&EPA
United States
Environmental Protection
Agency
EPA/600/R-19/239 | December 2019 | www.epa.gov/research
Benthic Ecological Condition
Assessment of the Coastal Waters of
Guam
Office of Research and Development
Center for Public Health and Environmental Assessment / Pacific Ecological Assessment Division
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EPA 620/R-19/239
December 2019
Benthic Ecological Condition Assessment of the
Coastal Waters of Guam
By
Walter G. Nelson1, Jesse Cruz2, Annie Leon Guerrero2, Julie Bailey-Brock3, Faith Cole4
Author Affiliations
1 Center for Public Health and Environmental Assessment
Pacific Ecological Systems Division
U.S. Environmental Protection Agency
Newport OR 97365 USA
Telephone: 1 (541) 867-4041
Email: nelson.walt@epa.gov
ORCID ID -0000-0002-1828-6137
2Guam Environmental Protection Agency
EMAS Division
Bldg, 17-3304, Mariner Ave.,
Barrigada, Guam, 96913
department of Biology
University of Hawai'i
2538 the Mall, Honolulu
Hawai'i, 96822
4 U.S. EPA retired
i
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Disclaimer
The analysis of information in this document has been funded wholly by the U.S. EPA. It has
been subjected to review by the Center for Public Health and Environmental Assessment, Pacific
Ecological Systems Division and approved for publication. The views expressed in this article
are those of the authors and do not necessarily represent the views or policies of the U.S. EPA.
Mention of trade names or commercial products does not constitute endorsement or
recommendation for use.
The appropriate citation for this report is:
W.G. Nelson, J. Cruz, A. L. Guerrero, J. Bailey-Brock, and F.A. Cole. 2019. Benthic
Ecological Condition Assessment of the Coastal Waters of Guam. EPA 600/R-19/239, U.S.
EPA, Office of Research and Development, Center for Public Health and Environmental
Assessment, Pacific Ecological Systems Division, Newport OR, 97365; 43 p.
ii
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Abstract
The U.S. Environmental Protection Agency, Guam EPA and other collaborators conducted a
pilot condition assessment of near-shore waters of Guam as part of the National Coastal
Assessment (NCA) program. Results indicated that chemical contamination of sediments by
heavy metals, PAHs, PCBs, and legacy pesticides did not occur at levels potentially harmful to
benthic systems, apart from limited areas within the highly altered Apra Harbor. There was also
no indication of contaminant-related sediment toxicity to amphipods, nor correlation of
holothurian tissue contamination with sediment contaminants. Similarly, there was little
indication of altered benthic community composition indicative of pollutant impacts. The NCA
survey results were consistent with results from other site-specific surveys of benthic condition
conducted from Guam coastal waters. Several provisional indicators (benthic substrate, fish
community, holothurian tissue contamination) proved operationally feasible to incorporate into
the NCA assessment approach, but until benchmark values can be determined, their use in
assessment of coastal condition will be limited. The pilot NCA assessment of Guam coastal
waters provides a baseline that may be particularly valuable for assessing environmental change
associated with currently proposed changes to military installations and population on the island.
iii
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the
Nation's land, air, and water resources. Under a mandate of national environmental laws, the
Agency strives to formulate and implement actions leading to a compatible balance between
human activities and the ability of natural systems to support and nurture life. To meet this
mandate, EPA's research program is providing data and technical support for solving
environmental problems today and building a science knowledge base necessary to manage our
ecological resources wisely, understand how pollutants affect our health, and prevent or reduce
environmental risks in the future.
The Center for Public Health & Environmental Assessment (CPHEA) develops human health
and environmental assessments that support EPA Program and Regional policies and decisions.
CPHEA conducts toxicological, clinical, ecological, epidemiological and citizen science studies
to assess the impact of environmental exposures to chemicals and other stressors on healthy
individuals, populations, and ecosystems, emphasizing people and ecosystems most susceptible
to the adverse effects of such exposures. CPHEA provides research, statistical methods, analysis
and modeling that helps interpret scientific study results and inform assessments or
programmatic decisions. This includes laboratory and field studies, pharmacokinetic and
ecological modeling, dose- and stress-response analysis, that help evaluate the results of studies
and determine public health or ecological impact. The Center evaluates and applies
environmental indicators of ecological and human systems to inform EPA programs, help
establish programmatic priorities and assess environmental impacts. CPHEA develops systems-
informed scientific approaches and conducts research to address complex environmental
problems, providing information and solutions that lead to improvements in environmental
condition, ecosystem service production, and human health and well-being.
CPHEA scientists, in collaboration with Guam EPA and other institutions, conducted a pilot
condition assessment of near-shore waters of Guam as part of the National Coastal Assessment
(NCA) program. The study found only low levels of chemical contaminants in sediments apart
from limited areas within the highly altered main harbor on the island. There was little
indication of pollutant impacts from other benthic condition indicators such as toxicity tests or
pollutant concentrations in sea cucumber tissue. The results reported here provide a valuable
baseline condition for Guam coastal waters that can be used to assess effects of future alterations
of military installations and population.
Wayne Casio, Director
Center for Public Health and Environmental Assessment
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Table of Contents
Preface ii
Disclaimer ii
Abstract iii
Foreword iv
List of Figures vii
List of Tables viii
List of Appendix Tables ix
List of Acronyms x
Acknowledgments xi
1.0 Introduction 1
2.0 Methods 2
3.0 Results 6
3.1 Sample Area Characteristics 6
3.2 Sediment Condition Indicators 7
3.2.1 Sediment Contaminants 7
3.2.2 Sediment Toxicity 8
3.2.3 Benthic Infaunal Community 9
3.3 Developmental Condition Indicators 20
3.3.1 Benthic Substrates 20
3.3.2 Fish 20
3.3.3 Holothurian Tissue 22
v
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4.0 Discussion 23
4.1 Sediment Condition Indicators 23
4.1.1 Sediment Contaminants 23
4.1.2 Sediment Toxicity 24
4.1.3 Benthic Infaunal Community 24
4.2 Developmental Condition Indicators 25
4.2.1 Benthic Substrates 25
4.2.2 Fish 25
4.2.3 Holothurian Tissue 26
4.3 Conclusions 26
5.0 References 28
6.0 Appendix Tables 31
vi
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List of Figures
Figure 2.1. Map showing National Coastal Assessment sample stations for Guam and
the two statistical design strata used in the study 3
Figure 3.2.1. Distribution of stations grouped by quartiles of benthic faunal abundance
from sediment samples 15
Figure 3.2.2. Distribution of stations grouped by quartiles of benthic faunal species
richness from sediment samples 16
Figure 3.2.3. Regression relationship of number of benthic infaunal species with
sediment percent fines 17
Figure 3.2.4. Cluster analysis for benthic infauna collection stations with a horizontal
slice (dotted black line) at 25% similarity 18
Figure 3.2.5. Results of nMDS analysis for benthic community composition for all
stations, coded with the two statistical sampling strata 19
Figure 3.3.1. Distribution of stations grouped by quartiles of total fish abundance from
underwater visual surveys 22
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Tables
Table 3.1.1. Soft-sediment benthic and fish community parameters, sediment percent
total organic carbon and percent fines, for each station in the Guam coastal condition
assessment, with summary statistics 7
Table 3.2.1. Sediment chemical contaminant concentrations for the Guam coastal
condition assessment compared to Effects Range Low (ERL) or Effects Range Medium
(ERM) concentrations, where available 10
Table 3.2.2. Benthic infaunal taxa with >100 individuals collected. The 28 taxa
composed 82% of total infaunal abundance 14
Table 3.3.1. The twenty-five most abundant fish taxa and frequency of station
occurrence observed during underwater visual surveys, representing 66% of the total
number of fishes observed 21
viii
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Appendix Tables
Appendix Table 3.1 A. Surface and bottom sample depth, temperature, salinity,
dissolved oxygen (DO) and pH for Guam benthic condition assessment stations 31
Appendix Table 3.1B. Estimated cumulative percent area of Guam near coastal bottom
area associated with observed values of sample depth, temperature, salinity and DO. .
33
Appendix Table 3.1C. Estimated cumulative percent area of Guam near coastal bottom
area associated with observed values of percent fine sediments and percent TOC. ... 36
Appendix Table 3.2.2A. Pearson Product Moment Correlation coefficients between
control corrected survivorship of the bioassay organism Ampelisca abdita and sediment
contaminant indicators 37
Appendix Table 3.2.2B. Pearson Product Moment Correlation coefficients for sediment
% fines and sediment metal contaminant concentrations 37
Appendix Table 3.2.3. Pearson Product Moment Correlation coefficients for benthic
abundance and species richness versus sediment % fines and TOC, for all data and for
data from the subset of stations with percent fines >5% 38
Appendix Table 3.3.1. Estimated cumulative percent area of Guam near coastal bottom
area associated with observed values of five composite habitat cover types, recorded
from underwater visual quadrat surveys 39
Appendix Table 3.3.2. Pearson Product Moment Correlation coefficients for percentage
cover of substrate type versus fish abundance or species richness 41
Appendix Table 3.3.3A. Comparison of sediment and holothurian tissue concentrations
for the five metals (arsenic, chromium, copper, lead, zinc) that were detected at
concentrations above the ERL at any station for the holothurian collections 42
Appendix Table 3.3.3B. Pearson Product Moment Correlation coefficients for sediment
and holothurian tissue concentrations for five metals (arsenic, chromium, copper, lead,
zinc) 43
IX
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CDF
CONUS
DO
EMAP
EPA
ERL
ERM
GCA
GED
GEPA
GRTS
nMDS
NCA
NCCA
NOAA
NTU
PAH
PCB
SD
TOC
Acronyms
Cumulative distribution function
Continental U.S.
Dissolved Oxygen Concentration
Environmental Monitoring and Assessment Program
U.S. Environmental Protection Agency
Effects Range Low
Effects Range Median
Guam Coast Assessment
Gulf Ecology Division, Gulf Breeze Florida
Guam Environmental Protection Agency
Generalized Random Tessellation Stratified
Nonmetric Multidimensional Scaling
National Coastal Assessment
National Coastal Condition Assessment
National Oceanic and Atmospheric Administration
Nephelometric Turbidity Units
Polycyclic Aromatic Hydrocarbons
Polychlorinated Biphenyls
Standard Deviation
Total Organic Carbon
x
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Acknowledgments
Underwater visual fish censuses were conducted by Val Porter (Brown), Brent Tibbets, and Jay
Gutierrez of the Guam Division of Aquatic and Wildlife Resources (at the time of survey), and
by Mike Gawel of Guam EPA (at the time of survey). Dr. William Cooke and Dr. Peter Slattery
provided the identification of benthic infaunal crustaceans. T Chris Mochon-Collura of U.S.
EPA analyzed the chlorophyll-a samples. We thank Dr. Jeff Hyland (NOAA retired) for initial
technical review of this paper, and James Markwiese (EPA) for review of QA/QC issues.
XI
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1.0 Introduction
The National Coastal Assessment (NCA) of the U.S. Environmental Protection Agency (EPA)
was established as a research effort to develop the methods for obtaining nationally consistent
information on the condition of coastal resources of the U.S. As a part of this program, a pilot
assessment of the condition of estuarine and near-coastal waters was conducted as a cooperative
program between the EPA and Guam Environmental Protection Agency (GEPA). The goals of
the program were to collect data on a standard set of environmental indicators that could be
incorporated into the NCA program (U.S. EPA 2008, 2012), which focused on soft-sediment
habitats, and to examine the utility of several additional indicators and methods more appropriate
to condition assessment in the mixed hard- and soft-bottom coastal environment typical of
Guam.
Guam has the largest population in Micronesia, with highest population density along the west-
central and northern regions (Crossett et al. 2008, Pinkerton et al. 2015), which include both
Tumon Bay, a center for a considerable tourist industry, and Apra Harbor which contains both
the commercial and military port facilities for the island. Northern Guam also is the location of
large military installations. Much of the shoreline in the west-central region has either been
altered (e.g. Apra Harbor), or has adjacent urbanized land use, while southern portions of the
island are less densely populated. Although it might be presumed that the magnitude of
anthropogenic impacts would be highest in the waters bordering the most urbanized shorelines of
Guam, this hypothesis needed to be tested. Coastal habitats include a variety of coral-reef types
(Burdick et al. 2008), algal-dominated hard substrates, and small areas of seagrasses and very
limited mangrove habitat (Burdick 2006). Threats to coastal resources from degraded water and
habitat quality include various impacts from marine transportation (shipping, boating, marinas,
tourism), nutrients and contaminants from both point and non-point sources, thermal effluent,
and especially for corals, sedimentation and heavy fishing pressure (Burdick et al. 2008, Nelson
et al. 2016).
Monitoring of the physical, chemical and bacteriological status of marine receiving waters is
conducted by Guam EPA, and there are several studies of point-source impacts or studies of
marine water quality at localized scales (Tsuda and Grosenbaugh 1977, Denton et al. 1999, 2005,
Bailey-Brock and Krause 2007, Barrett et al. 2001, Bailey-Brock et al. 2011). NOAA has
conducted a series of rapid assessments of coral-reef condition and has instituted a periodic
coral-habitat monitoring program on Guam (Burdick et al. 2008, Williams et al. 2012).
However, there is a general lack of quantitative baseline information for sediment and tissue
pollutant concentrations for Guam marine waters as a whole. The present study provides a
quantitative assessment for a number of indicators which may serve as a reference for future
changes in condition of primarily soft-sediment benthic habitats of Guam coastal waters.
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2.0 Methods
The Guam coastal assessment study utilized a Generalized Random Tessellation Stratified
(GRTS) survey design (Stevens and Olsen 2003), which allows estimation of the percentage area
(± Confidence Limits) of the resource being assessed that falls in specified condition categories,
e.g. below a water-quality criterion. There were two sampling design strata: "Estuary" (34
stations), consisting of both the limited true estuarine area together with the most enclosed
embayments on the coast line, and "Nearshore" (16 stations), which consisted of the remainder
of the coast line to a maximum depth of 18.3 m (60 ft). The inclusion of Apra Harbor within the
"Estuary" design stratum resulted in inclusion of six sites that were between 20 and 35 m depth.
Alternate site locations were included in the design in case original sites could not be sampled.
A total of 50 stations were successfully sampled over the period November 2004-August 2005,
with 5 original stations being replaced by alternate locations (Figure 2.1), resulting in data from
33 Estuary and 17 Nearshore stations.
Field methods are described in the U.S. EPA NCA Quality Assurance Project Plan document
(U.S. EPA 2001a) and the NCA Field Operations Manual (U.S. EPA 2001b). At each station,
measurements were obtained for characterization of a range of standard NCA parameters: 1)
community structure and composition of benthic macroinfauna (fauna retained on a 0.5-mm
sieve); 2) concentration of chemical contaminants in sediments (metals, pesticides, PCBs,
PAHs); and 3) general habitat conditions (water depth, dissolved oxygen (DO), salinity,
temperature, chlorophyll a, light transmittance, water-column nutrients, % silt-clay, total
organic-carbon (TOC) content of sediment). Because of the extensive presence of hard-bottom
habitat in the coastal waters of Guam, quadrat and transect assessments of hard-bottom
communities were added to the assessment. Bottom trawling was not feasible in Guam, and
underwater visual surveys of the fish community were conducted as an alternative assessment
method for fish communities. Water-column enterococci measurements were also added to the
Guam assessment as an indicator of bacterial contamination.
Both vertical water-column profiles (Hydrolab datasonde with temperature, salinity, depth,
dissolved oxygen, pH, turbidity (NTU)) and discrete water samples were collected at each station
to characterize water-column conditions. Water-column data are not presented in this paper but
are available upon request from GEPA.
Sediment samples were collected and analyzed for the standard NCA list of organic and
inorganic contaminants (U.S. EPA 2008), toxicity bioassays, determination of physical
characteristics, and infaunal community composition. Samples were obtained either by snorkel
or SCUBA divers who collected sediments into pre-cleaned jars (see below), or by use of a 0.04
m2 Van Veen grab sampler at deeper stations. Sediments from the grab were deposited in a
stainless-steel pan and subsamples were placed into jars of the same sizes used by the divers.
Separate subsamples were collected for organic contaminants (250 ml), inorganic contaminants
(125 ml), bioassays (2x2 L), TOC (125 ml), grain size (125 ml), and benthic infauna (-800
cm3).
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Apra-Harjbor
00 ™
Apra Harbor
Sample
Design
Category station
Estuary ) |
Near Shore | |
Map Location
Figure 2.1. Map showing National Coastal Assessment sample stations for Guam and the two
statistical design strata used in the study.
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Sediments for toxicity bioassasys were shipped to the Gulf Ecology Division of U.S. EPA
(GED), and transferred to the contract laboratory (TRAC Laboratories, Inc., Pensacola, FL)
where 10-day, solid-phase, acute toxicity tests were conducted with the marine amphipod
Ampelisca abdita. Procedures followed ASTM Protocol E1367-92 (ASTM 1991), the EPA
amphipod sediment toxicity testing manual (U.S. EPA 1994), and the EMAP Laboratory
Methods Manual (U.S. EPA 1995). There were five replicates per sediment sample and a
negative control consisting of sediment from the site where the amphipods were collected. Test
results are reported as control-corrected percentage survival.
Sediments for analysis of chemical contaminants were also shipped to GED and transferred to
the contract laboratory (GPL Laboratories (now Centauri Labs), Frederick, MD) which analyzed
for 15 metals, 20 PCB congeners, DDT and its primary metabolites, 13 additional chlorinated
pesticides (Aldrin, Alpha-Chlordane, Dieldrin, Endosulfan I, Endosulfan sulfate, Endrin,
Heptaclor, Heptaclor epoxide, Hexachorlorbenzene, Lindane (gamma BHC), Mirex, Toxaphene,
Trans-Nonachlor), and 23 polyaromatic hydrocarbons (PAHs) using EPA standard methods. A
complete list of compounds analyzed, together with a description of quality-assurance methods,
is given in U.S. EPA (2001a). Samples for total organic carbon (TOC) were analyzed by the
contract laboratory (B & B Laboratories, College Station, TX) using a Leco carbon analyzer.
The EPA NCA has used the Effects Range Low (ERL) and Effects Range Median (ERM)
concentrations (Long et al. 1995) of sediment contaminants as benchmarks for interpreting the
biological significance of observed contaminant concentrations (U.S. EPA 2004, 2008, 2012).
ERLs and ERMs have been developed for 28 chemicals or chemical groups and are presented
together with the sediment-contaminant results. Values for nickel are included but have very
low reliability since crustal concentrations of nickel may often bracket the ERM value for nickel
(Long et al. 1995).
A feasibility study was conducted to determine whether holothurians could be utilized to assess
tissue body burdens of chemical contaminants. Generally, one species per station was collected,
with species varying depending on station location (Aciinopyga maurilicma, Bohadschia argus,
Bohadsia marmorata, Holothuria atra, Holothuria edulis, Holothuria nobilis, Holothuria sp.).
Data were obtained from 28 stations, while samples from an additional 8 stations were delayed in
transit and were not analyzed. All samples were sent frozen to the contract laboratory (CRG
Laboratories, Torrance, CA) for analysis of the same suite of analytes determined for the
sediment samples.
A single sediment sample of approximately 800 cm3 was collected at each station for benthic
infaunal analyses, while field duplicate samples were also collected at 8 stations (3, 5, 9, 15, 26,
31, 35, 40). Collection was made with jars, 11.1 cm in diameter (surface area = 0.0097 m"2),
inserted into the sediment to a depth of approximately 10 cm — either directly into the seafloor
by divers for shallow stations, or as subsamples of sediment from grabs deployed at deeper
stations. Samples of this volume were considered adequate based on studies of the soft-bottom
infauna in Hawaii which tend to be both small and abundant (Nelson 1986, Swartz et al. 2000).
Benthic biological samples were fixed in their labeled collection containers with buffered
formalin. The fixed samples were elutriated using the technique of Sanders et al. (1965). This
method successfully removes from the sediment all organisms that are not heavily calcified. The
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samples were washed several times, and the water from each was poured through 0.5-mm mesh
sieves. Organisms retained on the sieve were transferred to alcohol, stained with rose bengal
solution, and stored in 70% ethanol. When large carbonate rubble fragments were collected in
the sediment samples, the rubble fragments were carefully washed and visually examined to
ensure that any organisms on the external surfaces were removed. The fragments were then
placed in a nitric acid bath for 24 hours or longer to dissolve the carbonate and to recover
organisms living in burrows (Brock and Brock 1977, Nelson 1986). Polychaetes and crustaceans
were identified to species wherever possible. Nematodes, oligochaetes, nemerteans, and several
other such taxa were not further identified. Molluscs, which represented only 0.9% of
abundance, were only identified to class level.
Limitations of visibility, depth, or safety considerations affected collection of visual fish
censuses and visual quadrat estimates of sessile benthic organisms within Apra Harbor. Where
environmental conditions permitted (32 stations), the fish community was censused by SCUBA
divers swimming along a 25-m transect line. This transect length has proven adequate in
sampling many Hawaiian benthic communities (Brock and Norris 1989). All fishes present in a
4 x 25 m corridor from the bottom to the surface were visually counted and standard length was
estimated. Length was converted to standing crop estimates using linear regression for species
where regression coefficients were available from the Hawaiian Islands (Brock 1954, Brock and
Norris 1989). Regressions were based on weight and body-length measurements of captured
fishes. These biomass estimates are not reported here but are available from the authors.
Exposed sessile benthic forms, such as corals and macroalgae, and substrate type were
quantitatively surveyed and recorded as percent cover by use of quadrat surveys at 35 stations.
A 1-m2 frame with a 16-point sample grid was placed at 5-m intervals along both sides (left and
right) of the transect line used for fish censuses (at 5, 10, 15, 20 and 25m). Substrate type was
identified under each point resulting in 160 records at each transect. With the macroalgae,
emphasis was placed on those species that were visually dominant, and no attempt was made to
quantitatively assess the multitude of microalgal species that constituted the algal turf often
present in coral reef habitats.
Data analysis included calculation of cumulative distribution functions (CDFs) to determine the
estimated percentage of the area sampled falling above or below parameter values of interest
(Diaz-Ramos et al. 1996). Analyses were conducted using the SAS® statistical package.
Equivalent programs for the R software environment are available at
https://archive.epa.gov/nheerl/arm/web/html/software.html. Because visual surveys (fish, sessile
organisms) in Apra Harbor were not conducted due to low visibility and safety issues, the area of
Apra Harbor was subtracted from the total area associated with the "Estuary" stratum for
computation of the CDFs for visual survey metrics. Estimations of percent area associated with
the visual sampling metrics thus refer to coastal waters of Guam excluding Apra Harbor.
Soft-bottom benthic community composition was examined with multivariate analyses using
PRIMER (6th Edition, Clarke and Gorley 2006). Species density data (abundance core"1) from
all stations (n=48) with number of taxa > 1 were 4t,1-root transformed to reduce the influence of
highly abundant species (Clarke and Warwick 2001). Field duplicate samples were excluded
from the analysis. Cluster analysis (CLUSTER) was then performed on a Bray-Curtis similarity
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matrix of the transformed data. To determine whether the a-priori designation of stations into
two sampling strata was reflected in the benthic community, nonmetric multidimensional scaling
(nMDS) was used to plot stations labeled as to stratum on a two-dimensional ordination plane
based on similarity of taxonomic composition. Individual measures of common benthic
attributes, such as taxa richness (numbers of taxa per sample), H' diversity (log2), total faunal
abundance, and abundances of numerically dominant taxa, were also recorded and examined in
relation to selected abiotic environmental factors.
3.0 Results
3.1 Sample Area Characteristics
Bottom depth at sample sites ranged from 0.1-35 m (Table 3.1.1), with 93.4 % of the sample area
estimated to be < 16.5 m (Appendix Tables 3.1A, 3. IB). There was little evidence of strong
vertical water-column stratification at any sample site. The largest surface-to-bottom salinity
difference was -0.8. Salinity ranged from 28.1 - 38.3 (psu) at the surface and 28.8 - 38.2 (psu) at
the bottom, with a maximum of only 20% of coastal area estimated to have salinity <30
(Appendix Tables 3.1 A, 3. IB). Surface temperatures ranged from 27.5 - 30.3 °C, and the bottom
temperature range was similar (27.5-30.1 °C). In both cases, approximately 82% of the coastal
area had temperatures within the range of 28 - 30 °C (Appendix Tables 3.1 A, 3. IB).
The soft-bottom habitats of Guam's coastal waters are predominantly sandy sediments.
Although percent fines ranged from 0 to 90% (Table 3.1.1), an estimated 84% of Guam soft-
bottom area would be classified (Flemming 2000) as sands (<5% fines), 5% as muddy sands (5
to 50 % fines), and 11% as sandy muds (>50 - 95 fines) (Appendix Table 3.1C). All but one
location with percent fines >5% were encountered within Apra Harbor (Table 3.1.1). TOO in
sediments ranged between 0.16 - 3.74 % (Table 3.1.1), with an estimated 76% of the area of
Guam coastal waters having <2% TOC (Appendix Table 3.1C). Sites with TOC >2% were
widely distributed and showed no spatial pattern. There was a weak but significant negative
correlation of percent TOC with depth (r =- 0.31; p = 0.03, n=50). For the entire set of sample
stations, there was no correlation of TOC with percent fines (p = 0.55). For the subset of stations
with percent fines >5% (14 sites within Apra Harbor plus one site in Talofofo Bay), there was a
positive relationship of percent TOC to percent fines (r = 0.67; p = 0.007).
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Table 3.1.1. Soft-sediment benthic and fish community parameters, sediment percent total organic carbon and percent fines, for each station in the
Guam coastal condition assessment, with summary statistics. Values of benthic metrics at Stations 3, 5, 9, 15. 26. 31, 35, and 40 represent a mean
of field duplicate samples. Taxa richness = No. taxa sample"1; Abundance = No. individuals sample"1; H' (log:) per sample.
Bottom
Benthic
Benthic
Fish
Station
depth
Taxa
Benthic
H'
Fish
Fish Taxa
H'
%
%
No.
Site Name
(m)
Richness
Abundance
index
Abundance
Richness
Index
TOC
Fines
1
Pagat Point
8.5
46
410
4.12
69
16
3.27
1.5
0
2
Mouth of Inner Harbor
13.3
26
165
3.26
0.2
18.6
3
Cetti Bay
0.5
42.5
283.5
4.35
63
3
1.15
2.2
0.4
4
Agat Marina Channel
3.5
40
306
3.42
157
19
3.27
1.3
0.2
5
Tumon Bay - Okura reef flat
1.1
39
369
4.57
2
2
1.00
1.6
0.4
6
Sasa Bay Mangrove
1
20
227
3.01
0.9
47.7
7
Aga Bay - Inarajan
0.2
16
102
2.81
93
6
1.33
0.8
0
8
Apra Harbor - near Dry Dock
28.5
10
22
2.95
2.5
88.9
9
East Hagatna Bay
0.7
39.5
888.5
3.35
29
6
1.06
2.3
2.5
10
Sasa Bay
10.5
7
20
2.42
1.9
87.2
11
Cocos Lagoon - Outside
5.5
48
274
4.57
94
17
3.55
2.5
0
13
West Adelup Park
0.3
23
98
3.70
113
17
3.39
2.2
0.4
14
Gaan Point Agat
1.2
22
449
1.76
91
14
3.35
0.4
0
15
Ylig Bay
13.5
33.5
169
3.54
21
8
2.67
0.9
0.2
16
Tipalao Bay
6.5
33
225
3
130
20
3.28
1.2
0.9
18
South Inner Harbor
10.5
1
1
0
1.4
87.4
19
Southeast Cocos Lagoon
1.3
52
1429
3.36
347
34
3.58
0.8
0.8
21
South of Alupang Island
7.5
58
341
4.46
159
27
3.75
0.6
0
22
Facpi Point
5
42
166
4.26
85
26
3.96
0.8
0
23
Talofofo Bay Bridge
5
0
0
0
1.9
68.1
25
Tanguisson Point
3
31
84
4.36
137
27
3.74
2.5
0
26
Piti Bomb Holes
1
41.5
753
3.52
23
7
2.51
0.4
0.6
27
Bile Bay
15.5
25
361
3.15
9
5
1.88
0.4
4.1
28
Apra Harbor-off Seaplane Ramp
34
10
25
2.96
0.5
56.7
29
Mamatguan Point
13.5
39
125
4.66
0.8
0.2
30
Agat Bay - Dadi Beach
0.9
33
227
3.19
80
16
2.94
1.3
0.3
31
East Inner Harbor
9.5
4
7
1.64
94
34
4.37
1.8
89.8
7
-------
Bottom Benthic
Station depth Taxa
No. Site Name (m) Richness
32 Apra Harbor Mouth 4 29
33 Mangilao Golf Course Terrace o.l 25
34 Mouth of Sasa Bay 20 12
35 South Cocos Lagoon 12 54.5
36 Apra Harbor - Kilo Wharf 24 38
37 Tumon Bay - Matapang 0.6 46
38 Port Authority Dock 12.6 23
39 Ulomai Beach - Inarajan o.2 28
40 Apra Harbor - Deep 35 3.5
41 East Hagatna Bay - Reef margin o.2 38
42 Asan Cut 3 47
43 Cocos Lagoon - mid 3 35
44 Apra Harbor - West Jade Shoals 26.5 10
45 West Hagatna Bay 0.4 30
46 Agat Bay Channel 0.8 35
47 TogchaBay 0.1 26
49 Pago Bay Reef Margin 4 23
50 South Sasa Bay 4 5 18
51 Ritidian Point 0.5 26
52 West Inner Harbor § 5
53 Sella Bay 16 5 48
54 Rizal Beach 10.5 26
55 Ypao Beach 0.3 38
Mean 75 28.9
SD 9.1 14.9
Max 35 58
Min o.l 0
Benthic
Fish
Benthic
H'
Fish
Fish Taxa
H'
%
%
Abundance
index
Abundance
Richness
Index
TOC
Fines
209
3.95
268
13
3.25
1.3
0
272
3.68
0.9
0
68
3.13
0.9
87.9
957.5
3.96
465
34
3.42
0.3
0.4
544
2.86
0.2
7.3
660
2.95
12
6
2.25
3.3
0.5
121
3.14
0.3
27.4
218
3.55
3.7
0
7
1.68
0.5
80.5
192
4.19
3.1
0.4
137
4.99
175
22
3.49
1.9
0.2
276
3.73
48
4
1.32
3.2
1.6
19
2.79
0.6
71.1
320
3.78
1
1
0.00
2.2
0.7
329
3.56
54
13
3.11
0.5
0.4
452
2.58
22
7
2.62
0.3
2.4
142
3.50
94
13
2.72
1.9
0
341
2.20
1.2
89.3
215
3.38
36
8
2.35
2
0.1
6
2.25
0.6
77.4
2678
2.73
26
5
1.57
0.3
1.6
175
3.41
134
28
3.81
3.1
0
486
3.83
14
9
2.90
0.3
0.4
327.0
3.20
y ->
14.6
2.75
1.4
20.1
436.5
1.00
112 8
10.6
1.05
1.0
33.7
2678
4.99
465
34
4.37
3.7
89.8
0
0
1
1
0
0.2
0
-------
3.2 Sediment Condition Indicators
3.2.1 Sediment Contaminants
The presence of chemical contaminants in sediments at levels likely to be harmful to benthic
organisms was limited. For example, no concentration of any chemical analyzed exceeded its
corresponding upper-range ERM threshold indicative of probable bioeffects (Table 3.2.1).
Concentrations of the thirteen non-DDT pesticides that were measured were all at non-detectable
levels. DDT and three of the six congeners analyzed were detected at only seven stations. Total
DDT in excess of the lower-threshold ERL value, below which significant bioeffects are not
expected, occurred in only an estimated 2% of the survey area (Table 3.2.1). All metals analyzed
exceeded detection limits, but with only an estimated 7-14% of sediment having concentrations
of either arsenic, chromium, copper or mercury between corresponding ERL and ERM values
(Table 3.2.1). Cadmium and lead also exceeded ERL values but in a very limited portion (<1%)
of the survey area. Of the 23 individual PAHs that were measured, only nine occurred at
detectable levels and none exceeded corresponding ERL values at any of the stations (Table
3.2.1). Summed low- and high-molecular-weight PAHs and total PAHs also occurred at very
low levels, over an order of magnitude below ERL values. PCBs were detected in sediments at
14 sites, but only an estimated 2% of area had concentrations that exceeded the ERL (Table
3.2.1). Of the sites which had one or more contaminants above the ERL values, 75% (12 of 16)
were in Apra Harbor.
3.2.2 Sediment Toxicity
Control-corrected survival of the amphipod Ampelisca abdita exposed to Guam sediments
ranged from 3.2% to >100%. Approximately 71% of the survey area had >80% survival in these
laboratory bioassays. There were no significant, negative correlations of amphipod survival and
sediment contaminant concentration, either expressed as total number of exceedances of ERL
values, or as concentrations of those individual contaminants with >1% area above the ERL
(Appendix Table 3.2.2A), although there was a nearly significant negative association of
amphipod survival and sediment Total PCBs (r = -0.28; p = 0.051). Amphipod survival was
negatively associated with sediment % TOC (r = -0.31; p =0.028), and positively correlated with
sediment percent fines (r = 0.35; p = 0.013). The significant positive correlations between
amphipod survival and arsenic, chromium and mercury concentration are most likely driven by
the strong (r from 0.51 - 0.86) positive correlations of the metals to increased percent fines
(Appendix Table 3.2.2B).
9
-------
Table 3,2.1. Sediment chemical contaminant concentrations for the Guam coastal condition assessment compared to Effects Range Low (ERL) or
Effects Range Medium (ERM) concentrations, where available. ND - non-detect
Parameter
Mean
STD
Maximum
Minimum
% Sample
Area >ERL
% Sample
Area >ERM
ERL
value
ERM
value
Metals (jig/g)
Antimony
0.19
0.59
4.0
ND
Arsenic
4.58
5.43
21.3
ND
13
0
8.2
70
Cadmium
0.10
0.26
1.3
ND
<1
0
1.2
9.6
Chromium
30.68
53.67
254
ND
13
0
81
370
Copper
22.32
43.20
217
ND
14
0
34
270
Lead
9.02
16.40
88.4
ND
<1
0
46.7
218
Manganese
193.9
312.7
1690
2.4
Mercury
0.04
0.08
0.27
ND
7
0
0.15
0.71
Nickel
15.93
25.24
97.9
ND
Selenium
0.48
0.84
2.4
ND
Silver
0.03
0.04
0.16
ND
0
0
1
3.7
Zinc
31.53
45.11
146
0.5
0
0
150
410
Organics (ng/g) PAHs
Acenaphthene
ND
-
ND
ND
0
0
16
500
Acenaphthylene
ND
-
ND
ND
0
0
44
640
Anthracene
ND
-
ND
ND
0
0
85.3
1100
Benz(a)anthracene
0.54
2.69
15
ND
0
0
19
540
Benzo(a)pyrene
1.36
4.19
18
ND
0
0
70
670
Benzo(b)fluoranthene
2.7
7.0
27
ND
Benzo(g,h)perylene
0.8
3.4
16
ND
Benzo(k)fluoranthene
0.5
2.4
12
ND
Biphenyl
ND
-
ND
ND
Chrysene
1.12
3.86
16
ND
0
0
160
2100
Dibenzo(a,h)anthracene
ND
-
ND
ND
0
0
240
1500
Dibenzothiophene
ND
-
ND
ND
2,6-dimethylnaphthalene
ND
-
ND
ND
Fluoranthene
2.08
5.3
20
ND
0
0
261
1600
Fluorene
ND
-
ND
ND
0
0
430
1600
Indeno( 1,2,3 -c,d)pyrene
0.5
2.4
13
ND
1 -methylnaphthalene
ND
-
ND
ND
-------
Parameter
Mean
STD
Maximum
Minimum
% Sample
Area >ERL
% Sample
Area >ERM
ERL
value
ERM
value
2-methylnaphthalene
ND
-
ND
ND
0
0
384
2800
1 -methylpnenanthrene
ND
-
ND
ND
Naphthalene
ND
-
ND
ND
0
0
63.4
260
Phenanthrene
ND
-
ND
ND
0
0
600
5100
Pyrene
2.4
5.22
16
ND
0
0
665
2600
2,3,5-trimethylnaphthalene
ND
-
ND
ND
Low molecular weight PAHs
0.24
1.7
12
ND
0
0
552
3160
High molecular weight PAHs
11.98
28.68
137
ND
0
0
1700
9600
Total PAHs
12.22
28.62
137
ND
0
0
4020
44800
DDT and Congeners
Total DDT
0.28
0.96
5.9
ND
2
0
2.2
27
2,4'-DDT
ND
-
ND
ND
4,4'-DDT
0.17
0.86
5.9
ND
2,4'-DDD
ND
-
ND
ND
4,4'-DDD
0.1
0.07
0.39
ND
2,4'-DDE
ND
-
ND
ND
4,4'-DDE
0.09
0.35
2.2
ND
<1
0
1.58
46.1
PCBs
Total PCBs
2.66
8.29
43.5
ND
2
0
22.7
180
-------
3.2.3 Benthic Infaunal Community
There were 19,721 benthic infaunal organisms, comprising 274 different taxa, that were
collected from the 58 samples. Polychaetes were dominant in terms of both abundance (8,582)
and taxa richness (141). Crustaceans were also abundant (5,671) and diverse (111 taxa). Of the
crustacean taxa identified to species, the Amphipoda were the most diverse taxon with 34
species. The top five, numerically dominant taxa consisted of Nematoda, the tanaid Leptochelia
dubia, a ctenodrillid polychaete Raphidrilus sp. A, a syllid polychaete Pionosyf/is heterocirrata,
and Copepoda, which together composed 53% of total abundance (Table 3.2.2). Mollusks were
uncommon, representing less than 1% of total abundance. The benthic samples had a mean
species richness of 28.9 taxa and a mean abundance of 327 individuals per sample (Table 3.1.1).
In spite of the relatively small volume of sediment collected, maximum species richness per
sample was 58, and maximum abundance was 2,678 organisms per sample (approximately =
2.76x 1 CP m~2). No organisms were collected at one site (23) in Talofofo Bay, a location that also
had the lowest bottom DO that was recorded (Table 3.1.1, Appendix Table 3.1A). Also, only 1
individual was collected at station 18 within Apra Harbor (Table 3.1.1). The H' diversity index
ranged widely from 0 to 4.99 (Table 3.1.1).
Guam does not currently have biological criteria for evaluating condition of their coastal waters,
so there are no relevant reference values for comparison. In the absence of such criteria, a sample
was evaluated based on how the value of a benthic attribute of interest compared to other
corresponding values for the overall population of samples ordered by quartiles. This provided a
basis for examining potential linkages between lower- versus higher-quartile benthic values and
the presence of any chemical contaminants or other controlling factors. A similar approach was
used recently by Balthis et al. (2017) to derive sediment-quality benchmarks for assessing risks
of oil-related impacts to the deep-sea benthos, based on data following the Deepwater Horizon
oil spill in the Gulf of Mexico. Presenting abundance data by quartiles indicates that stations in
the lowest quartile of abundance were largely located in Apra Harbor, with one site each near
Agana and in Talofofo Bay (Figure 3.2.1). Similarly, most stations in the lowest quartile of
species richness were in Apra Harbor, with one station in Talofofo Bay and one station at a site
on the southeast coast (Figure 3.2.2). Based on the cumulative distribution function,
approximately 15% of area of coastal waters has infaunal abundance > 500 individuals per
sample (Figure 3.2.1) and 28% of area has > 40 infaunal taxa per sample (Figure 3).
Sediment characteristics, particularly percent fines, appear to influence species richness and
abundance of the benthic infaunal community in Guam. There was a significant (r2 = -0.63 ;p<
0.001) negative relationship of species richness to percent fines (Figure 3.2.3) for all samples.
This relationship was driven primarily by the 15 sites with >5% fine sediments (r = -0.81; p
=0.0002; Appendix Table 3.2.3). There was no significant relationship of species richness to
TOC for all stations (p =0.9). However, since TOC was correlated with percent fines at sites
with >5% fines (Section 3.1), there was a significant negative relationship of species richness to
TOC (r = -0.57, p = 0.02; Appendix Table 3.2.3). There was a significant but weaker negative
correlation of total abundance to percent fines (r = -0.35, p = 0.01), while there was no
significant correlation with TOC (p = 0.17). A similar pattern was observed for the subset of
sites with > 5% fine sediments, with a significant negative relationship of abundance to percent
fines (r = -0.61; p = 0.02), but not to TOC (p = 0.14; Appendix Table 3.2.3).
12
-------
Cluster analysis (Figure 3.2.4) generally only grouped spatially proximate stations for those
stations located within Apra Harbor. At the far right of the cluster diagram, the group with
stations 6, 50, 10, 34 are all from Sasa Bay within Apra Harbor (Figure 5). At the far left of the
cluster diagram, the least similar station group consisted of stations 31 and 52 from Apra Inner
Harbor (Figure 5). The second least similar group consisted of stations 40, 28, 8, and 44 at the
east end of Apra Outer Harbor (Figure 5). The remaining Outer Apra Harbor stations were
relatively more similar to a spatially heterogeneous group of stations from other areas of coastal
Guam (Figure 5). The nMDS plot (Figure 3.2.5) indicates that there was little separation in
benthic community composition at stations between the two statistical sampling strata, Estuary
and Near Shore, with the exception that many stations within Apra Harbor tended to be outliers
from the remainder of the Guam benthic samples.
13
-------
Table 3. Benthic infaunal taxa with >100 individuals collected. The 28 taxa composed 82% of total
infaunal abundance. Frequency of occurrence includes field duplicate collections for a total possible n =
58. Taxon code A= Amphipoda, I = Isopoda, P = Polychaeta, T = Tanaidacea
Freq. of Taxon
Taxon
Abundance
Occurrence
Code
Nematoda
7 4
53
Leptochelia dubia
2*tv~>
34
T
Raphidrilus sp. A
1746
17
P
Pionosyllis heterocirrata
1348
35
P
Copepoda
1292
43
Oligochaeta
808
38
Sphaerosyllis sp. G
481
35
P
Nemertea
411
47
Myriochele oculata
410
13
P
Seba ekepuu
376
16
A
Pis tone sp. A
322
17
P
Exogone verugera
318
32
P
Capitella capitata
294
29
P
Micropodarke sp. A
242
21
P
Eriopisella sechellensis
225
8
A
Syllides bansei
198
10
P
Armandia intermedia
193
18
P
Onuphidae sp. A
185
19
P
Protodrilus sp. A
164
18
P
Rhynchospio sp. D
157
10
P
Typosyllis cornuta
157
26
P
Exogone longicornis
144
17
P
Bodotriidae spp.
143
26
I
Protodorvillea biarticulata
137
18
P
Capitellidae spp.
130
26
P
Platx hclminthes
122
22
Linopherus microcephala
110
26
P
Bivalvia
107
29
Subtotal abundance
Grand total abundance
16359
19723
14
-------
Apra Harbor
Apra Harbor
Abundance
O <101 (first quartile)
O >101 and <226 (second quartile)
• >226 and <421.3 (third quartile)
• >421.3 (fourth quartile)
100
20
500 1000 1500 2000 2500 3000
Infaunal Abundance
km
Figure 3.2.1. Distribution of stations grouped by quartiles of benthic fauna! abundance from sediment
samples.
15
-------
Apra Harbor
Apra Harbor
Species Richness
O <19.5 (first quartile)
O >19.5 and <29.5 (second quartile)
• >29.5 and <46.3 (third quartile)
• >46.3 (fourth quartile)
B 100
km
Number of Benthic Infaunal Taxa
Figure 3.2.2. Distribution of stations grouped by quartiles of benthic faunal species richness from
sediment samples.
16
-------
70
60 -
50 -
y = -0.35x + 35.97
r2 = 0.63, p< 0.001
9- 40
® 30
40 60
Percent Fines
100
Figure 3.2.3. Regression relationship of number of benthic infaunal species with sediment percent fines.
17
-------
Transform: Fourth root
Resemblance: S17 Bray Curtis similarity
0-r
20 —
40 —
>.
'l.
1
60 —
80-
100-
—i
^ CM O 03 CO
CO ID CNJ
^a)(NJ(DNCO0OOmLnNlOLONCOO)LnNCOO^(D^
co cocn^-OvJlot-cocolo ^ -*-co ^r
t- CO O) If) O) (N (D
ID CO ^ CNJ CO V-
oj a)
CNJ CNJ CNJ
CN] ^ CD o o ^
T- CO ID ID T- CO
Samples
Figure 3.2.4. Cluster analysis for benthic infauna collection stations with a horizontal slice (dotted black line) at 25% similarity. Solid black lines
designate significantly different clusters. Dotted red lines connect similar stations. Stations 18(1 organism) and 23 (0 organisms) were omitted
from the analysis.
18
-------
Transform: Fourth root
Resemblance: S17 Bray Curtis similarity
52
~
31
~
2D Stress: 0.19
Stratum
Near Shore
y Estuary
40
~
28
~
34
T
10
T
~
7
A
38
T
47
3a
~
1
6
s'V
T
49
~
Sl7 i3
33 15V32 4^0w ^
*39 A 5
^ Y5-r+
54
25 22T11T
A 29
~
1
~
A 42
~
Figure 3.2.5. Results of nMDS analysis for benthic community composition for all stations, coded with the two statistical sampling strata.
19
-------
3.3 Developmental Condition Indicators
3.3.1 Benthic Substrates
Many individual or composite taxa identified in the underwater field surveys were combined for
analysis into major categories such as "total coral cover", "total algal cover" and other
groupings. Non-living bottom (sand, rubble, rock) at a site ranged from 2.5-99 % cover, with a
median of approximately 35 % cover estimated for these coastal waters overall (Appendix Table
3.3.1). Live bottom was estimated to cover 20% or less of a site for approximately 16% of the
area of Guam coastal waters (excluding Apra Harbor; Appendix Table 3.3.1). Live-bottom
coverage of 90% or more at a site was estimated to occur for approximately 11% of coastal area.
Total coral coverage at a site ranged from 0 - 55%, with an estimated 34% of total area having at
least 10%) coral coverage, while 15% of area was estimated to have coral coverage between 35 -
55% (Appendix Table 3.3.1). The most frequently encountered coral species were Poriles lutea,
Monlipora sp, Goniaslrca ret (for mis, Porites lobala, Leptoria phrygia, and Pontes rus. Algal
coverage ranged from 0 - 93%, with a median of approximately 38% cover (Appendix Table
3.3.1). The most frequently encountered algal types were unidentified turf algae, Padina
boryana, an unidentified brown alga, Dictyota bartayresiana, crustose coralline algae, Halimeda
opunlia, and (\nilerpa racemosa. Seagrass (Enhalus acoroides, Halodule uninervis, Halophila
ova/is) occurrence was limited to an estimated 16% of bottom area, with only 6% of area having
coverage in the range of 10-18%), while 94% of coastal area was estimated to have seagrass
coverage < 0.6% (Appendix Table 3.3.1).
3.3.2 Fish
A total of 3145 fish, identified to 169 species or higher-level taxa, were recorded (Supplementary
Database). Abundance was dominated (87%) by six families: Pomacentridae, Labridae,
Gobiidae, Acanthuridae, Scaridae, and Blenniidae. Abundance and frequency of occurrence for
the 25 most abundant fish taxa observed are given in Table 3.3.1, which shows that some of the
abundant taxa (e.g. Chromis viridis) were very patchy, only being observed at 1-3 sites. Visually
observed fish abundance ranged from 1 to 465 per 100-m2 transect (mean = 98.3), number of fish
taxa observed ranged from 1 to 34 (mean = 14.6), and H' (log2) diversity ranged from 0 -4.6
(mean = 2.7) (Table 3.1.1). Fish abundance was not significantly correlated with four measures
of benthic substrate type (algal cover, coral cover, living substrate, non-living substrate), while
fish taxa richness was positively correlated only with percent coral cover (r=0.47, p=0,007;
Appendix Table 3.3.2).
As with benthic infauna, the lack of biological criteria for evaluating condition based on fish data
means there are no reference values for comparison. Therefore, data on fish abundance in the
present study were presented as quartiles and individual samples were evaluated in comparison
to the overall distribution of values across the total sample population (Figure 3.3.1). While
stations within the lowest quartile of fish abundance were scattered along most of the coast of
Guam, there was a concentration of such stations along the northwest coast from Agana to
Tumon Bay. From the cumulative distribution function (Figure 3.3.1), approximately 32% of
area of coastal waters has fish abundance >100 individuals per 100 m2
20
-------
Table 3,3.1. The twenty-five most abundant fish taxa and frequency of station occurrence observed
during underwater visual surveys, representing 66% of the total number of fishes observed.
Total Freq. of
Taxon
Common Name
Abundance
Occurrence
Chrysiptera brownriggii
surge damselfish
463
20
Chromis viridis
blue green damselfish
232
2
Labridae
wrasse sp.
223
14
Dascyllus aruanus
whitetail dascyllus
141
3
Scaridae
parrotfish sp.
134
8
Accmthurus nig/ ofuACiis
brown surgeonfish
108
14
Halichoeres sp.
halochoeres sp.
101
8
Halichoeres margaritaceus
pink-belly wrasse
82
3
Eviota sp.
dwarfgoby sp.
80
3
Plectroglyphidodon lacrymatus
whitespotted devil
74
7
Thalassoma quinquevittatum
fivestripe wrasse
65
10
Kelloggella cardinalis
cardinal goby
56
1
Ctenochaetus striatus
striated surgeonfish
46
12
Chlorurus sordidus
daisy parrotfish
44
12
Chrysiptera glauca
grey demoiselle
43
2
Gobiidae
goby sp
42
8
Stegastes fasciolatus
pacific gregory
42
3
Acanthurus triostegus triostegus
convict surgeonfish
40
8
Cirripectes variolosus
red-speckled blenny
35
2
Labroides dimidiatus
bluestreak cleaner wrasse
35
9
Dascyllus reticulatus
reticulate dascyllus
32
2
Entomacrodus striatus
reef margin blenny
32
1
Atherinidac
silversides sp.
30
1
Apogon angustatus
broadstriped cardinalfish
29
4
Plectroglyphidodon dickii
blackbar devil
29
7
Subtotal Fish Abundance
Grand Total Fish Abundance
2238
3145
21
-------
Apra Harbor
Apra Harbor
Fish Abundance
O <24 (first quartiie)
O >24 and <83 (second quartiie)
• >83 and <133 (third quartiie)
• >133 (fourth quartiie)
< 120
¦E 100
100 200 300 400 500
Fish Abundance
km
Figure 3.3.1. Distribution of stations grouped by quartiles of total fish abundance from underwater visual
surveys.
22
-------
3.3.3 Holothurian Tissue Contaminants
Except for cadmium and mercury, which were detected only infrequently (Cd, n=l; Hg, n=2),
most of the heavy metals (e.g., arsenic, chromium, copper, lead, nickel, selenium, zinc) were
consistently detected in holothurian tissue samples, but generally only at low levels (Appendix
Table 3.3.3A). Pesticides were almost never detected, while PCBs were detected at low levels
(2.3, 8.3 ng g"1 wet wt) at only two stations. There was no significant correlation of sediment
versus holothurian tissue values for arsenic, chromium or zinc (Appendix Table 3.3.3B).
Although there were significant positive relationships of sediment versus holothurian tissue
values for both copper (r= 0.53) and lead (r=0.98), in both cases significance was the result of
one (Cu) or two (Pb) sediment values that were 1-2 orders of magnitude above the remaining
values (Appendix Table 3.3.3 A). If data were analyzed without these extreme values, the
correlations were not significant (Cu, r=-0.013; Pb, r=0,16; Appendix Table 3.3.3B).
4.0 Discussion
In comparison to the coastline of the continental U.S. (CONUS) assessed under the EPA
National Coastal Assessment (NCA) and the subsequent National Coastal Condition Assessment
(NCCA), true estuarine area of Guam is very small, and salinity levels observed were generally
>30 psu. Unconsolidated sediments were estimated by the Guam Coastal Atlas (Burdick 2006)
to be 31.2 % of the near-coastal bottom area of Guam, with an estimated 98.5% of sediment
habitat being sand, which is consistent with the results from the EPA benthic assessment. Areas
of fine sediments in the present study were limited to the interior of Apra Harbor, and to
Talofofo Bay near the outlet of the Talofofo River which drains approximately 10% of the
surface area of Guam (Digital Atlas of Southern Guam, http://south.hydroguam.net/index.php).
The present study is unable to determine whether the high percentage of fine sediments at the
sites in Apra Harbor and Talofofo Bay are from anthropogenic disturbance or reflect natural
depositional environments. Denton and Morrison (2009) have noted fine sediment accumulation
near the Pago river mouth in Pago Bay to the north of Talofofo Bay as the result of watershed
erosional processes, and Burdick et al. (2008) have suggested that geological conditions and
anthropogenic alterations have led to increased sedimentation in southern Guam.
4.1 Sediment Condition Indicators
4.1.1 Sediment Contaminants
Concentrations of the chemical contaminants analyzed were generally below levels of concern
with respect to potential impacts to benthic infauna, based on comparison to published ERL and
ERM values. Moderate concentrations of arsenic, chromium, copper or mercury that exceeded
the ERL but not the ERM were principally found in the main commercial and military port areas
in Apra Harbor. Previous studies have reported on the sediment metals, PCBs and PAHs from
four harbors on the west coast of Guam (Denton et al. 1997, 1999; 2005a) and sediment metals
from Pago Bay (Denton et al. 2006, Denton and Morrison 2009). For the west coast harbors,
23
-------
some sample sites in all four harbors exceeded the ERL for some metals (mainly arsenic, copper,
mercury, lead and zinc), but no station had metal concentrations that exceeded the ERM. No
station in Pago Bay exceeded the ERL for any metal. Thus, studies to date agree that except for
some stations within harbors, particularly those closest to docks, there is little evidence of
significant chemical contamination of sediments, at least based on the substances analyzed
(metals, pesticides, PCBs, PAHs).
4.1.2 Sediment Toxicity
The results of sediment toxicity bioassays had a considerable range of values for survivorship of
the amphipod Ampelisca abdita exposed to Guam sediments. A, abdita was selected as the test
organism for Guam samples for consistency in both the test species and analytical laboratory to
better compare results to those obtained from CONUS samples. However, it has been shown
that the survival of this species may be negatively affected by sediments which have >95% sand
(U.S. EPA 1996), which was the case for 72% of the Guam sediment samples. All bioassay
results with less than 80% control corrected survival also had sediment that was >95% sand,
although an equal number of such samples showed survival greater than 80%. Since there was
no significant relationship of survival to measured contaminants in sediments, the high variation
in results indicates that this bioassay organism may not be a useful sediment quality indicator for
Guam marine sediments.
4.1.3 Benthic Infaunai Community
The collections of the soft-sediment benthic community from this study are generally similar to
those reported by Bailey-Brock and Krause (2007) in a more spatially limited study of infaunai
communities adjacent to two sewage outfalls on the west coast of Guam, and by Bailey-Brock et
al. (2011) from benthic faunal collections from the mid and outer regions of Apra Harbor.
Polychaetes were the dominant faunal component both in terms of abundance and species
richness in all three studies. Pionosy/lis heterocirrata was the second most abundant polychaete
species in the present study and is reported as the most abundant and widely distributed
polychaete in coral sands of the south shore of Oahu (Bailey-Brock et al. 2001, 2002). Similar
major taxa of Crustacea were collected, although they were not identified to species by Bailey-
Brock and Krause (2007).
Bailey-Brock et al. (2001, 2002) have suggested that in Hawaiian waters the polychaetes
Neanthes arenaceodoiifa and the (\ipitella capitata complex represent indicator species for
benthic organic enrichment associated with sewer outfalls. There was no indication of a
prevalence of these pollution-indicator species in the Guam soft-sediment benthos at any site.
(\ipiiella capitata and other capitellid polychaetes occurred at many stations, but represented
<2% of total infaunai abundance, and were not a numerical dominant at any station. N.
arenaceodonta was recorded but was relatively rare. In contrast, Bailey-Brock et al. (2011)
found a number of stations in the central region of Apra Harbor where capitellid polychaetes
represented up to 23% of total abundance and were the numerically dominant polychaete.
The pattern of reduced benthic infaunai species richness and dissimilar infaunai community
structure at the eastern end of Apra Harbor including Sasa Bay, compared to other sites, is
24
-------
consistent with the findings of Bailey-Brock et al. (2011) who found a tendency of lower taxa
richness and lower community similarities for stations on the eastern edge of Apra Harbor
proper. This area is in the approach to the naval base at inner Apra Harbor, and may experience
physical disturbance from ship traffic and dredging and may experience sediment input from
several small streams entering nearby Sasa Bay (Bailey-Brock et al. 2011).
Diminished benthic infaunal community abundance and particularly species richness was
associated with percentage of fine sediments. For Guam coastal waters, this pattern does not
appear to be associated with high TOC in the sediments, levels of sediment chemical
contaminants, or low bottom DO. There was no indication of reduced amphipod bioassay
survivorship associated with increased percentage of fine sediments. Crustaceans were rare at
many, but not all, muddier stations with >5% of fine sediments.
4.2 Developmental Condition Indicators
4.2.1 Benthic Substrates
The characterization of benthic substrates, based on percent coverage of various habitat types,
represents a potential developmental indicator for Guam coastal waters. Moreover, the data
collected in this study provide information that can be used for establishing baseline conditions
for the various habitat types recorded. Changes in the estimated coverage of various habitat
types might indicate changes in environmental conditions of concern, such as the decrease in
coral or seagrass coverage, or increases in coverage of algae, due to excess nutrients or other
factors. For example, green algae blooms have been recorded from Tumon Bay, fueled by
freshwater seepage enriched by runoff from the adjacent urbanized areas (Denton et al. 2005b).
Benthic substrate types and their spatial coverage have also been estimated and mapped using
satellite imagery at a minimum map unit of- 506 m2 by the Guam Coastal Atlas (GCA)
(Burdick 2006). While extensive ground validation data were collected at a scale ( l m2)
comparable to the NCA study, estimates of area of habitat types were based on the much larger
minimum map unit of the GCA. Data collected were for a similar period (2001-2004) to the
current study, and thus allow a cross comparison on estimates based on very different sampling
approaches. GCA estimated 2.3% of benthic habitat area for Guam included seagrass at >10%
coverage, while the NC A estimate was 6%, with 16% of area having some seagrass present.
GCA estimated 30% of area with coral cover greater than 10%, while NCA methods provided a
very similar estimate of 34%. The two methods differed widely in estimated area of the GCA
"uncolonized" bottom type, defined as substrate lacking >10% cover of any biological cover type
(Burdick 2006). GCA estimated 27.8% uncolonized bottom, while NCA estimated only 11% of
bottom with <10% living cover. For all algae types, GCA estimated -39% of bottom habitat,
whereas NCA estimated nearly 84% of bottom area had >10% algae. A principal reason for
differences in the estimates is most likely due to classification differences, e.g. GCA classifies
"macroalgae" habitat as having both >10 % macroalgae and <10% coral, whereas NCA simply
looks at occurrence of each separately.
25
-------
4.2.2 Fish
While monitoring of fish within nearshore waters of Guam has been frequently conducted
(Tupper 2007, Smith et al. 2009, Taylor et al. 2009, Williams et al. 2012), the methods and
metrics reported have varied widely, such that comparisons to the present study are difficult.
The most similar in spatial coverage is the detailed coral-reef, fish-assemblage study of Williams
et al. (2012), who sampled 133 randomized sites around the entire island except for the Apra
Harbor area. However, the study used stationary fish counts and reports biomass estimates rather
than abundance, in contrast to linear transects and fish abundance used by the NCA study.
Williams et al. (2012) observed highest biomass principally within marine preserve areas,
particularly the Pati Point, Tumon Bay, and Achang Reef Flat preserves. The NCA assessment
had no samples from the Pati Point area but did find most sites within the region of the Achang
Reef Flat to have abundance of fish within the third or fourth quartiles. The greatest contrast in
results was from Tumon Bay, where all NCA sites fell in the lowest quartile of fish abundance.
While this difference could be a result of different methods, full enforcement of no-take from the
marine preserves occurred in 2001, only three years prior to the NCA survey, but more than a
decade prior to the study by Williams et al. (2012). Fish surveys conducted by Smith et al.
(2009) in Inner Apra Harbor used similar methods to the present study and surveyed roughly
comparable areas. Despite the considerable habitat disturbance within the inner harbor, the
range of abundance (10-1025) and species richness per survey site (2-29) was similar to that
found in the NCA studies (1-465; 1-34). Inner Apra Harbor fish communities differed from the
composite for the NCA stations in being dominated by Apogonidae (cardinalfishes) and in
recording very few individuals and species of Labridae (wrasses), although there are too many
variables between studies to identify likely causes.
4.2.3 Holothurian Tissue Contamination
Previous studies have reported on the metal, PCB and PAH concentration from holothurian
tissue from four harbors on the west coast of Guam (Denton et al. 1999), and tissue metals from
Pago Bay (Denton et al. 2006, Denton and Morrison 2009). The two stations in the present study
with measurable tissue PCB were within the low end of the range (0.03 - 1279 ng g"1 wet wt)
recorded from Guam harbors. Relative to the range of values reported from harbors and Pago
Bay (see Table 9, Denton and Morrison 2009), the range of holothurian tissue values from the
present study for arsenic, chromium, lead and zinc were relatively similar. Some tissue values
for copper were 1-2 orders of magnitude higher than those from previous studies, but since there
does not appear to be a clear association of tissue and sediment copper concentration, local
sediment levels do not appear to explain the high biotic values observed. Although there were
limitations to the present data set, the lack of correlation of sediment and holothurian tissue metal
concentrations raises the question as to whether holothurian tissue can serve as a useful indicator
of marine sediment contamination.
4.3 Conclusions
The results of the NCA condition assessment of near-shore waters of Guam indicated that
chemical contamination of sediments by heavy metals, PAHs, PCBs, and legacy pesticides did
not occur at high bioeffect levels likely to cause significant impacts to benthic systems, apart
26
-------
from limited areas within the highly industrialized and altered Apra Harbor. Benthic attributes
appeared to be more correlated with natural controlling factors such as sediment % fines. These
results are supported by lack of indication of contaminant related sediment toxicity to
amphipods, and the lack of correlation of holothurian tissue contamination with sediment
contaminants. Similarly, benthic community composition gave little indication of altered
composition consistent with pollutant inputs. The NCA survey results are consistent with results
from other site-specific surveys conducted in more limited regions of Guam coastal waters.
Results indicated that there is little reason to utilize the statistical sampling strata applied in the
NCA sampling design to future studies. It may be of greater interest to stratify sampling with
respect to protection status of the waters, as in Williams et al. (2012).
The developmental indicators of fish community and holothurian tissue contamination were each
proved feasible to use within an assessment of condition for the shallow tropical habitats typical
of Guam but will remain of limited utility in the absence of clear benchmark values related to
environmental conditions. The assessment of extent of benthic substrates by probabilistic
sampling methods was consistent with more detailed habitat mapping efforts (GCA) and offers a
spatially scalable approach to assess habitat changes with considerably less effort than repeated
detailed mapping requires. A merging of methods for fish surveys combining the probability-
based approach used by NCA with the fish assessment methodology used by the NOAA
(Williams et al 2012) would be particularly productive, especially in the face of limitations on
federal resources to support environmental monitoring.
The NCA assessment of Guam coastal waters provides a baseline that may be particularly
valuable for assessing environmental change associated with modifications to the island (Nelson
et al. 2016) and its population (Burdick et al. 2008), should a proposed relocation of military
resources from Okinawa to Guam take place.
27
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5.0 References
ASTM (American Society for Testing and Materials). (1991). Guide for conducting 10-day static
sediment toxicity tests with marine and estuarine amphipods. ASTM Standard Methods
Volume 11,04, Method Number E-l367-90: ASTM, Philadelphia, PA.
Bailey-Brock, J. H., Cooke, W. J., Eberhardt, S., Lin, D., & Magalhaes, W. (2011). Benthic
infaunal community structure in sediments from Apra Harbor, Guam, Mariana Islands,
2010. (pp. 51): Water Resources Research Center, University of Hawaii atManoa,
Honolulu, HI, 96822.
Bailey-Brock, J. H., & Krause, E. R (2007). Benthic infaunal communities adjacent to the
sewage outfalls at Agana and Northern District, Guam, Northern Mariana Islands, 2005-
2007. (pp. 73): Water Resources Research Center, University of Hawaii atManoa,
Honolulu, HI, 96822.
Bailey-Brock, J. H., Paavo, B., Barrett, B., & Dreyer, J. (2001). Changes in pollution indicators
at the Sand Island Sewage Outfall. In OCEANS, 2001. MIS IEEE Conference and
Exhibition, 2001 (Vol. 3, pp. 1401-1407): IEEE, doi: 10.1 109/OCEANS.2001.968306.
Bailey-Brock, J. H., Paavo, B., Barrett, B., & Dreyer, J. (2002). Polychaetes associated with a
tropical ocean outfall: Synthesis of abiomonitoring program off O'ahu, Hawai'i. / aufrc
Science, 56(4), 459-479.
Balthis, W. L., Hyland, J. L., Cooksey, C., Montagna, P. A., Baguley, J. G., Ricker, R. W., et al.
(2017). Sediment quality benchmarks for assessing oil-related impacts to the deep-sea
benthos. Integrated Environmental Assessment and Management, 13(5), 840-851.
Barrett, B. M., Bailey-Brock, J. H., Paavo, B., Moretzsohn, F., & Kay, E. A. (2001). Benthic
sampling in the vicinity of sewage outfalls off Tanguisson and Agana, Guam, Mariana
Islands. (Vol. WRRC-2001-03): Water Resources Research Center, University of Hawaii
at Manoa, Honolulu, HI.
Brock, R. E., & Brock, J. H. (1977). A method for quantitatively assessing the infaunal
community in coral rock. Limnology and oceanography, 22(5), 948-951.
Brock, R. E., & Norris, J. E. (1989). An analysis of the efficacy of four artificial reef designs in
tropical waters. Bulletin of Marine Science, 44(2), 934-941.
Brock, V. E. (1954). A preliminary report on a method of estimating reef fish populations. The
Journal of Wildlife Mana^Lment, 18(3), 297-308.
Clarke, K. R., & Gorley, R. N. (2006). PRIMER V6: user manual-tutorial: Plymouth Marine
Laboratory.
Clarke, K. R., & Warwick, R. (2001). A further biodiversity index applicable to species lists:
variation in taxonomic distinctness. Marine Ecology Progress Series, 216, 265-278.
Crossett, K. M., Clement, C. G., & Rohmann, S. O. (2008). Demographic baseline report of US
territories and counties adjacent to coral reef habitats. NOAA, National Ocean Service,
Special Projects, pp. 65.
Denton, G. R., Concepcion, L. P., Wood, H., & Morrison, R. J. (2005a). Trace metals in
sediments of four harbours in Guam. Marine Pollution Bulletin, 50(10), 1133-1141.
Denton, G. R., & Morrison, R. J. (2009). The impact of a rudimentary landfill on the trace metal
status of Pago Bay, Guam. Marine Pollution Bulletin, 5
-------
Bay in Relation to Tntertidal Blooms of the Filamentous Green Alga. (pp. 53):
Enteromorpha claihraia. Technical Report 110. Water and Environmental Research
Institute of the Western Pacific, University of Guam, Mangilao, GU.
Denton, G. R., Concepcion, L. P., Wood, H. R., Eflin, V. S., & Pangelinan, G. (1999). Heavy
metals, PCBs and PAHs in marine organisms from four harbor locations on Guam. Water
and Environmental Research Institute of the Western Pacific, University of Guam.
Denton, G. R., Kelly, W., Wood, H. R., & Wen, Y. (2006). Impact of metal enriched leachate
from Ordot Dump on the heavy metal status of biotic and abiotic components in Pago
Bay. Technical Report 113 (pp. 63): Water and Environmental Research Institute (WERI)
of the Western Pacific, University of Guam, Mangilao, Guam 96923.
Denton, G. R., Wood, H. R., Concepcion, L. P., Siegrist, H. G., Eflin, V. S., Narcis, D. K., et al.
(1997). Analysis of in-place contaminants in marine sediments from four harbor locations
on Guam. Water and Environmental Research Institute of the Western Pacific, University
of Guam.
Diaz-Ramos, S., Stevens, D., & Olsen, A. (1996). EMAP statistical methods manual. (Vol.
EPA/620/R-96/002): US Environmental Protection Agency, Office of Research and
Development, Western Ecology Division, Corvallis, OR.
Flemming, B. (2000). A revised textural classification of gravel-free muddy sediments on the
basis of ternary diagrams. Continental Shelf Research, 20(10-11), 1125-1137.
Long, E. R., Macdonald, D. D., Smith, S. L., & Calder, F. D. (1995). Incidence of adverse
biological effects within ranges of chemical concentrations in marine and estuarine
sediments. Environmental Management, 19{ 1), 81-97.
Nelson, D. S., McManus, J., Richmond, R. H., King, D. B., Gailani, J. Z., Lackey, T. C., et al.
(2016). Predicting dredging-associated effects to coral reefs in Apra Harbor, Guam-Part
2: Potential coral effects. Journal of Environmental Management, 168, 111-122.
Nelson, W. G. (1986). Benthic infaunal sampling in vicinity of the Sand Island Ocean Outfall,
O'ahu, Hawai'i. Spec. Rep. 6: 20: 86. Water Resources Research Center, University of
Hawaii at Manoa, Honolulu, 117.
Pinkerton, K., Baker, D. M., Cuddy, M. R., Raymundo, L. J., Meyer, K. A.. & Kim, K. (2015).
Nitrogen dynamics on Guam as revealed by the seagrass Enhalus acoioides. Marine
Ecology Progress Series, 528, 117-126.
Sanders, H., Hessler, R., & Hampson, G. (1965). An introduction to the study of deep-sea
benthic faunal assemblages along the Gay Head-Bermuda transect. Deep Sea Research
andOceanographic Abstracts, 12(6), 845-867.
Smith, B. D., Donaldson, T. J., Schils, T., Reyes, A., Chop, K., & Dugger, K. (2009). Marine
Biological Survey of Inner Apra Harbor, Guam. University of Guam Marine Laboratory
Technical Report, 126, 46.
Stevens, D. L., & Olsen, A. R. (2003). Variance estimation for spatially balanced samples of
environmental resources. Environmetrics, 14(b), 593-610.
Swartz, R., Bailey-Brock, J., Cooke, W., & Kay, E. (2000). Benthic faunal sampling adjacent to
Sand Island Ocean Outfall, O 'ahu, Hawai 'i, September-October 1999. Project Report
PR-2000-06 (pp. 209): Water Resources Research Center, University of Hawaii at
Manoa, Honolulu, HI.
Taylor, B. M., Hilford, A., Mai shell A. L., & Priest, M. A. (2009). Quantitative assessment of
the reef fish in Apra Harbor. Guam. Section 8 in: Final Environmental Impact Statement
Guam and CNMI Military relocation, Appendix J: Supplemental Aircraft Carrier Marine
29
-------
Surveys.
http://guambuildupeis.us/documents/final/volume_9/Vol9_AppJ_%20Supplemental_Airc
raft_Carrier_Marine_Surveys.pdf.
Tsuda, R. T., & Grosenbaugh, D. A. (1977). Agat sewage treatment plant: impact of secondary
treated effluent on Guam coastal waters. Technical Report No. 3 (pp. 36): Water
Resources Research Center, University of Guam, Mangilao, Guam 96923.
Tupper, M. H. (2007). Spillover of commercially valuable reef fishes from marine protected
areas in Guam, Micronesia. Fishery Bulletin, J05(4), 527-537.
U.S. EPA. (1994). Methods for Assessing the Toxicity of Sediment associated Contaminants
with Estuarine and Marine Amphipods. (Vol. EPA/600/R-94/025): Office of Research
and Development, Narragansett, RI.
U.S. EPA. (1995). Environmental Monitoring and Assessment Program (EMAP): Laboratory
Methods Manual - Estuaries, Volume 1: Biological and Physical Analyses. (Vol.
EPA/620/R-95/008): Office of Research and Development, Narragansett, RI.
U.S. EPA. (1996). Ecological Effects Test Guidelines. OPPTS 850:1740 Whole sediment acute
toxicity invertebrates, marine. (Public Draft ed., Vol. EPA 712-C-96-355, pp. 12): Office
of Prevention, Pesticides and Toxic Substances.
U.S. EPA. (2001a). Environmental Monitoring and Assessment Program (EMAP): National
Coastal Assessment Quality Assurance Project Plan 2001-2004. (Vol. EPA/620/R-
01/002, pp. 198): Office of Research and Development, National Health and
Environmental Effects Research Laboratory, Gulf Ecology Division, Gulf Breeze, FL.
U.S. EPA. (2001b). National Coastal Assessment: Field Operations Manual. (Vol. EPA/620/R-
01/003, pp. 72): Office of Research and Development, National Health and
Environmental Effects Research Laboratory, Gulf Ecology Division, Gulf Breeze, FL.
U.S. EPA. (2004). National Coastal Condition Report II (Vol. EPA-620/R-03/002, pp. 286):
Office of Research and Development and Office of Water, Washington, D.C.
U.S. EPA. (2008). National Coastal Condition Report III. (Vol. EPA/842-R-08-002, pp. 300):
Office of Research and Development and Office of Water, Washington, D.C.
U.S. EPA. (2012). National Coastal Condition Report IV. (Vol. EPA-842-R-10-003, pp. 334):
Office of Research and Development and Office of Water, Washington, D.C.
Williams, I. D., Zamzow, J. P., Lino, K., Ferguson, M., & Donham, E. (2012). Status of coral
reef fish assemblages and benthic condition around Guam: a report based on underwater
visual surveys in Guam and the Mariana Archipelago, April-June 2011. US Department
of Commerce, National Oceanic and Atmospheric Administration, National Marine
Fisheries Service, Pacific Islands Fisheries Science Center.
30
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6.0 Appendix Tables
Appendix Table 3.1 A. Surface and bottom sample depth, temperature, salinity, dissolved oxygen (DO) and pH for Guam benthic condition
assessment stations.
Sample
Depth
(m) Temperature (°C) Salinity DO (mg l"1)
Station
#
B
S
B
S
B
S
B
1
8
30.29
30.14
32.16
32.2
6.09
5.78
2
12.8
28.23
28.49
28.99
29.04
6.33
5.72
3
0.5
28.55
28.55
34.38
34.38
6.84
6.84
4
3
28.57
28.5
28.99
28.99
6.39
5.67
5
0.7
28.59
28.74
31.17
31.85
5.97
6.5
6
1
30.07
30.06
28.09
28.88
4.68
4.51
7
0.2
29.27
29.27
33.54
6.41
6.41
8
15
29.12
28.73
28.75
28.76
5.59
5.41
9
0.5
27.57
27.57
31.7
31.7
5.66
5.66
10
10
28.27
28.14
33.66
33.47
5.9
5.31
11
5
28.55
28.36
33.31
33.47
6.47
5.89
13
0.1
28.94
28.94
7.76
7.76
14
1
27.61
27.61
33.16
33.18
4.88
4.5
15
13
29.24
29.26
33.45
33.62
5.88
5.87
16
6
28.33
28.33
32.9
33.11
6.3
i 9i
18
10
28.53
28.31
33.41
33.45
5.84
5.33
19
1
29.85
29.86
33.1
33.77
7.38
7.25
21
7
27.73
28.15
32.99
33.5
5.52
5.86
22
4.5
28.15
28.15
34.2
34.22
6.16
5.84
31
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Sample
Depth
(m) Temperature (°C) Salinity DO (mg l1)
Station
#
B
S
B
S
B
S
B
23
4.5
28.03
29.58
29.48
6.55
4.33
25
2.5
27.66
27.63
32.9
33.16
6.62
6.35
26
0.5
28.11
28.11
33.27
33.27
6.9
6.9
27
15
28.41
28.32
33.48
33.49
6.19
5.52
28
20
29.39
28.93
29.16
29.04
6.19
5.87
29
13
28.18
28.18
34.32
34.23
6.26
¦> (
30
0.9
27.83
27.84
34.16
34.14
4.73
4.65
31
9
28.81
28.45
33.59
33.47
6.02
5.84
32
3.5
28.84
29.01
33.13
33.45
6.16
5.8
33
0.1
29.81
29.81
34.11
34.11
8.78
8.78
34
19.5
29.06
28.56
28.92
28.97
6.37
5.51
35
1
29.86
29.87
33.58
33.57
6.32
( 2
36
20
29.87
29.48
32.21
32.35
6.47
71
37
0.6
29.22
29.27
33.13
33.04
8.38
8 47
38
12.1
29.2
28.79
28.08
28.98
5.3
39
0.2
30.01
30.01
33.61
33.61
8.81
8.81
40
20
29.42
28.97
33.56
33.53
5.56
5.34
41
0.1
29.19
29.19
33.21
33.21
7.55
7.55
42
2.5
28.5
28.43
34.45
34.44
6.78
6.18
43
2.5
29.07
29.08
32.74
32.86
6.45
6.18
44
24
29.38
28.89
33.62
33.64
6.11
5.15
45
0.2
28.51
28.51
33.41
33.41
6.44
6.44
46
0.5
27.45
27.45
33.14
33.14
6.1
6.1
47
0.1
29.24
29.24
31.12
31.12
7.91
7.91
49
3.5
30.18
30.06
32.23
32.22
5.65
5.28
50
4
28.32
28.29
38.27
38.22
5.74
5.46
-------
Sample
Depth
(m) Temperature (°C) Salinity DO (mg l1)
Station
#
B
S
B
S
B
S
B
51
0.5
29
29.02
29.57
29.59
8.78
7.41
52
10.5
29 91
29.26
30.02
30.05
5.87
5.11
53
16
29.23
29.02
30.03
30.03
6.22
5.46
54
10
29.44
29.34
33.58
33.79
5.91
5.63
55
0.1
29.67
29.67
33.02
33.02
6.8
6.8
Max
24
30.29
30.14
38.27
38.22
8.81
8 81
Min
0.1
27.45
27.45
28.08
28.76
4.68
4
Appendix Table 3.IB. Estimated cumulative percent area of Guam near coastal bottom area associated with observed values of sample depth,
temperature, salinity and DO.
Sample Depth
(m) Temperature (°C) Salinity DO (mg l"1)
Bottom Surface Bottom Surface Bottom Surface Bottom
% area
depth
% area
Temp
% area
Temp
% area
Sal
% area
Sal
% area
DO
% area
DO
7.51
0.1
1.10
27.45
1.10
27.45
1.17
28.08
1.13
28.76
1.10
4.68
1.10
4.33
16.12
0.2
2.19
27.57
2.19
27.57
2.33
28.09
2.26
28.88
2.19
4.73
2.19
4.50
18.31
0.3
3.29
27.61
3.29
27.61
3.50
28.75
3.39
28.97
3.29
4.88
3.29
4.51
19.40
0.4
7.04
27.66
7.04
27.63
4.67
28.92
4.52
28.98
4.38
5.30
4.38
4.65
24.25
0.5
8.14
27.73
8.14
27.84
9.59
28.99
8.28
28.99
5.48
5.52
5.48
4.81
25.35
0.6
9.23
27.83
9.23
28.11
10.75
29.16
10.54
29.04
6.58
5.56
6.58
5.11
26.45
0.7
10.33
28.03
10.33
28.14
14 ti
29.57
11.67
29.48
7.67
->y
7.67
5.15
27.54
0.8
11.43
28.1 1
15.18
28.15
!"> (8
30.02
15.42
29.59
8.77
to
8.77
5.28
28.64
0.9
15.18
28.15
18.94
28.18
19.43
30.03
19.18
30.03
9.86
5.66
9.86
5.31
30.83
1.0
18.94
28.18
20.03
28.29
23.19
31.12
20.31
30.05
10.96
5.74
10.96
5.33
31.93
1.1
20.03
28.23
21.13
28.31
24.35
31.17
24.06
31.12
12.05
5.84
12.05
5.34
36.78
1.2
21.13
28.27
24.88
28.32
25.52
31.70
25.19
31.70
13.15
5.87
13.15
5.41
-------
Sample Depth
(m)
Temperature (°C)
Bottom
Surface
Bottom
Surfi
% area
depth
% area
Temp
% area
Temp
'/ iu,i
40.53
1.3
22.22
28.32
25.98
28.33
29.27
49.14
3.0
23.32
28.33
29.73
28.36
30.44
52.89
3.5
27.07
28.41
30.83
28.43
31.61
55.08
4.0
28.17
28.50
31.93
28.45
35.36
56.18
4.5
29.27
28.51
33.02
28.49
40.28
61.03
5.0
30.36
28.53
36.78
28.50
41.45
64.79
5.5
35.21
28.55
37.87
28.51
42 (2
65.88
6.5
38.97
28.57
38.97
28.55
4( 7
66.98
7.5
40.06
28.59
40.06
28.56
48.71
70.73
8.5
41.16
28.81
41.16
28.73
49.87
71.83
9.5
42.26
28.84
42.26
28.74
51.04
75.12
10.5
43.35
28.94
43.35
28.79
52.21
76.21
11.6
47.11
29.00
44.45
28.89
53.37
77.31
12.6
48.20
29.06
45.54
28.93
57.13
78.40
13.3
51.96
29.07
46.64
28.94
59.46
85.91
13.5
53.05
29.12
47.74
28.97
63.22
89.67
15.5
54.15
29.19
48.83
29.01
66.97
93.42
16.5
55.25
29.20
56.34
29.02
70.73
94.52
20.0
56.34
29.22
60.10
29.08
71.89
95.62
24.0
60.10
29.23
61.19
29.19
76.81
96.71
26.5
67.61
29.24
64.95
29.24
77.98
97.81
28.5
71.36
29.27
69.80
29.26
81.74
98.90
34.0
72.46
29.38
74.65
29.27
82.90
100.00
35.0
73.55
29.39
75.75
29.34
84.07
74.65
29.42
76.84
29.48
87.82
75.75
29.44
77.94
29.58
88.99
34
Salinity
DO (mg l1)
Bottom Surface Bottom
Sal
% area
Sal
% area
DO
% area
DO
32.16
26.32
31.85
16.91
5.88
18.00
5.46
32.21
30.08
32.20
18.00
5.90
19.10
5.51
32.23
31.21
32.22
19.10
5.91
22.85
5.52
32.74
32.34
32.35
20.19
5.97
27.70
5.63
32.90
36.09
32.86
21.29
6.02
28.80
^ 66
32.99
37.22
33.02
25.04
6.09
32.55
^ 67
33.02
38.35
33.04
26.14
6.10
33.65
^ 71
33.10
39.48
33.11
27.24
6.11
34.75
5.72
33.13
40.61
33.14
32.09
6.16
38.50
5.78
33.14
44.37
33.16
36.94
6.19
39.60
5.80
33.16
45.50
33.18
40.69
6.22
44.45
5.84
33.21
46.63
33.21
44.45
6.26
45.54
5.86
33.27
47.76
33.27
45.54
6.30
50.39
5.87
33.31
48.89
33.41
4) U
6.32
54.15
-> 89
33.41
51.15
33.45
M) y
6.33
55.25
9">
33.45
57.16
33.47
M.4y
6.37
56.34
6.1U
33.48
60.92
33.49
55.25
6.39
61.19
6.18
33.54
62.05
33.50
59.00
6.41
64.95
6.23
33.56
63.18
33.53
60.10
6.44
68.70
6.35
33.58
66.93
33.54
63.85
6.45
72.46
6.41
33.59
70.69
33.57
68.70
6.47
73.55
6.44
33.61
74.44
33.61
(y 8o
6.55
74.65
6.50
33.62
78.20
33.62
73 -n
6.62
75.75
6.80
33.66
79.33
33.64
74.65
6.78
76.84
6.84
34.11
83.08
33.77
75.75
6.80
77.94
6.90
34.16
84.21
33.79
76.84
6.84
81.69
7.25
-------
Sample Depth
(m)
Temperature (°C)
Bottom
Surface
Bottom
% area depth % area
Temp
% area
Temp
76.84
29.67
79.03
29.67
80.60
29.81
82.79
29.81
84.35
29.85
86.54
29.86
88.11
29.86
90.30
29.87
89.20
29.87
94.05
30.01
90.30
29.93
96.24
30.06
94.05
30.01
100.00
30.14
95.15
30.07
96.24
30.18
100.00
30.29
Salinity
DO (mg l1)
Surface Bottom Surface Bottom
% area
Sal
% area
Sal
% area
DO
% area
DO
92.75
34.20
87.97
34.11
77.94
6.90
85.45
7.41
96.50
34.32
89.10
34.14
81.69
7.38
86.54
7.55
97.67
34.38
92.85
34.22
82.79
7.55
87.64
7.76
98.83
34.45
96.61
34.23
83.88
7.76
91.39
7.91
100.00
38.27
97.74
34.38
87.64
7.91
92.49
8.47
98.87
34.44
88.73
8.38
96.24
8.78
100.00
38.22
96.24
8.78
100.00
8.81
100.00
8.81
35
-------
Appendix Table 3.1C. Estimated cumulative percent area of Guam near coastal bottom area associated
with observed values of percent fine sediments and percent TOC.
%
% area % fines % area TOC
5.95
0.000
1.10
0.16
9.70
0.001
2.19
0.24
10.80
0.002
5.95
0.25
14.55
0.004
9.70
0.27
18.31
0.004
10.80
0.28
22.06
0.010
11.89
0.29
23.16
0.010
15.65
0.30
26.91
0.025
19.40
0.36
30.67
0.026
20.50
0.39
31.77
0.040
21.60
0.40
35.52
0.131
22.69
0.50
36.62
0.186
24.88
0.52
40.37
0.192
25.98
0.56
44.13
0.224
28.17
0.57
47.88
0.238
35.68
0.75
48.98
0.275
39.44
0.77
50.07
0.362
43.19
0.79
51.17
0.373
46.95
0.90
54.92
0.390
48.04
0.91
56.02
0.406
t2 89
0.93
57.12
0.412
i3 yy
1.16
58.21
0.433
33.U»
1.19
59.31
0.440
56.18
1.30
60.40
0.452
57.28
1.32
61.50
0.578
61.03
1.34
62.60
0.688
62.13
1.35
66.35
0.763
65.88
1.51
67.45
0.936
66.98
1.58
71.20
1.574
68.07
1.83
74.96
1.639
69.17
1.87
78.71
2.378
70.27
1.89
79.81
2.541
71.36
1.90
83.56
4.117
72.46
1.94
84.66
7.279
76.21
1.96
85.75
18 ->->0
77.31
2.15
86.85
27 4 0
78.40
2.21
87.95
47.661
79.50
2.23
89.04
56.656
80.60
2.34
36
-------
%
% area % fines % area TOC
90.14
68.111
91.23
71.132
92.33
77.361
93.42
80.514
94.52
87.239
95.62
87.444
96.71
87.873
97.81
88.919
98.90
89.304
100.00
89.848
84.35
2.46
85.45
2.49
89.20
2.54
90.30
3.07
91.39
3.09
95.15
3.21
96.24
3.26
100.00
3.74
Appendix Table 3.2.2A. Pearson Product Moment Correlation coefficients between control corrected
survivorship of the bioassay organism Ampelisca abdita and sediment contaminant indicators. Significant
P values in bold.
Contaminant
r
P
n
Arsenic
0.32
0.024
50
Chromium
0.34
0.016
50
Copper
-0.017
0.24
50
Mercury
0.32
0.023
50
DDT Total
-0.095
0.51
50
PCB Total
-0.278
0.051
50
ERL Count
0.06
0.67
50
% fines
0.35
0.013
50
% TOC
-0.31
0.028
50
Appendix Table 3.2.2B. Pearson Product Moment Correlation coefficients for sediment % fines and
sediment metal contaminant concentrations. Significant P values in bold.
Metal
r
P
n
Arsenic
0.65
<0.0001
50
Chromium
0.51
0.0001
50
Copper
0.86
<0.0001
50
Mercury
0.52
0.0001
50
37
-------
Appendix Table 3.2.3. Pearson Product Moment Correlation coefficients for benthic abundance and
species richness versus sediment % fines and TOC, for all data and for data from the subset of stations
with percent fines >5%. The correlation of TOC and percent fines is also shown. Significant P values in
bold.
Abundance Species richness TOC
Parameter
r
P
n
r
P
n
r
P
n
Percent fines
-0.35
0.013
50
-0.73
«0.0001
50
-0.09
0.547
50
Percent fines >5%
-0.61
0.017
15
-0.82
0.0002
15
0.67
0.007
15
TOC
-0.2
0.169
50
-0.02
0.9
50
TOC (with fines
>5%)
-0.4
0.14
15
-0.57
0.026
15
38
-------
Appendix Table 3.3.1. Estimated cumulative percent area of Guam near coastal bottom area associated with observed values of five composite
habitat cover types, recorded from underwater visual quadrat surveys. Estimated area excludes Apra Harbor which was not surveyed by this
method.
Total Algal Cover Total Coral Cover Living Cover Non-living Cover Total Seagrass Cover
Non-
lative
Algal
Cumulative
Coral
Cumulative
Living
Cumulative
living %
Cumulative
Seagrass
a
% cover
% area
% cover
% area
% cover
% area
cover
% area
% cover
61
0.00
40.68
0.00
4.61
0.63
1.20
2.50
83.77
0.00
9.21
1.25
46.49
1.25
10.42
2.50
5.81
3.75
92.98
0.63
16.23
2.50
48.90
3.13
11.62
19.38
10.42
6.88
94.19
10.63
17.43
12.50
50.11
3.75
16.23
20.00
11.62
9.38
95.39
16.88
18.64
14.38
51.31
5.00
17.43
23.75
17.43
16.88
100.00
18.13
19.84
24.38
55.92
5.63
22.04
29.38
26.65
18.13
24.45
26.88
60.52
8.13
23.25
30.00
35.86
21.25
25.66
27.50
66.34
10.00
24.45
31.25
37.07
21.88
26.86
28.13
67.54
11.88
25.66
34.38
38.27
23.75
31.47
28.75
72.15
12.50
26.86
36.25
42.88
25.00
32.67
29.38
76.75
16.88
28.07
39.38
44.08
28.13
33.88
30.00
81.36
18.75
29.27
40.00
48.69
31.88
38.48
33.13
85.97
23.13
33.88
40.63
49.89
35.00
39.69
34.38
87.17
25.63
38.48
41.25
54.50
40.00
44.30
35.63
91.78
35.63
39.69
41.88
55.70
48.75
46.71
37.50
92.98
36.88
44.30
43.13
60.31
56.88
51.31
39.38
94.19
41.88
45.50
51.25
61.52
58.13
55.92
41.25
95.39
53.75
50.11
60.00
66.12
58.75
57.12
41.88
100.00
55.00
51.31
63.13
70.73
59.38
61.73
42.50
55.92
68.13
71.93
60.00
62.93
47.50
57.12
71.88
73.14
60.63
67.54
58.75
61.73
75.00
74.34
63.75
72.15
59.38
62.93
76.25
75.55
65.63
39
-------
Total Algal Cover
Total Coral Cover
Living Cover
Non-living Cover Total Seagrass Cover
Cumulative
% area
Algal
% cover
Cumulative
% area
Coral
% cover
Cumulative
% area
Living
% cover
Cumulative
% area
Non-
living %
cover
76.75
62.50
64.14
78.13
76.75
68.75
77.96
63.75
73.35
78.75
77.96
70.00
79.16
68.75
82.57
81.88
82.57
70.63
80.37
78.13
88.38
83.13
83.77
76.25
84.98
78.75
89.58
90.63
88.38
80.00
89.58
79.38
94.19
93.13
89.58
80.63
94.19
83.13
98.80
96.25
95.39
97.50
98.80
88.75
100.00
97.50
100.00
99.38
100.00
93.13
Cumulative Seagrass
% area % cover
40
-------
Appendix Table 3.3.2. Pearson Product Moment Correlation coefficients for percentage cover of
substrate type versus fish abundance or species richness.
Abundance Species richness
Substrate
r
P
n
r
P
n
Algae
0.17
0.36
32
0.09
0.64
32
Coral
0.22
0.23
32
0.47
0.007
32
Living
0.24
0.19
32
0.29
0.11
32
Non-living
-0.3
0.2
32
-0.28
0.12
32
41
-------
Appendix Table 3.3.3A. Comparison of sediment and holothurian tissue concentrations for the five metals (arsenic, chromium, copper, lead, zinc)
that were detected at concentrations above the ERL at any station for the holothurian collections. Dwt -dry weight, wwt - wet weight. * - mean of
two replicates
As (sed)
As (tis)
Cr (sed
Cr (tis)
Cu
Cu (tis)
Pb (sed)
Pb (tis)
Zn (sed
Zn (tis)
^igg"1
^igg"1
^igg"1
Mgg1
(sed) ^g
^igg"1
^igg"1
^igg"1
Mgg"1
Mgg"1
EMAPStationID
dwt
wwt
dwt)
wwt
g"1 dwt
wwt
dwt
wwt
dwt)
wwt
GU04-0003
4.40
1.11
105.00
1.14
14.60
0.56
0.92
0.10
18.70
2.43
GU04-0004
6.60
1.64
10.00
1.08
3.75
0.38
0.57
0.03
6.25
3.37
GU04-0005
0.00
1.82
0.00
1.19
0.39
0.17
0.61
0.12
0.69
2.65
GU04-0007
3.90
4.89
0.00
0.82
1.20
0.37
0.65
0.09
1.90
2.13
GU04-0009
0.00
1.95
2.20
1.20
0.74
1.40
1.15
0.19
1.75
2.80
GU04-0010
10.30
1.81
70.70
0.84
43.90
0.43
22.00
0.27
86.00
2.27
GU04-0011
2.30
1.30
1.50
0.40
0.86
1.10
0.42
0.09
1.20
2.90
GU04-0013
1.10
0.90
1.70
0.60
1.30
1.50
1.30
0.16
3.20
2.20
GU04-0014
1.50
0.62
0 (P
0.41
0.00
0.21
0.94
0.00
5.10
1.97
GU04-0016
8.60
1.20
8 90
1.60
217.00
2.90
88.40
1.99
131.00
2.70
GU04-0021*
1.60
1.52
I.4U
0.96
1.10
0.27
2.50
0.08
4.00
2.13
GU04-0022
2.10
1.48
4.70
1.10
5.30
0.31
0.60
0.03
3.70
1.00
GU04-0025*
0.91
1.28
0.00
17.25
0.56
1.79
0.39
0.03
0.96
1.75
GU04-0026
0.75
2.50
3.95
1.04
1.30
0.61
0.34
0.10
3.95
2.54
GU04-0027
6.80
0.99
254.00
0.47
46.20
0.29
2.20
0.03
52.70
2.19
GU04-0029
2.50
2.30
1.50
0.60
1.50
2.70
0.42
0.06
1.90
2.40
GU04-0030
2.60
7.40
0.61
14.50
1.10
1.20
1.20
0.13
3.60
2.10
GU04-0033
0.00
3.20
0.00
1.30
0.44
0.10
0.57
0.04
0.50
1.20
GU04-0037
0.00
3.15
0.00
1.18
0.39
0.18
0.54
0.10
0.57
1.98
GU04-0039
3.10
5.23
0.62
1.85
1.90
0.53
0.58
0.08
2.90
2.37
GU04-0041
0.00
4.09
0.54
1.11
0.56
0.21
1.30
0.16
2.40
2.34
GU04-0042
1.60
1.04
0.74
0.65
3.20
0.29
1.10
0.06
3.60
1.94
GU04-0043
1.30
0.94
0.00
0.64
0.80
0.21
0.14
0.03
0.89
0.94
GU04-0045
1.30
2.51
4.50
1.09
2.40
0.27
1.60
0.11
4.60
1.31
GU04-0046
3.40
4.75
2.20
1.94
1.70
0.59
0.68
0.17
4.00
3.57
42
-------
As (sed)
As (tis)
Cr (sed
Cr (tis)
Cu
Cu (tis)
Pb (sed)
Pb (tis)
Zn (sed
Zn (tis)
t^gg"1
t^gg"1
t^gg"1
(sed) ng
l^gg"1
^igg"1
t^gg"1
t^gg"1
t^gg"1
EMAPStationID
dwt
wwt
dwt)
wwt
g"1 dwt
wwt
dwt
wwt
dwt)
wwt
GU04-0047
1.20
2.50
3.50
1.22
1.70
0.26
0.48
0.07
2.90
1.38
GU04-0051
1.50
1.91
0.99
0.26
3.00
0.26
1.10
0.04
3.20
2.39
GU04-0053
17.90
1.30
157.00
4.40
26.50
0.60
0.92
0.03
31.90
1.60
Max
17.90
7.40
254.00
17.25
217.00
2.90
88.40
1.99
131.00
3.57
Min
0.00
0.62
0.00
0.26
0.00
0.10
0.14
0.00
0.50
0.94
Appendix Table 3.3.3B. Pearson Product Moment Correlation coefficients for sediment and holothurian tissue concentrations for five metals
(arsenic, chromium, copper, lead, zinc). Significant P values in bold.1 highest sediment value removed,2 - two highest sediment values removed.
Metal
r
P
n
Arsenic
-0.15
0.42
28
Chromium
-0.05
0.79
28
Copper
0.53
0.004
28
Lead
0.98
<0.0001
28
Zinc
0.14
0.47
28
Copper1
-0.013
0.54
27
Lead2
0.16
0.43
26
43
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