Some toxic chemicals increase; others decline in Puget Sound fish

The importance of long-term environmental monitoring is driven home in a new study by toxicologists who have spent years examining chemical contamination in Puget Sound fish.

English sole sampling locations include both urban and rural areas of Puget Sound.
Archives of Env. Contamination and Toxicology

After 28 years of monitoring, researchers have confirmed that it is extremely difficult to remove polychlorinated biphenyls (PCBs) from the Puget Sound food web. In some locations, PCBs are actually increasing in bottom fish some 38 years after these chemicals were banned in the United States.

“Across the board, we’ve seen either no decline or even increases in our English sole, which is really kind of shocking considering all the remediation that has been going on,” said Jim West, a toxicologist with the Washington Department of Fish and Wildlife who I interviewed for a story in the Encyclopedia of Puget Sound.

The report, published in the Archives of Environmental Contamination and Toxicology, provides some bleak news about PCBs, but there are hopeful signs for other chemicals. For example, researchers were pleasantly surprised to find that toxic flame retardants containing polybrominated diphenyl ethers seem to be disappearing rapidly from the ecosystem less than a decade after the most toxic forms of PBDEs were banned in Washington state.

The study went to some lengths to make sure the decline in PBDEs in Pacific herring was not related to other factors — such as size, since the average herring is getting smaller over time.

“I now feel like this is a solid trend, and that’s really exciting,” Jim told me. “I believe it is related to our efforts in source control.”

Of course, we wouldn’t know about these long-term trends in chemical contamination were it not for long-term monitoring efforts. I discussed the importance of monitoring with Sandie O’Neill, a research scientist with WDFW. She is an author of the new study along with Jim West and Gina Ylitalo of NOAA’s Northwest Fisheries Science Center. See the related story “Monitoring helps to reveal hidden dangers in the food web” in the Encyclopedia of Puget Sound.

“We are changing people’s perspectives about contaminants throughout the (Puget Sound) watershed, including how such contaminants get into the food web,” Sandie told me.

As Sandie describes it, monitoring is needed in many aspects of ecosystem health. It can tell us whether nature is healing itself and whether restoration projects by humans are improving fish and wildlife habitat as well as human health.

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