Toxins
Toxins
How safe is it to eat fish from Puget Sound? As avid Pacific Northwest diver and fisherman, I have struggled with this very question for years. I’m not going to answer this question for you - you need to make your own decision. But what I will do is present some data and resources I have uncovered over the last 5 year on this topic. Please keep in mind that I am not a marine biologist or environmental scientist.
I used to fish in Puget Sound and the San Juan Islands when I was a kid. I got a lot of satisfaction providing my family a meal of rockfish, sole, lingcod, or perch on many a summer weekend. I became a salmon fisherman in early adulthood and did very well in the Puget Sound area for coho, chinook, and blackmouth salmon (young resident chinook). I thought I would be a big lingcod and rockfish spear fishermen when I started diving in 1996. After being in the water with these magnificent creatures, I quickly came to admire them and could not bring myself to hunt them underwater. I did continue to salmon fish for a number of years until I found some rather telling research on the Internet in 2003 regarding toxicity of Puget Sound blackmouth and adult chinook salmon. That study pretty much ended my Puget Sound salmon fishing activities.
This study was conducted by the Washington Department of Fish and Wildlife Puget Sound Ambient Monitoring Program. It revealed that Puget Sound salmon generally have elevated levels of PCBs stored in the lipids, or fatty body tissues. This report showed that chinook returning to the Duwamish River, which runs right though the heart of Seattle’s industrial area, scored the highest levels of PCBs for in-river salmon. Subsequent reports by the Puget Sound Ambient Monitoring Program confirmed Puget Sound salmon were burdened with PCB levels three to five times higher than other Pacific Northwest salmon and elevated levels of PBDEs. The high levels of these and other toxins in our local salmon have recently received public attention as our local orca population is currently on the decline, and toxins are considered one of several major culprits.
So why are toxins so bad?
Toxins are everywhere. All living bodies - fish, orcas and even yours and mine - are designed to deal with a certain level of toxins on a daily basis. The problem with toxins like PCBs and PBDEs is they are “persistent organic pollutants” (POPs), meaning that they do not break down in the environment. POPs also bioaccumulate - once they enter a living body, they generally stay in that body until that body dies. At that point the toxins either enter the body of the consuming entity, or if no consuming entity is involved, the toxins re-enter the sediments where they may eventually re-enter the food chain once they are consumed by species that filter sediment for organic matter. Then the cycle starts all over again. POPs are truly the gift that keeps on giving. Nice, huh?
These toxins accumulate in the fatty tissues (lipids) of animals. When you eat fish that has accumulated POPs over its lifetime, whatever POPs are in that piece of fish you eat become part you and are stored in your tissues. Mothers can actually purge some of these toxins from their bodies through breast milk, which is high in fat content. However, these toxins often end up in the mother’s breast-feeding young. The impact of these toxins upon young is still being researched.
Although there are literally dozens of toxins and heavy metals that are all problems in Puget Sound, most Puget Sound environments reports focus on one or two of the more pervasive POPs: PCBs and PBDEs
PCBs (polychlorinated biphenyl) were use in mass for a multitude of applications - everything from paints and adhesives to dielectric fluids for transformers. In the early 1970’s, high PCB levels were found in dead seabirds washing up on the east coast of the United States. Subsequent research on the adverse effects of PCBs on organisms established links between elevated PCB levels and impaired brain and immunity system development and certain cancers. Most modern countries have severely restricted or banned PCB production today. The US pretty much banned PCB production in 1976, but the damage was already done in many urban areas. Although quite a few areas around Western Washington are polluted with PCBs, the Duwamish Waterway tops the chart and was declared a Superfund cleanup site in 2000.
PBDEs (polybrominated diphenyl ethers) are currently the second most pervasive POP in northwest Washington waters, and may soon become the most pervasive. PDBEs were manufactured primarily as flame retardants and have been used in everything from furniture to automobiles to clothes. Like PCBs, PDBE’s continue to accumulate in the species ingesting the PDBE. Unlike PCBs, PDBEs can also find their way into organisms though inhalation. Because our homes are filled with goods made with PDBEs, this POP is prevalent in the dust in our homes. What is really concerning is children in the Pacific Northwest tend to have very high levels of PDBEs. PDBEs are also growing at an alarming rate in Pacific Northwest marine life. PDBEs are now known to cause liver, thyroid, and neurological toxicity and were not banned in Washington State until 2006.
Superfund clean-up sites
There are many ways toxins got into our environment. Many of them were discharged into our local waterways by industry. Some areas have become so inundated with these toxins that they are recognized by our federal government as “superfund cleanup sites” and received federal funding for the cleanup effort. Such sites throughout Puget Sound including Tacoma’s Commencement Bay and Eagle Harbor on Bainbridge Island. The most publicized site in our area is Seattle’s very own lower Duwamish Waterway which feeds into Elliot Bay. More than $70M has been spent on the Duwamish clean-up so far, however PCBs and many other toxins are still as prevalent as ever. These PCB came from industries that used the Duwamish Waterway as a chemical dumping ground through most of the 1900s. Companies such as Boeing and Weyerhaeuser have been implicated in contributing to this mess, but endless legal debates continue to rage regarding these and other companies actual involvement in this environmental catastrophe.
Toxins in salmon and tuna
Like tuna, salmon world-wide are carrying higher level of toxin and/or heavy metals than from decades past. Most salmon spend the majority of their growing cycle in open ocean where food is more plentiful. A six inch chinook smolt weighing several ounces may head to the ocean and return as a 50 pound mature adult only four years later. However, it is in these open oceans that tuna, salmon, and other fish are accumulating the majority of the toxins and heavy metals. How we treat our urban waterways is having a dire affect on fish that may never even come close to an urban area, such as tuna. As you probably know, some agencies already warn against consuming too much tuna due to elevated mercury content. What you might not know if there are similar warnings for Puget Sound salmon, groundfish, and shellfish.
Puget Sound salmon
The first study I saw regarding Puget Sound salmon was conducted in 1998 by the Puget Sound Ambient Monitoring Program. The report was entitled “Spatial Trends in the Concentration of Polychlorinated Biphenyls (PCBs) in Chinook (Oncorhynchus tshawytscha) and Coho Salmon (O. kisutch) in Puget Sound and Factors Affecting PCB Accumulation: Results from the Puget Sound Ambient Monitoring Program”. I can’t find this report online anymore, but the WDFW can forward it to you upon request. I also have a copy that I can forward you.
This detailed report analyzed “marine” and “in-river” chinook and coho salmon from a number of different locations throughout the Puget Sound area. The report concluded that marine fish (those that are likely to spend their adult life in Puget Sound rather than go to the open ocean) had higher levels of PCBs than in-river fish (mature fish presumably returning from the ocean to spawn in our local rivers). Chinook, which have more fatty tissue than coho, also generally stored higher levels of PCBs. The telling stats from this report are as follows:
In-river Puget Sound chinook PCBs: 49 parts per billion (ppb)
Marine Puget Sound chinook PCBs: 74 ppb
In-river Puget Sound coho PCBs: 26 ppb
Marine Puget Sound coho PCBs: 35 ppb
What was really discouraging was of all the in-river chinook tested, a chinook from the Duwamish River took top “honors”, testing for PCBs at well over 70 ppb. While this might at first make sense since the Duwamish Waterway is one of the most PCB laden waterways in the US, returning salmon spend very little time in the heavily polluted section of this waterway (about a five mile stretch). They essentially pass through it when returning to spawn and tend to not even feed once they enter fresh water. Curiously enough, returning coho salmon from the Duwamish River did not have higher levels of PCB when compared to coho salmon from other Puget Sound rivers. However, all Puget Sound coho salmon tested for higher levels of PCB than coho from other areas of the Northwest.
The significance of this report for me was two fold. First, all Puget sound salmon have elevated PCB levels compared to fish from Alaska, Oregon, and British Columbia. But what was really telling was that those “marine” fish that tend to spend their life in Puget Sound were even more toxic than “traditional” salmon that spend a good part of their life in open ocean. Puget Sound is obviously adding to this toxicity in a significant way.
The Department of Health responded by issuing an advisor that Puget Sound chinook salmon should only be eaten three time a month, and Puget Sound coho salmon should only be eaten 4 times a month. Much later, the Washington State Health Department also added their recommendation in limiting the consumption of Puget Sound salmon to one a week.
Many other reports have been issued regarding the well-being of Puget Sound and surrounding waters since the 1998 study. One report completed in 2008 entitled PERSISTENT ORGANIC POLLUTANTS IN CHINOOK SALMON(ONCORHYNCHUS TSHAWYTSCHA): IMPLICATIONS FOR RESIDENT KILLER WHALES OF BRITISH COLUMBIA AND ADJACENT WATERS conducted a similar analysis of PCBs in salmon from different locations. This study looked at salmon from several rivers in Washington and Canada. In this study, the Duwamish chinook tested for PCBs at 35 ppb, significant lower than the 1998 research findings. Interestingly, chinook from the Deschutes River in tested much higher in this later study at 56 ppb. Even fish from the lower Frazer River in Canada tested relatively high for PCBs at 49 ppb. As a comparison, the more “pristine” chinook in Johnstone Strait off northern Vancouver Island tested for PCBs at 9 ppb.
PCB levels in our salmon appear to be correlated to the amount of time that the salmon spends in Puget Sound waters. Fish hatcheries have been motivated to produce salmon that spend their lives in Puget Sound rather than venture out to the ocean to bolster a year-round sport salmon fishing industry. Hatcheries can influence salmon to stay in local waters by delaying the release of fry. The longer a salmon fry is penned and held at a freshwater hatchery, the more inclined it is not to venture to the ocean. In talking with one of the Muckleshoot Indians years ago on the Duwamish waterway (I think it was around 2003), he told me that the Muckleshoot hatchery was seeing larger returns of bigger chinook by delaying the release of the fry. This would infer that these salmon spend less time in the ocean and more time feeding in PCB laden Puget Sound. I might add that Safeway currently holds the contract to purchase the majority of salmon netted by the Muckleshoots on the Duwamish River.
From a PBDE perspective, things even get worse. Puget Sound chinook salmon have 5 to 17 times the levels of PDBEs than other west coast salmon.
So what does this all mean for salmon? It is very hard to tell. Puget Sound salmon are undoubtedly polluted, and this pollution is having a dire impact not only on the salmon, but animals that feed predominately on Puget Sound salmon (like orcas). The two studies referenced above are based on limited datapoints - it would be interesting to see tests for PCBs done every year on 100 samples from each major river. However, that data is not available.
Note that most other meats and animal by-products also contain similar levels of PCBs. Butter is one of the worst offenders and is listed at 70 ppb. However, eggs, chicken, pork, and steak all contain PCB levels ranging from 9 to 32 ppb. With levels not vastly different from most Puget Sound salmon, why hasn’t the Department of Health issued similar advisories recommending the restricted consumption of these foods? Is it because of the other toxins? It is indeed difficult to determine the truth and right course of action.
Toxins in groundfish
Groundfish are basically the resident food fish in our area that tend to stay in Puget Sound on or near the bottom. This category includes, flounder, sole, rockfish, lingcod, sculpins, and others. Unlike salmon, groundfish species tend not to be as nomadic. These fish tend to take up residency in an area and stay there for a long time - often their entire life. Sometimes they migrate from area to area seasonally, but most groundfish in Puget Sound tend to stay in Puget Sound most of their life. As an example, I have been visiting the same pair of rosy rockfish within 10 yards of the same rock during summer at a dive site in the Cape Flattery area for more than six years now.
This residency can work for or against the groundfish. If the resident has selected a pristine area and feeds on the invertebrates and small fish which also inhabit this are, toxin levels will most likely be very low - maybe even nil. However, if the fish takes up residence in a toxin superfund site, it will ultimately be dining on creatures that have ingested the toxins from the sediments. Even though these fish generally do not have as much fatty tissues as salmon to store the toxins, they do tend to accumulate extraordinarily high levels of PCBs, PDFEs, and other toxins and heavy metals. Please note that Washington State has declared that no one should eat ANY groundfish or invertebrates from the Duwamish River area.
Because there are over 100 species of groundfish in our area, groundfish studies are conducted on one of several representative species. The robust and every abundant English sole is one of those representative species that gets more than its fair share of disection and analysis. The Puget Sound Partnership has conducted extensive testing and monitoring of English sole in what they call “urban” and “non-urban” areas. As you might guess, urban areas are shorelines adjacent industrial, commercial, and heavy residential areas - basically most of the eastern shoreline of Puget Sound. The Puget Sound Partnership states that English sole living in urban areas have 10 times the PBDE levels as non-urban English soles. Even Puget Sound herring, a stable for salmon and many other Pacific Northwest species including seals and certain whales, have PBDE levels three times greater than what is considered normal.
Another prevalent toxin, PAHs (polycyclic aromatic hydrocarbons), are found at elevated levels in resident fish and invertebrates throughout Puget Sound. Many PAHs are known cancer causing carcinogens. Crabs associated with urban areas had six times the PAHs as non-urban areas. English sole associated with urban areas had 4 times the PAHs as their non-urban counterparts.
There are literally dozens of other toxins and heavy metals that are being tracked in Puget Sound. What we don’t know is how many other man-made contaminants are adversely impacting our local marine life. The Puget Sound Partnerships estimates that about 35% of the sites in Puget Sound currently have some level of sediment degradation, with about 1% being high degraded.
The bottom line is that most of the commercially important species of groundfish in Puget Sound have all but disappeared or are in sharp decline. I remember catching magnificent Pacific true cod in Puget Sound in the late 1970s off of Blake Island in central Puget Sound. The massive schools of Pacific true cod that once blessed our area are now a distant memory. Most of our native rockfish species are also struggling. A combination of pollutants, overharvest, habitat destruction, and warming water is having a negative impact on rockfish. Almost all species of rockfish in Puget Sound are now listed as endangered, threatening, or concerned. Rockfish egg yields are down by 75-90% from the 1970s. Pollution and toxins are the primary culprits. The same toxins that cause development and reproductive impairment and cancers in us have the same affect on the fish.
Top predators
POPs tend to gather in high concentrations in top predators. Current analysis by the Puget Sound Partnership states that Puget Sound’s southern resident orcas have PCB levels of 150 ppb for males and 50 ppb for females. Over 90% of the diet for a southern resident is salmon, and chinook salmon are preferred. The report also cites a study of sea pups of Gertrude Island in southern Puget Sound where PBDE levels have skyrocketed in the last twenty years and now reached levels in excess of 1000 ppb. Keep in mind that humans are also a top predator.
What to do
What you decide to do with this data is up to you. I have decided not to eat any groundfish from Puget Sound - not just for toxicity reason, but also based on the fact that most “table food” species in our areas are really struggling.
I keep going back and forward on salmon, but have pretty much abandoned salmon fishing. Toward the end of my salmon fishing careers, I targeted fish on the coastal rivers. However, current salmon stocks are decimated and need serious time to recover. I would personally like to see a 10 year ban on all saltwater and salmon fishing in Washington State.
If you do decide to eat Puget Sound fish, there are two general rules published by the FDA to help mitigate associated risks with PCBs and other lipid-stored toxins:
Skin fillets before cooking. Salmon store fats directly underneath the skin. Trim this fat and the
belly fat off salmon fillets.
Cook the fillets in way that promotes the tissue fat to drip from the fillet, like BBQing.
You can reportedly reduce the PCBs in a piece of fish by up to 50% by simply following the two steps listed above.
References
If you would like to get a better perspective of our problem, I highly recommend the following publications (all of which were referenced in this commentary):
State of the Sound 2007 - Puget Sound Action Team, 2007
http://www.psp.wa.gov/downloads/SOS07/2007_stateofthesound_fulldoc.pdf
Persistent Organic Pollutants in Chinook Salmon: Implications for Resident Killer Whales of British Columbia and Adjacent Waters. - O’Neill et al. 2008
http://www.allenpress.com/pdf/ENTC_28.1_148.pdf
Spatial Trends in the Concentration of Polychlorinated Biphenyls (PCBs) in Chinook (Oncorhynchus tshawytscha) and Coho Salmon (O. kisutch) in Puget Sound and Factors Affecting PCB Accumulation: Results from the Puget Sound Ambient Monitoring Program. Pages 312-328 - O’Neill et al. 1998 I cannot find this report online anymore, but I can email it to you is you wish.
Newspaper article from the Seattle PI regarding Puget Sound and Columbia River salmon toxicity:
http://www.seattlepi.com/local/156714_warning15.html
I used to fish in Puget Sound and the San Juan Islands when I was a kid. I got a lot of satisfaction providing my family a meal of rockfish, sole, lingcod, or perch on many a summer weekend. I became a salmon fisherman in early adulthood and did very well in the Puget Sound area for coho, chinook, and blackmouth salmon (young resident chinook). I thought I would be a big lingcod and rockfish spear fishermen when I started diving in 1996. After being in the water with these magnificent creatures, I quickly came to admire them and could not bring myself to hunt them underwater. I did continue to salmon fish for a number of years until I found some rather telling research on the Internet in 2003 regarding toxicity of Puget Sound blackmouth and adult chinook salmon. That study pretty much ended my Puget Sound salmon fishing activities.
This study was conducted by the Washington Department of Fish and Wildlife Puget Sound Ambient Monitoring Program. It revealed that Puget Sound salmon generally have elevated levels of PCBs stored in the lipids, or fatty body tissues. This report showed that chinook returning to the Duwamish River, which runs right though the heart of Seattle’s industrial area, scored the highest levels of PCBs for in-river salmon. Subsequent reports by the Puget Sound Ambient Monitoring Program confirmed Puget Sound salmon were burdened with PCB levels three to five times higher than other Pacific Northwest salmon and elevated levels of PBDEs. The high levels of these and other toxins in our local salmon have recently received public attention as our local orca population is currently on the decline, and toxins are considered one of several major culprits.
So why are toxins so bad?
Toxins are everywhere. All living bodies - fish, orcas and even yours and mine - are designed to deal with a certain level of toxins on a daily basis. The problem with toxins like PCBs and PBDEs is they are “persistent organic pollutants” (POPs), meaning that they do not break down in the environment. POPs also bioaccumulate - once they enter a living body, they generally stay in that body until that body dies. At that point the toxins either enter the body of the consuming entity, or if no consuming entity is involved, the toxins re-enter the sediments where they may eventually re-enter the food chain once they are consumed by species that filter sediment for organic matter. Then the cycle starts all over again. POPs are truly the gift that keeps on giving. Nice, huh?
These toxins accumulate in the fatty tissues (lipids) of animals. When you eat fish that has accumulated POPs over its lifetime, whatever POPs are in that piece of fish you eat become part you and are stored in your tissues. Mothers can actually purge some of these toxins from their bodies through breast milk, which is high in fat content. However, these toxins often end up in the mother’s breast-feeding young. The impact of these toxins upon young is still being researched.
Although there are literally dozens of toxins and heavy metals that are all problems in Puget Sound, most Puget Sound environments reports focus on one or two of the more pervasive POPs: PCBs and PBDEs
PCBs (polychlorinated biphenyl) were use in mass for a multitude of applications - everything from paints and adhesives to dielectric fluids for transformers. In the early 1970’s, high PCB levels were found in dead seabirds washing up on the east coast of the United States. Subsequent research on the adverse effects of PCBs on organisms established links between elevated PCB levels and impaired brain and immunity system development and certain cancers. Most modern countries have severely restricted or banned PCB production today. The US pretty much banned PCB production in 1976, but the damage was already done in many urban areas. Although quite a few areas around Western Washington are polluted with PCBs, the Duwamish Waterway tops the chart and was declared a Superfund cleanup site in 2000.
PBDEs (polybrominated diphenyl ethers) are currently the second most pervasive POP in northwest Washington waters, and may soon become the most pervasive. PDBEs were manufactured primarily as flame retardants and have been used in everything from furniture to automobiles to clothes. Like PCBs, PDBE’s continue to accumulate in the species ingesting the PDBE. Unlike PCBs, PDBEs can also find their way into organisms though inhalation. Because our homes are filled with goods made with PDBEs, this POP is prevalent in the dust in our homes. What is really concerning is children in the Pacific Northwest tend to have very high levels of PDBEs. PDBEs are also growing at an alarming rate in Pacific Northwest marine life. PDBEs are now known to cause liver, thyroid, and neurological toxicity and were not banned in Washington State until 2006.
Superfund clean-up sites
There are many ways toxins got into our environment. Many of them were discharged into our local waterways by industry. Some areas have become so inundated with these toxins that they are recognized by our federal government as “superfund cleanup sites” and received federal funding for the cleanup effort. Such sites throughout Puget Sound including Tacoma’s Commencement Bay and Eagle Harbor on Bainbridge Island. The most publicized site in our area is Seattle’s very own lower Duwamish Waterway which feeds into Elliot Bay. More than $70M has been spent on the Duwamish clean-up so far, however PCBs and many other toxins are still as prevalent as ever. These PCB came from industries that used the Duwamish Waterway as a chemical dumping ground through most of the 1900s. Companies such as Boeing and Weyerhaeuser have been implicated in contributing to this mess, but endless legal debates continue to rage regarding these and other companies actual involvement in this environmental catastrophe.
Toxins in salmon and tuna
Like tuna, salmon world-wide are carrying higher level of toxin and/or heavy metals than from decades past. Most salmon spend the majority of their growing cycle in open ocean where food is more plentiful. A six inch chinook smolt weighing several ounces may head to the ocean and return as a 50 pound mature adult only four years later. However, it is in these open oceans that tuna, salmon, and other fish are accumulating the majority of the toxins and heavy metals. How we treat our urban waterways is having a dire affect on fish that may never even come close to an urban area, such as tuna. As you probably know, some agencies already warn against consuming too much tuna due to elevated mercury content. What you might not know if there are similar warnings for Puget Sound salmon, groundfish, and shellfish.
Puget Sound salmon
The first study I saw regarding Puget Sound salmon was conducted in 1998 by the Puget Sound Ambient Monitoring Program. The report was entitled “Spatial Trends in the Concentration of Polychlorinated Biphenyls (PCBs) in Chinook (Oncorhynchus tshawytscha) and Coho Salmon (O. kisutch) in Puget Sound and Factors Affecting PCB Accumulation: Results from the Puget Sound Ambient Monitoring Program”. I can’t find this report online anymore, but the WDFW can forward it to you upon request. I also have a copy that I can forward you.
This detailed report analyzed “marine” and “in-river” chinook and coho salmon from a number of different locations throughout the Puget Sound area. The report concluded that marine fish (those that are likely to spend their adult life in Puget Sound rather than go to the open ocean) had higher levels of PCBs than in-river fish (mature fish presumably returning from the ocean to spawn in our local rivers). Chinook, which have more fatty tissue than coho, also generally stored higher levels of PCBs. The telling stats from this report are as follows:
In-river Puget Sound chinook PCBs: 49 parts per billion (ppb)
Marine Puget Sound chinook PCBs: 74 ppb
In-river Puget Sound coho PCBs: 26 ppb
Marine Puget Sound coho PCBs: 35 ppb
What was really discouraging was of all the in-river chinook tested, a chinook from the Duwamish River took top “honors”, testing for PCBs at well over 70 ppb. While this might at first make sense since the Duwamish Waterway is one of the most PCB laden waterways in the US, returning salmon spend very little time in the heavily polluted section of this waterway (about a five mile stretch). They essentially pass through it when returning to spawn and tend to not even feed once they enter fresh water. Curiously enough, returning coho salmon from the Duwamish River did not have higher levels of PCB when compared to coho salmon from other Puget Sound rivers. However, all Puget Sound coho salmon tested for higher levels of PCB than coho from other areas of the Northwest.
The significance of this report for me was two fold. First, all Puget sound salmon have elevated PCB levels compared to fish from Alaska, Oregon, and British Columbia. But what was really telling was that those “marine” fish that tend to spend their life in Puget Sound were even more toxic than “traditional” salmon that spend a good part of their life in open ocean. Puget Sound is obviously adding to this toxicity in a significant way.
The Department of Health responded by issuing an advisor that Puget Sound chinook salmon should only be eaten three time a month, and Puget Sound coho salmon should only be eaten 4 times a month. Much later, the Washington State Health Department also added their recommendation in limiting the consumption of Puget Sound salmon to one a week.
Many other reports have been issued regarding the well-being of Puget Sound and surrounding waters since the 1998 study. One report completed in 2008 entitled PERSISTENT ORGANIC POLLUTANTS IN CHINOOK SALMON(ONCORHYNCHUS TSHAWYTSCHA): IMPLICATIONS FOR RESIDENT KILLER WHALES OF BRITISH COLUMBIA AND ADJACENT WATERS conducted a similar analysis of PCBs in salmon from different locations. This study looked at salmon from several rivers in Washington and Canada. In this study, the Duwamish chinook tested for PCBs at 35 ppb, significant lower than the 1998 research findings. Interestingly, chinook from the Deschutes River in tested much higher in this later study at 56 ppb. Even fish from the lower Frazer River in Canada tested relatively high for PCBs at 49 ppb. As a comparison, the more “pristine” chinook in Johnstone Strait off northern Vancouver Island tested for PCBs at 9 ppb.
PCB levels in our salmon appear to be correlated to the amount of time that the salmon spends in Puget Sound waters. Fish hatcheries have been motivated to produce salmon that spend their lives in Puget Sound rather than venture out to the ocean to bolster a year-round sport salmon fishing industry. Hatcheries can influence salmon to stay in local waters by delaying the release of fry. The longer a salmon fry is penned and held at a freshwater hatchery, the more inclined it is not to venture to the ocean. In talking with one of the Muckleshoot Indians years ago on the Duwamish waterway (I think it was around 2003), he told me that the Muckleshoot hatchery was seeing larger returns of bigger chinook by delaying the release of the fry. This would infer that these salmon spend less time in the ocean and more time feeding in PCB laden Puget Sound. I might add that Safeway currently holds the contract to purchase the majority of salmon netted by the Muckleshoots on the Duwamish River.
From a PBDE perspective, things even get worse. Puget Sound chinook salmon have 5 to 17 times the levels of PDBEs than other west coast salmon.
So what does this all mean for salmon? It is very hard to tell. Puget Sound salmon are undoubtedly polluted, and this pollution is having a dire impact not only on the salmon, but animals that feed predominately on Puget Sound salmon (like orcas). The two studies referenced above are based on limited datapoints - it would be interesting to see tests for PCBs done every year on 100 samples from each major river. However, that data is not available.
Note that most other meats and animal by-products also contain similar levels of PCBs. Butter is one of the worst offenders and is listed at 70 ppb. However, eggs, chicken, pork, and steak all contain PCB levels ranging from 9 to 32 ppb. With levels not vastly different from most Puget Sound salmon, why hasn’t the Department of Health issued similar advisories recommending the restricted consumption of these foods? Is it because of the other toxins? It is indeed difficult to determine the truth and right course of action.
Toxins in groundfish
Groundfish are basically the resident food fish in our area that tend to stay in Puget Sound on or near the bottom. This category includes, flounder, sole, rockfish, lingcod, sculpins, and others. Unlike salmon, groundfish species tend not to be as nomadic. These fish tend to take up residency in an area and stay there for a long time - often their entire life. Sometimes they migrate from area to area seasonally, but most groundfish in Puget Sound tend to stay in Puget Sound most of their life. As an example, I have been visiting the same pair of rosy rockfish within 10 yards of the same rock during summer at a dive site in the Cape Flattery area for more than six years now.
This residency can work for or against the groundfish. If the resident has selected a pristine area and feeds on the invertebrates and small fish which also inhabit this are, toxin levels will most likely be very low - maybe even nil. However, if the fish takes up residence in a toxin superfund site, it will ultimately be dining on creatures that have ingested the toxins from the sediments. Even though these fish generally do not have as much fatty tissues as salmon to store the toxins, they do tend to accumulate extraordinarily high levels of PCBs, PDFEs, and other toxins and heavy metals. Please note that Washington State has declared that no one should eat ANY groundfish or invertebrates from the Duwamish River area.
Because there are over 100 species of groundfish in our area, groundfish studies are conducted on one of several representative species. The robust and every abundant English sole is one of those representative species that gets more than its fair share of disection and analysis. The Puget Sound Partnership has conducted extensive testing and monitoring of English sole in what they call “urban” and “non-urban” areas. As you might guess, urban areas are shorelines adjacent industrial, commercial, and heavy residential areas - basically most of the eastern shoreline of Puget Sound. The Puget Sound Partnership states that English sole living in urban areas have 10 times the PBDE levels as non-urban English soles. Even Puget Sound herring, a stable for salmon and many other Pacific Northwest species including seals and certain whales, have PBDE levels three times greater than what is considered normal.
Another prevalent toxin, PAHs (polycyclic aromatic hydrocarbons), are found at elevated levels in resident fish and invertebrates throughout Puget Sound. Many PAHs are known cancer causing carcinogens. Crabs associated with urban areas had six times the PAHs as non-urban areas. English sole associated with urban areas had 4 times the PAHs as their non-urban counterparts.
There are literally dozens of other toxins and heavy metals that are being tracked in Puget Sound. What we don’t know is how many other man-made contaminants are adversely impacting our local marine life. The Puget Sound Partnerships estimates that about 35% of the sites in Puget Sound currently have some level of sediment degradation, with about 1% being high degraded.
The bottom line is that most of the commercially important species of groundfish in Puget Sound have all but disappeared or are in sharp decline. I remember catching magnificent Pacific true cod in Puget Sound in the late 1970s off of Blake Island in central Puget Sound. The massive schools of Pacific true cod that once blessed our area are now a distant memory. Most of our native rockfish species are also struggling. A combination of pollutants, overharvest, habitat destruction, and warming water is having a negative impact on rockfish. Almost all species of rockfish in Puget Sound are now listed as endangered, threatening, or concerned. Rockfish egg yields are down by 75-90% from the 1970s. Pollution and toxins are the primary culprits. The same toxins that cause development and reproductive impairment and cancers in us have the same affect on the fish.
Top predators
POPs tend to gather in high concentrations in top predators. Current analysis by the Puget Sound Partnership states that Puget Sound’s southern resident orcas have PCB levels of 150 ppb for males and 50 ppb for females. Over 90% of the diet for a southern resident is salmon, and chinook salmon are preferred. The report also cites a study of sea pups of Gertrude Island in southern Puget Sound where PBDE levels have skyrocketed in the last twenty years and now reached levels in excess of 1000 ppb. Keep in mind that humans are also a top predator.
What to do
What you decide to do with this data is up to you. I have decided not to eat any groundfish from Puget Sound - not just for toxicity reason, but also based on the fact that most “table food” species in our areas are really struggling.
I keep going back and forward on salmon, but have pretty much abandoned salmon fishing. Toward the end of my salmon fishing careers, I targeted fish on the coastal rivers. However, current salmon stocks are decimated and need serious time to recover. I would personally like to see a 10 year ban on all saltwater and salmon fishing in Washington State.
If you do decide to eat Puget Sound fish, there are two general rules published by the FDA to help mitigate associated risks with PCBs and other lipid-stored toxins:
Skin fillets before cooking. Salmon store fats directly underneath the skin. Trim this fat and the
belly fat off salmon fillets.
Cook the fillets in way that promotes the tissue fat to drip from the fillet, like BBQing.
You can reportedly reduce the PCBs in a piece of fish by up to 50% by simply following the two steps listed above.
References
If you would like to get a better perspective of our problem, I highly recommend the following publications (all of which were referenced in this commentary):
State of the Sound 2007 - Puget Sound Action Team, 2007
http://www.psp.wa.gov/downloads/SOS07/2007_stateofthesound_fulldoc.pdf
Persistent Organic Pollutants in Chinook Salmon: Implications for Resident Killer Whales of British Columbia and Adjacent Waters. - O’Neill et al. 2008
http://www.allenpress.com/pdf/ENTC_28.1_148.pdf
Spatial Trends in the Concentration of Polychlorinated Biphenyls (PCBs) in Chinook (Oncorhynchus tshawytscha) and Coho Salmon (O. kisutch) in Puget Sound and Factors Affecting PCB Accumulation: Results from the Puget Sound Ambient Monitoring Program. Pages 312-328 - O’Neill et al. 1998 I cannot find this report online anymore, but I can email it to you is you wish.
Newspaper article from the Seattle PI regarding Puget Sound and Columbia River salmon toxicity:
http://www.seattlepi.com/local/156714_warning15.html
Emerald Diving
Explore the coastal and inland waters of
Washington and BC
Explore the coastal and inland waters of
Washington and BC
