, EL3
B. SAMPLING DATES
West Beach
Ebey's
Landing
Partridge
Point
Spring
Int.
4/6/77
4/25/78
4/7/77
4/26/78
4/8/77
4/27/78
Sub.
4/19/77
4/18/78
4/28/77
5/8/78
4/30/77
5/16/78
Sunn
Int.
7/2/77
6/20/78
7/1/77
6/21/78
6/30/77
6/22/78
ner
Sub.
8/10/77
6/29/78
8/22/77
6/30/78
8/26/77
7/1/78
Fall
Tnl-.
10/15/77
10/17/78
10/17/77
10/18/78
10/18/77
10/19/78
Sub,,
11/18/77
10/14/78
11/3/77
10/12/78
11/8/77
10/13/78
Winter
Int.
r-i/6/78
1/25/79
1/7/78
1/26/79
1/8/78
1/27/79
Sub.
1/24/78
1/21/79
2/13/78
1/18/79
2/6/78
1/??/79
11
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d. Algae. From the remaining 0.20m2 area all surface algae and all
macroinvertebrates larger than 1 cm were removed and preserved in 12% buffered
formalin. In the second year, all biota smaller than 1 mm were removed for
comparison of methods. This was possible because the area was not heavily
colonized by barnacles.
n 1 cm found on the algae were sorted, identified,
weighed and stored. In the second year all animals > 1 mm found on the algae
were sorted, identified, weighed and stored.
d. Cores. Sediment was washed through a 1.0 mm screen. The retained
sediment and organisms were flooded with .02% rose bengal dye in 35%
isopropyl alcohol. Material was left for at least 48 hours before sorting.
(All algae fragments and animals were removed and sorted to species. Each
species was identified, enumerated, weighed, and preserved for permanent
storage as described above.)
e. Subtidal Algae. Algae and animals were sorted to species and
treated as described in c. above.
12
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f. Subtidal Cores. Organisms were dyed in 0.02% rose bengal in 35%
isopropyl alcohol, sorted to species and treated as described above.
g. Sediment Samples. Samples for grain size analysis were dried at 80°C
for 24 hours then passed through a series of sieves into the following
fractions: > 0.065 mm; 0.065 to 0.125 mm; 0.125 to 0.5 mm; 0.5 to 1.0 mm;
1.0 to 2.0 mm; 2.0 to 4.0 mm; 4.0 to 64.0 mm and 64 to 256 mm.
TAXONOMY
Where possible organisms were identified to the species level. Some
groups (i.e., Oligochaetes, Nemerteans) are not well known and were identified
to higher taxonomic levels. Juvenile or fragmentary individuals were often
not identifiable to species. The taxonomic references used are listed in the
bibliography.
DATA PROCESSING
Data for each species taken by each collection method were coded using
the NOAA National Oceanographic Documentation Center (NODC) format. Data
were stored on computer tape and are available from the NOAA Environmental
Data and Information Service data library. The following categories of data
are on file:
I Intertidal Code Number
a. 0.20 m quadrat surface only
- algae > 1 mm 29
- epifauna > 1 mm 29
- selected invertebrates > 1 cm 42
2
b. 0.05m x 15 cm core
- cores 17
2 2
c. 0.01m selected quadrats (5 per 0.25m )
- scrapes 28
2
d. 0.25m x 30 cm deep core (1/2 inch mesh)
- live sieve 16
II Subtidal
2
a. 0.25m quadrat, surface airlift
0.7 m mesh
- algae > 1 mm 43
- epifauna > 1 mm 43
- selected invertebrates > 1 cm 44
2
b. 0.05m x 15 cm core, airlift
0.7 m mesh
- core 41
13
-------
DATA MANIPULATION
To compare data from various collection methods data were normalized to
a 0.25m2 quadrat , 15 cm in depth. Data from various collection methods were
recombined to create the 0.25m2 quadrat in the following manner:
I First Year Data:
a. Intertidal.
Normalized surface algae were produced by adding
the 0.20m2 and 5, 0.01m2 data together. Surface invertebrate data were
created by multiplying the 5, 0.01m2 data to 0.25m2. Infauna data were
created by multiplying the 0.05m2 x 15 cm data to 0.25m2 x 15 cm.
b. Subtidal.
For the first year there were no data for epifauna
> 1 mm. Data from selected animals > 1 cm were used instead. The 0.25m2 x
15 cm quadrat was created by: algae - 0.25m2 quadrat; surface invertebrates -
selected invertebrates > 1 cm; infauna - multiplying the 0.05m2 by 15 cm
deep core to 0.25m2.
II Second Year Data:
a. Intertidal.
The same procedure as for the first year inter-
tidal data was followed. In the second year all epifauna > 1 mm were identi-
fied. If desired, these data could be used instead of multiplying the 5,
0.01m areas.
b. Subtidal.
In the second year epifauna > 1 mm were identified
for the 0.25m2 surface scrape. The 0.25m2 quadrat was created by: algae -
0.25m2 quadrat; surface invertebrates - epifauna > 1 mm; infauna - multiply-
ing the 0.05m by 15 cm deep core data to 0.25m2.
DOMINANCE
Dominant species were identified for each stratum. Dominant species
were those species comprising at least 5% of the total number of individuals,
or at least 5% of the total biomass at a given stratum. Invertebrates having
10.0 g total weight or more were automatically classified as dominant and the
weight of that species was subtracted from the total weight for that stratum
before determining remaining dominant species.
STATISTICAL METHODS
Similarity Index
The similarity index used was:
2C
S A+B
14
-------
where: S = index of similarity, usually expressed as a percent
C = number of species in common
A = total number of species in Sample A
B - total number of species in Sample B
Species Diversity
Species diversity was calculated using the Shannon index of general
diversity:
H = z °i log ]H
N N
where: n^ = number of individuals for each species
N = number of species
Coefficient of Variability
The coefficient of variability as described by Ebelhart (1978) in which
the standard deviation is divided by the mean was used to evaluate variability
in data.
"t" Tests
Student's t tests were used to compare means (two-tailed) or to compare
a mean against 0 (one-1 ailed). The probability level of p = 0.05 was chosen
to define significant differences. When comparing sites and years, summer
data were used because species richness was greater than winter, and all
strata were sampled.
15
-------
SECTION 5
RESULTS
HABITAT DESCRIPTIONS
West Beach, Sand Habitat
The location of the sand habitat is shown in Fig. 1. A detailed diagram
of the site is given in Fig. 2. West Beach is an accretion beach. Littoral
drift sediment accumulates in this area resulting in a well established back-
shore berm. Wave action is moderate. The dominant visual feature of the
intertidal area is sand with occasional patches of gravel. No attached algae
were apparent offshore and when wave action was moderate surf was observed,
indicating an offshore bar. Beach slope was relatively gradual and the most
variable of the three habitats (Fig. 5). At the beginning of sampling (June
1977) beach width was 23 m. In January 1978 beach width was 54 m, indicating
the deposition of sand. By April 1978 beach width was reduced, and by June
1978 it was almost the same as June 1977. In January 1979 beach width remained
at around 27 m. The deposition of sand noted in the winter of the first year
sampling was not observed in the second winter sampling.
Subtidally the sediment of the sandy habitat was similar to the inter-
tidal area. Basically, the substrate was sand with some cobbles at shallow
depths and some silt at deeper depths. There was a difference related to
intertidal beach slope. During those sample times when beach slope was
relatively steep (Fig. 5) the -1.5 m and -2.1 m strata had patches of cobbles
covering about 20% of the bottom. These cobbles had no attached flora or
fauna. During the sample time when beach slope was most gradual (January
1979) the cobble patches were not observed.
An offshore sand bar was a persistent feature of this site subtidally.
The bar was present at all sample times between the -5.0 m and -7.0 m strata.
In all cases the -5.0 m sample was taken on the seaward side of the bar.
The -1.5 m and -2.5 m samples were taken on the landward side of the bar.
Sediment composition of intertidal and subtidal areas are given in
Table 2. Surface water temperature and salinity values for West Beach are
given in Table 3. Temperature ranged from 5° C to 13.5° C over the two years.
Salinity ranged from 29.8 °/oo to 34.0 °/oo.
Partridge Point, Cobble Habitat
The location of the cobble habitat is shown in Fig. 1. A detailed dia-
gram of the site is given in Figure 3. Partridge Point is one of a series of
erosional headlands along the west coast of Whidbey Island. Cobbles deposited
by erosional activity form the dominant feature of the beach, although a gravel
16
-------
m
CO
m
>
o
en
o
"U
m
m
CO
m
o
/-s
CO
G
o
AJUN.1977
JAN. 1978
X APR. 1978
- JUN.1978
O JAN. 1979
BEACH WIDTH (m)
-------
TABLE 2
SEDIMENT COMPOSITION AT SAMPLING SITES. Values are percent of the sample in each size class of the
Wentworth Scale: cobbles, 64-256 mm; pebbles, 4-64 mm; granules, 2-4 mm; sand 0.062-4 mm; silt,
0.004-0.062 mm. "First" is first year sample period, "second" is the second year.
Spring
0) <1) iH
rH rH 0)
J3 ,0 > T> W
& 2 W C rH
O 0) M CO iH
O Pk O CO CO
WEST BEACH (sand)
+6.0' first
second
+3.0' first
second
+0.0' first
second
-1.5 m first
second
-5.0 m first
second
-10.0 m first
second
0 49 11 34 0
0 75 3 21 0
0 57 11 28 0
0 54 3 42 0
0 57 3 37 0
0 5 2 93 0
0 -0 0 100 0
0 0 0 99 0
0 0 0 100 0
0 0 0 99 0
0 0 0 98 2
0 0 0 97 3
PARTRIDGE POINT (cobble)
+6.0' first
second
+2.01 first
second
+0.0' first
1 second
-1.5 m first
second
20 48 11 16 0
0 99 0 1 0
0 68 6 22 0
0 66 9 25 0
7 53 9 25 0
0 50 13 37 0
40 31 3 21 0
28 20 10 41 0
Summer
T3 4J
& 43 n> (3 rH
O 0) h (0 *H
u PM o co co
0 4 1 95 0
0 52 6 41 0
0 64 6 30 0
0 41 6 53 0
0 44 5 51 0
0 1 0 99 0
36 48 4 14 0
0 0 0 99 0
0 0 0 99 0
0 0 0 99 1
0 0 0 97 3
0 0 0 95 4
0 44 25 30 0
0 36 58 60
30 37 7 26 0
0 55 9 36 0
0 49 11 39 0
6 48 6 40 0
46 20 3 30 0
0 42 11 45 0
Fall
TJ -p
,jQ ,0 Oi C rH
0 0) M CO -H
O PM O CO CO
0 5 1 94 0
0 72 4 25 0
0 76 6 18 0
0 55 15 31 0
0 67 10 23 0
0 49 11 40 0
0 0 0 99 0
0 1 0 99 0
0 0 0 99 0
0 0 0 99 0
0 0 0 96 4
0 0 0 96 4
10 59 7 23 0
15 17 7 62 0
24 50 6 19 0
28 46 7 20 0
8 49 8 35 0
45 35 4 15 0
0 43 10 46 0
0 85 2 13 0
Winter
-0 -M
,0 43 «d C5 H
0
-------
TABLE 2 (continued)
-5.0 m first
second
-10.0 m first
second
EBEY'S LANDING
+6.01 first
second
+3.0' first
second
0.0' first
second
-1.5 m first
second
-5.0 m first
second
-10.0 m first
second
Spring
(U 0) rH
H rH -O *J
,0 .0 CO (2 i-H
O fl) ri Cd iH
CJ (X, O CO CO
0 46 15 36 0
0 56 9 35 0
0 33 12 51 0
0 34 10 55 1
(gravel)
0 59 9 28 0
0 59 8 33 0
0 57 15 23 0
0 52 20 28 0
0 75 6 16 0
0 81 5 13 0
13 72 4 5 0
14 63 5 18 0
0 30 18 48 0
0 45 10 44 0
0 20 25 51 0
0 14 22 63 1
Summer
0) 0) rH
rH rH OJ
,0 ,£) > T3 -U
,O & Cd {3 rH
O 0) rl Cd -rl
CJ PM O CO CO
0 58 11 30 0
0 48 11 41 0
0 31 10 57 1
0 34 14 49 3
0 38 10 52 0
0 21 23 56 0
0 79 11 11 0
0 46 20 33 0
0 62 11 26 0
29 45 10 16 0
33 53 5 9 0
43 47 4 7 0
0 3 28 67 0
0 24 11 63 0
1 28 13 57 1
0 46 13 39 1
Fall
01 Q) rH
rH rH (U
,£> ft > T3 4J
& ,£> Cd 0 rH
O 0) rl (d iH
CJ PL. O C/3 CO
0 58 18 24 0
0 32 11 56 0
0 31 15 53 1
0 36 16 46 1
0 33 2 65 0
0 8 2 90 0
0 55 10 35 0
0 53 16 30 0
0 82 3 15 0
0 65 16 18 0
0 63 7 28 0
24 71 2 3 0
0 20 . 8 72 0
0 3 5 89 1
0 46 12 51 1
0 21 16 61 1
Winter
0) Q) rH
rH rH (!)
.0 ,0 > T3 -W
& ,O «d C rH
O 0) rl Cd iH
U PL, U CO CO
0 57 12 31 0
0 60 15 24 0
0 37 14 47 1
0 34 15 48 2
0 67 12 20 0
0 49 11 40 0
0 70 11 19 0
0 61 9 30 0
0 73 10 17 0
0 54 8.5 37 0
21 19 3 80
0 74 6 20 C
0 35 13 50 0
0 22 11 64 3
0 49 8 41 1
0 36 15 48 0
VO
-------
TABLE 3
SURFACE TEMPERATURE (°C) AND SALINITY (°/oo)
FOR SITES AT TIMES OF SAMPLING
WEST BEACH
(sand)
Intertidal
Subtidal
77/78
78/79
77/78
78/79
PARTRIDGE POINT
(cobble)
Intertidal
Subtidal
77/78
78/79
77/78
78/79
EBEY'S LANDING
(gravel)
Intertidal
Subtidal
77/78
78/79
77/78
78/79
Spring
Temp*
9,0
10.0
8.5
9.0
9.0
11.0
9.0
10.0
9.0
11.0
8.5
10.0
Sal.
29.8
29.0
30.7
30.0
30.4
34.0
30.7
29.0
30.4
32.0
31.0
31.0
Summer
Temp.
13.5
12.0
12.5
11.0
13.5
8.5
12.0
12.0
13.0
11.0
12.0
12.0
Sal.
29.1
32.0
30.0
30.1
30.0
31.0
31.1
31.0
32.0
Fall
Temp.
9.0
10.0
8.5
10.0
9.0
10.0
8.0
9.0
9.0
9.0
9.0
9.0
Sal.
33.7
31.0
32.3
31.0
31.2
32.0
32.1
30.0
33.1
31.0
31.4
33.0
Winter
Temp. Sal.
7
5
8
6
7
6
7
6
7
5
8
6
.0 32.
.0
.0 30.
.0
.0 31.
.0
.0 32.
.0
.0 32.
.0
.0 30.
.0
1
4
6
7
1
4
20
-------
band is presented at the high tide area. Beach slope (Fig. 6) is relatively
gradual, intermediate to that of the sand and gravel habitats. The beach
width between the +6' and -I1 tide heights was 38 m. Slope through the two
years was relatively constant indicating little or no accumulation of sediment.
In the mid to upper tide zone the cobbles were bare. In the lower tidal
area, however, cobbles were covered by algae. Data on algae cover through
the two years at the cobble habitat are given in Table 4. Cover was most
dense at the 0' and -I1 strata. Little algae was found above the +3' stratum.
Algae cover was greater in summer than in winter. Beneath the cobble layer
the sediments were relatively fine. Data on sediment composition are given
in Table 2.
Subtidally the habitat at Partridge Point resembled the intertidal
habitat. The -1.5 m stratum was composed of cobbles (20-25 cm in diameter)
with a pebble sand matrix between. Algae were common on the cobbles,
indicating the cobbles were relatively stable. In most areas Laminaria
formed an overstory with red algae as common understory species. Patches
of the eel grass Phyllospadix were also common at that depth.
The -2.5 m stratum was similar to the -1.5 m stratum with the exception
that soft tubed polychaetes in the fines between the cobble indicated little
movement of the sediment by wave action. From -2.5 to -5.0 m pebble and sand
began to predominate over cobbles. Nereocystis became more abundant in this
area. From -5 m to -10 m depth a sand/pebble/silt substrate predominated
(Table 2).
Surface temperature and salinity values for Partridge Point are given
in Table 3. Temperature ranged from 7.0 to 13.0°C through the year. Salinity
ranged from 30.1 to 32.7 °/oo.
Gravel Habitat, Ebey's Landing
The location of the sample site at Ebey's Landing is shown in Fig. 1.
A detailed diagram of the site is given in Fig. 4. This gravel habitat is
located in a littoral drift transport area. The dominant visual feature of
the intertidal zone is gravel and patches of coarse sand. In the shallow sub-
tidal area occasional patches of Nereocystis can be seen in summer and fall.
The site is located in an area that is rip-rapped above the +8.01 tide
height to protect the roadway from wave action. North and south of the road
area the bank is stable and covered with vegetation. Beach slope at the
gravel site (Fig. 7) is steeper than at the sand or cobble habitats. This is
characteristic of beaches where there is little erosion of backshore cliffs
or accumulations of littoral drift material. Beach slope changed with season.
The width of the beach from the +6' to -I1 tidemarks ranged from 26 m in
January 1978 to 16 m in June and July 1979. Apparently there was an accumula-
tion of sediment in winter months. Sediment material in the intertidal area
was mostly gravel (Table 2). There was little change in composition of
sediment with tide height or season. During the simmer sample period, a
layer of cobbles was observed at the -I1 stratum. These cobbles provided a
substrata for the algae Enteromorpha linza.
21
-------
TABLE 4
PARTRIDGE POINT ALGAE COVER (in percent). Strata are tide height in
feet. Each value is. the mean of eight observations of 0.25 m2 areas.
- indicates no observation was made.
+6.0
+5.0
+4.0
+3.0
+2.0
+1.0
o.o
-1.0
Spring
77/78 78/79
0 1
- -
- -
- -
4 8
- -
67 62
- -
Summer
77/78
0
0
0
0
1
18
76
87
78/79
0
3
3
7
20
22
89
99
Fall
77/78 78/79
0 0
- -
- -
- -
4 5
_ _
68 22
_ _
Winter
77/78
0
0
3
1
1
2
5
32
78/79
0
0
0
0
2
5
7
37
22
-------
T)
m
CO
m
>
o
X
CO
o
T3
m
U)
o
o
CO
w
r~
m
-1
Q
O
15
JUN. 1977
JAN. 1978
D JUL. 1978
O JAN. 1979
20 25 30 35
BEACH WIDTH (m)
40 45 50 55
-------
CD
C
50
m
m
>
o
:r
o
-o
m
V.
m
CO
ST
+6
m
f-
: +4
O
LU
UJ
O
h-
+ 2
-1
JAN. 1978
JUN.1979
JAN. 1979
APRIL 1978 x
OCT. 1978 x
10
15 20 25 30 35 40
BEACH WIDTH (m)
45 50 55
-------
Subtidally the habitat at Ebey's Landing changed considerably from the
gravel of the intertidal area (Table 2). At -1.5 » stratum cobbles of
approximately 20 cm in size covered approximately 9CU of the surface. In
the sample area observation indicated that wave action moved the cobbles.
The only organisms observed were filamentous diatoms. Approximately 50 m
to the north of the sample site, more stable cobbles with up to ten species
of red and brown algae were observed, indicating more stable cobble conditions
in that area. At the -2.5 m stratum conditions were similar to the -1.5 m
stratum. At the -5.0 m stratum the cobble bottom began to give way to sandy
and gravel patches that had dense patches of the eelgrass Zostera marina.
Algae growth on cobbles indicated that wave action did not turn over cobbles
at this depth. From the -5 to -10 m strata the bottom was almost totally
sand and gravel (Table 2). Clam shells and worm castings indicated a stable
infauna.
Surface temperature and salinity values for Ebey's Landing are given in
Table 3. Temperature ranged from 7.0 to 9.0° through the year. Salinity
ranged from 30.4 to 32.1 °/oo.
SPECIES RICHNESS
The following discussion of species richness, abundance, and biomass
evaluate data from a number of collection methods that have been combined to
represent all organisms 1 mm in size and larger from a 0.25m2 by 15 cm deep
volume. Appendix 1 gives the values of mean number and mean wet weight for
each species found at each stratum, season, site, and year. Included in
Appendix 1 are standard deviations, total number of individuals, total biomass,
and species diversity indices.
Data from a collection method that was not included in the recombination
(0.25 cm2 by 30 cm deep, 0.5 inch mesh size live sieve) are treated separately.
Species Richness, Sites Combined
A total of 990 species were collected from the three sites during the
study period641 in the first year and 735 in the second. The similarity
index for the two years was 66.1% (Table 5), indicating that approximately
two-thirds of the species were found in both years.
Species Richness by Site
The cobble site (Partridge Point) had the highest species richness (Table
5) of the three sites (770 species) followed by the gravel site (Ebey's
Landing, 612 species) and the sand site (West Beach, 336 species). The number
of species in each of the two years collected at each site was less than the
total and was relatively constant (Table 5). Similarity indices for each
site for the two years were: West Beach, 58%; Partridge Point, 60%; and
Ebey's Landing, 59%. That is, at each site approximately 60% of species were
found in both years while 40% occurred in only one of the two years.
When intertidal and subtidal species richness between sites is examined
(Table 5) the differences between sites are more pronounced. The cobble site
25
-------
TABLE 5
SUMMARY OF SPECIES RICHNESS AND SIMILARITY INDEX VALUES
A. Sites combined. B. By sites. C. Intertidal only, subtidal only, and those
species at both intertidal and subtidal areas of each site. D. Similarity
between sites.
A. Total Species all Sites
first year 641
second year 735
both years 990
number of species common between years 455
Similarity between years = 66.1%
B. Total Species by Sites , ., _. ,
both first second common
West Beach
Partridge Point
Ebey's Landing
Similarity between
West Beach
Partridge Point
Ebey's Landing
336 249 223 136
770 522 533 335
612 425 444 257
sites first and second year:
57.6%
60.1
59.1
C. Intertidal and Subtidal Species by Site
First year both Second year both
West Beach
Partridge Point
Ebey's Landing
Similarity between
West Beach
Partridge Point
Ebey's Landing
Int. Sub. Int. Sub.
only only I & S only only I & S
31 183 35 29 155 39
121 213 188 104 231 248
23 362 40 22 352 71
intertidal and subtidal regions:
First year Second year
24.6 29.8
52.9 59.7
17.2 27.5
26
(continued)
-------
TABLE 5 (continued)
D. Similarity Between Sites
1. West Beach - Partridge Point
Intertidal only
Subtidal only
Both
First
18.1
38.4
35.5
Second
19.5
36.8
37.5
2. West Beach - Ebey's Landing
Intertidal only
Subtidal only
Both
First
37.2
40.6
40.6
Second
32.3
38.6
42
3. Ebey's Landing - Partridge Point
First
Intertidal only
Subtidal only
Both
Second
21.0
61.0
57.2
22.4
70.9
65.4
27
-------
(Partridge Point) had a relatively higher similarity (approximately 53-59%)
between intertidal and subtidal species richness than the sand and gravel
sites (17-30%). Also, the intertidal species richness at the sand and
gravel sites was lower than the cobble site. The inte'rtidal flora and fauna
at the cobble site was richer than the sand and gravel site and was more
similar to the subtidal species richness.
The intertidal flora and fauna of the sand, cobble, and gravel sites
were not very similar (Table 5). Values ranged from 18 to 37%, the lowest
being the similarity between West Beach and Partridge Point and the highest
between West Beach and Ebey's Landing.
At subtidal areas, the gravel and cobble sites (Table 5) had relatively
high similarity (61-71%) while the similarity between gravel and sand (38-40%)
and cobble and sand (37-38%) were relatively low.
The picture that emerges is that the gravel and sand sites have distinct
intertidal and subtidal flora and fauna that were not very similar, that the
cobble site had a more similar intertidal and subtidal flora and fauna,
and that the subtidal regions of the cobble and gravel site were relatively
similar.
Species Richness by Strata
The relatively low species richness of the intertidal areas of the sand
and gravel sites is reflected in the graphs of number of species at each
stratum (Figs. 8 to 10). At West Beach and Ebey's Landing the total number
of species collected at each stratum was generally less than 20, with the value
for each year lower than the total (Figs. 8 and 10).
At the cobble site, there was a relatively higher species richness at
all .strata except the +6.0' and +5.01 heights (Fig. 9). Species richness
at the cobble site increased with decrease in tide height to a value of 200
species at the -1.0* height. In general, at all sites there were more species
collected the second year than the first, although it is not clear if the
differences were significant.
At subtidal strata the species richness at these three sites each showed
a different pattern. At the cobble site species richness decreased at the
-1.5 m stratum and, although gradually increased with increasing depth, at
-10.0 m it was still lower than species richness at the -l.O1 stratum. At the
gravel site species richness increased rapidly with depth from the -1.5 m to
-10 m strata. Species richness at the cobble and gravel sites were relatively
similar from the -1.5 m to -10 m strata. This similarity corresponds to the
index of similarity for the two habitats at subtidal strata (65%, Table 5).
The sand habitat showed yet another pattern at subtidal strata. At the -1.5 m
and -2.5 strata species richness was relatively low at approximately 15
species per stratum. At the -5.0 m stratum species richness increased to 45
species and continued to increase through the -10 m stratum. However, species
richness at these depths at the sand habitat was lower than the gravel and
cobble habitats. The reason for the relatively low species richness at the
-1.5 m and -2.5 m strata of the sand habitat was probably the unstable nature
28
-------
a;
w
w
110 -4
100 H
90 J
80 H
70
WEST BEACH
. First Year Only
Q Second Year Only
Both Years Combined
£ 60
(tf
w
a
50
40 H
30 H
20
10
0
+5' +4' +3' +2' +0' 0.0' -1' -1.5m -2.5m -5.0m -7.5m -10.(
STRATA (NOT TO SCALE: INTERTIDAL IN FEET; SUBTIDAL IN METERS).
FIGURE 8 MEAN NUMBER OF SPECIES PER STRATUM, WEST BEACH
29
-------
190 .
180
170
160
150
140
130
£ no
en
bl
04
t/J
It.
0
os
ti!
100
90
80
70
60
50
40
30 .
20
10 .
PARTRIDGE POINT
First Year Only
O Second Year Only
X Both Years Combined
+6' +5' +4' +3' +2' +1' 0.0 -1' -1.5m -2.5m -5.On -7.5m -10.0m
STRATA (NOT TO SCALE: INTERTIDAL IN FEET; S'JBTIDAL IN METERS).
FIGURE 9 MEAN NUMBER OF SPECIES PER STRATUM, PARTRIDGE POINT
30
-------
180
170
160
150 .
140 -
130
EBEYS LANDING
First Year Only
O Second Year Only
X Both Years Combined
+6' +5' +4' +3' +2' +1' 0.0 -1' -1.5m -2.5m -5.0m -7.5m -10.0m
STRATA (NOT TO SCALE: INTERTIDAL IN FEET; SUBTIDAL IN HETERS)
FIGURE 10 MEAN NUMBER OF SPECIES PER STRATUM, EBEY'S LANDING
31
-------
of the substrate. These strata were inside the offshore bar and were
probably subjected to relatively high movements of the substrate. Also,
Fig. 5 indicates that the shallow subtidal strata also showed a seasonal
shift in substrate.
In general, there were more species collected at both intertidal and
subtidal areas in the second year than the first, although at each site the
pattern of distribution of species richness with depth was similar in the
two years of study.
Species Richness by Season
Table 6 gives the number of species collected at intertidal strata for
each site for each of the four seasons. For the gravel and sand habitats
species richness in summer and fall sample periods was higher than spring
or winter. At the cobble habitat species richness was greatest in the
summer.
Species richness at subtidal strata (Table 6) also showed variation
with season through the two years of study. For the sand habitat species
richness varied from 67 to 116 species; for the gravel habitat from 151 to
259 species, and for the cobble habitat from 161 to 264 species. However,
there was no consistent pattern of variation with season at any of the
habitats.
Species Richness byTaxonomic Groups
Approximately 90% of species collected in the study belong to one or
another of twelve taxonomic groups (Table 7) including three groups of
algae and nine groups of animals. The total number of species of each
taxonomic group for the study is given in Table 7. The dominant taxonomic
group was the polychaete worms with 250 species collected. In successive
order of dominance followed the red algae, amphipods, gastropods, and
bivalves. For the polychaetes the gravel habitat had the highest representa-
tion with approximately 73% of the total polychaete species collected. The
cobble habitat had approximately 69% while the sand habitat had approximately
49%. For other taxonomic groups, however, the highest representation was
generally at the cobble habitat, followed by the gravel, then sand habitat.
In all taxonomic groups the sand habitat had the lowest representation.
The representation of taxonomic groups in the intertidal and subtidal
portions of each habitat are also given in Table 7. At the gravel site all
taxonomic groups had richer representation at subtidal than at inter-
tidal strata.
At the cobble site some taxonomic groups had more intertidal species
than subtidal. Green algae, barnacles, and echinoderms all had more species
intertidally than subtidally. The remaining taxonomic groups at the cobble
habitat had greater subtidal representation.
32
-------
TABLE 6
SPECIES RICHNESS BY SEASON ALL SITES
For fall and spring all strata were combined and means taken. For
summer and winter only those strata that corresponded to fall and
spring were summed. Int - intertidal, Sub - subtidal, 1st - first
year samples, 2nd - second year samples.
WB
P.P.
EL
Int
Sub
Int
Sub
Int
Sub
Spring
1st
21
113
112
161
19
157
2nd
19
83
148
211
23
197
Summer
1st
21
67
185
212
24
187
2nd
27
98
233
264
63
259
Fall
1st
24
108
143
162
34
190
Winter
2nd
25
116
101
253
25
226
1st
17
95
161
179
19
207
2nd
33
83
182
255
22
189
33
-------
TABLE 7
SPECIES RICHNESS IN MAJOR TAXONOMIC GROUPS
(Seasons and Strata Combined)
Green algae
Brown algae
Red algae
Polychaetes
Gastropods
Chitons
Bivalves
Barnacles
Isopods
Amphipods
Decapods
Echinoderms
Total number of
species - both
years
a
cu
M-l 4J
o o
cu
( _J
CU H
rO O
8 0
p
pj CO
cu
H -H
cd o
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23
28
186
250
70
18
62
8
39
98
51
18
M
cd
cu
^
4-1
CO
H
H
M-l
i-H
cd
4J
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19
20
140
172
45
17
45
7
29
64
38
13
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cd
cu
^1
*O
rj d
cd o
4J U
o cu
H co
14
24
131
188
56
10
44
6
27
75
37
12
Total number of species,
first and second years
c* ^
o cd
cd cu
cu >%
pq
4J
4J CO
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4
0
17
86
12
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20
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10
40
14
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cu
pQ *\£j
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3
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90
11
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21
1
7
32
14
6
4J
d
H
O
Pi
M
cu cd
00 0)
a 5*.
H
M 4J
4J CO
M M
Cd -H
P-4 *W
12
14
122
132
36
15
28
5
17
47
27
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9
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120
145
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W 44
9
12
77
123
24
11
26
4
18
40
25
9
bo
d
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TJ H
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cd cu
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CO *d
- d
>> o
cu u
f> 0)
H CO
9
16
74
122
26
8
26
3
17
50
25
6
Total number of intertidal
species - first and second
years
/^ M
o cd
cd cu
o >-,
pq
4J
4-1 CO
CO M
CU -H
0
0
1
17
4
0
1
0
3
13
4
0
j^
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o cu
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cu
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0
1
0
23
3
0
3
1
2
11
3
1
4J
d
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cu cd
00 CU
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^ 4J
4J CO
cd i-i
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10
8
63
60
23
7
10
5
14
26
11
6
4J
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p . Lj
cd
cu cu
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9
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71
93
30
7
12
4
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29
18
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43 01
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0
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38
5
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5
14
5
0
CO
(continued)
-------
TABLE 7 (continued)
in
Green algae
Brown algae
Red algae
Polychaetes
Gastropods
Chitons
Bivalves
Barnacles
Isopods
Amphipods
Decapods
Echinoderms
Total number of subtidal
species - first and second year
.C l-i
u cd
cd cu
cu >>
4-1
4J CO
CO 1-4
cu i-i
**"
4
0
16
60
9
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20
0
9
32 :
13
5
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JZ cd
U CU
cd ^>
cu
G
4J 0
CO U
cu cu
£5 CO
3
1
3
80
10
0
20
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6
28
13
6
4-J
c
H
O
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cu cd
60 0)
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jj 4J
4J CO
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cd -H
pL| M-l
5
11
100
79
24
12
26
3
10
41
22
4
4-1
H
O
p 1 Lj
cd
cu cu
00 >,
-o
H -O
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3
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106
122
25
8
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3
17
52
22
8
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T)
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9
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76
90
24
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37
21
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74
114
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6
-------
NUMBERS OF INDIVIDUALS AND BIOMASS
The patterns of distribution of numbers of species with site, strata,
and season have been examined above. To determine if total numbers of
individuals and biomass (wet weight) followed a similar pattern, the mean
number of individuals and the mean biomass per 0.25m for each stratum and
site were plotted (Figs. 11 to 14). In this analysis keep in mind that algae
are represented only by biomass, animals by numbers of individuals and biomass.
Numbers of Individuals
Figs. 11 and 12 show that in the intertidal area there was a large vari-
ability in numbers of individuals per 0.25m2 at all sites and seasons. The
cobble and gravel sites were more similar, particularly at lower tide heights.
The sand habitat had relatively low numbers of individuals throughout the
intertidal zone. These patterns corresponded reasonably well with those of
the distribution of species with tide height (Figs. 7-10).
A number of features of the curves in Figs. 11 and 12 bear mention.
The greatest number of individuals per 0.25m2 were observed at the gravel
habitat (Ebey's Landing). At intertidal strata the large values (Fig. 12)
were caused almost entirely by the amphipod Paramoera mohri. This species
tended to be clumped in narrow bands through the lower intertidal area. In
the first year the peak of abundance was at the O.O1 tide height; in the
second year it was at the +1.0' tide height. It is interesting to note that
if sampling were conducted only at the +3.0' and 0.0' tide heights, the small
peaks at the +4.0' and +5.0* heights in both years and the larger peak noted
in the second year would have been entirely missed.
The peak in abundance at the -2.5 m height (Fig. 12) was due almost
entirely to the amphipod Ischyroceros sp. This species did not occur at all
in the first year at this depth although it was found at relatively low
densities at the -5.0 m and -1.5 m depths.
At the cobble site, the greater number of individuals per stratum
(Fig. 11) generally reflected the greater species richness observed (Fig. 9).
Two points from Fig. 11 bear mention. In the second year at the +2.0' and
+1.0' tide heights there are peaks not observed in the first year. The bulk
of the density at these two strata were due to the polychaete worm
(Protodorvillea gracilis) and to Oligochaetes. At the -1.5 m and -2.5 m
strata (Fig. 11) second year values were also considerably greater than first
year values. These peaks were due to higher densities of Oligochaetes and
the gastropod Lacuna variegata.
The curves of densities for West Beach (Fig. 11) show uniform low
values through the intertidal areas, increasing with depth subtidally. The
difference between first and second year values at the -10.0 m stratum was
due primarily to reduced numbers of the bivalve Psephidia lordi and the
phoxocephalid amphipods in the second year.
36
-------
7
6 .
CM
° 2
g
a.
"o X
> Q
1
S 7
z 5
First Year
O Second Year
WEST BEACH
PARTRIDGE POINT
+6' +5' +4' +3' +2' +1' 0.0 -I1 -1.5m -2.5m -5.0m -7.5m -10.0m
STRATA (NOT TO SCALE: INTERTIDAL IN FEET; SUBTIDAL IN METERS)
FIGURE 12 MEAN NUMBER OF INDIVIDUALS PER 0,25
EBEY'S LANDING
37
-------
EBEYS
LANDING
First Year
O Second Year
+6' +5' +«' +3' +2' +1' 0.0 -1' -1.5m -2.5m -5.0m -7.5m -10.0m
STRATA (NOT TO SCALE: INTERTIDAL IN FEET; SUBTIDAL IN METERS)
FIGURE 11 MEAN NUMBER OF INDIVIDUALS PER 0,25 w2,
WEST BEACH AND PARTRIDGE POINT
38
-------
Biomass
Figures 13 and 14 show the distribution of biomass for each stratum
at the three sites. West Beach (Fig. 13) showed a uniformly low biomass
through the intertidal strata. At the subtidal strata values were greater
than at the intertidal strata (although they were lower than values for sub-
tidal strata at the other sites). The curve of biomass with strata for
West Beach (Fig. 13) corresponds well with graphs of species richness
(Fig. 8) and numbers of individuals (Fig. 11).
At Ebey's Landing there was relatively low biomass at intertidal
strata except for the +2.0' and +1.0' strata in the second year. The
values were due almost entirely to the amphipod Paramora mohri. Subtidally
at Ebey's Landing there were peaks of biomass at the -1.5 m and -2.5 m
strata that were due primarily to algae, and at the -10.0 m stratum that
were due to bivalves.
At Partridge Point, the curves of biomass with strata (Fig. 14) showed
close agreement between the two years. The peaks in biomass at the 0.0',
-l.O1, -1.5 m, and -2.5 m strata were due primarily to algae.
CHANGE IN NUMBERS OF INDIVIDUALS AND BIOMASS WITH SEASON
The patterns of change in numbers of individuals and biomass per 0.25m2
with season at each site are shown in Figures 15 to 18. For all sites the
summer generally had the greatest number of individuals with no clear dif-
ferences between years. At Ebey's Landing (Fig. 16) the first year values
appear much greater than the second. However, the data used to prepare the
curve for the second year did not show values for the +1.0' and +2.0' strata.
Values of biomass with season (Figs. 17 and 18) did not correspond well
with density. Also, there was no clear pattern of change of biomass with
season. At West Beach (Fig. 17) there was no clear pattern with biomass
and season. At Partridge Point, although density was greatest during summer,
biomass was similar in spring, summer and fall.
At Ebey's Landing maximum biomass was in summer corresponding to maxi-
mum density.
DOMINANT SPECIES
Those species that comprised either 5% of the total number of indivi-
duals or 5% of the total biomass of a given stratum were defined as dominant
species (see Methods). Dominant species are listed for each stratum in
Appendix 1. A summary of the distribution of dominant species at the three
sites is given in Table 8. For the intertidal regions of West Beach and
Ebey s Landing (where species richness was relatively low, approximately
5-15 species) often every species was dominant. For the intertidal region
of Partridge Point, and for the subtidal regions of all sites, the number
of dominant species was around 10% of the total number of species.
39
-------
400
300
200
100 .
0
700
in
ta
g 5°° -J
I
400 -
O
300
200 .
First Year
O Second Year
a
a a
. First Year
O Second Year
100
WEST BEACH
EBEYS
LANDING
+6' +5' +4' +3' +2' +V 0.0 -1' -l.Sni -2.5m -5.0m -7.5m -10.0m
STRATA (NOT TO SCALE: INTERTIDAL IN FEET; SUBTIDAL IN METERS)
FIGURE 13 MEAN NET WEIGHT BIOMASS PER 0,25 M2,
WEST BEACH AND EBEY'S LANDING
40
-------
800
700
PARTRIDGE POINT
. First Year
O Second Year
+6' +5' +4' +3' +2' +1' 0.0 -I1 -1.5m -2.5m -5.0m -7.5m -10.0m
STRATA (NOT TO SCALE: INTERTIDAL IN FEET; SUBTIDAL IN METERS)
FIGURE 14 MEAN NET WEIGHT PER 0,25 M2, PARTRIDGE POINT
41
-------
rn
o
rH
X
w
§
5 4
4 4
3 4
2 J
>
es
O
OS
ta
PU
1 .
0
I
| ,
1
1
1 I ,
i 1 !
First Year
Second Year
First Year
Second Year
WEST BEACH
PARTRIDGE POINT
I
1
1
1
i i
1 !
'
i
i i
i
i
i
i
i
1
SPRING SUMMER FALL WINTER
FIGURE 15 MEAN NUMBER OF INDIVIDUALS PER SEASON, WEST BEACH,
PARTRIDGE POINT, FOR WEST BEACH, VALUES ARE MEANS
OF +6,0', +3,0' AND +0,0' TIDE HEIGHTS, FOR
PARTRIDGE POINT, VALUES ARE MEANS OF +6,0', +2,0',
AND +0,0' TIDE HEIGHTS,
42
-------
11 -
10 -
4 9 '
m
CM
° 8
w
P-
-T 7
o
fH
X
*+^s
co 6 -
Q
£ 5
h~4
o
z
1-, ^
4
o
2 3
1 2
2
1
0
1
1
1
1 !
EBEYS LANDING
First Year
Second Year
1 i I!
SPRING
SUMMER
FALL
WINTER
FIGURE 16 MEAN NUMBER OF INDIVIDUALS PER SEASON., EBEY'S
LANDING, VALUES ARE MEANS OF +6,0', +3,0'
AND +0,0' TIDE HEIGHTS,
43
-------
o
to
z
<:
w
200 4
100 H
CM
J!
W
Pu
CO
CO
§ 400
e>
300 4
200
100
First Year
Second Year
First Year
> Second Year
SPRING
WEST BEACH
EBEYS LANDING
SUMMER
FALL
WINTER
FIGURE 17 MEAN WET WEIGHT BIOMASS PER SEASON, WEST BEACH
AND EBEY'S LANDING, VALUES ARE MEANS FROM
+6,0', +3,0' AND +0,0' TIDE HEIGHTS
44
-------
CM
in
o
w
tn
en
o
>-{
pa
H
o
500-
400
300-
200-
100
PARTRIDGE POINT
First Year
Second Year
SPRING
SUMMER
FALL
WINTER
FIGURE 18 MEAN WET WEIGHT BIOMASS PER SEASON, PARTRIDGE
POINT, VALUES ARE MEANS FROM +6,0', +2,0'
AND +0,0' TIDE HEIGHTS
45
-------
TABLE 8
SUMMARY OF DISTRIBUTION OF DOMINANT SPECIES IN SUMMER AND WINTER SAMPLE PERIODS
For each site and stratum, the total number of species collected in both years, the total number of
dominant species in both years, the number of dominant species in each of the two years, and the
number of species that were dominant in both years.
+6.0'
+5.0'
+4.0'
+3.0'
+2.0'
+1.0'
0.0
-1.0'
-1.5 m
-2.5 m
-5.0 m
-7.5 m
-10.0 m
WEST BEACH (Summer)
total
//sp
12
17
7
19
4
7
12
11
36
40
88
98
95
total
//dom
7
13
7
12
4
5
11
6
11
10
9
10
12
//dom
1st
year
5
9
2
8
4
0
6
4
6
6
7
8
9
//dom //dom
2nd both
year years
4 2
5 1
5 0
5 1
1 1
5 0
6 1
2 0
5 0
7 3
5 3
7 5
7 4
PARTRIDGE
total
//sp
21
59
77
110
146
142
226
216
202
192
189
166
202
total
//dom
8
12
21
17
18
19
24
20
27
27
20
20
16
POINT (Summer)
//dom //dom
1st 2nd
year year
6 2
9 7
15 13
12 10
8 11
11 13
16 14
15 11
12 18
12 20
12 10
11 12
10 9
//dom
both
years
0
4
7
5
1
5
6
6
3
5
2
3
3
total
//sp
12
10
10
18
16
17
25
60
120
183
181
161
189
EBEY'S
total
//dom
7
5
8
6
6
7
7
13
20
22
19
17
20
LANDING (Summer)
//dom //dom //dom
1st 2nd both
year year years
54 2
34 2
54 1
34 1
34 2
45 2
44 2
49 0
12 10 2
13 11 2
10 12 3
12 8 3
13 10 3
JS
ON
(continued)
-------
TABLE 8 (continued)
+6.0'
+5.0'
+4.0'
+3.0'
+2.0'
+1.0'
0.0
-1.0' '
-1.5 m
-2.5 m
-5.0 m
-7.5 m
-10.0 m
total
#sp
5
6
5
6
8
22
7
7
21
40
76
81
99
WEST BEACH
total //dom
//dom 1st
year
5 3
6 4
5 2
3 2
4 2
9 1
7 4
7 3
6 3
5 4
8 5
10 7
12 10
(Winter)
//dom //dom
2nd both
year years
3 0
2 0
3 0
2 1
2 0
8 0
4 1
5 1
4 1
4 3
6 3
10 7
7 5
PARTRIDGE
total
//sp
21
29
89
74
95
98
120
183
129
172
139
135
166
total
//dom
7
11
17
16
16
18
18
19
12
11
21
9
20
POINT (Winter)
//dom //dom
1st 2nd
year year
2 7
9 7
13 8
12 9
11 9
12 10
11 12
14 10
8 9
9 7
14 11
5 5
16 5
//dom
both
years
2
5
4
5
5
5
6
5
5
5
4
1
1
EBEY'S LANDING (Winter)
total
//sp
9
5
4
11
5
10
14
12
106
85
121
140
169
total
//dom
9
1
3
8
4
7
3
2
18
16
13
16
17
//dom //dom
1st 2nd
year year
3 6
1 1
2 2
3 7
3 3
1 7
1 3
2 2
10 11
10 6
9 6
11 7
12 8
//dom
both
years
0
1
1
2
2
1
1
2
3
0
2
2
3
-------
In each of the two years the number of dominant species at each stratum
was similar. However, when the lists of those species that were dominant at
both years at a given stratum are examined (Table 8) it is clear there was
little similarity in those species that were dominant the first year, and
those that were dominant in the second. In general, only 10-20% of the
dominant species were dominant at a given stratum in both years.
To characterize the dominant flora and fauna of the intertidal and sub-
tidal areas of the three sites, those species that were dominant at each
stratum in each of the two years were examined (Table 9). Distinct differ-
ences between the sites were evident. At West Beach the only group consis-
tently dominant in the intertidal area was the Nemerteans. Subtidally at
West Beach the clam Psephidia lordi and phoxocephalid amphipods were charac-
teristic of all strata below -2.5 m in both summer and winter. The polychaete
Onuphis sp was also common at subtidal strata. Seasonal variation was noted
in the distribution of the polychaete Scoloplos pugetensis. This worm was
dominant both years in the winter at depths greater than -2.5 m. It was not,
however, dominant during the summer collection periods.
At the cobble site, Partridge Point, the distinct intertidal flora and
fauna referred to in the discussion of species richness was evident in the
distribution of dominant species (Table 8), although no single species
characterized all intertidal strata. The more common dominant species in-
cluded : the polychaete Onuphis sp and Protodorvillea gracilis, the snails
Littorina sitkana and L_. scutulata, Oligochaetes, and the crab Hemigrapsus
nudus. Algae were dominant at the 0.0' tide height during summer collections
but not during winter.
Subtidally at Partridge Point (Table 9) no species was dominant at most
of the strata. A few species (Spiophanes bombyx) and Modiolus rectus) were
dominant both summer and winter.
At the gravel site (Ebey's Landing) only Nemerteans and the amphipod
Paramora mohri were common dominant species at intertidal strata (Table 9).
Subtidally at Ebey's Landing (Table 9) algae were important dominant
species to the -7.5 m stratum. Algae were dominant in both summer and
winter. Except for Oligochaetes, no species was dominant over a range of
strata subtidally. Also, except for some algae, no species were dominant
both summer and winter. It is not possible to determine if this represents
seasonal variation or some other factor.
In the analysis of similarity between sites the subtidal regions of
Partridge Point and Ebey's Landing were similar (61-70%). A comparison of
the dominant species subtidally at Partridge Point and Ebey's Landing, how-
ever, showed little similarity (Table 9). Only four species occurred as
dominants at the subtidal areas of these two sites (Protodorvillea gracilis,
Desmareatia ligulata, Callophyllis flabellulata, and Glycymeris subobsoletus).
48
-------
TABLE 9
LIST OF THOSE SPECIES THAT WERE DOMINANT IN BOTH OF
THE YEARS' SAMPLING FOR SUMMER AND WINTER
West Beach
+6.0'
+5.0'
+4.0'
+3.0'
+2.0'
+1.01
0.0'
-1.0'
-1.5 m
-2.5 m
-5.0 m
-7.5 m
-10.0 m
SUMMER
Nemertea
Nemertea
none
Nemertea
Nemertea
none
Phoxocephalidae
none
none
Psephidia lordi
Phoxocephalidae
Dendr aster excentricus
Onuphis sp
Psephidia lordi
Phoxocephalidae
Onuphis sp
Mysella tumida
Psephidia lordi
Phoxocephalidae
Ophiuroidea
Onuphis sp
Psephidia lordi
Phoxocephalidae
f\i. 1.- j j
WINTER
Nemertea
Oligochaetes
none
none
Nemertea
none
none
Nemertea
Nemertea
Phoxo cephalidae
Scoloplos pugettensis
Psephidia lordi
Phoxocephalidae
Scoloplos pugettensis
Psephidia lordi
Phoxocephalidae
Onuphis sp
Scoloplos pugettensis
Mysella tumida
Psephidia lordi
Leptochelia savignyi
Phoxocephalidae
Ophioroidea
Onuphis sp
Scoloplos pugettensis
Psephidia lordi
Phoxo cephalidae
Ophiuroidea
49
-------
TABLE 9 (continued)
801 f.'l ST., S.Yu
WASHINGTON, D.C.
SUMMER
WINTER
Partridge Point
+6.0'
+5.0'
+4.0'
+3.0'
+2.0'
+1.0'
0.0'
none
Nematoda
Onuphis sp
Littorina sitkana
Onuphis sp
Cirratulus cirratus
Littorina sitkana
Littorina scutulata
Nucella lamellosa
Hemigrapsus nudus
Anthopleura elegantissma
Onuphis sp
Oligochaeta
Littorina sitkana
Hemigrapsus nudus
Oligochaeta
Enteromorpha linza
Protodorvillea gracilis
Cirratulus cirratis
Oligochaeta
Lacuna variegata
Iridaea sp
Rhodoemela larix
Odonthalia floccosa
Oligochaeta
Lacuna variegeta
Hyale sp
Littorina sitkana
Paramoera mohri
Pholoe minuta
Hemipodus borealis
Protodorvillea gracilis
Oligochaeta
Littorina sitkana
Onuphis sp
Oligochaeta
Littorina sitkana
Paramoera mohri
Onuphis sp
Oligochaeta
Littorina sitkana
Littorina scutulata
Hemigrapsus nudus
Onuphis sp
Protodorvillea gracilis
Oligochaeta
Littorina sitkana
Hemigrapsus nudus
Nematoda
Protodorvillea gracilis
Oligochaeta
Notoacmea scutum
Hemigrapsus nudus
Anthopleura elegantissma
Typosyllis sp
Protodorvillea gracilis
Thelepus crispus
Oligochaeta
Hemigrapsus nudus
50
(continued)
-------
TABLE 9 (continued)
SUMMER
WINTER
-1.5 m
-2.5 m
-5.0 m
-7.5 m
-10.0 m
Alaria marginata
Phyllospadix scouleri
Oligochaeta
Laminaria setchelli
Odonthalia floccosa
Phyllospadix scoulerjL
Onuphis sp
Oligochaeta
Micropodarke dubia
Oligochaeta
Laminaria setchelli
Micropodarke dubia
Oligochaeta
Desmarestia ligulata
Callophyllis flabellulata
Polyneura latissma
Laminaria groenlandica
Alaria mangmata
Hesionura coineaui difficilis
Protodorvillea gracilis
Oligochaeta
Laminaria groenlandica
Phyllospadix scouleri
Onuphis sp
Oligochaeta
Typosyllis sp
Micropodarke dubia
Glycymeris subobsoletus
Oligochaeta
Cancer oregonensis
Glycymeris subobsoletus
Astarte alaskensis
Ebey's Landing
+6.01
+5.0'
+4.0'
+3.0'
+2.0'
Nemertea
Paramoera mohri
Nemertea
Paramoera mohri
Paramoera mohri
Paramoera mohri
Nemertea
Paramoera mohri
none
Paramoera mohri
Paramoera mohri
Nemertea
Paramoera mohri
Nemertea
Paramoera mohri
(continued)
51
-------
TABLE 9 (continued)
SUMMER
WINTER
+1.0
Nemertea
Paramoera mohri
Paramoera mohri
0.0'
-l.O1
-1.0'
Paramoera mohri
none
Maria marginata
Egregia menziesii
Iridaea cordata
Oligochaeta
Lacuna variegata
Paramoera mohri
Nemertea
Paramoera mohri
Rhodomela larix
Protodorvillea gracilis
Thelepus crispus
Oligochaeta
Hyale sp
-1.5 m
Lacuna sp
Melita sp
Pterygophora californica
Capitella capitata
Pontogeneia sp
-2.5 m
-5.0 m
Aoroides columbiae
Pontogeneia sp.
Enteromopha linza
Zostera marina
Portodorvillea gracilis
none
Zostera marina
Leptochelia savignyi
-7.5 m
Costaria costata
Spiophanes bombyx
Psephidia lordi
Spiophanes bombyx
Glycymeris subobsoleta
-10.0 m
Desmarestia ligulata
Callophyllis flabellulata
Modiolus rectus
Callophyllis flabellulata
Botryoglossum farlowianum
Modiolus rectus
52
-------
LIVE SIEVES
Results of sampling by live sieves are given in Table 10. At the sand
and gravel sites no fauna were found in the first year and these sites were
not sampled the second year. At the cobble site, however, fauna were
regularly found at the 0.0 and+2.0'strata and occasionally collected at the
+6.0' stratum. Most species collected were epifaunal; bivalves were found
occasionally. Apparently the substrate at the cobble site (mostly clay
below 15-20 cm) is not suitable for large bivalves. The epifaunal species
assemblage is apparently different at the +2.0' and 0.0' strata. For
example, Hemigrapsus which is common at +2.0' gives way to Pugettia at the
0.0' level. There is no apparent pattern between the two years sampling.
SPECIES DIVERSITY INDICES
The species diversity index for each site, stratum, year, and season
is given in Table 11. In general, the cobble site (Partridge Point) had
higher diversity than the gravel (Ebey's Landing) or sand site (West Beach).
Highest diversity was found at the deepest sampling stratum (-10 m) .
There was no evident pattern of change in diversity with season although
indices were generally greater in summer than winter.
At intertidal strata the species diversity indices of two of the three
sites were similar. The sand site (West Beach) and the gravel site (Ebey's
Landing) had relatively low species diversity in the intertidal.
At all sites in the intertidal there was no evident pattern of diversity
indices with change in stratum. For example, the range of indices found at
the +6' stratum was similar to the range found at the O.O1 stratum.
At subtidal strata there was less difference between the three sites
than there was at intertidal strata. At any given stratum the sand site
(West Beach) had the lowest species diversity. The other two sites
(Partridge Point and Ebey's Landing) had similar diversity indices subtidally.
The highest diversity indices were observed at the deepest stratum
(-10 m) . Except for this, however, there was no evident pattern of change
in diversity with change in depth at subtidal strata. There was no apparent
difference in the pattern of distribution of species diversity indices
between the two years' sampling.
ANALYSIS BY "t" TEST
Seasonal Variation, Summer vs. Winter
Differences in mean number of individuals and mean weights for summer
and winter were examined statistically with the students' "t" test. Each
stratum at each site was examined. Table 12 lists those species that had a
significant difference in either mean weight or mean numbers (p = 0.05) for
each of the three sites and two years.
53
-------
TABLE 10
PARTRIDGE POINT LIVE SIEVE (0.25m2 by 30 cm deep; 0.5" mesh) SPECIES LISTS, MEAN COUNT AND MEAN WET
WEIGHT, n = 4. (West Beach and Ebey's Landing had no fauna and were not sampled the second year.)*
0.0'
ct
Anthopleura elegantissima
ct
Epiactis prolifera
ct
Katharina tunicata
ct
Mopalia lignosa .
_____ M ^|-
ct
Acmaea mitra
. - .. ^£
Collisella pelta ^
ct
Notoacmaea persona
ct
Notoacmaea scutum .^.
Dlodora aspera ._
ct
Nucella lamellosa
wt
Spring
0.3
0.5
2.2
9.8
FIRST YEAR
Summer
0.8
3.3
Fall
0.8
0.8
1.5
4.4
0.3
1.2
Winter
0.3
0.2
0.3
5.1
0.3
2.3
0.3
0.7
0.3
1.3
1.0
3.3
1.3
4.2
SECOND YEAR
Spring
1.5
3.2
0.3
2.1
3.3
8.6
2.0
5.5
Summer
0.3
0.6
0.3
2.6
0.3
0.6
( conti
Fall
0.8
2.5
0.8
2.4
nued")
Winter
1.5
9.4
1.8
3.9
1.8
5.7
Ui
-------
TABLE 10 (continued)
Searlesia dira ct
Protothaca stamlnea °.
wt
ct
Saxidomus giganteus
n A wt
ct
Idotea wosnesenskii
wt
ct
Pagurus hirsutiusculus
^t
i
Pugettia gracilis ct
o -a wt
ct
Oregonia gracilis
B Ja wj-
ct
Hemigrapsus nudus
wt
ct
Cancer oregonensls
wt
ct
Leptasterias hexactis
wt
ct
Psvchrohites naradoxiin
^ wt
FIRST YEAR
Spring
0.3
1.0
0.3
33.9
1.0
2.1
2.0
11.8
0.8
2.6
0.5
1.9
0.3
1.0
Summer
1.3
0.6
0.3
0.3
0.8
1.1
1.0
7.3
0.3
1.3
Fall
1.5
1.4
1.0
1.7
0.3
1.0
1.3
3.3
Winter
1.5
1.1
0.3
0.3
4.8
16.6
0.5
0.1
SECOND YEAR
Spring
0.3
0.4
0.3
0.2
0.3
0.5
0.3
0.2
0.3
0.1
1.5
4.3
Summer
0.5
0.4
0.8
0.4
Fall
3.3
25.2
(contim
Winter
1.3
0.8
1.3
6.4
ued)
Ln
Ul
-------
TABLE 10 (continued)
+2.0'
Anthopleura elegantissima
Wt
Collisella pelta c*
* wt
ct
Notoacmaea scutum
___________ ^-.
ct
Notoacmaea persona
ct
Littorina sitkana
wt
Nucella emarginata .
, 0 ^
ct
Nucella lamellosa
y£
ct
Searlesia dira
ct
Saxidomus giganteus
ct
Idotea wosnesenskii
ct
Pagurus hirsutlusculus .
o - Wt
FIRST YEAR
Spring
0.3
0.2
0.3
0.1
5.5
5.3
1.0
2.0
0.3
15.4
0.3
0.1
Summer
1.8
2.1
0.8
1.1
0.3
2.1
3.0
1.7
Fall
0.3
0.2
3.5
3.3
0.3
0.7
0.3
0.7
0.3
0.3
0.3
0.1
Winter
0.8
1.5
0.3
0.4
0.8
2.4
1.5
1.1
Spring
1.0
2.6
2.5
5.8
0.5
1.2
SECOND YEAR
Summer
1.8
1.8
4.0
4.9
1.8
9.5
11.8
10.3
0.5
0.2
Fall
0.3
2.1
0.3
0.2
2.5
4.9
0.3
1.3
1.0
0.5
Winter
0.3
0.6
0.5
1.3
Inur,^
in
ON
-------
TABLE 10 (continued)
ct
Hemigrapsus nudus
wt
ct
Leptasterias hexactis
WL
ct
Gobiesox meandricus
wt
ct
Leptocottus armatus
wt
+6.0*
ct
Nucella lamellosa
. .... ,., W£
ct
Hemigrapsus nudus
ct
Leptasterias hexactis
Notoacmea persona
ct
Searlesia dira
Notoacmea sp
FIRST YEAR
Spring
3.0
15.2
1.5
1.4
0.3
2.9
0.3
1.9
2.0
1.7
4.0
1.9
0.3
0.2
Summer
2.2
3.0
0.8
0.7
1.8
8.7
1.8
13.3
0.5
1.1
1.0
0.7
1.0
0.9
Fall
0.5
3.8
0.5
0.3
Winter
1.3
2.9
SECOND YEAR
Spring
3.5
28.1
0.3
0.8
0.3
1.7
Summer
2.8
18.6
1.5
1.9
0.3
1.9
Fall
5.0
44.7
Winter
1.8
5.7
0.3
1.2
*In the first year report (Webber, 1979), a systematic error occurred in the live sieve data (Table 15)
where both weights and counts were divided by an incorrect sample number of 3 instead of 4 for spring,
summer and fall means. This error has been corrected in this report and Table 10 reflects the correct
mean values.
-------
TABLE 11
SPECIES DIVERSITY INDICES (SHANNON INDEX) FOR EACH SITE, SEASON, STRATUM AND YEAR
WB - West Beach, PP - Partridge Point, EL - Ebey's Landing. 1 - first year, 2 -
second year. Blanks indicate no sample taken.
J
+6.0'
+5.0'
CO
8 +4.0'
,i
"§ +3.0'
i_i
* +2.0'
^|
g +1.0'
M
g 0.0'
« -1.0'
to
-S -1.5 m
o
g, -2.5 m
CO
-5.0 m
-7.5 m
-10.0 m
SPRING
PP
1
2.2
3.4
3.8
3.5
3.3
4.3
2
1.2
4.0
3.9
3.2
3.8
4.1
EL
1
2.2
1.8
0.5
2.0
3.7
4.3
2
1.2
2.5
1.5
3.5
4.1
4.6
WB
1
1.5
2.1
1.3
2.6
2.5
3.6
2
2.2
1.1
2.3
2.3
3.4
3.8
SUMMER
PP
1
2.6
2.5
2.6
3.5
2.5
2.1
2.9
3.3
3.3
3.8
3.8
3.4
4.6
2
1.2
2.8
3.4
3.0
3.5
3.1
3.9
4.0
4.1
3.8
4.1
3.8
4.1
EL
1
2.1
1.2
2.0
1.0
1.6
1.5
1.5
1.3
3.0
4.0
4.0
3.8
4.5
2
2.6
1.5
1.7
2.2
0.9
1.1
1.9
3.5
3.6
4.4
4.3
4.1
4.7
WB
1
1.7
2.0
0.7
2.4
1.2
0
2.1
1.2
3.0
2.3
2.9
2.7
3.1
2
2.0
1.7
1.4
2.6
0
1.5
2.3
2.0
2.3
2.7
2.5
3.5
3.2
Cn
00
(continued)
-------
TABLE 11 (continued)
+6.0'
+5.0'
m +4.0'
V
3 +3.0'
£ +2.0'
£ +1.0'
8 o.o1
0)
S -i.o'
Q
to 1.5 m
0)
o 2 . 5 in
0)
OT* -5.0 m
-7.5 m
-10.0 m
FALL
PP
1
2.7
3.6
3.9
3.8
3.6
4.5
2
2.3
3.8
3.8
4.5
4.3
4.8
EL
1
2.3
0.6
1.8
4.2
4.3
4.7
2
2.4
2.1
2.4
3.9
4.0
4.8
WB
1
2.4
3.2
1.7
2.2
3.1
3.7
2
0.9
2.8
2.5
2.7
3.1
3.6
WINTER
PP
1
0.9
3.1
2.5
3.0
3.8
3.6
3.8
3.9
2.9
3.9
3.7
3.3
4.3
2
1.9
2.1
3.0
3.2
3.8
2.2
4.0
4.1
3.2
4.3
4.2
4.3
4.6
E]
1
1.7
0.3
0.4
2.2
1.3
0.4
1.0
1.0
3.8
3.7
4.2
3.8
4.7
j
2
1.7
0
0
1.9
1.3
1.7
1.5
1.3
3.2
2.4
4.2
4.3
4.8
Wj
1
1.0
1.9
0.7
0.7
0.6
0
1.0
1.3
2.3
2.5
3.0
3.2
3.9
,
2
0.9
0.7
1.0
1.8
0.7
2.9
1.1
1.7
2.1
1.9
3.2
3.5
3.5
vo
-------
TABLE 12
SPECIES WITH SIGNIFICANT DIFFERENCES (p = 0.05) IN MEAN NUMBER AND/OR WEIGHT
BETWEEN SUMMER AND WINTER SAMPLE PERIODS. The year indicates whether the
species showed significant differences in the first, second, or both years.
Summer/winter refers to the season in which the value was greater. #/Wt
refers to whether numbers of individuals, weight or both were significantly
different.
Year
Summer/Winter #/Wt
WEST BEACH
-10.0 m
Pholoe minuta
Phyllodoce sp
Prionospio cirrifera
Spiophanes bombyx
Axinopsida serricata
Tellina modesta
Psephidia lordi
Phoxo cephalidae
-7.5 m
Scoloplos pugettensis
Armandia brevis
Owenia fusiformis
Phoxocephalidae
ii
Onuphis sp
Spiophanes bombyx
Nucula tenuis
Clinocardium ciliatum
Psephidia lordi
Leptochelia savignyi
1 S #
1 W #
1 S #
1 S *
1 S wt
1 S #
1 S wt
1 S #
1 W *
W //
W #
*
2 S wt
2 W wt
2 W f
W #/wt
2 W I
S #/wt
2 W wt
(continued)
60
-------
TABLE 12 (continued)
Year
-5.0 m
-2.5
-1.5
-1.0'
Psephidia lordi
Photis sp
Phoxocephalidae
Phoxocephalidae
Glycinde picta
m
Psephidia lordi
Diastylis sp
Phoxocephalidae
it
m
Phoxocephalidae
n
Psephidia lordi
to +6.0'
none
PARTRIDGE POINT
-10.0
-7.5
m
Callophyllis flabellulata
Protodorvillea gracilis
m
Nicomache personata
Chone sp
Lacuna variegata
1
2
1
1
2
2
1
1
1
2
1
2
2
1
1
2
2
2
Summer/Winter ///Wt
S
S
S
S
W
S
W
S
S
W
W
S
S
S
S
W
W
S
///wt
//
//
//
///wt
1
//
//
//
///wt
//
///wt
///wt
wt
*
///wt
wt
£
( continued)
61
-------
TABLE 12 (continued)
Year
«
Cyclocardia ventricosa
Psephidia lord!
Aoriodes columbiae
Leptosynapta clarki
-5.0 m
Nematoda
Hemlpodus borealis
Spio filicornis
Maldanidae
Pinnixa occidentalis
Polyneura latisslma
Micropodarke dubia
Typosyllis sp
Onuphis sp
Spiophanes bombyx
Myella tumida
Psephidia lordi
Leptochelia savignyii
Pontogeneia sp
Cancer oregonensis
-2.5 m
Oligochaeta
ti
Micropodarke dubia
Typosyllis sp
Exogone lourei
Polycirrus kerguelens
2
2
2
2
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
1
2
2
2
2
2
Summer /Winter
W
W
W
W
S
W
S
W
S
S
S
W
S
W
S
S
W
S
8
S
S
W
W
S
#/wt
wt
///wt
#
#
#/wt
#
wt
#
#
wt
#/wt
#
#
#/wt
*
#
#
#
#
I
f
#
#/wt
#/wt
*
(continued)
62
-------
TABLE 12 (continued)
Year
Lacuna variegata
Glycymeris subobsoleta
Amphilochus litoralis
Aoroides columbiae
Pontogeneia sp
Ischyroceros sp
Heptacarpus brevirostrus
Pugettia richii
-1.5 m
Lacuna variegata
Barleeia sp
Ampithoe sp
Pontogeneia sp
Ischyroceros sp
-l.O1
Nemertea
Chaet ozone sp
Exosphaeroma amplicauda
Hyale sp
Monostroma f us cum
Gigartina papillata
Exogone sp
Natica clausa
Idotea aculeata
Hyale sp
Parallorchestes ochotensis
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
2
2
2
2
2
2
2
Summer /Winter
S
S
S
W
W
W
S
W
S
S
S
S
S
W
W
S
S
W
W
W
S
W
W
S
///wt
f
#/wt
#
#
f/wt
#/wt
#
#
#
#/wt
wt
#/wt
#/wt
//
£
#
wt
wt
wt
#
wt
wt
#/wt
wt
(continued)
63
-------
TABLE 12 (continued)
Year
0.0'
Rhodomela larix
Idotea sp
Platynereis bicanaliculata
Lumbrineris sp
Boccardia columbiana
Cirratulus cirratus
Notoacmea scutum
Lacuna variegata
Barleeia sp
Natica clausa
laniropsis kincaidii
Amp it hoe sp
Hyale sp
Pugetti richii
Leptasterias hexactis
+1.01
Notoacmea scutum
Exogone lourei
Thelepus crispus
Idotea wosnesenskii
+2.0'
Littorina sitkana
ii it
Gigartina papillata
Hemipodus borealis
Cirratulus cirratus
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
1
2
2
2
1
2
2
2
2
Summer/Winter #/Wt
S
S
S
W
S
8
W
S
S
S
S
S
8
8
S
W
S
S
S
W
W
S
S
S
wt
#
#
#
wt
wt
//
#/wt
#/wt
#/wt
#
#
#/wt
wt
#
#/wt
#
#
wt
#/wt
#/wt
wt
#
#/wt
(continued)
64
-------
TABLE 12 (continued)
+3.0'
+4.0'
+5.0'
EBEY'S
-10.0
Year
Chaetozone sp
Thelepus crispus
Oligochaeta
Lacuna variegata
Exosphaeroma amplicauda
Idotea wosnesenskii
-
Onuphis sp
Protodorvillea gracilis
Exogone lourei
Gnorimosphaeroma oregonensis
Typosyllis sp
Hemipodus borealis
Oligochaeta
Notoacmea persona
, +6.0'
LANDING
m
Desmarestia ligulata
Callophyllis flabellulata
Scalibregma inflatum
Armandia brevis
Nicomache personata
2
2
2
2
2
2
1
1
2
2
1
1
1
2
1
1
1
1
1
Summer /Winter
S
S
S
S
S
S
W
S
S
S
S
S
S
none
S
S
S
S
S
#/wt
#
#
wt
#/wt
wt
#
wt
#
#
#/wt
#
#
#/wt
#
wt
wt
wt
#/wt
wt
-^ r»/wi4- ! «i«^«4 I1 *
65
-------
TABLE 12 (continued)
Year
Owenia fusiformis
Saxidomus giganteus
Melita sp
Ophiuroidea
Fholoe minuta
Eteone longa
Typosyllis sp
Aonides sp
Mediomastus ambiseta
Owenia fusiformis
Oligochaeta
Calyptraea fastigiata
Mysella tumida
Mya arenaria
-7.5 m
Nematoda
Spiophanes bombyx
it H
Travisia brevis
Oligochaeta
Psephidia lordi
n it
Corophium sp
Leptosynapta clarki
Typosyllis sp
Owenia fusiformis
Margarites pupillus
Mysella tumida
1
1
1
1
2
2
2
2
2
2
2
2
2
2
1
1
2
1
1
1
2
1
1
2
2
2
2
Summer /Winter
W
w
W
w
s
s
s
s
w
s
s
s
w
w
w
s
s
s
s
s
s
8
s
8
s
#/Wt
#
#
#
//
#
#
#
//
wt
wt
#
#
#
wt
#
wt
///wt
#
//
#/wt
#
1
wt
#
#
f
#/wt
(continued)
66
-------
TABLE 12 (continued)
Year
-5.0 m
Spio filicornis
ii H
Anaitides maculata
Micropodarke dubia
Platynereis bicanaliculata
Hemipodus borealis
Prionospio steenstrupi
Spiophanes cirrata
Chaet ozone sp
Mediomastus ambiseta
Nicomache personata
Owenia fusiformis
Lacuna variegata
Psephidia lord!
Leptochelia savignyi
Ampithoe sp
Aoroides columbiae
Ischyroceros sp
-2.5 m
Prionospio steenstrupi
Atylus sp
Mediomastus ambiseta
Pontogeniea sp
Phoxocephalidae
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
1
1
2
2
2
Summer /Winter
S
S
W
S
S
W
W
S
W
W
W
W
S
S
S
W
W
S
S
W
S
S
W
V.
#/Wt
#
#
#
#
wt
#
wt
#
//
#
#
#/wt
#
#
wt
#
wt
#/wt
#
#
#
#
#/wt
(continued)
67
-------
TABLE 12 (continued)
Year Summer/Winter #/Wt
-1.5 m
Lacuna variegata 2 S #
Pontogeniea sp 2 S #
Heptacarpus brevirostrus 2 S #
-l.O1
Armandia brevis 2 S //
Lacuna variegata 2 S #
Leptochelia savignyi 2 S //
0.0'
Paramoera mohri IS//
+1.0' none
+2.0' none
+3.01 none
+4.0'
Oligochaeta 2 S #
+5.0' none
+6.0' none
68
-------
West Beach. At the sand site there were no significant seasonal differ-
ences in numbers or weight per species found at the intertidal strata
(Table 12). At subtidal strata the percent of species with significant dif-
ferences ranged from around 5% to 17% of the total number of species. The
bulk of species showed significant differences in mean number. Only a few
showed differences in mean weight. Except for the -10.0 m stratum, there
were approximately the same number of significant differences in each of the
two years. At -10.0 m there were 20 species with significant differences the
first year and 13 the second.
At all strata only a few species were significant in both years. In most
cases the species that showed significant differences the first year were
different than the second year (Table 12).
Table 12 shows that more species had higher numbers or weights in
summer compared to winter. Twenty species had higher values of mean number
or weight in summer, and only 12 had greater values in winter.
Partridge Point. Unlike the sand or gravel site, Partridge Point had a
number of species with significant differences in mean number or weights at
intertidal strata (Table 12). From +4.0' to -1.0' tide heights approximately
5-10% of species showed significant differences. More species had significant
differences in mean number than mean weight. Only a few species had signifi-
cant differences in numbers and weight. More species in the second year (72)
showed significant differences than the first year (22). Only one species
was significantly different in both years.
At subtidal strata there were fewer significant differences in number and
weight at the cobble site compared to the gravel and sand sites (Table 12) .
The percent of significant species at subtidal strata was approximately 5%.
Most species had significant differences in mean numbers. Fewer had signifi-
cant differences in mean weight. Only a few species showed significant dif-
ferences in both numbers and weights. There were more significant differences
in the second year than the first. There was only one species significant in
both years.
Table 12 shows that at the cobble sites more species had greater mean
numbers of individuals or weight in summer (59) than in winter (30) . There
was no evident pattern of summer or winter dominance with tide height or sub-
tidal depth. At both intertidal and subtidal strata the fraction of species
with summer or winter dominance was similar.
Ebey's Landing. At intertidal strata the gravel site was similar to
West Beach in that almost no species showed significant differences between
summer and winter (Table 12). At the 0.0' tide height Paramoera mohri showed
significant higher numbers in summer.
At subtidal strata the percent of species with significant differences
ranged from 0 to around 10% (Table 12). More species had significant differ-
ences in mean number than mean weight. Only a few species showed significant
differences in numbers and weight. Twenty species had significant differences
in the first year, 41 in the second. Only three species showed significant
differences in both years.
69
-------
Table 12 shows Ebey's Landing had higher numbers of weights in summer.
Forty-one species had higher values in simmer; 19 had higher weights in
winter. The amphipod Paramoera mohri, although numerous at most intertidal
strata, were only significantly greater in summer at the 0.0' tide height.
Differences Between Years
Students' "t" test was used to identify species with significant differ-
ences in abundance or biomass between the two years at each site for the
summer sample period. Table 13 gives a list of species at each stratum show-
ing whether the numbers and/or weights were significantly different, and
whether the first year was greater than the second.
At the intertidal strata of West Beach there were no significant differ-
ences in abundance or density between the first and second years. At most
subtidal strata about 5-10% of the species showed significant differences.
In most cases they were species that were dominant in either or both of the
two years. Most showed significant differences in both numbers and weights.
Ten species had greater numbers or weights in the first year, and ten in the
second year.
The intertidal strata of Partridge Point (Table 13) showed a number of
significant differences in abundance or weights between the two years. Most
were not dominant species. Twenty-one species had greater numbers and/or
weights in the second year, nine in the first.
Approximately 5% of species at the subtidal strata of Partridge Point
showed significant differences in number and/or weights between the two years
(Table 13). Only in one case was the species dominant. Nine species had
greater numbers and/or weight in the first year, 15 in the second.
Only three species at the intertidal strata of Ebey's Landing showed
significant differences between the two years (Table 13). All were dominant
in either the first or second year. In the subtidal area at Ebey's Landing
about 5% of species showed significant differences between the first and
second years. Eight were significantly greater in the first year, 10 in the
second.
VARIABILITY
Since standard deviation increases with the mean it is not a convenient
relative measure of variability of data. The coefficient of variability
(Eberhart, 1978) allows rapid comparison of variability in data sets. The
C.V. is the standard deviation divided by the mean.
Eberhart has compiled C.V. data for a range of sampling methods for
flora and faunal groups. For benthos he reports C.V. of between 0.4 and 0.8.
To appraise variability of data in this study it was assumed that those species
with a C.V. < 1.0 had acceptable variability, that is, the sample area and
replicate number were adequate to provide data that could be used for statisti-
cal comparison. Those species that had C.V. of 1.0 or greater are assumed
to have unacceptable variability for statistical comparison.
70
-------
TABLE 13
SPECIES WITH SIGNIFICANT DIFFERENCES (p = 0.05) IN MEAN NUMBER AND/OR
WEIGHT BETWEEN THE FIRST AND SECOND YEAR SAMPLE PERIODS. The #/wt re-
fers to whether mean number of individuals or biomass or both were
greater. The year refers to when the higher value was observed. D
indicates that the species was dominant at that stratum in one of the two
years. Only summer data were examined.
WEST BEACH
-10.0 m
-7.5 m
-5.0 m
-2.5 m
Wt/#
Pholoe minuta
Prionospio cirrifera
Nucula tenuis
Psephidia lordi
Phoxo cephalidae
Ophiuroidea
S co lop los pugettensis
Prionospio cirrifera
Nucula tenuis
Axinopsida serricata
Mysella tumida
Psephidia lordi
Ophiuroidea
Scoloplos pugettensis
Spiophanes bombyx
Protomediea
Phoxocephalidae
wt/#
#
wt
#/wt
#/wt
#/wt
#
//
wt/#
#/wt
*
wt
*
#/wt
wt
l/wt
'
Year
1
1
1
1
1
1
2
2
2
2
2
1
2
2
1
1
1
Dominant
D
D
D
D
D
D
D
D
D
D
D
D
D
(continued)
71
-------
TABLE 13 (continued)
Wt/// Year Dominant
-1.5 m
-1.0 m
0.0
+1.0; -
PARTRIDGE
-10.0 m
-7.5 m
-5.0 m
Psephidia lordi
Diastylis sp
Phoxocephalidae
none
none
6.0' none
POINT
Callophyllis flabellulata
Pterosiphonia sp
Protodorvillea gracil
Chaetozone sp
Scalibregma inflatum
Exogone lourei
Rhodymenia palmata
Pterosiphonia sp
Nemertea
Nematoda
Spio filicornis
Pinnixa occidentalis
Leptosynapta
Polyneura latissima
///wt 2 D
// 2
///wt 2 T)
wt 1 D
wt 2
// 1
wt 1
// 1
// 2
wt 1
wt 2
wt 2
wt 1
wt 1
1 1
wt 1
wt 2
72
(continued)
-------
TABLE 13 (continued)
Wt/// Year Dominant
-2.5 m
Desmarestia ligulata
Exogone lourei
Nereis sp
Spio filicornis
Polycirrus kereguelensis
Glycmeris subobsoleta
Aoroides columbiae
Hyale sp
-1.5 m
Haliclystus auricula
Hyale sp
-1.0 in
Rhodomela larix
Nematoda
Chaetozone sp
Natica clausa
Idotea aculeata
Amp it hoe
Hyale sp
0.0
Gigartina pap ilia t a
Rhodomela larix
Sphaerosyllis pirifera
Nereis sp
Hemipodus borealis
wt 2
// 2
// 2
#o
t.
// 2
// 2
// 2
// 2
// 2
wt 2
wt ID
// 2
// 2
wt 2
# 2
# 1
wt 1 . D
wt 2
wt 2 D
// 1
// 1
(continued)
73
-------
TABLE 13 (continued)
+1.0'
+2.0'
+3.0'
+4.0'
+5.0'
+6.0'
Wt/# Year
Folydora columbiana
Thelepus crispus
Natica clausa
Pugettia gracilis
Exogone lourei
Thelepus crispus
Enteromorpha linza
Gigartina papillata
Exogone lourei
Chaetozone sp
Lacuna variegata
Exosphaeroma amplicauda
Exogone lourei
Littorina scutulata
Gnorimosphaeroma oregonensis
None
Littorina scutulata
None
# 2
# 2
# 2
# 1
// 2
# 2
wt 2
wt 2
// 2
# 2
// 2
wt 2
# 2
wt 1
wt 2
# 1
Dominant
D
D
D
D
D
D
(continued)
74
-------
TABLE 13 (continued)
EBEY'S
-10.
-5.
-2.
-1.
-1.
Wt/// Year
LANDING
0 m
Desmarestia ligulata
Chaetozone sp
Armandia brevis
Nicomache personata
Owenia fusiformis
Mya arenaria
0 m
Micropodarke dubia
Psephidia lordi
Photis sp
Annandia brevis
Synchelidium shoemakeri
5 m
Annandia brevis
Synchelidium shoemakeri
5 m
Alaria marginata
Heptacarpus sp
0 m
Enteromorpha linza
^^^^^^^^^^^^^^^^^^^^^» ^^»-WI»«
Exo sphaer oma amplicauda
Gnorimosphaeroma oregonensis
wt 1
// 1
// 1
// 1
///wt 2
// 2
// 2
A 2
If «
///wt 2
wt 1
// 1
wt 1
// 1
wt 2
///wt 2
wt 2
///wt 2
///wt 2
Dominant
D
D
D
D
D
D
D
(continued)
75
-------
TABLE 13 (continued)
Year
Dominant
O.O1
+4.01
Hemipodus borealis
Gnorimosphaeroma oregonensis
+1.0' None
+2.0' None
+3.0' None
Oligochaeta
+5.0' None
+6.0' None
wt
#/wt
1
2
D
D
76
-------
A summary of C.V. data is given in Table 14. For the replicates at
each site, season and strata, the percent of the number of species that had
a C.V. of 1.0 or greater is shown.
As Table 14 shows, the number of species with unacceptable variability
is high, in almost all cases well above 50%. In the upper intertidal areas
of the sand habitat, unacceptable variability was often 100% of the species.
There were no apparent differences in C.V. data between the two years.
Two factors should be kept in mind when examining Table 14. The +6',
+3T and 0 strata, at the sand and gravel habitats had a replicate number of 5.
The +6, +2 and 0.0 strata at the cobble site had a replicate number of 4.
All other strata of each of the sites had a replicate number of 3. The
difference between 3 and 5 replicates did not appear to have any pronounced
effect on variability. In fact, in general, variability was generally lower
in subtidal samples when sample size was 3. Quantitative applications of
these data are limited by the high variability.
77
-------
TABLE 14
SUMMARY OF COEFFICIENT OF VARIATION (sd/mean). - indicates no sample.
Percent values are the percent of species with a CV of 1.0 or greater.
SAND (WEST BEACH)
Spring
First year total #sp
% C.V. >_ 1.0
Second year total #sp
% C.V. _> 1.0
Stunner
First year total #sp
% C.V. >_ 1.0
Second year total #sp
% C.V. >_ 1.0
Fall
First year total #sp
% C.V. _> 1.0
Second year total #sp
% C.V. >. 1.0
Winter
First year total #sp
% C.V. >^ 1.0
Second year total #sp
% C.V. >. 1.0
+6
3
100
6
67
5
100
10
90
10
90
10
90
3
100
3
100
+5
-
-
-
-
9
100
9
89
-
-
-
-
4
50
2
100
+4
-
-
-
-
2
100
5
100
-
-
-
-
2
100
3
66
+3
4
75
10
100
10
100
11
91
15
73
13
85
4
100
3
100
+2
-
-
-
-
4
100
1
100
-
-
-
-
2
100
7
86
+1
-
-
-
-
-
-
7
71
-
-
-
-
1
100
21
95
0
2
100
9
100
6
83
7
57
21
95
18
89
5
30
4
100
-1
-
-
-
-
4
100
8
75
-
-
-
-
3
100
5
80
-1.5
18
50
12
92
24
58
14
50
25
80
24
25
17
65
9
67
-2.5
-
-
-
-
14
57
32
66
-
-
-
-
32
69
19
74
-5.0
26
58
58
62
48
58
49
59
57
70
57
65
39
59
49
59
-7.5
-
-
-
-
58
57
60
48
-
-
-
-
50
44
56
37
( continued)
-10.0
45
67
66
68
58
50
61
57
73
44
81
60
73
58
47
57
00
-------
TABLE 14 (continued)
COBBLE (PARTRIDGE POINT)
Spring
First year total #sp
% C.V. _> 1.0
Second year total #sp
% C.V. _> 1.0
Summer
First year total #sp
% C.V. >_ 1.0
Second year total #sp
% C.V. _> 1.0
Fall
First year total #sp
% C.V. >_ 1.0
Second year total //sp
% C.V. >_ liO
Winter
First year total #sp
% C.V. >_ 1.0
Second year total //sp
% C.V. _> 1.0
+6
7
86
24
45
15
100
7
83
13
85
11
82
12
100
14
92
+5
-
-
-
-
19
68
47
74
-
-
_
22
86
17
62
+4
-
-
-
-
32
73
57
63
-
-
56
79
14
66
+3
-
-
-
-
46
70
82
83
-
-
44
66
41
48
+2
39
85
72
51
66
73
101
76
52
83
54
100
49
69
71
80
+1
-
-
-
-
41
78
115
50
-
-
53
74
51
71
0
73
74
129
55
74
66
169
66
79
63
89
91
55
80
95
67
-1
-
-
-
-
86
63
154
55
-
-
77
68
132
57
-1.5
70
78
109
90
68
96
166
69
69
74
156
54
40
78
111
65
-2.5
-
-
-
-
73
68
149
52
-
-
_
64
64
122
63
(cc
-5.0
50
62
130
50
82
63
132
66
63
54
117
78
78
42
105
62
ntinue
-7.5
-
-
-
-
61
64
113
55
-
-
_
52
71
102
49
d)
-10.0
79
61
118
60
93
55
142
72
75
45
127
53
77
62
119
62
\o
-------
TABLE 14 (continued)
GRAVEL (EBEY'S LANDING)
Spring
First year total #sp
% C.V. :> 1.0
Second year total #sp
% C.V. 1 1.0
Summer
First year total #sp
% C.V. 1 1.0
Second year total #sp
% C.V. 1 1.0
Fall
First year total #sp
% C.V. 1 1.0
Second year total #sp
% C.V. 1 1.0
Winter
First year total #sp
% C.V. 1 1.0
Second year total #sp
% C.V. 1 1.0
+6
7
100
6
100
5
80
10
80
11
91
11
45
3
66
6
100
+5
-
-
-
-
4
75
9
89
-
-
-
-
6
100
1
100
+4
-
-
-
-
5
40
6
50
-
-
-
-
3
100
2
100
+3
5
100
18
67
7
100
14
86
12
92
13
100
6
67
7
100
+2
-
-
-
-
7
29
12
76
-
-
-
-
4
75
3
100
+1
-
-
-
-
9
56
13
77
-
-
-
-
5
60
7
86
0
10
90
11
100
12
83
20
75
24
89
16
50
,
8
100
9
100
-1
-
-
-
-
19
79
49
65
-
-
-
-
10
60
5
80
-1.5
13
77
84
70
48
69
81
57
78
59
110
52
61
80
35
82
-2.5
-
-
-
-
62
71
144
69
-
-
-
-
49
76
22
59
-5.0
62
69
100
59
75
44
139
64
76
63
93
67
71
65
85
50
-7.5
-
-
-
-
71
55
112
52
-
-
-
-
66
64
94
70
-10.0
81
65
123
71
90
61
132
49
83
57
139
45
84
56
115
57
-------
SECTION 6
DISCUSSION
WEST COAST OF WHIDBEY ISLAND BEACH SYSTEM
The west coast of Whidbey Island is a series of beaches that are
erosional, transport, or accretional in nature. Unconsolidated glacial
deposits on uplands serve as sediment sources . Exposure to southerly and
westerly winds provides moderate wave action from the Strait of Juan de Fuca.
Generally the erosional beaches are cobble, the transport beaches gravel,
and the accretion beaches sand. The sampling sites were chosen to reflect
the three primary habitats.
The substrate characteristics at subtidal strata are, in general, simi-
lar to the intertidal substrate, except that with increasing depth and
decreased wave action the proportion of silt in the substrate increases.
On the west coast of Whidbey Island, wave energy, temperature, and
salinity were all similar at the three sites. Differences observed in
intertidal and shallow subtidal communities are believed to be the result of
different substrate types.
Species richness at the three intertidal habitats is related to substrate
stability. At the gravel and sand habitats wave action causes movement of
beach material through the year. Species richness is reflected in this. At
the sand and gravel habitats there is a relatively poor species representa-
tion. (More species were found intertidally at the gravel habitat than the
sand habitat.) Only polychaetes and amphipods were dominant organisms inter-
tidally at the sand site, and they were distributed at low intertidal strata.
Species found at these strata were more widely distributed subtidally.
Amphipods, oligochaete worms, polychaete worms, and nemerteans were the
only dominant intertidal organisms at the gravel site. The amphipods,
oligochaetes and probably nemerteans were a distinct intertidal fauna. The
amphipod Paramoera mohri which was very common at the intertidal area of the
gravel site, had virtually no subtidal distribution.
The sand site then had virtually no distinct intertidal community and
that of the gravel site was relatively meager compared to the cobble site.
However, both algae and invertebrates were well represented in the inter-
tidal area at the cobble site. Many community groups had a distinct inter-
tidal presence. In the algae groups, red algae found at the intertidal strata
were generally not found in the subtidal. Polychaetes at the cobble site were
common at the intertidal strata. Although all but one of the polychaete
81
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species also had a subtidal distribution, a number had their peak of abundance
in the intertidal strata. Gastropods, barnacles, decapods and echinoderms
all had a distinctive intertidal distribution.
Species richness at subtidal strata at the sand and gravel habitats was
much greater than at intertidal strata. Species richness at the cobble
habitat in the subtidal area was lower than in the intertidal. There were
distinct differences between the subtidal communities at the three habitats.
The gravel and sand habitats at subtidal strata had a similarity index of 39%.
The similarity between the cobble and sand was also low (38%) but between
cobble and gravel it was relatively high (63%). The similarity is apparently
related to substrate type. At the sand habitat the substrate in the subtidal
area continued as sand with increasing silt content. The gravel habitat,
however, had patches of cobble habitat in the subtidal area. Algae that
require a stable substrate for attachment were common at the cobble and gravel
habitats. Algae were virtually absent at sand habitat.
Bivalve abundance increased with increasing depth at all habitats. At
the gravel and sand habitats polychaetes increased in number of species with
depth. However, that pattern was not noted at the sand habitat. Gastropods
were common at subtidal strata at both the gravel and cobble sites but not
the sand site. Amphipods were common in the subtidal at the gravel and sand
habitats but not the cobble habitat. Cobble and sand habitats were most
distinctly different with the gravel site being similar to the cobble with
some community groups and similar to the sand with others.
There are, then, distinct communities at the three habitats in the
Whidbey Island beach system. At the sand and gravel site the clearest defined
communities are subtidal with only a meager intertidal representation. At
the cobble site there is a well developed, distinct intertidal community as
well as a distinct subtidal community.
Some species stand out as being associated with various habitats. The
amphipod Paramoera mohri was very common only in the intertidal at the gravel
habitat. Amphipods of the group Phoxocephalidae were very common in the sub-
tidal area at the sand site. The snail Littorina sitkana was very common in
the intertidal area at the cobble site.
CHANGES WITH TIME
Seasonal Changes
There was a maximum number of individuals in summer and in general
maximum biomass at each site in fall and winter. Seasonal patterns in
separate community groups, however, did not always agree with the general
pattern. The amphipod Paramoera mohri did show a clear summer peak in
numbers. However, for some community groups response differed according
to strata. At the cobble site oligochaetes were more numerous in winter
at lower strata. In some groups different species varied in patterns of
abundance. At the cobble habitat the polychaete Onuphis sp had a peak
in numbers in summer while Thelepus crispus had greater numbers in winter.
82
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Seasonal changes then appear to be more complex than the general pattern
and must be examined on a species-by-species basis.
Yearly Change
In general the species richness, numbers of individuals, biomass, species
diversity indices, coefficients of variation, and numbers of species with
significant differences between summer and winter, had similar values at given
strata of the three sites in each of the two years' sampling. However, the
species composition between the years was variable with similarities ranging
between 58 and 60% for the three sites. That is approximately 40% of the
species observed in the second year at a given stratum were not present in
the first year and vice versa. Also, this variability in species composition
was reflected in the analysis of dominant species. There was relatively
little similarity between the species dominant at a given stratum in the
first year and those dominant in the second year. Finally, when the lists of
species that showed significant differences in number or weights between
summer and winter were compared stratum by stratum there was little similar-
ity between the two years.
An explanation of the variability in community structure is not possible
at this time. It may be related to sampling error. That is that sample size
area or replicate number were inappropriate to the community. Or it may be
that the community structure is variable over time with structural changes in
species that do not greatly affect the overall structure of the community.
An analysis of functional types in the community would address this possibil-
ity.
EVALUATION OF SAMPLE METHODS AND ERRORS
Sample Methods. Since sample methods were designed to sample the great-
est number of organisms possible, it is unavoidable that some species were
inadequately sampled. Large relatively rare organisms (sea stars, crabs)
were not taken at the study site. Also, macroalgae at the subtidal strata
were probably inadequately sampled because of the relatively small sample
size. For one species at least, it is known that sample area was inadequate.
At both the cobble and gravel sites the kelp Nereocystis luetkeana was common
in the shallow subtidal areas. However, this species was not sampled at
either site; sample area was too small.
Another probable sample error was the procedure used for sampling the
cobble site intertidally. The procedure required the removal from top and
sides of cobbles' organisms from 5, 0.01 m2 areas. It was extremely diffi-
cult under field conditions to accurately fix boundaries of the five subsample
areas. It is possible to examine the effect of using the 5, 0.01 m2 areas
using the second year NOAA data. Files contain data for epifauna > 1 mm in
size collected from (a) the 5, 0.01 m2 areas, and (b) from the remaining
0.02 m area. The effect of using either of these data to reconstruct the
0.25 mz quadrat could be examined.
Errors in data may result from the methods used to combine data from
various collection methods into a single 0.25 m2 quadrat. In the first year
83
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ep'ifauna from 1 mm to 1 cm from subtidal sites were not sampled and conse-
quently are not part of the data used to reconstruct the 0.25 m2. Also,
readers who compare data from the first year in this report to the data used
in the report for the first year (Webber, 1979) should note that in Webber,
1979 invertebrates > 1 cm in size were included in the 0.25 m2 quadrats.
Those data were not included in this report.
A number of errors of various forms exist in the data sets. Species
richness data assume that all entries for a given site are unique species.
Not all groups were identified to species levels. For example, nemerteans
and oligochaetes were not identified. This tended to underestimate species
richness. On the other hand, unique entries were made that tended to over-
estimate species richness. Unique entries were made for the following:
i. fragments of organisms were often identified to the genus level.
ii. juvenile forms could often not be identified to species and were
entered as a genus sp
iii. detritus was often entered to indicate a contribution towards
biomass.
iv. egg masses and larval forms were entered as encountered.
Other errors will be found in the data sets. Spelling errors result in
redundant listings that tend to overestimate lists of taxa. As well, with
some species, identification in the first year was tentative and the entry
made as a genus. In the second year, these species were confirmed and the
full listing was used.
As the data on coefficients of variability showed, the sampling procedures
used in this study resulted in data with relatively high variability. Such is
the difficulty of community analysis studies in intertidal and shallow subtidal
areas. These communities have a high degree of variability due primarily to
variable environmental conditions and patchiness in distribution. Limits of
time and money restrict such community studies to basically a descriptive
level. Any statistical comparison must take into account the high variabil-
ity of the data so as to not lead to erroneous conclusions.
COMPARISON TO OTHER AREAS
Similar intertidal and shallow subtidal community analyses have been done
in recent years in other areas of Puget Sound. Nyblade (1978) studied areas
along the Strait of Juan de Fuca, and Webber and Smith (1978) studied areas in
Rosario Channel and southern Georgia Strait. The first year data in this
report were compared to data from these other areas. A summary of data on
species richness, number of individuals and biomass for the first year only,
for cobble, sand, and gravel habitats is given in Tables 15 through 17.
84
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Sand Habitat
Sand sites compared include North Beach Sand and Kydaka on the Strait
of Juan de Fuca (Nyblade, 1978), West Beach on Whidbey Island and Birch Bay
on southern Georgia Strait (Webber and Smith, 1978) (Table 15).
Species richness intertidally at these sites is apparently affected by
the degree of exposure. West Beach, North Beach sand and Kydaka are all
exposed and have relatively low but similar species richness. Birch Bay,
which is more protected, had relatively greater species richness. West Beach
had the lowest species richness.
At subtidal strata species richness at West Beach and Kydaka were simi-
lar, but that of North Beach sand was relatively higher and was more similar
to the species richness of gravel and cobble habitats (Tables 16, 17).
Mean numbers of individuals at subtidal strata, however, were similar
between North Beach sand and West Beach sand. Kydaka had relatively lower
mean numbers.
Kydaka also showed the lowest mean biomass of the three sites.
Cobble Habitat
Cobble habitats compared include Morse Creek and North Beach (Nyblade,
1978) from the Strait of Juan de Fuca, Shannon Point, near Anacortes (Webber
and Smith, 1978) and Partridge Point on Whidbey Island (Table 16). All
cobble habitats showed greater species richness intertidally than the sand
or gravel habitats. At all cobble habitats there was an increase in species
number with decrease in tide height. Sites generally had similar values of
species richness at intertidal strata although Shannon Point tended to have
the greatest number of species per stratum through the intertidal range.
The highest number of species (149) was noted at Morse Creek at the O.O1
stratum. However, at the +1' stratum the highest number of species was found
at Shannon Point (118). At +4.0' stratum, Shannon Point and Partridge Point
had a greater number of species than did Morse Creek or North Beach.
When numbers of individuals were compared, however, Morse Creek and
North Beach had greater numbers of individuals per 0.25 m2 at most strata than
Shannon Point or Partridge Point (except the 0.0' strata where Partridge Point
had the greatest number of individuals per 0.25 m2).
When biomass was examined, at the lower strata Partridge Point and Shannon
Point had greater biomass per 0.25m2 than Morse Creek and North Beach. Since
both Morse Creek and North Beach had greater numbers of individuals at the
strata the size of organisms must have been relatively small at those habitats.
At the higher strata intertidally (+5.0' to +7.0') Shannon Point had
a greater biomass than the other cobble habitats. Since Morse Creek and North
Beach had greater numbers of individuals at these strata, again the size of
organisms must have been relatively small.
85
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TABLE 15
COMPARISON OF SAND SITES. North Beach Sand, Kydaka Beach - Strait of Juan de Fuca.
West Beach - Whidbey Island. Birch Bay - Southern Georgia Strait. For West Beach
only first "year data were used. Data for North Beach and Kydaka Beach from Nyblade
(1978); for Birch Bay from Webber (1979). Numbers of individuals are mean values
per 0.25 m. Biomass values are mean grams of wet weight tissue per 0.25 m^.
Elevation
+7.0'
+6.0'
+5.0'
+4.0'
+3.0'
+2.01
+1.0'
0.0'
-1.0
-5.0
-10.0
North Beach Sand
(moderate exposure)
m
0)
«H
m o
O 0>
(X
tfe 03
4
9
4
7
10
11
9
18
163
109
O 00
H 00
1i
H
«4-l (J
0 01
«. §
28
32
38
39
40
37
38
H
M-l *H 03
O *O iH
71
78
58
60
112
60
125
i
biomass
28
31
35
36
39
37
37
-------
TABLE 16
COMPARISON OF COBBLE SITES. North Beach, Morse Creek - Strait of Juan de Fuca.
Partridge Point - Whidbey Island. Shannon Point - Anacortes. For Partridge Point
only the first year data were used. Data for North Beach and Morse Creek from
Nyblade (1978); for Shannon Point from Webber (1979). Numbers of individuals are
mean values per 0.25 m'. Biomass values are mean grams of wet weight per 0.25 m .
Elevation
+7.0'
+6.0'
+5.0'
+4.0'
+3.0'
+2.0'
+1.0'
+0.0'
-1.0'
-5.0'
-10.0'
North Beach
(moderate exposure)
0
8
25
44
23
54
49
75
78
i
CO *O CO
CO
O M-l -H CO 0
OJ O T3 iH O
CX d rt -H
CO =H
fc-S 3
31
658
6,404
4,128
2,623
1,952
7,749 1,
13,252 1,
1,805
962
biomass
0.7
16
328
199
243
807
239
406
140
128
Shannon Point
(moderate exposure)
CO
H
M-l O
O (U
ex
=fc CO
20
35
43
58
70
114
116
118
45
i
H
MH -H co
O 13 r-t
C Cd
=Jt= t-l 3
400
700
1,100
975
1,000
1,050
750
900
1,100
biomass
50
150
180
175
180
630
350
200
100
00
-------
At subtidal strata the cobble habitats of Morse Creek and Partridge
Point showed no clear pattern of dominance in species number, number of
individuals or biomass. At -5.0 m Partridge Point had a greater number of
species and individuals and greater biomass. At -10 m Morse Creek had a
greater number of species and individuals but lower biomass than Partridge
Point. The size of organisms at Morse Creek must have been relatively small
at this stratum.
Gravel Habitat
Gravel sites compared included Dungeness Spit and Twin Rivers (Nyblade,
1978) on the Strait of Juan de Fuca. Ebey's Landing on Whidbey Island and
Legoe Bay (Webber and Smith, 1978) on the Northwest side of Lummi Island
(Table 17).
At intertidal strata, species richness was relatively low. Of the sites
Legoe Bay showed the greater species richness with up to 23 species taken at
the +5.0* stratum. Except for Ebey's Landing where the amphipod Paramoera
mohri was so common, the numbers of individuals and biomass generally followed
species richness. Legoe Bay generally had the greatest number of individuals
and biomass per stratum.
There was no clear pattern of change in species numbers with change in
tide height at any of the gravel habitats except Ebey's Landing where there
was an increase in species richness at the 0.0* and -1.0' strata.
At subtidal strata, there were no clear patterns of change in species
richness, numbers of individuals or biomass at -5.0 m and -10 m at the three
gravel sites: at the -5.0 m stratum, Twin Rivers had the greatest number of
species and individuals, but lowest biomass indicating relatively small
organisms. At the -10.0 m Ebey's Landing had the highest species number,
number of individuals and biomass.
Species richness, numbers of individuals and biomass subtidally at the
gravel habitat were similar to that of the cobble habitats.
88
-------
TABLE 17
COMPARISON OF GRAVEL SITES. Dungeness Spit, Twin Rivers - Strait of Juan de Fuca.
Ebey's Landing - Whidbey Island. Legoe Bay - Lunnni Island. For Ebey's Landing only
first year data were used. Data for Dungeness Spit and Twin Rivers from Nyblade
(1978)i for Legoe Bay from Webber (1979). Numbers of individuals^are mean values per
0.25 m . Biomass values are mean grams of wet weight per 0.25 m .
Elevation
+7.0'
+6.0'
+5.0'
+4.0'
+3.0'
+2.0'
+1.01
+0.0'
-1.0'
-5.0'
-10.0'
Dungeness Spit
(exposed)
CO
-------
REFERENCES
1. TAXONOMIC REFERENCES
Abbott, I. A., and G. J. Hollenberg. Marine Algae of California. Stanford
University Press. 1975. 832 pp.
Banse, K., and K. D. Hobson. Benthic erantiate polychaetes of British
Columbia and Washington. Bull. Fish. Res. Bd. Canada. 1974. 185:1-11.
Barnard, J. L. The families and genera of Marine Gamaridean Amphipods.
Bull. U.S. Nat. Mus. 1969. 271:1-535.
Barnard, J. L. Identification of gammaridean amphipods. In: R. I. Smith
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Coan, E. V. The Northwest American Tellinidae. Veliger 14. 1971.
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Coan, E. V. Preliminary Review of the North American Carditidae.
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Fauchald, K. The Polychaete Worms. Definitions and Keys to the Orders,
Families and Genera. Natural History Museum of Los Angeles County
Science Series 28. 1977. 1-190.
Hartman, 0. Atlas of the Errantiate Polychaetous Annelids from California.
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Hartman, 0. Atlas of the Sedentariate Polychaetous Annelids from
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Hatch, M. H. The Chelifera and Isopoda of Washington and Adjacent Regions.
Univ. Wash. Publ. Biol. 1947. 10:155-274.
Kozloff, E. N. Keys to the Main Invertebrates of Puget Sound, the San
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Menzies, R. J. Some Marine Asellote Isopods from Northern California with
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Menzies, R. J. A Review of the Systematics and Ecology of Genus Exosphaeroma
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90
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(Crustacean: Isopods, Sphaeromatidae). Amer. Mus. Novit. //1683, 1954,
24 p.
Scagel, R. F. Marine Algae of British Columbia and Northern Washington.
Part I.' Chlorophyceae. Nat. Mus. Canada Bull. #207. 1966. 257 pp.
Schmitt, W. L. The Marine Decapod Crustacea of California. Univ. Calif,
Publ. Zool. ^3. 1921. 1-470.
Smith, A. G. Preliminary Review of West Coast Chiton Nomenclature.
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Smith, R. I., and J. T. Carlton, eds. Light's Manual; Intertidal
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Widdowson, T. B. The Marine Algae of British Columbia and Northern
Washington: A Revised List and Keys. Part I Phaeophyceae. Syesis.
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Widdowson, T. B. Part II. Rhodophycea. Syesis. 1974. 7^:143-186.
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Battelle Northwest. BiologicalBaseline. Pacific Northwest Laboratories,
Richland, Washington. 1974. 59 pp.
D.O.E. Baseline studies of Puget Sound. Washington State Department
of Ecology. Olympia. 1978.
Eberhart, L. Appraising Variability in Population Studies. J. Wildl.
Management. 42(2). 207-238.
NOAA. MESA, The Puget Sound Project; Marine Ecosystems Analysis Program,
Boulder, Colorado. 1978.
Nyblade, C. F. The Intertidal and Shallow Subtidal Benthos of the Strait
of Juan de Fuca, 1976-1977. NOAA/ERL Tech. Memo. No. MESA-26, Boulder,
Colorado. 1978.
Nyblade, C. F. The Strait of Juan de Fuca Intertidal and Shallow Subtidal
Benthos. DOC, EPA Technical Report, 600 7/79/213. Washington, D.C. 1979.
Webber, H. H. Intertidal and Shallow Subtidal Benthos of the West Coast of
Whidbey Island, 1977-78. NOAA/ERL Tech. Memo, No. MESA-37. Boulder,
Colorado, 1979.
Webber, H. H., and G. F. Smith. A Biological Sampling Program of Inter-
tidal Habitats of Northern Puget Sound. Washington State Department of
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91
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