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Title
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ANALYSIS OF PUGET SOUND NEARSHORE SEDIMENT AND GHOST SHRIMP (Neotrypaea californiensis) SPECIMENS IN GRAY WHALE (Eschrichtius robustus) FEEDING SITES
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Date
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2021
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Creator
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Bungum, Megan
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Identifier
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Thesis_MES_2021_BungumM
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extracted text
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ANALYSIS OF PUGET SOUND NEARSHORE SEDIMENT AND GHOST SHRIMP
(Neotrypaea californiensis) SPECIMENS IN GRAY WHALE (Eschrichtius robustus)
FEEDING SITES
by
Megan Bungum
A Thesis
Submitted in partial fulfillment
of the requirements for the degree
Master of Environmental Studies
The Evergreen State College
(October 2021)
© 2021 by Megan Bungum. All rights reserved.
This Thesis for the Master of Environmental Studies Degree
by
Megan Bungum
has been approved for
The Evergreen State College
by
___________________
John Kirkpatrick
Member of the Faculty
_______
Date
ABSTRACT
Analysis of Puget Sound nearshore sediment and ghost shrimp (Neotrypaea californiensis)
specimens in gray whale (Eschrichtius robustus) feeding sites.
Megan Bungum
The purpose of this study is to evaluate the environmental health of migratory gray whale
(Eschrichtius robustus) feeding sites and their preferred Puget Sound prey, ghost shrimp
(Neotrypaea californiensis). This was determined by examining the presence and/or
concentration of known biologically adverse contaminants. The concentrations of
Polychlorinated biphenyls (PCBs), Mercury (Hg), and Aluminum (Al) were evaluated from nearshore sediment and ghost shrimp specimen samples in two known gray whale feeding sites
located in the Whidbey Island Basin of Puget Sound. An additional sampling site, located in Port
Susan, was also evaluated for near-shore sediment samples. This sampling site lies ~4.89
nautical miles NW from observed feeding sites and was chosen for its ghost shrimp population
and public accessibility. Samples (n = 10) of near-shore sediment were collected from area
sediment (n = 5) in the three sites during an active feeding period of the migratory Puget Sound
gray whales, February – April 2021. Samples (n = 2) of ghost shrimp specimens (n = 4) were
also collected from several gray whale feeding pits in an active feeding site during this period.
Hg was not detected in any of the samples analyzed. Al concentrations were detected in all
sediment and animal samples analyzed (Sample ID #3 = 6,720 mg/kg, Sample ID #4 =
6,170mg/kg, Sample ID #5 = 6,610 mg/kg, Sample ID #6 = 692 mg/kg) from the second survey
period, in April 2021. The Al concentrations were noted as elevated according to the Washington
Department of Ecology’s Clarc table of soil method A unrestricted land use. PCBs were detected
in a single sediment sample taken from a gray whale feeding pit (Sample ID #5) as the Aroclor
1016 and Aroclor 1260. The value of Aroclor 1016 (Sample ID #5 = 1.7mg/kg) was notably
higher than the recommended parameters set by the Washington Department of Ecology’s Clarc
table of soil protective of groundwater saturated (0.12 mg/kg). The value of Aroclor 1260
(Sample ID #5 = 2.1mg/kg) was also substantially higher than the recommended parameters set
by the Washington Department of Ecology’s Clarc table of soil method B noncancer (0.5mg/kg)
and soil protective of groundwater saturated (0.036mg/kg).
Table of Contents
List of Figures ................................................................................................................................. v
List of Tables ................................................................................................................................ vii
Acknowledgements ...................................................................................................................... viii
Chapter One: Migratory Gray Whales ............................................................................................ 1
Introduction ................................................................................................................................. 1
Population History & Unusual Mortality Event (UME) ......................................................... 2
Chapter Two: Literature Review: Toxicity of Contaminant Materials ........................................... 6
Introduction: Overview of Essential & Non-essential Metals .................................................... 6
Toxicity of Non-Essential Metals ............................................................................................... 7
Aluminum ................................................................................................................................ 7
Mercury ................................................................................................................................... 9
Toxicity of PCBs ....................................................................................................................... 10
Chapter Three: Methods ............................................................................................................... 13
Site Selection ............................................................................................................................. 13
Chapter Four: Results ................................................................................................................... 21
Chapter Five: Discussion .............................................................................................................. 26
Comparison of Historic Puget Sound Sediment Contaminant Values to Survey Collection
Values ........................................................................................................................................ 26
Total Al Concentrations......................................................................................................... 26
Aroclor 1016 concentrations ..................................................................................................... 33
Aroclor 1260 concentrations ..................................................................................................... 40
Conclusion .................................................................................................................................... 49
References ..................................................................................................................................... 50
Appendix ....................................................................................................................................... 55
Combined Lab Results .............................................................................................................. 55
Near-shore sediment sampling period (1) February 2021 ..................................................... 55
Near-shore & ghost shrimp specimen sampling period (2) April 2021 ................................ 58
iv
List of Figures
Figure 1. Total gray whale (Eastern and Western Pacific gray whale) distribution range in the
Northern Pacific Ocean……………………………………………………………………………3
Figure 2. Comparison of 2019-2020 and 1999-2000 Unusual Mortality Event Eastern Gray
Whale stranding frequencies………………………………………………………………………4
Figure 3. Metal-ion reaction series depicting iron and suggesting a pathway for Al3+, which can
produce prooxidant and superoxide……………………………………………………………….8
Figure 4. Gray whale feeding site locations (1990-2014) of the Whidbey Basin in Puget
Sound…………………………………………………………………………………………….13
Figure 5. Field collection sites for two survey periods (Feb-April 2021).………………………15
Figure 6. Gray whale feeding pit with deceased ghost shrimp in center, Langley waterfront,
Langley, WA (Sample ID# = 6). ………………………………………………………………...17
Figure 7. Concentrations (mg/kg) of PCBs Aroclor 1016 and Aroclor 120 detected in collection
sytite samples (1-6) during the second survey sampling period…………………………………21
Figure 8. Comparison of observed Aroclor 1016 concentrations detected to respective
Washington Department of Ecology Clarc table value for soil protective of groundwater
saturated………………………………………………………………………………………….22
Figure 9. Comparison of observed Aroclor 1260 concentrations detected to respective
Washington Department of Ecology Clarc table value for soil protective of groundwater
saturated and soil method B noncancer………………………………………………………….23
v
Figure 10. Total aluminum concentrations (mg/kg) detected in collection samples (3-6) during
the second survey sampling period………………………………………………………………24
Figure 11. Histogram of Total Al concentrations of DOE Puget Sound benthic sediment data
(1989-2019)………………………………………………………………………………………32
Figure 12. ArcGIS hot spots of total Al concentrations from DOE Puget Sound benthic sediment
data (1989-2019) and survey sample collections………………………………………………...33
Figure 13. Histogram of Aroclor 1016 concentrations of DOE Puget Sound benthic sediment
data (1989-2019)…………………………………………………………………………………39
Figure 14. ArcGIS hot spots of Aroclor 1016 concentrations from DOE Puget Sound benthic
sediment data (1989-2019) and survey sample collections……………………………………...40
Figure 15. Histogram of Aroclor 1260 concentrations of DOE Puget Sound benthic sediment
data (1989-2019)…………………………………………………………………………………47
Figure 16. ArcGIS hot spots of Aroclor 1260 concentrations from DOE Puget Sound benthic
sediment data (1989-2019) and survey sample collections……………………………………...48
vi
List of Tables
Table 1. Near-shore sampling location ID, location, type, and estimated tidal level (feet) during
two field sampling periods (February-April 2021)………………………………………………16
Table 2. Libby Environmental, INC total Aroclor 1016 and Aroclor 1260 concentrations (mg/kg)
of near-shore sediment and ghost shrimp specimens from two collection periods (February-April
2021)……………………………………………………………………………………………..19
Table 3. Fremont, INC total Aluminum concentrations (mg/kg) of field sampling 2 sites (Sample
ID# 3,4,5, & 6)…………………………………………………………………………………...20
Table 4. Washington State Department of Ecology - CLARC Soil Unrestricted Land Use Table
(Methods A, B, Groundwater Protection, and Soil Leaching Parameters)………………………25
Table 5. Total Al concentrations (mg/kg) of DOE Puget Sound benthic sediment data (19892019) by Van Veen grab sampling………………………………………………………………27
Table 6. Aroclor 1016 concentrations (mg/kg) of DOE Puget Sound benthic sediment data
(1989-2019) by Van Veen grab sampling………………………………………………………..34
Table 7. Aroclor 1260 concentrations (mg/kg) of DOE Puget Sound benthic sediment data
(1989-2019) by Van Veen grab sampling………………………………………………………..41
vii
Acknowledgements
I would like to extend my sincere gratitude to my thesis reader, John Kirkpatrick, for
supporting me through my thesis process. We experienced an-ever changing landscape while
working together through the Covid-19 pandemic and I appreciate your adaptability,
recommendations, and thoughtful critiques of my project.
I would also like to thank our Assistant Director of the MES program, Averi Azai, who
has been ever helpful and instrumental in aiding all students through their thesis process. I would
like to extend my gratitude to our program director, Kevin Francis, and our interim director, John
Withey, for providing us with the support and tools we needed to navigate our thesis to
completion at home.
Thank you to the volunteers at South Sound Stewards, who assisted me in identifying
migratory gray whale feeding sites, as well as ghost shrimp population hot spots.
Thank you to Kodey Eley, the owner of Libby Environmental INC, for your extensive
analytical knowledge and expert interpretations.
Finally, thank you to the Cascadia Research Collective and John Calambokidis, for
providing the foundation of my thesis research questions. This organization has studied
migratory gray whales in Puget Sound for decades, and without their continued passion for this
species, none of my work would have been possible.
viii
Chapter One: Migratory Gray Whales
Introduction
Gray whales (Eschrichtius robustus) are an iconic mysticeti (baleen) species to the
western coast of the United States of America, which are famous for having the longest
migratory journey (~22,000 km; NOAA 2021) of known mammals. The gray whale spends its
breeding and calf rearing months in the waters of Baja, Mexico, and travels to arctic waters near
Alaska to feed on the highly productive blooms of benthic sea life (Usha et al. 1993). As gray
whales migrate along the western coast of the United States, they travel past or through Puget
Sound, Washington between the months of December-February (south-bound migration) and
February-May (north-bound migration) (Usha et al. 1993). These whales have been observed
entering this urban coastline in search of benthic prey since the 1980’s.
Although the vast majority of gray whales on the migratory path do not enter Puget
Sound to feed, some do and they are referred to as “Sounders”, “Saratoga Grays”, or “Puget
Sound Regulars” (Usha et al. 1993). These whales have been shown to recruit others to enter
Puget Sound and an overall increase in gray whales entering this area has risen yearly (Usha et
al. 1993). This rise in individuals entering Puget Sound in search of prey has also been linked to
poor body conditions and emancipated whales (Varanasi et al. 1993). This raises the question of
a possible lack of food resources for migratory whales, which may force them off their pathways
in search of prey in this region.
The prey which these whales seek in Puget Sound is presumed to be the ghost shrimp
(Neotrypaea californiensis) (Usha et al. 1993). Gray whales consume their prey by sucking in
large quantities of water and sediment and then filtering out the excess materials to trap the prey
1
in their baleen (Weitkamp et al. 1992). The consumption of urban coastal sediment by this
species raises questions about the possible contamination of sediment by heavy metals, mercury,
and anthropogenic compounds, such as PCBs, which may have negative health effects.
Population History & Unusual Mortality Event (UME)
Gray whales were once commonly found throughout the Northern Hemisphere, with
robust populations residing in both the Northern Atlantic and Northern Pacific Oceans (NOAA
Fisheries 2020). The Northern Atlantic populations were eradicated in the 18th century by what is
presumed to be commercial whaling practices, environmental stressors, or a combination of both
(Bruniche-Olsen et al. 2018). The remains of these populations are now limited in their
geographic distribution to the Northern Pacific Ocean, with two distinct subpopulations,
“stocks”, inhabiting the western coasts of North America (Eastern Pacific Gray Whale) and the
eastern coasts of Asia (Western Pacific Gray Whale) (NOAA Fisheries 2020) (Figure 1; NOAA
Fisheries 2021).
2
Figure 1. Total gray whale (Eastern and Western Pacific gray whale) distribution range in the
Northern Pacific Ocean, highlighted in blue. (NOAA Fisheries 2020).
The Eastern Pacific stock gray whales migrate annually along the western coast of North
America, where strandings and Unusual Mortality Events (UME) have increased over the past 20
years (Stimmelmayr & Gulland 2020). The first documented UME took place in 1999-2000,
where a total of 651 gray whales stranded (Raverty et al. 2020). This UME accounted for an
overall net loss of nearly 20% of the Eastern Pacific stock population (Laake et al. 2012). For
comparison, the previous mean annual stranding rate was estimated to be only 41 individuals
between the years of 1995-1998 (Raverty et al 2020). This figure remained at or below 28
individuals until 2019 (Raverty et al 2020). In 2019 another UME took place, in which a total of
215 total gray whale stranded (Figure 2; NOAA Fisheries 2020) (Raverty et al. 2020).
3
Figure 2. Comparison of 2019-2020 (2019 = Orange, 2020 = Green) and 1999-2000 (1999 =
Light Blue, 2000 = Dark Blue) UME Eastern Gray Whale stranding frequencies (NOAA
Fisheries 2020).
A single identifiable cause of these Eastern stock strandings and UMEs is currently
unknown, but several research studies have explored hypotheses of potential toxins and
contaminants as a source of mortality. Gray whales may be especially predisposed to
contaminants and toxins due to their near shore feeding habitats and sediment filter feeding
mechanism. The consumption of sediment, especially from heavily developed urban coastal
regions like the Puget Sound, raises questions about possible ingestion of foreign materials,
toxins, and contaminants. Heavily urbanized coasts provide chronic exposure to environmental
chemicals (Wise et al. 2019) and some of these compounds are associated with negative health
effects through the process of bioaccumulation and storage in tissues.
4
A further exploration of the sediment quality in known feeding sites, with concentrations
of potential contaminants, such as aluminum, mercury, and PCBs are needed to address these
questions and concerns. Along with an assessment of sediment quality data, it is also essential to
examine literature on the toxicity, biological pathways, and source of these contaminant
materials.
5
Chapter Two: Literature Review: Toxicity of Contaminant Materials
Introduction: Overview of Essential & Non-essential Metals
There are two general forms of metals which effect the biological functioning of large
pelagic marine mammals, and these are separated into the groups of essential metals and nonessential metals. Essential metals are those which are required for proper biological functioning
and biochemical processes, and these include; copper, zinc, iron, and selenium (Bowles 1999).
These essential metals are generally required in low doses to sustain biogeochemical processes
and an imbalance in concentrations can produce disease or other deleterious effects (Bowles
1999). The non-essential metals are those which are not known to provide biological or
biochemical function to marine mammals and are instead often toxic at low levels (Bowles
1999). These non-essential metals include mercury, lead, aluminum, and cadmium (Bowles
1999).
These two types of metals can enter the pelagic environment in a variety of ways and
have the propensity to bioaccumulate in cells. These metals can exist in the water column and
benthic sediment by both natural and anthropogenic routes. The natural existence of metals can
be sourced from erosion, volcanic activity, and inputs from freshwater sources (Bowles 1999).
The anthropogenic sources of metals can be attributed to waste disposal, mining operations,
industrial inputs, fossil fuels, and the use and disposal of chemicals (Bowles 1999). These
metals have the ability to bio magnify or bioaccumulate in cells by becoming stored in soft and
hard tissues (Martinez-Finley et al. 2012). Both types of metals are presumed to use the same
cellular transport pathways to enter cells and can be taken into the body through pulmonary
(inhalation), cutaneous (skin), or oral ingestion routes (Martinez-Finley et al. 2012).
6
The bioaccumulation and biomagnification of non-essential metals affects members of
the cetacean family differently, and this is due to both the physiological manner in which they
ingest prey and the trophic level of prey items (Kershaw & Hall 2019). The taxonomic family of
cetacean is split into the two suborders of Odontocetes (toothed whales) and the Mysticeti
(baleen whales). The Odontocetes use their toothed mouths to feed primarily higher in the
trophic food chain and ingest a variety of fish, birds, squid, shark, and other cetaceans (Barros &
Clarke 2009). The Mysticeti, which include the gray whale species, are filter feeders which
ingest water and sediment which is then filtered out to trap prey which is much lower on the
trophic food chain. A few examples of these prey items include a variety of small fish,
zooplankton, shrimp, and krill (Barros & Clarke 2009). Due to the bioaccumulation and
biomagnification properties of non-essential metals, the ingestion of higher trophic level prey
leads to greater levels of toxicity in the suborder Odontocetes (Kershaw & Hall 2019).
Toxicity of Non-Essential Metals
Aluminum
Aluminum exists in nature, primarily in rocks and minerals, as the most naturally
abundant metal on Earth’s surface (Perrollaz et al. 1990). Aluminum is rarely found in its
elemental form and is instead most prevalent as a trivalent Al3+ metal (Perrollaz et al. 1990). The
toxicity of aluminum is associated with its bioaccumulation in skeletal and soft tissues and is a
controversial neurotoxin (Perrollaz et al. 1990). Since Al is a non-essential metal, with no known
biological function in mammalian bodies, it is presumed that excess amounts detected in tissues
are adverse.
7
The controversial neurotoxic effects of Al stem from studies of Alzheimer’s Disease
(AD), multiple sclerosis, Parkinson’s Disease, and dementia in humans. Al is known to be
present in human brain tissue and is shown to accumulate with age (Exley 2014). This
accumulation of Al and other metals in the human brain are linked to the pathogenesis of AD
(Percy et al. 2011). AD can be characterized by an unusual distribution of metal ions, such as
iron, aluminum, copper, and zinc in the human brain (Percy et al. 2011). The free metal cation of
Al3+ is both highly biologically reactive and biologically available to neurological cells (Exley
2014). It is proposed that the ease of oxidation of Al3+ may lead to a chemical reactive pathway
(Figure 3; Percy et al. 2011.), which creates reactive oxygen species (O2-, H2O2, HO) and
prooxidants (AlO22+) harmful to biological processes (Percy at al. 2011).
Figure 3. Metal-ion reaction series depicting iron (Fe3+) and suggesting a pathway for Al3+,
which can produce prooxidant and superoxide (Percy et al. 2011).
In human and lab animal trials, Al3+ is also shown to be deposited in skeletal, liver, and
kidney cells. These studies further revealed links between Al toxicity and renal (kidney) failure
in rats (Martinez-Finley et al. 2012). The effects of Al on cetaceans are currently unknown, but a
study of juvenile gray whale necropsies discovered Al concentrations which were in relatively
high concentrations in liver (4,200 ng/g wet weight), kidney (2,800 ng/g wet weight), and brain
8
tissues (1,000 ng/g wet weight) (Tilbury et al. 2002). The highest overall levels of Al observed in
this study came from the stomach contents (3,900,000 ng/g wet weight) of the juvenile gray
whales, and it was suggested that this may be due to the bioavailability of Al in sediment, along
with the diet, feeding behavior, and feeding location preferences (Tilbury et al. 2002).
Mercury
Mercury (Hg) exists in nature in two distinct physical forms, as vapor (Hg0) and
methylmercury compounds (CH3Hg+) (Clarkson 1997). The main source of Hg on earth occurs
naturally, in a global Hg cycle, through geological activity (volcanoes and geothermal vents),
erosion , plant growth, degassing from aquatic and terrestrial environments, and burning of
biomass (Gwoerk et al. 2016). Hg can become water soluble and enter marine aquatic systems
through surface gas exchanges, or as input from land run-off and freshwater sources (Clarkson
1997). Hg accumulates in marine sediments, which become a substantial sink for Hg (Gwoerk et
al. 2016), and is known to undergo many transformations, including methylation (Clarkson
1997). The methylation of Hg by benthic bacteria (Clarkson 1997) causes the binding of Hg to
biological proteins (Qiying et al. 2021). These Hg containing proteins then bioaccumulate up the
trophic food chain through predator/prey interactions (Clarkson 1997).
The toxicity of Hg is attributed to its bioaccumulation effects in soft tissues and is a wellknown neurotoxin, genotoxin, and immunotoxin (Kershaw & Hall 2019). The toxicity of Hg in
cetaceans is linked to hepatic (liver) and renal damage (Kershaw & Hall 2019). Hg is known to
cross the blood barrier in utero and is suggested to effect juvenile and adult cetaceans differently
(Bolea-Fernandez et al. 2019). In a study of long-finned pilot whales, it was shown that Hg
9
levels were higher in the muscle tissues of juvenile whales and lower in the liver tissues (BoleaFernandez et al. 2019). The opposite of this was shown in adult whale tissue, with higher levels
of Hg observed in the liver tissues and lower levels observed in muscle tissues (Bolea-Fernandez
et al. 2019). It was suggested that this difference in Hg levels identified in tissues may be due to
changes in Hg metabolism and detoxification mechanisms (Bolea-Fernandez et al. 2019). The
movement of Hg from liver to muscle tissue, may be a detoxification technique to protect
sensitive organs (Bolea-Fernandez et al. 2019).
It has also been hypothesized that Hg contamination may affect members of the cetacean
family differently, with high contaminant levels reported in some members of cetaceans who
show no signs of toxicity (Kershaw & Hall 2019). The demethylation process and the interaction
of selenium (Se) with methyl mercury (MeHg) may account for the high levels of Hg in cetacean
tissues with no outward signs of toxicity (Kershaw & Hall 2019). However, the unique feeding
mechanism of the gray whale, which involves the continuous filtering of benthic sediment
material, may especially expose this cetacean to the more toxic form of MeHg (Gui D et al.
2014). The methylation of Hg occurs in benthic sediments, where the less toxic form of aqueous
Hg is converted to the highly neurotoxic MeHg by sulfate and iron reducing bacteria (Gui D et al
2014). MeHg can both biomagnify and bioaccumulate in soft tissues, and this creates health
concerns to the individual and greater trophic food chain (Gui D et al. 2014).
Toxicity of PCBs
10
Polychlorinated biphenyls (PCBs) are anthropogenic compounds which do not occur
naturally in the environment. The toxicity of PCBs is attributed to their lipophilic nature and
ability to both biomagnify and bioaccumulate in soft tissues, such as, fat and blubber (Jones & de
Voogt 1999). PCBs are a part of a broader group of synthetic substances, known as persistent
organic pollutants (POPs), which are known to cause neurotoxicity, reproductive failure, cancer,
and immunotoxicity (Mongillo et al. 2012). The affinity of PCBs and other POPs to accumulate
and magnify in fat and blubber tissue creates a specific threat to cetacean species, and this is due
to its release from blubber tissue into the bloodstream and its transference to offspring during
gestation and lactation. The migratory Eastern Pacific stock of gray whales depend on the
breakdown of their blubber storage to make a successful round-trip journey, and this may cause
toxic levels of PCBs to enter sensitive tissues and the bloodstream.
A blubber biopsy study of PCB concentrations in killer whales (n = 47) which inhabit the
greater Salish Sea, has revealed concerning levels of PCBs (Ross et al. 2000). These biopsies
were taken from three separate communities of killer whales, which are the northern residents,
southern residents, and the transients (Ross et al. 2000). The transient killer whales, which are
migratory and feed on marine mammals, had the highest levels of PCB contaminants (males: 251
± 54.7 mg/kg, females: 58.8 ± 20.6 mg/kg) (Ross et al. 2000). The southern residents, which
reside year-round in Puget Sound and feed on salmon, had the second highest levels of PCB
contaminants (males: 146.3 ± 32.7 mg/kg, females: 55.4 ± 19.3mg/kg) (Ross et al. 2000). The
northern residents, which reside in Canadian waters and feed on salmon, had the lowest levels of
PCB contaminants (males: 37.4 ± 6.1 mg/kg, females: 9.3 ± 2.8 mg/kg) (Ross et al. 2000). It is
suggested that the higher concentrations of PCBs observed in the southern resident killer whales
11
(SRKW), which consume similar prey to the northern residents, may be due to localized
contaminated prey or deposits of PCBs (Ross et al. 2000).
Further research into predicted levels of PCB and PBDE accumulations in SRKW tissue
revealed that calves were projected to contain the highest levels of total PCBs and PBDEs
(polybrominated diphenyl ethers) of any age class, followed by adult males, then postreproductive females (Mongillo et al. 2012). It is noted that PCBs have caused behavioral
changes in mice, and calf mortality in bottlenose dolphins, but no such conclusive links have
been reached with the SRKW (Mongillo et al. 2012). This study did note that the SRKW is one
of the most PCB contaminated cetacean species in the world and that PBDEs were shown to
increase exponentially with age class (Mongillo et al. 2012).
Although the SRKW may be especially contaminated with PCBs and PBDEs, in waters
which it shares with migratory gray whales, those contaminant levels have been declining in
other local species. In a 2013 study of blubber biopsies taken from juvenile harbor seals, it was
revealed that PCBs, PBDEs, PCDEs (polychlorinated diphenyl ethers), and PCNs
(polychlorinated naphthalene) have declined in Salish Sea harbor seals (Ross et al. 2013). This
study observed an overall decrease (71% - 98%) of PCBs, PCDEs, and PCNs in harbor seal
tissue from 1983 to 2013 (Ross et al 2013). It is noted, however, that the highest levels of PCBs
and PCDEs observed in this study were taken from harbor seal populations which reside in
southern Puget Sound waters (Ross et al. 2013).
12
Chapter Three: Methods
Site Selection
Three sites were chosen for field sampling, based on previous literature and observations
(Figure 4; CRC 2014) of heavily concentrated gray whale feeding pits and known ghost shrimp
population sites. Accessibility to sites was also taken into consideration.
Figure 4. Gray whale feeding site locations (1990-2014) of the Whidbey Basin in Puget Sound
(Cascadia Mammal Research Center 2014). Sampling locations (2021) added by the author, in
black circles.
13
The sites used for field sampling in this study are located in the Whidbey Island Basin
and Saratoga Passage of Puget Sound, on the islands of Camano and Whidbey (Figure 5.). The
sites selected on Whidbey Island are located on its eastern portion and include the Langley
Waterfront in Langley, WA, and Hidden Beach in Greenbank, WA. Both sites have been
recorded as annual feeding grounds for migratory gray whales. The site selected on Camano
Island is located on the northeastern portion of the island and includes the Iverson Trail Preserve
Beach. This site is not known as a gray whale feeding ground and lies ~ 4 to 5 nautical miles
NW of annually observed feeding grounds. This site was chosen for its known ghost shrimp
population, proximity to observed feeding grounds, and public accessibility.
14
Figure 5. Field collection sites for two survey periods (Feb-April 2021) submitted using the
ArcGIS Survey123 application.
Sample Collection
Near-shore sediment sample collection (Sample ID# = 1-5) was performed using a
suction device, “clam-gun”, to retrieve sediment cores during two low-tide (tide < 1ft) survey
periods (February & April 2021) (Table 1). Appropriate measures were taken to avoid crosscontamination of samples during the sample collection phase.
15
Table 1. Near-shore sampling location ID, location, type, and estimated tidal level (feet) during
two field sampling periods (February-April 2021).
Sample
ID
1
Location Name
Longitude Latitude
Date
Time
Sample
Type
Tide (ft)
estimate
-122.408
48.0423
2/5/2021
5:12PM sediment
0.5
-122.44
48.2125
2/6/2021
6:35PM sediment
-0.38
3
Langley Waterfront
Iverson Trail
Preserve
Iverson Trail
Preserve
-122.44
48.2114 4/17/2021 5:48PM sediment
-0.058
4
Hidden Beach
-122.56
48.1277 4/18/2021 3:17PM sediment
0.7
5
Langley Waterfront
-122.408
48.0417 4/18/2021 4:08PM sediment
0.2
6
Langley Waterfront
-122.408
48.0417 4/18/2021 4:11PM
0.2
2
animal
Upon collection, the sediment samples were placed in clean glass test tubes, with wooden
cork stoppers, and labeled with location, estimated tidal level, depth, and dominant sediment
texture. Duplicate samples (n = 2) were taken from each collection site, and the GPS coordinates
were recorded with ArcGIS Survey 123, to provide a total of 10 sample collections for potential
laboratory analysis. Gray whales were observed to be actively feeding, via reported sightings and
feeding observations from trained observers of the Orca Network group, during both survey
periods. The presence of ghost shrimp tunnel boring was noted at all collection sites, and a high
level of sandy substrate was noted.
Ghost shrimp specimen collection was performed during one survey period (April) on the
Langley waterfront site, in Langley, WA (Sample ID# = 6). Several gray whale feeding pits (4)
were observed during the low tide and collection was taken from both live and dead ghost shrimp
16
within these pits (Figure 6.). Duplicate samples (n = 2) of ghost shrimp specimens (4) were
collected to submit for total laboratory analysis of this site.
Figure 6. Gray whale feeding pit with deceased ghost shrimp in center, Langley waterfront,
Langley, WA (Sample ID# = 6) (April 2021).
Laboratory Analysis
Sediment and ghost shrimp samples were analyzed for Mercury (Hg) and Polychlorinated
biphenyls (PCBs) concentrations at Libby Environmental, INC (3322 South Bay Road NE
Olympia, WA 98506). These were near-shore sediment (Sample ID# = 1-5) and ghost shrimp
17
specimen samples (Sample ID# = 6). Libby Environmental, INC standard operating procedures
were used to analyze the samples, as described below.
The method used for Hg analysis is a cold-vapor atomic absorption procedure (EPA
Method 7471), which measures the Resource Conservation and Recovery Act (RCRA) analyte in
soils, sediments, bottom deposits, and sludge type materials. The Hg is reduced to its elemental
vapor state and its absorption is measured by an atomic absorption spectrophotometer. All
samples were prepared by utilizing a well homogenized sample, which was then submitted to
one of two digestion methods involving potassium permanganate (KMnO₄) solution. The
samples were then analyzed by constructing a calibration curve, which determines the peak
height and Hg values. The typical detection limit for this method is 0.000.2 mg/L, and the
Practical Quantitation Limit (PQL) is 0.5 mg/kg. Quality control was performed using a labcontrolled sample of Hg matrix spike values, duplicate collection samples, and a Relative
Percent Difference (RPD). All samples were within the acceptable recovery limits for matrix
spikes (75% - 125%) and acceptable RPD limits (20%). There were no detected levels of Hg
present in any of the submitted samples (Sample ID# 1-6) (Appendix 1.).
The method used for PCBs analysis was gas chromatography (EPA Method 8082) to
determine the concentration of PCBs as Aroclors or individual PCB congeners. The samples
were well homogenized and prepared for extraction with methylene chloride and acetone. The
samples were then analyzed by gas chromatography for the Aroclors 1016, 1260, 1221, 1232,
1242, and 1254. The sample peaks were then compared to the known Aroclor standards. The
PQL for this analysis is 0.1mg/kg. Quality control was performed using a lab-controlled sample,
a blank sample, and duplicate collection samples. All samples were within the acceptable
recovery limits for surrogate (65% -135%), acceptable recovery limits for matrix spikes (75% 18
125%), and acceptable RPD limits (20%) (Appendix 1.). There were no detectable PCBs present
in sample IDs# 1,2,3,4, and 6. There were PCBs detected in one collection sample (Sample ID#
= 5) in the form of PCB congener Aroclor 1016 (1.7mg/kg) and Aroclor 1260 (2.1mg/kg) (Table
2.). These values are >1 order of magnitude above the PQL.
Table 2. Libby Environmental, INC total Aroclor 1016 and Aroclor 1260 concentrations (mg/kg)
(nd = none detected) of near-shore sediment and ghost shrimp specimens from two collection
periods (February-April 2021)(* indicates detected value).
Sample
ID
1
2
3
4
5
6
Location Name
Langley Waterfront
Iverson Trail
Preserve
Iverson Trail
Preserve
Hidden Beach
Langley Waterfront
Langley Waterfront
Aroclor 1016 Aroclor 1260
Concentration Concentration
(mg/kg)
(mg/kg)
nd
nd
Collection
Date
2/6/2021
Date
Analyzed
2/10/2021
Matrix
sediment
nd
nd
2/7/2021
2/10/2021
sediment
nd
nd
1.7*
nd
nd
nd
2.1*
nd
4/17/2021
4/18/2021
4/18/2021
4/18/2021
4/21/2021
4/21/2021
4/21/2021
4/21/2021
sediment
sediment
sediment
animal
Fremont Analytical (3600 Fremont Ave N, Seattle, WA, 98103) analyzed near-shore
sediment (Sample ID# = 3,4,5) and ghost shrimp specimen samples (Sample ID# = 6) for total
aluminum (Al) concentrations. Fremont Analytical standard operating procedures were used to
analyze the samples.
The method used for Total Al analysis is the EPA Method 6020B, which utilizes
inductively coupled plasma-mass spectrometry (ICP-MS) to determine heavy metal
concentrations. The samples were well homogenized and digested with an acid solution. The
19
samples were then filtered and analyzed by mass spectrometry. The method blank for this
analysis reported no value of Al detected below a reporting limit of 7.87 mg/kg. Quality control
was performed using a lab-controlled sample of Al matrix spike values, duplicate collection
samples, and a Relative Percent Difference (RPD). The PQL for this analysis is 0.05 mg/L. All
samples were within the acceptable recovery limits for matrix spikes (75% - 125%) and
acceptable RPD limits (20%) (Appendix 1.). Total Al concentrations were detected in all the
submitted samples (Sample ID# 3,4,5, & 6) (Table 3.). All measurements were >1 order of
magnitude above the PQL and often >2.
Table 3. Fremont, INC total Aluminum concentrations (mg/kg) of field sampling 2 sites (Sample
ID# 3,4,5, & 6) (April 2021).
Sample
ID
3 (April
1A)
4 (April
2A)
5 (April
3A)
6 (April
4B)
Location Name
Iverson Trail
Preserve
Aluminum (mg/kg)
Return Limit
(RL)
Collection
Date
Date
Analyzed
Matrix
6720
159
4/17/2021
4/27/2021
sediment
Hidden Beach
6170
157
4/18/2021
4/27/2021
sediment
Langley Waterfront
6610
153
4/18/2021
4/27/2021
sediment
Langley Waterfront
692
7.87
4/18/2021
4/22/2021
animal
20
Chapter Four: Results
There were no detected levels of Hg from any samples taken during the two survey
periods (February – April 2021). There were no detected levels of PCBs from any samples taken
during the first survey period, in February 2021. Total Al concentration levels were not tested on
any samples during the first survey period.
There were two detected PCB contaminant concentration results reported, and both
findings were from the second sampling period (April 2021). The laboratory analysis revealed
elevated Al and PCB congener concentrations in one sample (Sample ID# =5). The elevated
PCBs were of the congeners Aroclor 1016 and Aroclor 1260 (Figure 7.).
Total Aroclor 1016 and Aroclor 1260 Concentrations
(mg/kg) of Collection Site Samples (1-6)
Concentration (mg/kg)
2.5
2.1
2
1.7
1.5
1
0.5
0
1
2
3
4
5
6
Collection Site #
Aroclor 1016
Aroclor 1260
Figure 7. Concentrations (mg/kg) of PCBs Aroclor 1016 and Aroclor 120 detected in collection
site samples (1-6) during the second survey sampling period (April 2021).
21
Notable PCBs were detected in one near-shore collection sample (Sample ID# = 5),
which was taken from an observed gray whale feeding pit, located at the Langley Waterfront, in
Langley, WA, on April 18th, 2021. The resulting PCB values detected were of Aroclor 1016
(1.7mg/kg) and Aroclor 1260 (2.1mg/kg) (Table 3.). The detected Aroclor 1016 concentration
(Sample ID# 5 = 1.7mg/kg) was markedly above the threshold values defined by the Washington
Department of Ecology’s Clarc table (Table 5.) of soil protective of groundwater saturated (0.12
mg/kg). The detected Aroclor 1260 concentration (Sample ID# 5 = 2.1mg/kg) was also
substantially higher than the Washington Department of Ecology’s Clarc table (Table 5.) value
of soil method B noncancer (0.5mg/kg) and soil protective of groundwater saturated
(0.036mg/kg). A comparison of the observed Aroclor congener values to the Washington
Department of Ecology’s Clarc table values are represented in Figures 8 & 9.
Comparison of Observed Aroclor 1016 Concentrations
(mg/kg) to DOE Clarc Table Value (mg/kg)
1.7
1.8
PCB Concentration (mg/kg)
1.6
1.4
1.2
1
0.8
0.6
0.4
0.2
0.12
0
Aroclor 1016 Soil Protective of
Groundwater Saturated
Aroclor 1016
Figure 8. Comparison of observed Aroclor 1016 (color = orange) concentrations detected
(Sample ID# = 5) to respective Washington Department of Ecology Clarc table value (color =
blue) for soil protective of groundwater saturated.
22
Comparison of Observed Aroclor 1260
Concentrations (mg/kg) to DOE Clarc Tables Values
(mg/kg)
PCB Concentrations (mg/kg)
2.5
2.1
2
1.5
1
0.5
0.5
0.036
0
Aroclor 1260 Soil Protective Aroclor 1260 Soil Method B
of Groundwater Saturated
Noncancer
Aroclor 1260
Figure 9. Comparison of observed Aroclor 1260 (color = orange) concentrations detected
(Sample ID# = 5) to respective Washington Department of Ecology Clarc table value (color =
blue) for soil protective of groundwater saturated and soil method B noncancer.
Total Al concentrations of diluted samples (Sample ID #3 = 6,720 mg/kg, Sample ID# 4
= 6,170mg/kg, Sample ID# 5 = 6,610 mg/kg, Sample ID# 6 = 692 mg/kg) were detected in four
samples taken from three near-shore sediment samples and one ghost shrimp specimen sample
during the second survey period, on April 17th – April 18th, 2021 (Figure 10).
23
Total Al Concentrations (mg/kg) of Collection Site Samples
(3-6)
Collecton Site ID
#6 Langely Waterfront (animal)
692
#5 Langley Waterfront (sediment)
6610
#4 Hidden Beach (sediment)
6170
#3 Iverson Trail Preserve (sediment)
6720
0
1000
2000
3000
4000
5000
6000
7000
8000
Al concentration (mg/kg)
Figure 10. Total aluminum concentrations (mg/kg) detected in collection samples (3-6) during
the second survey sampling period (April 2021).
Sample # 5 (sediment) & Sample #6 (animal) were both taken from an observed gray
whale feeding pit on the Langley Waterfront, in Langley, WA. The values of total Al detected in
the sediment and animal samples analyzed are of notable concentrations according to the
Washington Department of Ecology’s Clarc table (Table 4.) of soil method A unrestricted land
use.
24
Table 4. Washington State Department of Ecology - CLARC Soil Unrestricted Land Use Table
(Methods A, B, Groundwater Protection, and Soil Leaching Parameters) (WA DEPT of
ECOLOGY February 2021)
Chemical
Group
Metals
PCBs
PCBs
Chemical
Name
Aluminum
Aroclor 1016
Aroclor 1260
Soil
Method A
Unrestricted Land
Use
(mg/kg)
Soil
Method B
Noncancer
(mg/kg)
80000
5.6
Soil
Method B
Cancer
(mg/kg)
14
0.5
Soil
Protective
Groundwater
Vadose @ 13
degrees C
(mg/kg)
480000
Soil
Protective
Groundwater
Saturated
(mg/kg)
24000
0.12
0.036
25
Chapter Five: Discussion
Comparison of Historic Puget Sound Sediment Contaminant Values to Survey Collection
Values
Although there are still many unknowns on the topic of toxicology and contaminant
effects to cetaceans, we do have historic tangible data available of their concentrations in Puget
Sound marine benthic sediments. The Washington Department of Ecology monitors the
concentrations of compounds in both the marine water-column and marine benthic sediments.
The marine benthic sediment data was collected by Van Veen grab sampling, during the time
period of 1989-2019. These values are not static and can fluctuate over time, and so they are
subject to influence by factors such as seasonality, depth, temperature, circulation, and point and
non-point source inputs (Washington Department of Ecology 2021). For the purpose of this
research, the concentration values of Al, and PCB congeners Aroclor 1016 and Aroclor 1260 will
be evaluated in Island County of Washington State only.
Total Al Concentrations
Total Al concentrations (mg/kg) of the Washington Department of Ecology’s Van Veen
grab sampling (n = 71) from Island County have been sorted in Table 5 by increasing value of
concentration. The majority of samples in Island County were taken in the Saratoga Passage (n =
20). A histogram of the total Al concentrations is depicted in Figure 11. An R analysis of the
total Al values is as follows: minimum value = 6030 mg/kg, 1st quartile = 18300 mg/kg, median
= 21250 mg/kg, mean = 35821 mg/kg, 3rd quartile = 68000, maximum value = 87000.
26
The total Al values from the second survey collection (Sample ID #3 = 6,720 mg/kg,
Sample ID# 4 = 6,170 mg/kg, Sample ID# 5 = 6,610 mg/kg, Sample ID# 6 = 692 mg/kg) are
similiar to the minimum value (6030 mg/kg) found in the DOE database. These values are also
well below the mean value of 35821 mg/kg. A spatial analysis (Figure 12) of hot spots (large
clusters of high values) of the DOE total Al concentrations reveals survey sampling sites lie
outside of the hot spot concentration zones.
Table 5. Total Al concentrations (mg/kg), in increasing value, of DOE Puget Sound benthic
sediment data (1989-2019) by Van Veen grab sampling (Department of Ecology 2021).
Location Name
Field
Total Al
Collection
(mg/kg)
Latitude (DD)
Longitude
(DD)
Date
USELESS BAY
4/1/1992
6030
47.98517
-122.49149
USELESS BAY
6/30/1998
6820
47.98152
-122.50338
USELESS BAY
6/30/1998
7180
47.98152
-122.50338
USELESS BAY
6/30/1998
8500
47.96341
-122.50795
SKAGIT BAY
7/2/1997
9300
48.30833
-122.49163
SARATOGA
6/30/1997
9820
48.11163
-122.49257
6/30/1997
10600
48.11163
-122.49257
4/1/1993
11300
48.25617
-122.625
PASSAGE
SARATOGA
PASSAGE
OAK HARBOR
27
SKAGIT BAY
4/1/1991
12100
48.29533
-122.4885
SKAGIT BAY
7/2/1997
12200
48.26747
-122.51675
OAK HARBOR
4/1/1992
13400
48.25617
-122.625
OAK HARBOR
4/1/1991
14500
48.25617
-122.625
SKAGIT BAY
7/2/1997
14800
48.27085
-122.54587
OAK HARBOR
4/1/1989
15400
48.25617
-122.625
WEST BEACH,
4/1/1991
16800
48.39933
-122.671
OAK HARBOR
7/2/1997
17600
48.27445
-122.65198
OAK HARBOR
7/3/1997
17900
48.2839
-122.63665
OAK HARBOR
7/3/1997
18200
48.28528
-122.6372
PORT SUSAN
4/1/1993
18600
48.17317
-122.45775
SOUTH OF OAK
7/2/1997
18600
48.2558
-122.64643
PORT SUSAN
4/1/1989
18700
48.17317
-122.45775
SARATOGA
4/1/1990
18900
48.09792
-122.47134
4/1/1993
18900
48.09792
-122.47134
OAK HARBOR
7/3/1997
18900
48.28528
-122.6372
SARATOGA
4/1/1989
19100
48.09792
-122.47134
WHIDBEY ISLAND
HARBOR
PASSAGE
SARATOGA
PASSAGE
PASSAGE
28
SARATOGA
4/1/1992
19400
48.09792
-122.47134
6/24/1997
19600
48.05778
-122.39025
6/30/1997
19600
48.2228
-122.55915
7/1/1997
19600
48.23717
-122.58813
6/30/1997
20300
48.15583
-122.53523
4/1/1991
20600
48.09792
-122.47134
PORT SUSAN
4/1/1992
20600
48.17317
-122.45775
SARATOGA
6/30/1997
20600
48.06138
-122.42585
6/30/1997
20800
48.13888
-122.5436
OAK HARBOR
4/1/1990
20900
48.25617
-122.625
PORT SUSAN
6/23/1997
21600
48.16963
-122.4178
PENN COVE
7/1/1997
21600
48.23615
-122.6658
HOLMES HARBOR,
4/1/1992
21700
48.08833
-122.55051
PASSAGE
SARATOGA
PASSAGE
SARATOGA
PASSAGE
NORTHERN
SARATOGA
PASSAGE
SARATOGA
PASSAGE
SARATOGA
PASSAGE
PASSAGE
SARATOGA
PASSAGE
WHIDBEY ISLAND
29
SARATOGA
6/30/1997
21700
48.06138
-122.42585
PORT SUSAN
6/23/1997
22200
48.16963
-122.4178
PORT SUSAN
4/1/1990
22300
48.17317
-122.45775
PORT SUSAN
4/1/1991
23000
48.17317
-122.45775
MOUTH OF PENN
7/1/1997
23000
48.24283
-122.62218
PENN COVE
7/1/1997
23100
48.22472
-122.71052
PENN COVE
7/1/1997
23800
48.23168
-122.69357
SARATOGA
6/30/1997
40600
48.11163
-122.49257
6/30/1997
44000
48.11163
-122.49257
USELESS BAY
6/30/1998
46500
47.96341
-122.50795
SOUTH OF OAK
7/2/1997
53300
48.2558
-122.64643
USELESS BAY
6/30/1998
58300
47.98152
-122.50338
SKAGIT BAY
7/2/1997
59200
48.30833
-122.49163
SARATOGA
6/30/1997
64100
48.15583
-122.53523
6/30/1997
69300
48.13888
-122.5436
7/2/1997
69300
48.30833
-122.49163
PASSAGE
COVE
PASSAGE
SARATOGA
PASSAGE
HARBOR
PASSAGE
SARATOGA
PASSAGE
SKAGIT BAY
30
PENN COVE
7/1/1997
69400
48.22472
-122.71052
PENN COVE
7/1/1997
70300
48.23168
-122.69357
SKAGIT BAY
7/2/1997
72200
48.27085
-122.54587
SARATOGA
6/24/1997
72700
48.05778
-122.39025
SKAGIT BAY
7/2/1997
74400
48.26747
-122.51675
NORTHERN
7/1/1997
74500
48.23717
-122.58813
6/30/1997
74600
48.06138
-122.42585
6/30/1997
76400
48.2228
-122.55915
PENN COVE
7/1/1997
76500
48.23615
-122.6658
OAK HARBOR
7/3/1997
77000
48.28528
-122.6372
OAK HARBOR
7/3/1997
77300
48.2839
-122.63665
OAK HARBOR
7/2/1997
77900
48.27445
-122.65198
OAK HARBOR
7/3/1997
78200
48.28528
-122.6372
MOUTH OF PENN
7/1/1997
78600
48.24283
-122.62218
PORT SUSAN
6/23/1997
85700
48.16963
-122.4178
PORT SUSAN
6/23/1997
87000
48.16963
-122.4178
PASSAGE
SARATOGA
PASSAGE
SARATOGA
PASSAGE
SARATOGA
PASSAGE
COVE
31
mg/kg
Figure 11. Histogram of Total Al concentrations of DOE Puget Sound benthic sediment data
(1989-2019) by Van Veen grab sampling (Washington Department of Ecology 2021) generated
by Social Science Statistics. For reference, results in this study varied from 692 mg/kg – 6720
mg/kg.
32
Figure 12. Survey sample collection sites (collection sites = black diamonds) and hot spots (blue
= low, purple = medium, red = high, yellow = very high) of total Al concentrations from DOE
Puget Sound benthic sediment data. Generated with ArcGIS.
Aroclor 1016 concentrations
Aroclor 1016 concentrations (mg/kg) of the Washington Department of Ecology’s Van
Veen grab sampling (n = 78) from Island County have been sorted in Table 6 by increasing value
of concentration. A histogram of the Aroclor 1016 concentrations is depicted in Figure 13. An R
analysis of the Aroclor 1016 values is as follows: minimum value = 0.001200 mg/kg, 1st quartile
= 0.005100 mg/kg, median = 0.009765 mg/kg, mean = 0.008627 mg/kg, 3rd quartile = 0.010175
mg/kg, maximum value = 0.019000 mg/kg.
33
The Aroclor 1016 value from the second survey collection (Sample ID# 5 = 1.7 mg/kg) is
remarkedly above both the DOE database mean (0.008627 mg/kg) and maximum value
(0.019000 mg/kg) of this area. This value also exceeds the DOE Clarc value of soil protective of
groundwater saturated (0.12 mg/kg) and is therefore both abnormally high and potentially
concerning. A spatial analysis (Figure 14) of hot spots of the DOE Aroclor 1016 concentrations
reveals survey sampling sites lie outside of the known hot spot concentration zones.
Table 6. Aroclor 1016 concentrations (mg/kg), in increasing value, of DOE Puget Sound benthic
sediment data (1989-2019) by Van Veen grab sampling (Department of Ecology 2021).
Location Name
Field
PCB Aroclor
Collection
1016
Date
Concentration
Latitude (DD)
Longitude (DD)
(mg/kg)
OAK HARBOR
7/2/1997
0.0012
48.27445
-122.65198
PSEMP_LT-40007
4/30/2018
0.00126
48.22609563
-122.5437651
SARATOGA
6/30/1997
0.0016
48.15583
-122.53523
PSEMP_LT-40015
4/22/2019
0.0017
48.08877563
-122.448545
USELESS BAY
6/6/2003
0.0048
47.936462
-122.447223
PSAMP_SP-3855
6/18/2014
0.0048
47.950614
-122.47886
PSAMP_SP-3187
6/19/2014
0.0048
47.999232
-122.566721
PASSAGE
34
SOUTH OF
6/13/2008
0.0049
47.847345
-122.418419
USELESS BAY
6/17/2002
0.005
47.945124
-122.471458
USELESS BAY
6/17/2002
0.005
47.945124
-122.471458
MUTINY BAY
6/24/2002
0.005
47.989749
-122.554923
PSAMP_SP-783
6/18/2014
0.005
47.943468
-122.482832
PSAMP_SP-2063
6/19/2014
0.005
47.927478
-122.448443
PSAMP_SP-3203
6/19/2014
0.005
47.987084
-122.561603
PSAMP_SP-1443
6/19/2014
0.005
47.965792
-122.509161
EAST OF
6/13/2008
0.0051
47.894683
-122.362001
PSAMP_SP-1807
6/18/2014
0.0051
47.950305
-122.465638
PSAMP_SP-3343
6/18/2014
0.0051
47.976061
-122.50084
PSAMP_SP-2319
6/18/2014
0.0051
47.97828
-122.483775
PSAMP_SP-2319
6/18/2014
0.0051
47.97828
-122.483775
PSAMP_SP-2831
6/18/2014
0.0051
47.961127
-122.487157
PSAMP_SP-1571
6/19/2014
0.0051
47.959997
-122.501224
POSSESSION
6/1/2009
0.0052
47.939653
-122.336727
USELESS BAY
6/30/1998
0.0054
47.96341
-122.50795
USELESS BAY
6/30/1998
0.0054
47.98152
-122.50338
USELESS BAY
6/30/1998
0.0054
47.98152
-122.50338
USELESS BAY
6/30/1998
0.0056
47.96341
-122.50795
POSSESSION PT.
POSSESSION PT.
SOUND
35
SKAGIT BAY
7/2/1997
0.0057
48.30833
-122.49163
SKAGIT BAY
7/2/1997
0.0065
48.26747
-122.51675
SARATOGA
6/30/1997
0.0068
48.11163
-122.49257
SKAGIT BAY
7/2/1997
0.007
48.27085
-122.54587
PORT SUSAN
6/23/1997
0.0078
48.16963
-122.4178
PORT SUSAN
6/23/1997
0.0079
48.16963
-122.4178
SARATOGA
6/6/2007
0.0092
48.15079
-122.54696
6/6/2007
0.0094
48.139553
-122.544899
SARATOGA PASS
6/11/2007
0.0094
48.067587
-122.449544
HOLMES HARBOR
6/6/2007
0.0096
48.043554
-122.51557
SARATOGA PASS
6/11/2007
0.0096
48.041723
-122.378578
SARATOGA PASS
6/5/2007
0.0097
48.237088
-122.63562
PSEMP_LT-209R
5/3/2016
0.00983
48.29533
-122.4885
PSEMP_LT-19
4/27/2016
0.00985
48.09792
-122.47134
SKAGIT BAY
6/5/2007
0.0099
48.291669
-122.486003
HOLMES HARBOR
6/6/2007
0.0099
48.036152
-122.526755
SARATOGA PASS
6/11/2007
0.0099
48.108076
-122.451612
SARATOGA PASS
6/11/2007
0.0099
48.0584
-122.417132
OAK HARBOR
7/3/1997
0.01
48.28528
-122.6372
PASSAGE
PASSAGE
SARATOGA
PASSAGE
(NORTH)
36
SKAGIT BAY
6/5/2007
0.01
48.275939
-122.520873
CRESENT HARBOR
6/5/2007
0.01
48.286562
-122.579053
SARATOGA PASS
6/5/2007
0.01
48.231155
-122.583858
6/5/2007
0.01
48.200165
-122.548387
6/6/2007
0.01
48.178308
-122.575625
HOLMES HARBOR
6/6/2007
0.01
48.107718
-122.56206
HOLMES HARBOR
6/6/2007
0.01
48.062865
-122.520724
POSSESSION
6/7/2007
0.01
47.989157
-122.343898
PORT SUSAN
6/8/2007
0.01
48.168488
-122.41852
SARATOGA PASS
6/11/2007
0.01
48.067092
-122.443248
PORT SUSAN
6/11/2007
0.01
48.057499
-122.35367
PSEMP_LT-209R
5/3/2016
0.0101
48.29533
-122.4885
PSEMP_LT-209R
5/3/2016
0.0102
48.29533
-122.4885
PENN COVE
7/1/1997
0.011
48.23615
-122.6658
MOUTH OF PENN
7/1/1997
0.011
48.24283
-122.62218
OAK HARBOR
7/3/1997
0.011
48.28528
-122.6372
OAK HARBOR
7/3/1997
0.011
48.2839
-122.63665
(NORTH)
SARATOGA
PASSAGE
SARATOGA
PASSAGE
SOUND
COVE
37
POSSESSION
6/7/2007
0.011
48.001263
-122.352855
PORT SUSAN
6/8/2007
0.011
48.117441
-122.399167
PSEMP_LT-19
4/27/2016
0.0113
48.09792
-122.47134
PSEMP_LT-19
4/27/2016
0.0117
48.09792
-122.47134
SARATOGA
6/24/1997
0.012
48.05778
-122.39025
7/1/1997
0.012
48.23717
-122.58813
6/30/1997
0.013
48.2228
-122.55915
PENN COVE
7/1/1997
0.013
48.23168
-122.69357
SOUTH OF OAK
7/2/1997
0.013
48.2558
-122.64643
6/30/1997
0.015
48.06138
-122.42585
OAK HARBOR
4/1/1993
0.016
48.25617
-122.625
SARATOGA
6/30/1997
0.016
48.13888
-122.5436
PENN COVE
7/1/1997
0.016
48.22472
-122.71052
PORT SUSAN
4/1/1993
0.018
48.17317
-122.45775
SOUND
PASSAGE
NORTHERN
SARATOGA
PASSAGE
SARATOGA
PASSAGE
HARBOR
SARATOGA
PASSAGE
PASSAGE
38
SARATOGA
4/1/1993
0.019
48.09792
-122.47134
PASSAGE
mg/kg
Figure 13. Histogram of Aroclor 1016 concentrations of DOE Puget Sound benthic sediment
data (1989-2019) by Van Veen grab sampling (Washington Department of Ecology 2021)
generated by Social Science Statistics. For reference, the Aroclor 1016 value observed in this
study is 1.7 mg/kg.
39
Figure 14. Survey sample collection sites (collection sites = black diamonds, high observed
value = yellow diamond) and hot spots (blue = low, purple = medium, red = high, yellow = very
high) of Aroclor 1016 concentrations from DOE Puget Sound benthic sediment data. Generated
with ArcGIS.
Aroclor 1260 concentrations
Aroclor 1260 concentrations (mg/kg) from the Washington Department of Ecology’s Van
Veen grab sampling (n = 95) have been sorted in Table 7 by increasing value of concentration. A
histogram of the Aroclor 1260 concentrations is depicted in Figure 15. An R analysis of the
Aroclor 1260 values is as follows: minimum value = 0.001200 mg/kg, 1st quartile = 0.005100
40
mg/kg, median = 0.00990, mean = 0.01054 mg/kg, 3rd quartile = 0.01200 mg/kg, maximum
value = 0.06000 mg/kg.
The Aroclor 1260 value from the second survey collection (Sample ID# 5 = 2.1 mg/kg) is
also substantially above two Clarc Table values, the soil method B noncancer (0.5 mg/kg) and
soil protective of groundwater saturated (0.036 mg/kg). This value (2.1 mg/kg) is also well above
the mean value (0.01054 mg/kg) and the maximum value (0.06000 mg/kg) of the DOE study
area. The PCB values found during this survey study require further investigation and survey
sampling to ensure safe parameters for humans and cetaceans alike. A spatial analysis (Figure
16) of hot spots of the DOE Aroclor 1260 concentrations reveals survey sampling sites lie
outside of the known hot spot concentration zones. It is noted, however, that both hot spots for
Aroclor concentrations lie in the same geographic area. This area is located ~5.15 nautical miles
NW from Sample ID #5. The current also flows in the direction from the noted hot spot towards
where Sample ID #5 was collected. It is possible that a point or non point source of PCBs in the
form of Aroclor 1016 and 1260 is located near this hot spot.
Table 7. Aroclor 1260 concentrations (mg/kg), in increasing value, of DOE Puget Sound benthic
sediment data (1989-2019) by Van Veen grab sampling (Department of Ecology 2021).
Location Name
Field
Aroclor 1260
Latitude (DD)
Longitude (DD)
Collection
Concentration
Date
(mg/kg)
OAK HARBOR
7/2/1997
0.0012
48.27445
-122.65198
PSEMP_LT-40007
4/30/2018
0.00126
48.22609563
-122.5437651
41
SARATOGA
6/30/1997
0.0016
48.15583
-122.53523
USELESS BAY
6/6/2003
0.0048
47.936462
-122.447223
PSAMP_SP-3855
6/18/2014
0.0048
47.950614
-122.47886
PSAMP_SP-3187
6/19/2014
0.0048
47.999232
-122.566721
SOUTH OF
6/13/2008
0.0049
47.847345
-122.418419
PSEMP_LT-209R
5/3/2016
0.00491
48.29533
-122.4885
PSEMP_LT-19
4/27/2016
0.00492
48.09792
-122.47134
USELESS BAY
6/17/2002
0.005
47.945124
-122.471458
USELESS BAY
6/17/2002
0.005
47.945124
-122.471458
MUTINY BAY
6/24/2002
0.005
47.989749
-122.554923
PSAMP_SP-783
6/18/2014
0.005
47.943468
-122.482832
PSAMP_SP-2063
6/19/2014
0.005
47.927478
-122.448443
PSAMP_SP-3203
6/19/2014
0.005
47.987084
-122.561603
PSAMP_SP-1443
6/19/2014
0.005
47.965792
-122.509161
PSEMP_LT-209R
5/3/2016
0.00505
48.29533
-122.4885
PSEMP_LT-209R
5/3/2016
0.0051
48.29533
-122.4885
EAST OF
6/13/2008
0.0051
47.894683
-122.362001
PSAMP_SP-1807
6/18/2014
0.0051
47.950305
-122.465638
PSAMP_SP-3343
6/18/2014
0.0051
47.976061
-122.50084
PSAMP_SP-2319
6/18/2014
0.0051
47.97828
-122.483775
PASSAGE
POSSESSION PT.
POSSESSION PT.
42
PSAMP_SP-2319
6/18/2014
0.0051
47.97828
-122.483775
PSAMP_SP-2831
6/18/2014
0.0051
47.961127
-122.487157
PSAMP_SP-1571
6/19/2014
0.0051
47.959997
-122.501224
POSSESSION
6/1/2009
0.0052
47.939653
-122.336727
PSEMP_LT-40015
4/22/2019
0.00533
48.08877563
-122.448545
USELESS BAY
6/30/1998
0.0054
47.96341
-122.50795
USELESS BAY
6/30/1998
0.0054
47.98152
-122.50338
USELESS BAY
6/30/1998
0.0054
47.98152
-122.50338
USELESS BAY
6/30/1998
0.0056
47.96341
-122.50795
PSEMP_LT-19
4/27/2016
0.00565
48.09792
-122.47134
SKAGIT BAY
7/2/1997
0.0057
48.30833
-122.49163
PSEMP_LT-19
4/27/2016
0.00585
48.09792
-122.47134
SKAGIT BAY
7/2/1997
0.0065
48.26747
-122.51675
SARATOGA
6/30/1997
0.0068
48.11163
-122.49257
SKAGIT BAY
7/2/1997
0.007
48.27085
-122.54587
SKAGIT BAY
4/1/1991
0.0075
48.29533
-122.4885
PORT SUSAN
6/23/1997
0.0078
48.16963
-122.4178
PORT SUSAN
6/23/1997
0.0079
48.16963
-122.4178
SARATOGA
6/6/2007
0.0092
48.15079
-122.54696
SOUND
PASSAGE
PASSAGE
43
SARATOGA
6/6/2007
0.0094
48.139553
-122.544899
SARATOGA PASS
6/11/2007
0.0094
48.067587
-122.449544
HOLMES HARBOR
6/6/2007
0.0096
48.043554
-122.51557
SARATOGA PASS
6/11/2007
0.0096
48.041723
-122.378578
SARATOGA PASS
6/5/2007
0.0097
48.237088
-122.63562
SKAGIT BAY
6/5/2007
0.0099
48.291669
-122.486003
HOLMES HARBOR
6/6/2007
0.0099
48.036152
-122.526755
SARATOGA PASS
6/11/2007
0.0099
48.108076
-122.451612
SARATOGA PASS
6/11/2007
0.0099
48.0584
-122.417132
PORT SUSAN
4/1/1992
0.01
48.17317
-122.45775
USELESS BAY
4/1/1992
0.01
47.98517
-122.49149
OAK HARBOR
7/3/1997
0.01
48.28528
-122.6372
SKAGIT BAY
6/5/2007
0.01
48.275939
-122.520873
CRESENT HARBOR
6/5/2007
0.01
48.286562
-122.579053
SARATOGA PASS
6/5/2007
0.01
48.231155
-122.583858
6/5/2007
0.01
48.200165
-122.548387
6/6/2007
0.01
48.178308
-122.575625
6/6/2007
0.01
48.107718
-122.56206
PASSAGE
(NORTH)
(NORTH)
SARATOGA
PASSAGE
SARATOGA
PASSAGE
HOLMES HARBOR
44
HOLMES HARBOR
6/6/2007
0.01
48.062865
-122.520724
POSSESSION
6/7/2007
0.01
47.989157
-122.343898
PORT SUSAN
6/8/2007
0.01
48.168488
-122.41852
SARATOGA PASS
6/11/2007
0.01
48.067092
-122.443248
PORT SUSAN
6/11/2007
0.01
48.057499
-122.35367
PENN COVE
7/1/1997
0.011
48.23615
-122.6658
MOUTH OF PENN
7/1/1997
0.011
48.24283
-122.62218
OAK HARBOR
7/3/1997
0.011
48.28528
-122.6372
OAK HARBOR
7/3/1997
0.011
48.2839
-122.63665
POSSESSION
6/7/2007
0.011
48.001263
-122.352855
PORT SUSAN
6/8/2007
0.011
48.117441
-122.399167
SARATOGA
6/24/1997
0.012
48.05778
-122.39025
7/1/1997
0.012
48.23717
-122.58813
6/30/1997
0.013
48.2228
-122.55915
7/1/1997
0.013
48.23168
-122.69357
SOUND
COVE
SOUND
PASSAGE
NORTHERN
SARATOGA
PASSAGE
SARATOGA
PASSAGE
PENN COVE
45
SOUTH OF OAK
7/2/1997
0.013
48.2558
-122.64643
OAK HARBOR
4/1/1991
0.015
48.25617
-122.625
SARATOGA
4/1/1991
0.015
48.09792
-122.47134
PORT SUSAN
4/1/1991
0.015
48.17317
-122.45775
WEST BEACH,
4/1/1991
0.015
48.39933
-122.671
6/30/1997
0.015
48.06138
-122.42585
OAK HARBOR
4/1/1993
0.016
48.25617
-122.625
SARATOGA
6/30/1997
0.016
48.13888
-122.5436
PENN COVE
7/1/1997
0.016
48.22472
-122.71052
PORT SUSAN
4/1/1993
0.018
48.17317
-122.45775
SARATOGA
4/1/1993
0.019
48.09792
-122.47134
PORT SUSAN
4/1/1989
0.02
48.17317
-122.45775
OAK HARBOR
4/1/1990
0.02
48.25617
-122.625
SARATOGA
4/1/1990
0.02
48.09792
-122.47134
4/1/1992
0.02
48.25617
-122.625
HARBOR
PASSAGE
WHIDBEY ISLAND
SARATOGA
PASSAGE
PASSAGE
PASSAGE
PASSAGE
OAK HARBOR
46
SARATOGA
4/1/1992
0.02
48.09792
-122.47134
4/1/1992
0.02
48.08833
-122.55051
OAK HARBOR
4/1/1989
0.026
48.25617
-122.625
SKAGIT BAY
4/11/1994
0.027
48.29533
-122.4885
SARATOGA
4/1/1989
0.036
48.09792
-122.47134
4/1/1990
0.06
48.17317
-122.45775
PASSAGE
HOLMES HARBOR,
WHIDBEY ISLAND
PASSAGE
PORT SUSAN
mg/kg
Figure 15. Histogram of Aroclor 1260 concentrations of DOE Puget Sound benthic sediment
data (1989-2019) by Van Veen grab sampling (Washington Department of Ecology 2021)
47
generated by Social Science Statistics. For reference, the value of Aroclor 1260 observed in this
study is 2.1 mg/kg.
Figure 16. Survey sample collection sites (collection sites = black diamonds, high observed
value = yellow diamond) and hot spots (blue = low, purple = medium, red = high, yellow = very
high) of Aroclor 1260 concentrations from DOE Puget Sound benthic sediment data. Generated
with ArcGIS.
48
Conclusion
In conclusion, the current Unusual Mortality Event (UME) and overall increase in
Eastern Pacific gray whale stock strandings continue without an identifiable source(s). Of the
many hypotheses proposed, the contamination and pollution of marine benthic sediments, and
their communities, remains in the forefront. Benthic sediments are important biogeochemical
sinks for substances, and the unique feeding strategy of the Eastern Pacific gray whale may
therefore predispose them to an exceptional risk for contamination and mortality. The
concentrations of PCBs in the form of Aroclor 1016 (Sample ID# 5 = 1.7mg/kg) and Aroclor
1260 (Sample ID# 5 = 2.1mg/kg) taken from a known gray whale feeding site, which is visited
almost annually, raise concerns of potential soil and groundwater contamination. The
concentrations of Al detected in this study (Sample ID #3 = 6,720 mg/kg, Sample ID# 4 =
6,170mg/kg, Sample ID# 5 = 6,610 mg/kg, Sample ID# 6 = 692 mg/kg) also raise concerns of
potentially hazardous metals detected for unrestricted land use. The continued anthropogenic
altering of oceanic chemistry, and increased acidification of our oceans, may lead to an increased
release of benthic heavy metal compounds, such as Al. There is currently no known toxicology
of Al, Hg, and PCBs to either gray whales or their ghost shrimp prey. Further research into these
topics is needed to continue to understand and support the viability of these key species.
49
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54
Appendix
Combined Lab Results
Near-shore sediment sampling period (1) February 2021
55
56
57
Near-shore & ghost shrimp specimen sampling period (2) April 2021
58
59
60
61
62
63
64
