High concentrations of polybrominated diphenyl ether (PBDE), a chemical compound used in fire retardants, have been found in steelhead trout in the Nisqually River system, and some evidence is pointing to a wastewater treatment facility operated by the town of Eatonville as the source.
A paper published in late 2017 in the Journal of Aquatic Animal Health — co-authored by Sandra O’Neill, a senior researcher with state Fish and Wildlife’s marine resources division — found that “30-50 percent of fish sampled from each habitat type in the Nisqually River system had PBDE concentrations high enough to potentially increase their susceptibility to naturally occurring pathogens.”
The study largely looked at infection and toxic contaminant exposure in out-migrating trout from the Skagit, Snohomish, Green-Duwamish and Nisqually rivers, and other associated habitats.
PBDE concentrations recorded in fish from the south Puget Sound region were also significantly higher — roughly three to five times — than those measured in the central and northern parts of the region.
Based on the “unexpected” levels of PBDE and disproportionate levels found in the fish, researchers say their data suggests a source upstream.
At least one additional study on the source causing the high concentration of the fire retardants is expected soon, though the COVID-19 pandemic has put many research efforts for state biologists on hold.
“Basically, we may or may not be able to do it this year. It will probably be postponed, but we’ll finish the planning this year,” O’Neill said.
While PBDE toxins haven’t been known to directly affect juvenile steelhead survival significantly, the infection could be dire to development, swimming abilities and susceptibility to viruses, said David Troutt, natural resources director of the Nisqually Indian Tribe.
Levels that have been observed on the Nisqually River exceed the levels known to indirectly affect the survivability of the population, he said.
“It’s certainly not the only factor,” Troutt said. “All these things sort of work together, unfortunately, in this perfect storm that has led to the significant collapse of the Nisqually steelhead. And so, probably dealing with one issue isn’t going to solve the problem for us. We’re going to have to deal with all the issues. We need healthy fish leaving the Nisqually River and less seals and sea lions eating them to and from the river.”
A study published this year led by a NOAA fisheries biologist confirmed that harbor seals have become an ever-growing threat to the native steelhead populations at the mouth of the Nisqually River. A total of 16 percent of the fish they recorded were found in the stomachs of the gluttonous marine mammals.
Steelhead trout are a unique species of fish that develop differently depending on their environment. Naturally spawning fish populations in the Puget Sound and many other populations have been listed and protected under the federal Endangered Species Act since 2007.
For many hundreds of years, the native people of the Nisqually River have depended on the fish populations, which return upriver toward the end of the year and have traditionally kept families fed throughout the winter months.
The steelhead run on the Nisqually River had been one of the strongest in the Puget Sound, Troutt said, until the 1990s when it collapsed. Runs had numbered more than 7,000 strong yearly before the downturn, but now average about 500.
Troutt said the river’s modern fish count quota, which is at about 2,000 fish a year, has only been reached a small number of times. The population statewide is about 10 percent of its historic size and is facing possible extinction.
“It’s been 30 years of no fishing for steelhead on the Nisqually,” Troutt said. “I have a generation of fishermen on the river now that have never caught a Nisqually steelhead, and that’s a problem.”
For a long time, the state and tribe have been looking at what has been causing the decline. One of the large impacts to the population has been harbor seals, which have been consuming large portions of the juvenile fish heading out toward the Strait of Juan de Fuca.
Toxin studies started about five years ago, Troutt said. So when O’Neill and her colleagues discovered large concentrations of PBDE, that alarmed them.
According to a followup analysis of the study, the thought was that the pollutant was sourced from one or a mix of the following sources which feed into Nisqually River tributaries; three wastewater treatment facilities, a major stormwater outfall, surface stormwater runoff dump by Weyerhaeuser, JBLM, and the University of Washington Pack Forest lands.
But after testing those areas at three different sites, evidence seemed to point upstream on the Mashel, the second-largest tributary into the Nisqually which also supports about 30 percent of the river’s steelhead population.
“Our intent is to work with (the Town of Eatonville) to solve this problem if it is indeed coming from the wastewater treatment facility,” Troutt said, adding later that “it shouldn’t be any great surprise that it’s where it’s coming from. Almost everything we wear and own and wash — clothes, especially kids clothes — and furniture, and all that stuff all have some amount of PBDEs in it and so it’s likely entering the system through our daily use of water.”
Troutt said if research were to look at other wastewater treatment facilities that feed into other rivers around the state, he’d bet that trace concentrations of PBDEs would be found there as well.
Abby Gribi, town administrator at the Town of Eatonville, said they’ve never been contacted by the Nisqually Indian Tribe or the state on this issue, and noted that a call from a Nisqually Valley News reporter was the first time she or any of her staff had heard of it.
The past 14 years, the town’s treatment facility has received “outstanding results” on testing and the water that they put back into the Mashel River, she said. The facility was retrofitted in the 1990s and is currently at about 60-percent capacity, Gribi said.
Despite causing adverse health effects in fish, PBDEs and flame retardants are not regulated in treatment facilities by the state Department of Ecology, O’Neill said.
On the Department of Ecology’s website, the department claims it has a long history of taking action against manufacturers that produce the toxins. Most recently, in 2016, the state amended the Children’s Safe Products Act to ban the use of five flame retardant chemicals in children’s products and residential furniture.
The state Legislature also directed Ecology and the Department of Health to study whether six additional retardants should be added to a list of chemicals of high concert to children.
O’Neill, who has worked with Fish and Wildlife studying mostly marine species since 1989, said it’s largely been documented that while the concentration of PBDE’s in the Nisqually are alarming, it was not the highest concentration they’ve ever seen while testing fish.
For example, juvenile chinook in the Duwamish River system have been recorded to have higher concentrations, but the Nisqually steelhead had the highest recorded concentrations they’ve seen in a steelhead population.
In the followup study, which looked at narrowing down the source of the toxin, O’Neill and her colleagues took samples from the river flow and from biofilm, which is the green algae-like material often found on rocks in riverbeds.
What they found was that the biofilm material overall had larger concentrations of PBDEs than the passive filters they put in the river and streams.
Biofilm is often at the base of many marine animal food chains, O’Neill said, so it’s possible fish could be digesting the bugs that eat the PBDE-high biofilm.
“I think this is an issue that the Department of Ecology in the coming years will decide whether they need to be regulated and to what extent,” she said. “The question is, are they getting into the food web and getting distributed and accumulated downstream? We don’t know that yet.”
It’s also not known how long fire retardants last in the biofilm and in the river systems in general. The impact could be small, but that’s not currently known.
While COVID-19 hasn’t been helpful, it will give the tribe and state some additional time to plan their further studies.
O’Neill said in addition to looking at the broader impacts of PBDEs on the Nisqually and confirming the source, they also hope to look at steelhead stomach samples in populations that gather and rear regularly in the river.
But that could be difficult to perform on a fish as rarely seen as the Nisqually steelhead.