A Shared Fate

Introduction
Toxins In Marine Mammals An Impending Global Catastrophe
Dolphins Are Not Food - Health Consequences for Japanese Consumers
Cancer In Dolphins - An Emerging Threat
Multiple Myeloma in Dolphins
POPs Fact Sheet
Mercury Fact Sheet
The Inability Of Dolphins To Metabolize Certain PCBs
CYP1A1 - A Telltale Gene
The Striking Similarity Between Human and Dolphin Genomes
The International Myeloma Foundation Identifies Potential Link Between Genetic Pathways And Environmental Risks For Myeloma
New Bioaccumulations of Toxins in Resident Coastal Dolphins Signal Dangers of Human Myeloma
Multiple Myeloma, Clusters, Clues and Dioxin

INTRODUCTION

The growing presence of toxic chemicals in the marine environment presents a crisis unlike any ever faced on this planet. Vast quantities of toxic chemicals enter the waterways and oceans of the world each day and accumulate then bio-magnify in the marine food chain. In a time when we have reduced the number of large pelagic fish by ninety percent and the bio-mass of the oceans by seventy percent, we are poisoning much of the living marine resources that remain. This has staggering global implications for ocean life and human health.

A level of 100 ppm of mercury has been found in a bottlenose dolphin killed for food in Japan – a level more than 100 times that accepted by Japanese health authorities

There are many ways by which humans absorb, ingest or inhale dangerous chemicals. We intend to show in this report that fish, contaminated by organochlorines and heavy metals, are a newly recognized delivery system for chemicals which may cause a range of negative impacts on human health, including cancer, suppressed immune function and endocrine disruption which affects fertility.

Dolphins, toothed whales, large tuna and swordfish are among the marine creatures with highest levels of contamination because they feed at the apex of the food chain.

This report will document many, but by no means all, the locations where chemical toxicants have been found in marine mammals. Marine mammals feed at the top of the ocean food chain and thus are sentinels of the health of the waters in which they swim. Because humans eat many of the same fish as marine mammals we are well advised to be aware of the plight of marine mammals around the world. We are only one step removed from them only because we eat fewer fish than they.

Those eating marine mammals are leveraging the concentrations of toxins they ingest – a top predator (human) eating another top predator (a dolphin). We document the levels of contaminants in dolphins killed and eaten at Taiji, Japan. This is among the last of the villages where dolphins are hunted and where the meat is commonly eaten. We find that to have to use evidence of contamination levels in dolphins as a way of ending one of the most barbaric hunts of wild animals on earth to be tragically ironic.

One dolphin eater at Taiji was found to have more than 30 ppm of mercury in his body. A medical specialist advised that he be hospitalized immediately.

Though industrialized nations banned many persistent organic pollutants (POPs) three decades ago, their persistence plagues marine mammals and, increasingly, human beings worldwide. Today overwhelming evidence indicates that heavy metals such as mercury and persistent organic pollutants such as polychlorinated biphenyls (PCBs), dioxins and more recently PBDEs (flame retardants) have an adverse impact on reproductive health, immune and endocrine function and are carcinogenic for marine mammals and human beings.

Carcinogens are present in the environment of the St. Lawrence Estuary Belugas. Sediments of the Saginaw River, part of Beluga habitat, contain 500 – 4500 ppb of total PAHs dry weight.

Scientists have been finding higher and higher levels of man-made chemicals in marine mammals.In recent years marine mammals have been victims of mass mortalities and alarming population declines. These events have caused marine mammal science to expand their studies of the impact of chemically induced immune suppression, which is emerging as a contributing factor in epizootic events, condemning marine mammals to death from viral agents that are common in the environment and normally harmless.

During the late winters of 2007 and 2008 in two separate unusual mortality events (UME) more than two hundred bottlenose dolphins washed ashore near Galveston, Texas. The cause of this UME is as yet unknown.

In a report that stunned many, the February 2008 issue of Science reported, “The impact of humans has now reached every square mile of earth’s oceans and strongly impacted 40% of marine ecosystems. The implications are ominous for ocean creatures and humans alike. “

Some 100,000 synthetic chemicals are in use today around the world with another 1,000 being introduced into the environment each year. More than 90% have never been tested for their effects on human health. There is abundant evidence that many of these chemicals have serious, even deadly impacts on wildlife and humans.

Chemicals enter the marine environment in many ways – fertilizer run off and use of pesticides in agriculture and home gardening and maintenance; industrial waste, dumping and airborne emissions, even chemicals such as flame retardants used in everyday products are carried around the globe by wind and ocean currents.

San Francisco Bay harbor seals have some of the highest levels of PBDEs ever recorded. A doubling time of 1.8 years was reported in blubber of harbor seals from San Francisco Bay between 1989 – 1998.

The contaminants in our waters are not limited to heavy metals and organochlorines. When drinking water for some 41-million Americans was tested by the Associated Press during 2007, pharmaceuticals were found in alarming quantities. Those reported include antibiotics, mood stabilizers and six hormones. Tests were conducted in the nation’s 50 largest cities and smaller water providers in all 50 states.

A major focus of BlueVoice.org’s work is to identify the locations in which marine mammals have displayed high levels of toxic chemicals or been victims of anomalous mortality events. In many of these areas, we see human cancer clusters. We are collaborating with experts in human medicine to identify correlates between contamination in marine mammals and diseases, including cancers, in humans.

Scientists working at Texas A & M have found that the dolphin genome and the human genome as “basically the same.”

Dr. Gregory Bossart of the Harbor Branch Research Institute and his
colleagues have found orogenital neoplasia in Atlantic bottlenose dolphins in Florida. Lingual papillomas and squamous cell carcinoma and genital papillomas have also been found in Indian River dolphins.

It is important to remember that clean fish are an important component of a healthy diet, providing Omega 3 fatty acids and many other benefits. But that is ONLY TRUE if the fish are relatively free of contamination. While fish with high levels of Omega 3 fatty acids are regarded at heart healthy, they are not so when they contain high levels of mercury which disrupts the nervous system’s control of the heart. They then become a serious detriment to the hearts of both humans and marine mammals.

In the spring of 1987 bottlenose dolphins began washing up on the coast of New Jersey. This enormous and highly alarming die-off of hundreds – perhaps thousands of dolphins – has never been satisfactorily explained.

The Center for Disease Control and Prevention conducts a large, ongoing survey that has found 148 chemicals in Americans of all ages, including lead, mercury, dioxins and PCBs.

Other scientists have detected antibacterial agents from liquid soaps in breast milk, infants’ cord blood and the urine of young girls. Estrogen excreted by women taking birth control pills has proven to alter the sex of fish. In 2005, the Environmental Working group found an average of 200 chemicals in the cord blood of 10 newborns, including carcinogens and neurotoxins.

Chemicals such as PCBs can be virtually undetectable in water but magnify exponentially up the food chain so that a top predator may have 25-million times the concentrations found in the water it lives in. These toxicants are lipophylic and concentrate in the fatty tissues of mammals.

Chemicals present in many pesticides, petroleum products, plastics, and products such as furniture, computers and baby’s clothing can disrupt the endocrinal or hormonal systems of mammals. These chemicals are known as xenoestrogens because they mimic the action of naturally produced estrogens.

Examples of hermaphroditism have been found in fish in the U.K. in Polar bears in Svalbard and alligators with diminutive penises have been reported in Florida.

Man-made chemical pollutants have now made their way into the deep-sea food web contaminating squids and octopods. These species are food for many deep-diving toothed whales and dolphins as well as other predators.

In a study to be published in the journal Marine Pollution Bulletin, Michael Vecchione of NOAA Fisheries’ National Systematics Laboratory et al report finding chemical contaminants in nine species of cephalopods.

“It was surprising to find measurable and sometimes high amounts of toxic pollutants in such a deep and remote environment,” Vecchione said. Among the chemicals detected were tributyltin (TBT), polychlorinated biphenyls (PCBs), brominated diphenyl ethers (BDEs), and dichlorodiphenyl-trichloroethane (DDT).

Cephalopods are the primary food for 28 species of odontocetes, the sub-order of cetaceans that have teeth and include beaked, sperm, killer and beluga whales and narwhals as well as dolphins and porpoises.

This report is part of an effort at prevention of cancers such as multiple myeloma and other B cell lymphomas – cancers that have been clearly proven to be caused by exposure to toxic chemicals. To date prevention of cancer has largely been ignored in favor of treatment.

We call on government to address the introduction of toxic chemicals into our environment in a manner diametrically opposite to the way we now do it.

At this time there is virtually no requirement for testing of chemicals before they are put into use. If public policy operated under a precautionary principle then any indication of harm, rather than retroactive proof of harm, would trigger regulatory action. Today chemicals can be put into the air, waterways, baby clothing and thus into the bloodstreams of all living creatures without prior proof that they are safe.

We make no pretense that the information in this document is exhaustive. Indeed it is merely suggestive of the dreadful crisis we face from heavy metal and organochlorine contamination of the environment. We invite additions, and if necessary, correction to this report.

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TOXINS IN MARINE MAMMALS AN IMPENDING GLOBAL CATASTROPHE

This paper documents some of the locations in which marine mammals have displayed high levels of toxic chemicals or been victims of disease or unusual mortality events. It is clear from both the severity and frequency of such events that marine mammals worldwide face major threats to their health and in some populations decline or extinction.

In addition to concern for the marine mammals and health of the oceans we are increasingly aware of the adverse impact high levels of toxins in the oceans are having on human populations, including mercury poisoning, endocrine disruption and cancer. We have launched a research project to identify areas around the world where marine mammals show high toxic levels in proximity to human populations that eat the same fish as those marine mammals.

We are collaborating with cancer specialists to identify correlations between contamination levels in marine mammals and cancers in humans who eat fish from the same area.

This is by no means a complete listing of relevant locations and events and we invite contributions to it.

CALIFORNIA
San Francisco Bay harbor seals have high levels of Polybrominated diphenyl ethers (PBDEs) – flame retardants. A doubling time of 1.8 years was reported in blubber of harbor seals from SFB between 1989 – 1998.

Jianwen She et al, of the Hazardous Materials Laboratory, California Department of Toxic Substances Control in 2002 analyzed samples from 11 archived harbor seals (Phoca vitulina Richardsi) from the San Francisco Bay and breast adipose tissue samples from 23 women. The levels of PBDEs in human tissue samples were in the low ng/g fat range, with PBDEs 47, 153, 154, 99, and 100 as the major congeners. Average ?PBDEs (86 ng/g fat) in these California women are the highest human levels reported to date. The PBDEs measured in harbor seal blubber were the same major congeners as those measured in the human tissues. PBDE 47 was the highest among all congeners measured in both human tissue and seal blubber samples. The concentrations of PBDEs in harbor seals in the San Francisco Bay have increased dramatically over the past decade, with current levels among the highest reported for this species.

Harbor seals can be used to identify regional contamination hotspots.

In California Sea Lions high levels of DDTs and polychlorinated biphenyls (PCBs) in blubber have been associated with cancer and reproductive failure. Substantial organochlorine (OC) burdens, especially DDTs, are transferred from female sea lions to their fetuses in utero.

Urogenital cancer is endemic in California sea lions (CSL). A gamma herpes virus has been identified in 100% of urogenital carcinomas in three different studies. There is a statistical association of cancer in females and the presence of beta hemolytic Streptococus. There is a statistical association between contaminants, particularly PCBs, and urogenital cancer incidence. Urogenital carcinomas in CSLs may involve interaction between a venereal herpes virus, bacterial flora and POPs.

Salmonella bacteria causes diarrhea in animals and humans. A number of fecal pathogens have been identified in California marine mammals. Salmonella prevalence averages 4% in sea lions, harbor seals. Elephant seals and sea otters, as well as many bird species. Marine Mammal Salmonella, Miller et al.

Harmful Algal Blooms (HABs) There is strong evidence that marine mammal strandings along the coast of California are caused by harmful algal blooms. One of the main culprits is domoic acid poisoning. Domoic acid is a powerful neurotoxin produced by a single-celled algae of the genus Pseudo-nitzschia. It accumulates in shellfish and fish that feed on the algae, such as anchovies and sardines.

Marine biotoxins resulting from HABs have been shown to be lethal to dolphins and other marine mammals that have ingested contaminated fish. HABs often involve brevitoxin, a neurotoxin produced by some species of dinoflagellate such as, Karenia brevis and Ptychodiscus brevis. Brevitoxin is associated with a growing number of 'red tide' events around the world.

In 1998, the first confirmed domoic acid poisoning of marine mammals occurred on the California coast. During a month long period, 70 California sea lions stranded along the central California coast near San Luis Obispo – all suffered from the clinical symptoms of the poisoning, which include head weaving, tremors and convulsions. The majority of the affected animals were adult females of which 50 percent were pregnant. No adult males were affected. Two years later a similar outbreak occurred in the same region when 187 sea lions stranded with the poisoning. More than half of the sea lions affected with domoic acid poisoning died in both instances.

The origin of the domoic acid responsible for this mortality event was a bloom of P. australis that developed in Monterey Bay in May of 1998. Anchovies collected during the peak of the bloom had high levels of domoic acid in their tissues. “California sea lions are high level predators, feeding on species that often enter the human seafood market such as anchovies, sardines, salmon and squid,” said Dr. Frances Gulland of the California Marine Mammal Center.

“These sub-lethal effects of domoic acid on California sea lions are likely to be similar to effects that could occur in humans if they were to be exposed to similar levels of this toxin by eating contaminated seafood.” – Dr. Frances Gulland

The Marine Mammal Center in Sausalito, California has been one of the leading organizations tracking the strandings of Sea Lions and aiding in their recovery and re-introduction to the wild.

Outbreaks continued in southern and central California waters with nearly 1,000 sea lions affected in 2005.

In 2007 blooms of algae which produce the neurotoxin domoic acid, first appeared in southern California early in the spring and then moved north along the Central Coast. Hundreds of seabirds and marine mammals died.

The domoic acid levels in Southern California have been even higher than those detected in Monterey Bay. Large numbers of marine animals have been affected, including dolphins.

In humans, consumption of seafood contaminated with the toxin causes amnesic shellfish poisoning.

1987-88 EAST COAST OF USA
Beginning in the spring of 1987 bottlenose dolphins began washing up on the coast of New Jersey. This enormous and highly alarming die-off of hundreds of dolphins (in reality the number of deceased dolphins is certainly vastly higher than the number of stranded dolphins would indicate. Many dolphins were lost at sea and never counted). The strandings progressed from New Jersey south along the Atlantic seaboard finally ending near Cape Canaveral, Florida in early 1988. By one estimate at least 2,500 dolphins were lost. Alarmingly high levels of contaminants were found in many of the stranded dolphins. After months of study an expert contracted by the US government concluded that the die-off was the result of red tide generated brevitoxin. Many scientists, pointing to the high levels of toxins in many of the dolphins necropsied, disputed this conclusion vigorously and called that finding a cover up.

FLORIDA
Sarasota Bay. Trace elements of methyl mercury have been found in bottlenose dolphins in this body of water. High brominated flame retardant (BFRs) concentrations have been detected in dolphins near urban Sarasota Bay and rural St. Joe Bay in the Florida panhandle. The presence of BFRs in all dolphin samples indicates contamination is wide spread.

Dr. Randy Wells is quoted in National Geographic Online as saying that although dolphin numbers in these waters have risen slightly over the last few decades, scientists are trying to understand why so many firstborn calves die: Less than a quarter live out their first year, compared with 70 to 80 percent of subsequent births.

One reason may be man-made pollutants and the transfer of chemical contaminants to calves through milk, according to Wells, a conservation biologist with the Chicago Zoological Society and director of the Mote Marine Laboratory for Marine Mammal and Sea Turtle Research in Sarasota. Since 1970, Wells has led the world's longest-running dolphin study.

Some dolphins in the Sarasota Bay area have pollutant levels among the highest ever recorded, according to Wells.

East Coast Florida through South Carolina. Several unusual mortality events have occurred in recent years increasing concern for the health of bottlenose dolphins along the east coast of the United States. The heavy metals Aluminium, Chromium, Manganese, Copper, Zinc, Arsenic, Selenium, Strontium, Rubidium, Molybdenm and Vanadium were all discovered in the tissues of dolphins. Levels in blood and skin are above levels thought to be harmful to health.

Indian River, Florida
Dr. Gregory Bossart of the Harbor Branch Research Institute and his colleagues have been studying dolphins and the ecology of the Indian River Lagoon (IRL) for nearly two decades. He has found orogenital neoplasia in Atlantic bottlenose dolphins. Lingual papillomas and squamous cell carcinoma and genital papillomas have also been found in dolphins of this body of water. Bossart’s may be the first report of genital papillomas in free ranging bottlenose dolphins from Atlantic coastal waters.

Comprehensive health examinations were conducted from 2003 – 2004 on 155 bottlenose dolphins during capture-release in the IRL and Charleston, SC (CHS). Some 30% of IRL dolphins had infectious diseases such as lobomycosis according to Dr. Bossart. Mucocutaneous neoplasia associated with novel papilloma and herpes viruses were documented in both populations.

The St. Lucie River which flows into the IRL carries significant quantities of agricultural runoff.

Necropsy and photo identification data on IRL bottlenose dolphins have shown a high prevalence of infectious and inflammatory diseases of the skin and other organs.

Mitchum and Bossart et al have compared OC pesticides, PCBs, PBDEs and polycyclic aromatic hydrocarbons (PAHs) levels in dolphins from the IRL and Charleston, SC (CHS). Mean concentrations of PCBs were similar in the two locations, highest in male dolphins and lowest in females of reproductive age. Total DDT was higher for CHS dolphins compared to IRL dolphins. CHS dolphins had higher PBDEs. The males had among the highest levels of this chemical ever found in marine mammals.

In an abstract entitled lobomycosis in Atlantic Bottlenose Dolphins from Indian River Lagoon, Florida, Reif et al report the presence of lobomycosis, a mycotic infection caused by a yeast-like organism, among bottlenose dolphins. The prevalence among the dolphins tested from the southern part of the IRL was 30%. “We report the emergence of a rare fungal disease in Florida bottlenose dolphins in epidemic proportions. Humans are also susceptible to Lacazia loboi, a yeast-like organism. “ The report went on to say that environmental stressors may contribute to the unusually high prevalence of the disease.

According to Dr. Greg Bossart, there is dolphin pox virus in the Indian River Lagoon. This doesn’t hurt the animal but points to pathological stress. 100% of IRL dolphins had pox versus the usual 2% found in dolphins in other locations.

Florida Panhandle
In 1999 and 2004 there were two unusual mortality events that took the lives of 227 dolphins in the area of St. Joseph’s Bay. The average number of dolphins that strand along the panhandle per year is eight.

More than 103 dolphins died in St. Joseph's Bay and the surrounding area in Florida beginning March 10, 2004. NOAA Fisheries declared an Unusual Mortality Event for the panhandle on March 17. Several forms of algae were found in the surrounding waters. In addition, preliminary results showed domoic acid (a biotoxin produced by Pseudo-nitzschia) and brevetoxin (a biotoxin produced by Karenia brevis) in samples taken from the dolphins.

Dolphin carcasses that were located (many were not) had been dead for an extended period prior to recovery making tests for cause of death difficult. Preliminary results on dolphin tissues from the initial event indicated the following:

Florida Marine Research Institute (FMRI) scientists detected high concentrations of brevetoxin in dolphin tissues (stomach, liver, kidney, lung, cerebellum) and fluids (blood, urine); the highest concentrations of brevetoxins were found in the animals' stomachs.

The time period for the unusual mortality event (March – April) corresponds to the timing of similar mortality events in Texas.

Immune panels suggest a high level of parasitic infection and/or compromised immune response in the St. Joseph Bay population of bottlenose dolphins.

Florida, general
The EPA has listed 16 polycyclic aromatic hydrocarbons (PAHs) as priority pollutants because of their carcinogenic effects on aquatic organisms. PAHs have been found around electricity generating plants and in ports in Florida.

Recently manatees have shown symptoms characteristic of PAH accumulation: e.g. impaired immune response, prolonged healing times, and eye pathology.

CHARLESTON, SC (CHS) (See Indian River, Florida for paired studies)
CHS dolphins have a higher levels of persistent chemicals, including emerging chemicals such as perflourinated compounds and PBDEs and higher levels of resistance to antibiotics (70%) than IRL dolphins.

Perflourinated compounds (PFAs) are persistent, bio-accumulating contaminants used in stain repellants, paper protectors, paint and polishes. High concentrations have been detected in plasma of dolphins in Charleston, SC and Delaware Bay, NJ.

Antibiotic resistant E.coli were found in wild dolphins in Florida and South Carolina. The widespread use of antibiotics in humans, pets and agriculture may lead to the development of multi-drug resistant bacteria. Most antibiotics tested have been shown to be persistent. Resistant genes are readily transmitted creating the potential for establishment of resistant bacteria within aquatic life. The most common bacteria to which dolphins were resistant were Ampicillin, Amoxicillin, Penicillin, Cephalothin, Cefoxitin, Erythromycin, Trimethoprim, Sulphiazol, and Osytetracycline. Aquatic Mammals, 1/1/07, Bemiss, Bossart, et. al.

When drinking water was tested by the Associated Press for some 41-million Americans, pharmaceuticals including antibiotics, mood stabilizers and sex hormones were found. Tests were conducted in the nation’s 50 largest cities and smaller water providers in all 50 states.

Rehtanz, Bossart et al reported in 2005 the first known case of cetacean papilloma virus has been detected in a bottlenose dolphins at CHS.

GULF OF MAINE
Susan Shaw, founder of the nonprofit Marine Environmental Research Institute (MERI) in Blue Hill, Maine, which conducts scientific research and education on the impacts of pollution on marine life reported findings at the Marine Mammal Society Conference in Cape Town, South Africa in December, 2007. Her research on northwestern Atlantic harbor seals shows that toxic chemical levels, especially in pups, are as high as any in the world.
According to Dr. Shaw, “Over the past three years this population has experienced recurring disease outbreaks and high mortality rates. While the specific disease agent is unclear, our studies show that these seals carry high levels of PBDEs, PCBs, and other chemicals in their tissues that may be compromising their immune responses.”

This population is affected by recurring epizootics and mass mortalities. Some of the young seals are carrying up to 4-thousand ppm of PBDEs in fatty tissues. PCB levels are as high as 60 ppm in the young animals.

Their toxic equivalency for Dioxin like toxicity is also fairly high in the 200 ppt lipid weight range. Also high levels of polyflourinated compounds have been found in these seals.

CAPE MAY, NJ
Hepatic panels suggest impaired liver function for many dolphins sampled near Cape May, NJ

TEXAS
Unusual mortality events have occurred along the Texas coast with alarming frequency. Most recently in 2007 and 2008 during March and April. In 2008 116 bottlenose dolphins were recovered in the Galveston area. Because the dolphins were generally in a state of advanced decomposition when found the cause of death could not be attributed. However there was no indication the deaths were the result of fisheries interaction. Traces of domoic acid were found in the three freshest dolphins from 2007. D. Cowan, a pathologist with the Texas Marine Mammal Stranding Network, suggested that brevitoxin was involved and warned that this could be harmful to humans.

WESTERN NORTH ATLANTIC AND GULF OF MEXICO
The brominated flame retardant (BFR) and hexabromocyclodocane (HBCD) are products still in use with environmental release levels rivaling that of PCBs prior to its discontinuation. PBDEs are toxicologically similar to PCBs, which were banned decades ago, though little is known about HBCD toxicity. PBDE concentrations are ten-fold greater and increasing more rapidly in Americans than in Western Europe where many of the brominated chemicals have been banned.

WASHINGTON, SEATTLE
The killer whales inhabiting Puget Sound and surrounding waters are some of the best-known and most beloved marine mammals on earth. The identities of all members of the pod are known; in some cases the family tree can be identified going back decades.

These orca may also be the most contaminated marine mammals on earth. And from 1995 – 2000 ten of the males in J, K, and L pods died. While there is no absolute proof that they died from contaminants such as PCBs, their carcasses did contain astronomical levels of these deadly toxins.

According to Dr. Ken Balcomb, “We’ve attributed most of the mortality to the PCB levels in the tissues. Their immune systems are depressed, much like AIDs, so they don’t defend themselves against common bacteria. And also their reproductive systems don’t develop.” Females survive better than males because when a mother orca nurses her calf she offloads huge amounts of chemicals such as PCBs that are stored in her lipid rich milk. Often first-born calves do not survive. But second and third born survive after the mother is unburdened of much of her toxic load.

Flame retardants used worldwide in manufacturing vehicle parts and computers have been found in Puget Sound orcas. Traces of industrial strength fire retardant have also been detected in wild and farm raised salmon.

Harbor seals in Puget Sound carry seven times the levels of PCBs as their counterparts in the Straights of Georgia, BC, Canada. Levels of PBDEs are approaching those of PCBs, indicating a significant new chemical concern for these marine mammals.

EASTERN NORTH PACIFIC
Using blubber and remote biopsy samples, organochlorine profiles were correlated to the prey species of three different groups of killer whales – resident fish eaters, transient mammal eaters and offshore animals that consume large pelagic fish. Resident fish eaters had low OC contamination in relation to transient killer whales. OC results for some offshore killer whales were high, even though they eat fish. This suggests they eat high trophic level species such as shark or tuna which bio-accumulate contaminants over long lifetimes.

NORTH PACIFIC OCEAN
Stellar sea lions have undergone a drastic decline in population over the past three decades, which has led to their being listed as endangered. The precise reason for this decline is unknown. However PCBs are present in high concentrations in the environment. High concentrations of POPs have been found to cause adverse affects in the reproductive and immune systems of marine mammals. According to Hulck et al in Persistent Organic Pollutants in Blubber of Male Stellar Sea Lion from Different Locations in the Northern Pacific Ocean, “Our hypothesis is that the Stellar sea lion population decline or the failure to recover is due to long term exposure to POPs. The decine may also be the result of translocation of their prey species due to changes in water temperature.”

PBDE compounds were found in blubber from seals harvested in the Bering Sea subsistence harvest in Alaska. Due to their recent introduction PBDEs are a relatively recent suite of chemicals for concern. Their chemical structure is similar to PCBs and they are thought to be disruptive of thyroid function. Results indicate that lower brominated congeners of PBDEs are present in the Bering Sea environment. From PBDE Compounds in Blubber from Bering Sea Sussistence Harvest of Ice Seals In Alaska, Quackenbush.

CANADA
St. Lawrence Estuary (SLE) Belugas: The Beluga population has dropped from an estimated 5,000 to a current estimate of 500-600. The SLE Belugas were protected from hunting by the Canadian government starting in 1980 but so far have shown no sign of recovery.

SLE Belugas are contaminated by PAHs. Levels of epithelial cancer of the proximal intestine, gastric cancer, gastrointestinal epithelial cancer, and mammary cancers are high in SLE Beluga.

This is consistent with the hypothesis that PAHs are involved in the etiology of cancer in these animals. Cancer of the proximal intestine is rare among all species including humans except in circumstances where the animal has been exposed to pesticides.
It is frequent in bovine and ovine species exposed to herbicides such as 2,4-dichlorophenoxyacetic acid. An interaction between a virus and environmental carcinogenic compounds may be at work in the SLE Belugas. Particles consistent with papilloma viruses have been observed in a significant number of carcasses. Other carcinogens are present in the environment of the SLE Belugas. Benzopyrene has been found in high concentrations in blue mussels after transplantation into the Saguenay River, part of the Beluga habitat. Sediments of the Saguenay River contain 500 – 4500 ppb of total PAH dry weight, a concentration level significantly higher than Osaka harbor where PAH concentrations are 2870 ppb. These chemicals originate from upstream Aluminum smelters. SLE Belugas feed in sediments. These observations suggest that SLE Belugas ingest PAHs in benthic invertebrates (those living at the deepest water level and in sediment) that may contribute to the elevated rate of digestive tract cancers in the population. Martineau et al.

Martineau in Cancer in Wildlife reports “The rate of cancer in the SLE Beluga population is higher than in any other population of wild terrestrial or aquatic animals”.

Cancer was observed in 27% of adult animals found dead, a percentage similar to that found in humans. A cancer rate of 163 per 100,000 animals is much higher than in domestic animals and humans. Environmental toxins are thought to be a precipitating factor in these cancers. Thirty per cent of cancers affecting SLE beluga are found in the intestine, close to the stomach.

The human population living in this area is afflicted by rates of cancer higher than found in other parts of Quebec and Canada in general. Some of these cancers are epidemiologically related to PAHs.

The SLE Beluga are also contaminated by heavy metals, PCBs, DDT, and their metabolites, which can, in some cases be more toxic than the original chemical.
Gastrointestinal epithelial cancers were the most frequent found in beluga in the SLE. Martineau, Environmental Health Perspectives

Cetaceans have high levels of CYP1A and low levels of CYP2B. SLE belugas have elevated levels of both enzymes, probably because CYP are induced by high levels of PCBs.” Elevated CYP1A levels may trigger intestinal cancer by activating ingested PAHs into carcinogenic compounds.” Martineau Environmental Health Perspectives 3/2002

PBDEs were determined in blubber samples of 54 stranded adult beluga whales between 1988 and 1999 in the St. Lawrence Estuary. The accumulation of PBDEs in belugas showed exponential increase throughout the time period. Increasing levels of PBDEs have been reported in human milk during thi