Coho salmon

Tag: Coho salmon

Salmon experts predict more wild coho but fewer Chinook in Puget Sound this year

Greater numbers of wild coho salmon are expected to return to Puget Sound later this year, according to forecasts released last week, but threatened Puget Sound Chinook stocks are likely to see another decline.

Graph: Washington Department of Fish and Wildlife

The 2021 salmon forecasts were announced Friday during an online video conference with sport and commercial fishers and other interested people (TVW telecast). The annual meeting serves to launch negotiations that, when completed in April, will prescribe fishing seasons for the coming summer and fall.
Protecting so-called “weak stocks” from fishing pressure continues to be a challenge. Salmon managers with the Washington Department of Fish and Wildlife will consult with representatives of area tribes to identify times and places for fishing that will still allow adequate numbers of spawning salmon to get back to their home streams.
Low numbers of salmon predicted for some areas of Puget Sound will force managers to make some tough choices, said Fish and Wildlife Director Kelly Susewind.
Graph: Washington Department of Fish and Wildlife

“If every salmon run across the state was healthy, our jobs would be easy,” he said in a news release. “But the unfortunate truth is that some stocks just won’t be able to support fisheries and are likely to impact fisheries even for healthier runs. We’ll work hard alongside the co-managers to stay within our shared conservation goals while still offering chances to get out and fish this year whenever possible.”
Some 246,000 wild coho are expected to return to Puget Sound this year, up about 51 percent from last year but still 15 percent below the 10-year average, said Chad Herring, a fishery policy analyst for Fish and Wildlife. In contrast, hatchery coho are expected to increase by 8 percent.
Graph: Washington Department of Fish and Wildlife

While fishing opportunities could come from the increased coho run, managers must be careful to protect wild Chinook, which remain at risk of extinction. This year’s total Chinook run size (hatchery and wild, not including spring Chinook) is estimated to be down 11 percent from last year’s forecast of 233,000 fish and 2 percent below the recent 10-year average. Keep in mind that the recent 10-year average for wild Chinook is 24 percent below the 10-year average recorded when Puget Sound Chinook were placed on the Endangered Species List back in 1999 — so things are not looking good for Chinook.
The Department of Fish and Wildlife recently began increasing production of Chinook at some hatcheries in an effort to help the Southern Resident Killer Whales, which frequent Puget Sound and consume a lot of salmon, primarily Chinook. The result of that increased production could be seen in coming years, although the effects on wild Chinook have been hotly debated.
Graph: Washington Department of Fish and Wildlife

Wild Chinook make up just 12 percent of the total run size, with hatchery Chinook making up the remainder, so one strategy for increasing fishing opportunities while protecting wild fish is to shift fishing efforts to “terminal areas” closer to the hatcheries during carefully timed periods.
To protect wild Chinook and coho, anglers may be allowed to keep only hatchery fish while releasing wild fish. Young hatchery Chinook and coho are typically marked by removing their adipose fins before release. During the COVID-19 pandemic, marking equipment housed in special mobile units went into operation around the clock to get the work done while limiting the number of staffers working in confined spaces, according to Kelly Cunningham. director of the Fish Program for WDFW. The marking program successfully handled between 140 million and 160 million juvenile salmon with no delay in their scheduled release, he said.
Graph: Washington Department of Fish and Wildlife

Chum salmon, largely taken by commercial fishers, have been in a general decline since their historical peak in 2002, research biologist Mickey Agha said during Friday’s conference.
“Last year, I noted that in 2019 we had the lowest Puget Sound return since 1979,” Agha said. “Unfortunately, preliminary estimates for 2020 are revealing a return only slightly higher.”
The graph showing the chum forecast, shown on this page, includes a year-old forecast of a higher run last year, because the hard data about the actual run size are still being compiled. That goes for the other species as well.
“As many of you in the chum industry are aware, it was a rather poor year fishing for the limited opportunity that was available,” Agha said. “South Puget Sound and Hood Canal returned poorly, as compared to the long-term averages. Nevertheless, there were some bright spots where we met conservation goals head-on and reached our escapement goals (for the number of spawners reaching their home streams). That was along the coast for a few populations and for a few populations in the Central to North Puget Sound.”
Graph: Washington Department of Fish and Wildlife

Chum returns to Puget Sound this year are expected to be only slightly better than for 2019, one of the worst years on record. Hatchery fish make up roughly half the run size of fall chum salmon. The total run size this year is estimated at 526,000.
Meanwhile, 2021 will be a “pink year,” as it is called, reflecting the fact that the vast majority of pink salmon spawn in odd-numbered years. The past decade has been a period of both boom and bust for pinks, which are almost all wild salmon. This year, about 2.9 million pinks are expected to return to Puget Sound, vastly outnumbering chum. That return would be similar to 2019, following a very low year in 2017.
Elsewhere, anglers online for Friday’s presentation heard some welcome news about coho in the Columbia River. The forecast calls for 1.6 million fish among the early and late runs, a dramatic increase from last year’s 363,000, according to estimates.
Graph: Washington Department of Fish and Wildlife

Although that big number is encouraging, there is a need to protect other at-risk stocks in the region, said Kyle Adicks, intergovernmental salmon manager for Fish and Wildlife.
“All of our forecasting indicates a strong coho return to the Columbia, but a lot can change between now and when the fish start to arrive, including out in the ocean,” Adicks said in a news release. “We’ll be keeping a close eye throughout this year’s salmon-season-setting process on stocks of low abundance.”
Fishing along the Washington Coast is expected to be a mixed bag, with some stocks up and others down. Poor returns anticipated for the Queets and other coastal rivers could limit fishing off the coast, despite the large numbers of coho returning to the Columbia River.
Graph: Washington Department of Fish and Wildlife

All these forecasts are based on computer modeling that factors in many variables, from the number of juvenile salmon that leave the streams to the number of adult salmon returning in the previous cycle to the number of “jacks” that return a year before they are due. Also considered are ocean conditions, such as temperature, which have a major influence on the movement of salmon and their food supply.
Higher surface temperatures in the ocean off the West Coast in recent years are believed to be a major factor in the decline of salmon, which tend to do better in cooler waters. Global warming can affect salmon through every life stage, from the stream where they hatch out of gravel to the Pacific Ocean where they grow and mature.
Making things worse is a recurring patch of warm ocean water nicknamed “the blob” by Washington State Climatologist Nick Bond. Sometimes stretching from California to Alaska, the highest temperatures since 1982 were recorded during a period from 2014 to 2016. (See map at top of this page.) Last year, the blob’s reappearance brought temperatures nearly as high.
Lower-than-average sea surface temperatures have prevailed near the equator during February, portending better conditions for salmon in the Northwest. Map: NOAA’s Climate Prediction Center

Since then, ocean temperatures have declined to more normal conditions, which should benefit salmon, according to Marisa Litz, research scientist for Fish and Wildlife who spoke during Friday’s meeting. Other good news is the current mountain snowpack of between 95 and 150 percent of normal, which should help provide adequate flows of cool water during the critical spring period for young salmon, she said.
The Pacific Ocean currently remains in a cooler phase called La Niňa, which has resulted in below-normal ocean temperatures from the west-central Pacific Ocean to our region along the coast, according to a report released yesterday by NOAA’s Climate Prediction Center (PDF 3.3 mb).
“In the last week, negative anomalies strengthened across most of the equatorial Pacific Ocean,” the report says, providing additional atmospheric evidence of La Niña conditions.
The federal forecasters say there is a 60-percent chance that our current ocean conditions will transition by June to neutral — that is more average conditions midway between the cooler La Niña and the warmer El Niño. These more normal conditions are likely to persist into fall, according to most models.
These cooler ocean temperatures should help with the growth and survival of salmon that return to Puget Sound in the next couple years, although many other factors also play a role in the lives of salmon.
The latest salmon forecasts, a list of upcoming public meetings, and other information, can be seen on the North of Falcon webpage on the Department of Fish and Wildlife’s website.

Salmon experts predict more wild coho but fewer Chinook in Puget Sound this year

Greater numbers of wild coho salmon are expected to return to Puget Sound later this year, according to forecasts released last week, but threatened Puget Sound Chinook stocks are likely to see another decline.

Graph: Washington Department of Fish and Wildlife

The 2021 salmon forecasts were announced Friday during an online video conference with sport and commercial fishers and other interested people (TVW telecast). The annual meeting serves to launch negotiations that, when completed in April, will prescribe fishing seasons for the coming summer and fall.
Protecting so-called “weak stocks” from fishing pressure continues to be a challenge. Salmon managers with the Washington Department of Fish and Wildlife will consult with representatives of area tribes to identify times and places for fishing that will still allow adequate numbers of spawning salmon to get back to their home streams.
Low numbers of salmon predicted for some areas of Puget Sound will force managers to make some tough choices, said Fish and Wildlife Director Kelly Susewind.
Graph: Washington Department of Fish and Wildlife

“If every salmon run across the state was healthy, our jobs would be easy,” he said in a news release. “But the unfortunate truth is that some stocks just won’t be able to support fisheries and are likely to impact fisheries even for healthier runs. We’ll work hard alongside the co-managers to stay within our shared conservation goals while still offering chances to get out and fish this year whenever possible.”
Some 246,000 wild coho are expected to return to Puget Sound this year, up about 51 percent from last year but still 15 percent below the 10-year average, said Chad Herring, a fishery policy analyst for Fish and Wildlife. In contrast, hatchery coho are expected to increase by 8 percent.
Graph: Washington Department of Fish and Wildlife

While fishing opportunities could come from the increased coho run, managers must be careful to protect wild Chinook, which remain at risk of extinction. This year’s total Chinook run size (hatchery and wild, not including spring Chinook) is estimated to be down 11 percent from last year’s forecast of 233,000 fish and 2 percent below the recent 10-year average. Keep in mind that the recent 10-year average for wild Chinook is 24 percent below the 10-year average recorded when Puget Sound Chinook were placed on the Endangered Species List back in 1999 — so things are not looking good for Chinook.
The Department of Fish and Wildlife recently began increasing production of Chinook at some hatcheries in an effort to help the Southern Resident Killer Whales, which frequent Puget Sound and consume a lot of salmon, primarily Chinook. The result of that increased production could be seen in coming years, although the effects on wild Chinook have been hotly debated.
Graph: Washington Department of Fish and Wildlife

Wild Chinook make up just 12 percent of the total run size, with hatchery Chinook making up the remainder, so one strategy for increasing fishing opportunities while protecting wild fish is to shift fishing efforts to “terminal areas” closer to the hatcheries during carefully timed periods.
To protect wild Chinook and coho, anglers may be allowed to keep only hatchery fish while releasing wild fish. Young hatchery Chinook and coho are typically marked by removing their adipose fins before release. During the COVID-19 pandemic, marking equipment housed in special mobile units went into operation around the clock to get the work done while limiting the number of staffers working in confined spaces, according to Kelly Cunningham. director of the Fish Program for WDFW. The marking program successfully handled between 140 million and 160 million juvenile salmon with no delay in their scheduled release, he said.
Graph: Washington Department of Fish and Wildlife

Chum salmon, largely taken by commercial fishers, have been in a general decline since their historical peak in 2002, research biologist Mickey Agha said during Friday’s conference.
“Last year, I noted that in 2019 we had the lowest Puget Sound return since 1979,” Agha said. “Unfortunately, preliminary estimates for 2020 are revealing a return only slightly higher.”
The graph showing the chum forecast, shown on this page, includes a year-old forecast of a higher run last year, because the hard data about the actual run size are still being compiled. That goes for the other species as well.
“As many of you in the chum industry are aware, it was a rather poor year fishing for the limited opportunity that was available,” Agha said. “South Puget Sound and Hood Canal returned poorly, as compared to the long-term averages. Nevertheless, there were some bright spots where we met conservation goals head-on and reached our escapement goals (for the number of spawners reaching their home streams). That was along the coast for a few populations and for a few populations in the Central to North Puget Sound.”
Graph: Washington Department of Fish and Wildlife

Chum returns to Puget Sound this year are expected to be only slightly better than for 2019, one of the worst years on record. Hatchery fish make up roughly half the run size of fall chum salmon. The total run size this year is estimated at 526,000.
Meanwhile, 2021 will be a “pink year,” as it is called, reflecting the fact that the vast majority of pink salmon spawn in odd-numbered years. The past decade has been a period of both boom and bust for pinks, which are almost all wild salmon. This year, about 2.9 million pinks are expected to return to Puget Sound, vastly outnumbering chum. That return would be similar to 2019, following a very low year in 2017.
Elsewhere, anglers online for Friday’s presentation heard some welcome news about coho in the Columbia River. The forecast calls for 1.6 million fish among the early and late runs, a dramatic increase from last year’s 363,000, according to estimates.
Graph: Washington Department of Fish and Wildlife

Although that big number is encouraging, there is a need to protect other at-risk stocks in the region, said Kyle Adicks, intergovernmental salmon manager for Fish and Wildlife.
“All of our forecasting indicates a strong coho return to the Columbia, but a lot can change between now and when the fish start to arrive, including out in the ocean,” Adicks said in a news release. “We’ll be keeping a close eye throughout this year’s salmon-season-setting process on stocks of low abundance.”
Fishing along the Washington Coast is expected to be a mixed bag, with some stocks up and others down. Poor returns anticipated for the Queets and other coastal rivers could limit fishing off the coast, despite the large numbers of coho returning to the Columbia River.
Graph: Washington Department of Fish and Wildlife

All these forecasts are based on computer modeling that factors in many variables, from the number of juvenile salmon that leave the streams to the number of adult salmon returning in the previous cycle to the number of “jacks” that return a year before they are due. Also considered are ocean conditions, such as temperature, which have a major influence on the movement of salmon and their food supply.
Higher surface temperatures in the ocean off the West Coast in recent years are believed to be a major factor in the decline of salmon, which tend to do better in cooler waters. Global warming can affect salmon through every life stage, from the stream where they hatch out of gravel to the Pacific Ocean where they grow and mature.
Making things worse is a recurring patch of warm ocean water nicknamed “the blob” by Washington State Climatologist Nick Bond. Sometimes stretching from California to Alaska, the highest temperatures since 1982 were recorded during a period from 2014 to 2016. (See map at top of this page.) Last year, the blob’s reappearance brought temperatures nearly as high.
Lower-than-average sea surface temperatures have prevailed near the equator during February, portending better conditions for salmon in the Northwest. Map: NOAA’s Climate Prediction Center

Since then, ocean temperatures have declined to more normal conditions, which should benefit salmon, according to Marisa Litz, research scientist for Fish and Wildlife who spoke during Friday’s meeting. Other good news is the current mountain snowpack of between 95 and 150 percent of normal, which should help provide adequate flows of cool water during the critical spring period for young salmon, she said.
The Pacific Ocean currently remains in a cooler phase called La Niňa, which has resulted in below-normal ocean temperatures from the west-central Pacific Ocean to our region along the coast, according to a report released yesterday by NOAA’s Climate Prediction Center (PDF 3.3 mb).
“In the last week, negative anomalies strengthened across most of the equatorial Pacific Ocean,” the report says, providing additional atmospheric evidence of La Niña conditions.
The federal forecasters say there is a 60-percent chance that our current ocean conditions will transition by June to neutral — that is more average conditions midway between the cooler La Niña and the warmer El Niño. These more normal conditions are likely to persist into fall, according to most models.
These cooler ocean temperatures should help with the growth and survival of salmon that return to Puget Sound in the next couple years, although many other factors also play a role in the lives of salmon.
The latest salmon forecasts, a list of upcoming public meetings, and other information, can be seen on the North of Falcon webpage on the Department of Fish and Wildlife’s website.

Discovery of toxic chemical in tires spurs scientific and regulatory interest

The discovery of a mysterious chemical that kills coho salmon in urban streams is expected to spawn new research throughout the world while possibly inspiring new demands for protective regulations.
The deadly chemical, associated with automobile tires, was identified by researchers at the University of Washington’s Center for Urban Waters, which is affiliated with the Puget Sound Institute. The findings were published yesterday in the journal “Science.” I wrote about this discovery and more than 20 years of related scientific investigations in PSI’s online magazine “Salish Sea Currents.”
“This is an important finding,” said Erik Neatherlin, executive coordinator of the Governor’s Salmon Recovery Office. “We have known that stormwater is an issue. Now we can talk about the specific culprit (affecting coho).”

A dying female coho salmon in the Lower Duwamish spotted by Puget Soundkeeper volunteers in October 2017. Photo: Kathy Peter
A dying female coho salmon in the Duwamish River, 2017 // Photo: Kathy Peter

A chemical known as 6-PPD is often added to tires to extend their useful life. The additive works by reacting with ground-level ozone before the ozone can damage the tire’s rubber. The chemical reaction produces 6-PPD-quinone, a compound apparently never studied until now. The newly discovered compound is estimated to be more than 100 times as toxic as the parent compound, 6-PPD.
Neatherlin said the logical course toward solving the problem for coho involves strategies to reduce stormwater pollution and finding safer alternatives to 6-PPD. State and federal agencies, Indian tribes, salmon-recovery groups and industry should work together on this, he said.
“I see this as an opportunity to work directly with industry and to find alternatives to this preservative,” Neatherlin said. “We will need to do follow-up scientific studies. I don’t think we need to pit folks against each other right now.”
The findings reported in the new scientific paper are being reviewed by chemists working for tire manufacturers, according to Sarah Amick of the U.S. Tire Manufacturers Association. The tire scientists are already working with the UW researchers and regulatory agencies, she said.
“We welcome the continued opportunity to work with them,” said Amick, who is vice president of environment, health, safety and sustainability for the association. Findings from the latest study must be validated before moving forward, she said, adding that it is “premature” to discuss alternative chemicals that could protect tires from ozone.
The association, which represents 13 major tire companies, is committed to not only the safety of tires but also the protection of human health and the environment, Amick said. An industry-funded research effort, known as the Tire Industry Project, has been studying the environmental effects of tires, including tire-wear particles.
“It is our obligation to understand our products’ impacts on the environment,” she said.
[iframe align=”right” width=”560″ height=”315″ src=”https://www.youtube.com/embed/vxmojuC_dJE”%5D
Ed Kolodziej, a UW associate professor and a senior author of the new paper, said he expects the findings to inspire other researchers to launch investigations into numerous issues raised by the research. They range from basic questions about how long 6-PPD-quinone persists under various environmental conditions to how the chemical affects lesser-known species.
Nat Scholz, a marine zoologist with NOAA’s Northwest Fisheries Science Center, said tires are used in automobiles throughout the world, and stormwater is a problem everywhere. It is important to learn what other species might be affected by tire chemicals, he said. Another big question is whether toxic compounds can accumulate in animal tissues and whether greater concentrations are found in species higher on the food web, a process called bioaccumulation.
Tire chemistry, which has been of interest in several European countries, also plays a role in human health. Artificial turf and crumb rubber used on playfields typically are made with ground-up tires, and researchers say they expect ongoing studies into the health effects of such uses on athletic fields.
Coincidentally, while the new study on tire chemicals was undergoing formal review, artificial turf containing ground-up tires was washing downstream in the Puyallup River from the Electron Dam in Pierce County. The artificial turf had been installed as part of a temporary water-diversion structure during reconstruction of the dam. During late July and August, high flows damaged a plastic liner, allowing pieces of artificial turf and tire particles to wash downstream. That unpermitted use of artificial turf has come under heavy criticism. Long-term effects of that incident remain under investigation, and the latest study reported in “Science” could raise new implications about the extent of the damage.
While 6-PPD-quinone produces dramatic and deadly effects for coho salmon, as reported yesterday, stormwater exposure seems to have little effect on chum or sockeye, based on previous studies. Steelhead and Chinook may be affected but to a lesser degree than coho.
Studies into how the toxic chemical affects the physiology of salmon are underway, and experts expect that other studies will be proposed to better understand the toxic effects of 6-PPD-quinone exposure on a variety of species, including humans.
In portions of California and Oregon, coho salmon are listed as threatened or endangered under the Endangered Species Act. The new findings on this toxic chemical in tires could bring more funding to answer questions about the threats to salmon. A need to better understand subtle effects of tire chemicals on steelhead and Chinook as well as other species could lead to increased research attention, as federal and state authorities develop recovery plans for threatened and endangered salmon along the West Coast.
Michelle Chow, who worked on the coho mortality studies as a UW graduate student, now serves as stormwater and toxics policy manager for Washington Environmental Council.
The recent identification of the deadly chemical related to tires is “a huge step forward,” Chow said, but it is essential not to lose track of the big picture.
“We know that stormwater has this effect,” she said, “but we don’t know what the other effects might be on the food web — from insects up to southern resident orcas. It is important to remember that we have found one chemical for this particular issue, but there are so many other chemicals in stormwater.”
Studies have shown that filtering stormwater through natural soils and vegetation can significantly reduce the overall toxicity. While it would be impossible to install such “green infrastructure” everywhere, things can be done in strategic locations, Chow said. Meanwhile, minimizing impervious roads and driveways throughout the region can reduce the amount of stormwater going into salmon streams.
Now that researchers have identified the chemical responsible for killing coho, Chow would like to see the Washington Department of Ecology gather all available information about tire chemistry from the tire manufacturers. The state agency can demand such information under a 2019 law that created the Safer Products for Washington program.
“We have to start thinking about the different possibilities,” she said. “We need to find out if a safer alternative exists. We are hoping that (industry officials) are thinking about how they can work quickly to start solving this problem.”
Safer Products for Washington involves designating chemicals of highest concern, determining if alternative chemicals are available and deciding if regulations are needed to protect people and the environment. Five classes of chemicals are currently in the second year of a four-year review. A new round of review for new priority chemicals will begin in 2022, and anyone can offer suggestions about what chemicals should be considered for study, said Lauren Tamboer, spokeswoman for the program.
Officials can be expected to debate whether the tire chemical 6-PPD should be considered a priority chemical under the Safer Products program. Another approach, if alternative chemicals are available, is for the Legislature to simply ban 6-PPD from tires at a future date.
That was the approach used to eliminate copper in automobile brake pads, after it was found that copper affects the sense of smell in coho salmon, potentially disrupting their ability to avoid predators and find their way home. The Washington Legislature approved the ban in 2010. California quickly followed, paving the way for new national standards. That was nine years before the Safer Products law was approved. Although it took time to implement, the ban on copper has proven successful, and several alternative brake materials are now on the market. Check out Water Ways, Nov. 6.
The 20-year effort to figure out what was killing the coho makes for a compelling story, one that has already captured the attention of news reporters across the U.S. and in Europe. Here are some of the stories published so far:

  • New York Times: “How Scientists Tracked Down a Mass Killer (of Salmon)”
  • Los Angeles Times: “Scientists solve mystery of mass coho salmon deaths. The killer? A chemical from car tires”
  • Seattle Times: “Tire dust killing coho salmon returning to Puget Sound, new research shows”
  • Marin Independent Journal: “Study finds California salmon face deadly threat from car tires”
  • CNN: “Salmon have been dying mysteriously on the West Coast for years. Scientists think a chemical in tires may be responsible”
  • UPI: “Toxic tire additive blamed for massive coho salmon die-offs”
  • The Guardian: “Pollution from car tires is killing off salmon on US west coast, study finds”
  • Science magazine: “Common tire chemical implicated in mysterious deaths of at-risk salmon”
  • The Daily Mail: “Toxic chemicals used to stop car tyres wearing out too fast are leaching into rivers and killing off salmon, researchers warn”
  • Chemistry World: “Tyre chemical drives mystery salmon deaths”

Discovery of toxic chemical in tires spurs scientific and regulatory interest

The discovery of a mysterious chemical that kills coho salmon in urban streams is expected to spawn new research throughout the world while possibly inspiring new demands for protective regulations.
The deadly chemical, associated with automobile tires, was identified by researchers at the University of Washington’s Center for Urban Waters, which is affiliated with the Puget Sound Institute. The findings were published yesterday in the journal “Science.” I wrote about this discovery and more than 20 years of related scientific investigations in PSI’s online magazine “Salish Sea Currents.”
“This is an important finding,” said Erik Neatherlin, executive coordinator of the Governor’s Salmon Recovery Office. “We have known that stormwater is an issue. Now we can talk about the specific culprit (affecting coho).”

A dying female coho salmon in the Lower Duwamish spotted by Puget Soundkeeper volunteers in October 2017. Photo: Kathy Peter
A dying female coho salmon in the Duwamish River, 2017 // Photo: Kathy Peter

A chemical known as 6-PPD is often added to tires to extend their useful life. The additive works by reacting with ground-level ozone before the ozone can damage the tire’s rubber. The chemical reaction produces 6-PPD-quinone, a compound apparently never studied until now. The newly discovered compound is estimated to be more than 100 times as toxic as the parent compound, 6-PPD.
Neatherlin said the logical course toward solving the problem for coho involves strategies to reduce stormwater pollution and finding safer alternatives to 6-PPD. State and federal agencies, Indian tribes, salmon-recovery groups and industry should work together on this, he said.
“I see this as an opportunity to work directly with industry and to find alternatives to this preservative,” Neatherlin said. “We will need to do follow-up scientific studies. I don’t think we need to pit folks against each other right now.”
The findings reported in the new scientific paper are being reviewed by chemists working for tire manufacturers, according to Sarah Amick of the U.S. Tire Manufacturers Association. The tire scientists are already working with the UW researchers and regulatory agencies, she said.
“We welcome the continued opportunity to work with them,” said Amick, who is vice president of environment, health, safety and sustainability for the association. Findings from the latest study must be validated before moving forward, she said, adding that it is “premature” to discuss alternative chemicals that could protect tires from ozone.
The association, which represents 13 major tire companies, is committed to not only the safety of tires but also the protection of human health and the environment, Amick said. An industry-funded research effort, known as the Tire Industry Project, has been studying the environmental effects of tires, including tire-wear particles.
“It is our obligation to understand our products’ impacts on the environment,” she said.
[iframe align=”right” width=”560″ height=”315″ src=”https://www.youtube.com/embed/vxmojuC_dJE”%5D
Ed Kolodziej, a UW associate professor and a senior author of the new paper, said he expects the findings to inspire other researchers to launch investigations into numerous issues raised by the research. They range from basic questions about how long 6-PPD-quinone persists under various environmental conditions to how the chemical affects lesser-known species.
Nat Scholz, a marine zoologist with NOAA’s Northwest Fisheries Science Center, said tires are used in automobiles throughout the world, and stormwater is a problem everywhere. It is important to learn what other species might be affected by tire chemicals, he said. Another big question is whether toxic compounds can accumulate in animal tissues and whether greater concentrations are found in species higher on the food web, a process called bioaccumulation.
Tire chemistry, which has been of interest in several European countries, also plays a role in human health. Artificial turf and crumb rubber used on playfields typically are made with ground-up tires, and researchers say they expect ongoing studies into the health effects of such uses on athletic fields.
Coincidentally, while the new study on tire chemicals was undergoing formal review, artificial turf containing ground-up tires was washing downstream in the Puyallup River from the Electron Dam in Pierce County. The artificial turf had been installed as part of a temporary water-diversion structure during reconstruction of the dam. During late July and August, high flows damaged a plastic liner, allowing pieces of artificial turf and tire particles to wash downstream. That unpermitted use of artificial turf has come under heavy criticism. Long-term effects of that incident remain under investigation, and the latest study reported in “Science” could raise new implications about the extent of the damage.
While 6-PPD-quinone produces dramatic and deadly effects for coho salmon, as reported yesterday, stormwater exposure seems to have little effect on chum or sockeye, based on previous studies. Steelhead and Chinook may be affected but to a lesser degree than coho.
Studies into how the toxic chemical affects the physiology of salmon are underway, and experts expect that other studies will be proposed to better understand the toxic effects of 6-PPD-quinone exposure on a variety of species, including humans.
In portions of California and Oregon, coho salmon are listed as threatened or endangered under the Endangered Species Act. The new findings on this toxic chemical in tires could bring more funding to answer questions about the threats to salmon. A need to better understand subtle effects of tire chemicals on steelhead and Chinook as well as other species could lead to increased research attention, as federal and state authorities develop recovery plans for threatened and endangered salmon along the West Coast.
Michelle Chow, who worked on the coho mortality studies as a UW graduate student, now serves as stormwater and toxics policy manager for Washington Environmental Council.
The recent identification of the deadly chemical related to tires is “a huge step forward,” Chow said, but it is essential not to lose track of the big picture.
“We know that stormwater has this effect,” she said, “but we don’t know what the other effects might be on the food web — from insects up to southern resident orcas. It is important to remember that we have found one chemical for this particular issue, but there are so many other chemicals in stormwater.”
Studies have shown that filtering stormwater through natural soils and vegetation can significantly reduce the overall toxicity. While it would be impossible to install such “green infrastructure” everywhere, things can be done in strategic locations, Chow said. Meanwhile, minimizing impervious roads and driveways throughout the region can reduce the amount of stormwater going into salmon streams.
Now that researchers have identified the chemical responsible for killing coho, Chow would like to see the Washington Department of Ecology gather all available information about tire chemistry from the tire manufacturers. The state agency can demand such information under a 2019 law that created the Safer Products for Washington program.
“We have to start thinking about the different possibilities,” she said. “We need to find out if a safer alternative exists. We are hoping that (industry officials) are thinking about how they can work quickly to start solving this problem.”
Safer Products for Washington involves designating chemicals of highest concern, determining if alternative chemicals are available and deciding if regulations are needed to protect people and the environment. Five classes of chemicals are currently in the second year of a four-year review. A new round of review for new priority chemicals will begin in 2022, and anyone can offer suggestions about what chemicals should be considered for study, said Lauren Tamboer, spokeswoman for the program.
Officials can be expected to debate whether the tire chemical 6-PPD should be considered a priority chemical under the Safer Products program. Another approach, if alternative chemicals are available, is for the Legislature to simply ban 6-PPD from tires at a future date.
That was the approach used to eliminate copper in automobile brake pads, after it was found that copper affects the sense of smell in coho salmon, potentially disrupting their ability to avoid predators and find their way home. The Washington Legislature approved the ban in 2010. California quickly followed, paving the way for new national standards. That was nine years before the Safer Products law was approved. Although it took time to implement, the ban on copper has proven successful, and several alternative brake materials are now on the market. Check out Water Ways, Nov. 6.
The 20-year effort to figure out what was killing the coho makes for a compelling story, one that has already captured the attention of news reporters across the U.S. and in Europe. Here are some of the stories published so far:

  • New York Times: “How Scientists Tracked Down a Mass Killer (of Salmon)”
  • Los Angeles Times: “Scientists solve mystery of mass coho salmon deaths. The killer? A chemical from car tires”
  • Seattle Times: “Tire dust killing coho salmon returning to Puget Sound, new research shows”
  • Marin Independent Journal: “Study finds California salmon face deadly threat from car tires”
  • CNN: “Salmon have been dying mysteriously on the West Coast for years. Scientists think a chemical in tires may be responsible”
  • UPI: “Toxic tire additive blamed for massive coho salmon die-offs”
  • The Guardian: “Pollution from car tires is killing off salmon on US west coast, study finds”
  • Science magazine: “Common tire chemical implicated in mysterious deaths of at-risk salmon”
  • The Daily Mail: “Toxic chemicals used to stop car tyres wearing out too fast are leaching into rivers and killing off salmon, researchers warn”
  • Chemistry World: “Tyre chemical drives mystery salmon deaths”
Stormwater picks up contaminants from vehicles. Photo: Daniel Parks (CC BY-NC 2.0) https://www.flickr.com/photos/parksdh/7014755513

Could tire discovery go beyond impacts on coho?

Scientists have suspected for several years that chemicals from tire wear particles are to blame for the deaths of thousands of coho salmon that have returned to spawn in Puget Sound’s urban streams. Sometimes referred to as “pre-spawn mortality” or “urban runoff mortality syndrome,” these deaths typically occur in streams near roads, and scientists have been analyzing a wide variety of automobile-derived chemicals to see if they produced similar toxic effects.
Now, thanks to some painstaking detective work by our partners at the University of Washington Center for Urban Waters (our groups are affiliated and share lab space) and many other collaborators, researchers can point to 6-PPD-quinone, a derivative from a preservative in tires called 6-PPD. The finding is as unexpected as it is fraught with implications. The chemical comes about only when the tire preservative is exposed to naturally occurring ground-level ozone in the environment creating a “transformation product” not previously identified. A paper outlining the discovery is published today (Dec. 3) in the journal Science and you can read more details from Christopher Dunagan in our magazine Salish Sea Currents.

A dying female coho salmon in the Lower Duwamish spotted by Puget Soundkeeper volunteers in October 2017. Photo: Kathy Peter
A dying female coho salmon in the Lower Duwamish spotted by Puget Soundkeeper volunteers in October 2017. Photo: Kathy Peter

In some ways the research on 6-PPD-quinone is just beginning. What started out as a local mystery could now catalyze studies around the world. Scientists wonder if the newly identified chemical is harming more than just coho.
“This is the first thing I’ve worked on in my career where I have no idea where the story ends,” says the paper’s co-senior author Ed Kolodziej. “It’s kind of what keeps you up at night. You’re wondering, ‘How wide is it?'”
Tires and similar rubber products are found everywhere in the world, he points out, and while 6-PPD-quinone has not been shown to kill some other species of salmon (it doesn’t appear to harm chum, for example) there is speculation that the impacts could be more widespread.
“We just have no idea,” he says. “All these questions are just totally wide open because there’s just no information out there.”
Given the potential ramifications, scientists may now begin to search for similar impacts among often vulnerable species such as stream invertebrates and amphibians, but it is also clear that humans are sometimes exposed to similar 6-PPD compounds. “We know the 6-PPD parent compound [has been documented] in house dust,” Kolodziej offers as an example. It also occurs in recycled tires that are used for crumb rubber playing fields and gym mats. “We’re generating a billion tires a year globally that need to be disposed of,” says Kolodziej. “All these things and all those recycled products likely contain some level of 6-PPD and the 6-PPD quinone as well. So, humans, I think, have a variety of exposure pathways.”
Could that endanger human health? “Again, we just have no idea,” Kolodziej says. 
What is known, however, are the implications for coho salmon. In the short term, Kolodziej hopes that the revelations in the Science paper will at least lead to more “salmon safe” tires.
“Tires need these preservative chemicals to make them last,” Kolodziej told UW News. “It’s just a question of which chemicals are a good fit for that and then carefully evaluating their safety for humans, aquatic organisms,” and other species, he says. “We’re not sure what alternative chemical we would recommend, but we do know that chemists are really smart and have many tools in their toolboxes to figure out a safer chemical alternative.”

View a video about the discovery below.

Copper is being phased out of brake pads to reduce harm to salmon, other creatures

Manufacturers of automobile parts are facing their first deadline for removing copper from brake pads. Most seem to be well prepared to meet the new requirements under Washington state law.
In 2010, Washington was the first state in the nation to outlaw copper in brake pads, after scientists discovered that the metal can severely affect the behavior of salmon. California soon followed, and by 2015 the industry came together with a nationwide agreement to phase out copper in brake pads.
By the end of this year, new brake pads must have no more than 5 percent copper by weight. By 2025, the limit is reduced to 0.5 percent. New cars going on the market must all have the new low-copper brakes. Some allowances have been made for auto-repair shops and retail stores that need to use up existing inventories.
Over time, reducing the amount of copper in brakes — and thus in roadway runoff — is expected to improve conditions for salmon and other aquatic organisms, according to officials with the Washington Department of Ecology.
[iframe align=”right” width=”560″ height=”315″ src=”https://www.youtube.com/embed/VkuwnYYElIA”%5D
I first learned about the toxic effects of copper in 2012, when Jen McIntyre, a Washington State University researcher, was studying how copper impairs the sense of smell in coho salmon. (Kitsap Sun, July 11, 2012). One dramatic experiment was shown in a video (this page), which reveals the behavior of young salmon with and without copper in the water.
Normally, when a predator attacks a group of salmon, the smell of torn flesh will alert nearby fish to the danger. They will suddenly stop moving about and hunker down to avoid predation.
Watch the green light at the top of the video screen and notice how the two coho are behaving. In the top view, the water contains no copper, while the bottom view shows a fish exposed to copper. At first, the two fish are acting alike, but when the light turns red and the “alarm odor” is added, you can see one fish taking steps to avoid predation and the other still swimming about, much more likely to being eaten.
Since the sense of smell is critical to helping spawning salmon find their way back to their home stream from the ocean, copper may confuse their travel, which could hinder survival of the entire local population. Various effects of copper are reported in a brief article in “Fish Pathology.”
Copper was used for years in many brake pads for its ability to dissipate heat and allow for stable and smooth braking. Despite the value of copper, manufacturers were convinced by scientific research that the metal can be harmful in the environment, and they cooperated in a 10-year phase-out plan. (See 2010 news release from Copper Development Association.)
[iframe align=”right” width=”560″ height=”315″ src=”https://www.youtube.com/embed/MZWkG0PVTdA”%5D
Now, manufacturers are reporting that replacement materials have been found and are being incorporated into newer brake pads. Some materials even offer added benefits, such as reducing brake noise, according to reports. See Hitachi Chemical’s handout on advanced brake pads using graphite and titanite. More common materials included in brake pads are ceramics, Kevlar and carbon semi-metallic, according to “Common Brake Pad Questions …” on the “Know Your Parts” website sponsored by the Automotive Aftermarket Suppliers Association.
In reading the literature about brake pads, I quickly realized that these seemingly simple parts are highly engineered and critical to the proper functioning of a car — and well they should be, given that brakes may be the key to avoiding a car crash and reducing injury.
Materials and brake design are quite complicated. Among the articles offering advice for consumers:

I suspect, based on these and other articles, that the newer brake pads may cost somewhat more than the old ones, particularly for products made with advanced materials used for the highest performance. But if you pay someone to install your brakes, you probably won’t notice much difference in the overall cost.
The new requirements for brake pad materials are outlined in a memorandum of understanding signed by the federal Environmental Protection Agency, Environmental Council of States and eight industry groups representing brake manufacturers and suppliers. The MOU covers how the new brakes are tested, certified and identified for compliance with the new requirements.
Edge codes embedded on the brake pads identify the specific product and specify whether the brakes meet one of three levels of compliance. The codes include one of three letters: “A,” “B” or “N,” with “B” meeting the requirements coming up at the end of this year and “N” meeting the most stringent standards with less than 0.5 percent copper and no asbestos, chromium, lead, mercury, cadmium or antimony.

Coho salmon can be affected by copper in the water.
Photo: NOAA, Southwest Fisheries Science Center

“The industry is ahead of schedule,” according to Laurie Holmes, senior director for environmental policy with the Motor & Equipment Manufacturers Association. She added that manufacturers of friction materials used in brakes have been working hard to produce new materials for environmental protection as well as performance.
As of this month, about 60 percent of the brake pads registered for use with NSF International already meet the certification “B” or “N,” with nearly 50 percent at the higher “N” level.
A “leaf mark” logo on brake-pad packaging tells the purchaser what level of compliance has been reached. One, two or three leaves are colored in to represent “A,” “B,” or “N” compliance.
Unmarked products manufactured before the new standards went into effect may be sold until 2025, according to guidance from the Washington Department of Ecology. See also Ecology’s 2016 report to the Legislature: Washington’s Better Brakes Law: A national model for improving water quality (PDF 558 kb).
In Washington, the Department of Ecology will be in charge of making sure that manufacturers, retailers and installers follow the rules for copper in brake pads.
“Our goal at Ecology is to keep people in compliance,” said Lauren Tamboer, spokeswoman for Ecology’s Hazardous Waste and Toxics Reduction Program. Eventually, Ecology officials plan to conduct testing of brake pads being sold in Washington to ensure compliance with the regulations.
According to EPA statistics, Washington state motorists were putting 250,000 pounds of copper into the environment in 2011, shortly after passage of the new law. Based on estimates in California, as much as 61 percent of that copper will be eliminated as a result of the new brake pad materials.

Tidal forest as viewed from an inner waterway of Otter Island in the Snohomish River estuary. Photo: Jeff Rice/PSI

The lost tidal forests of Puget Sound

Hundreds of years ago, old-growth cedar and spruce loomed over estuaries and bottom lands throughout Puget Sound, creating what are known as tidal forests. These forests were the Pacific Northwest’s answer to the Everglades — giant spongy swamps with a touch of saltwater that made up some of the finest salmon habitat in the region.
This week we travel to Otter Island, one of the last of these forests. It is a journey into Puget Sound’s past and maybe, scientists hope, its future.
Read the full story in Salish Sea Currents.

A dying female coho salmon in the Lower Duwamish spotted by Puget Soundkeeper volunteers in October 2017. Photo: Kathy Peter

Chemicals from automobile tires suspected in coho deaths

Findings authored this month by University of Washington scientists at the Center for Urban Waters and their collaborators provide new insight into “urban runoff mortality syndrome” affecting Puget Sound coho.  
By Jeff Rice
Chemicals linked to automobile tires have been found in stormwater associated with the widespread deaths of coho salmon in Puget Sound. The findings were presented this month in the journal Environmental Science & Technology and elevate tires as a prime suspect in “urban runoff mortality syndrome,” a condition that has been endangering coho salmon runs in the region.
For nearly two decades, researchers have been mystified by sudden die-offs of coho entering Puget Sound’s urban streams, particularly after it rains. The syndrome is thought to affect more than a third of the coho’s local range and may wipe out some spawning stocks entirely, scientists say.
As runoff from rain and snow flows downhill into Puget Sound, it picks up toxic chemicals from roadways and other surfaces. This deadly mixture will kill adult coho salmon within hours of exposure, but scientists have so far been unable to identify which of the potentially thousands of chemicals found in stormwater are lethal to the fish or where they come from.
While the authors caution that the findings do not show a definitive link between tires and coho deaths, they report that “the results indicate that [tire wear particles] are an under-appreciated contaminant source in urban watersheds.” They argue that the assessment of tires as a potential source of toxic contaminants should be a research priority.
The paper, co-authored by scientists at the University of Washington Center for Urban Waters, identifies a “chemical signature” of tire particles present in water samples where coho mortality was observed [Editor’s note: the Center for Urban Waters is a partner and collaborator with the Puget Sound Institute].
The paper’s lead author, University of Washington research scientist Kathy Peter, compared the findings to a chemical fingerprint. “We detect as many chemicals as possible in [each water sample],” Peter says, “and the chemicals that we detect in every sample that killed a coho are the chemical fingerprint of the mortality syndrome.”
Samples included stormwater runoff from the 520 bridge in Seattle and two other locations around Puget Sound where coho salmon were found dead or dying from exposure to stormwater. Researchers found chemicals from tire wear particles in every sample. Other chemicals from automotive sources such as motor oil, gear oil and antifreeze were also present in smaller numbers, but those from tire wear particles had the clearest chemical signature. Scientists have long suspected vehicles and roadways as a major culprit because the coho deaths most often occur in proximity to roads.
The research is part of a collaboration between scientists at the University of Washington, Washington State University, and NOAA. Authors of the paper include UW scientists at the Center for Urban Waters, the Southern California Coastal Water Research Project, NOAA and Washington State University School of the Environment.
The study was conducted using a new method of non-targeted screening of stormwater samples through high resolution mass spectrometry conducted at the Center for Urban Waters labs in Tacoma. These sensitive instruments allow scientists to identify hundreds to thousands of chemical compounds at low levels in every sample.
“When you run a stormwater sample, you might see 1,000 or 2,000 features, and each feature is a chemical,” Peter told our publication Salish Sea Currents earlier this year. “Some of them will be natural, but some will be synthetic compounds that you need to test.”
Paper co-author Ed Kolodziej of the University of Washington heads the lab where the study was conducted and will continue research into contaminant signatures of stormwater with support from a recent NSF grant. The project includes a collaboration with citizen scientists who will alert project members to salmon die-offs as they are happening. Kolodziej’s team will then collect and analyze water and tissue samples from these sites.
While scientists continue their research into identifying the chemical source of urban runoff mortality syndrome, scientists at Washington State University and NOAA have found that a relatively simple mixture of sand and soil can filter out many of the contaminants and can prevent the deadly effect on fish. Wildlife managers across the West Coast are hoping to eventually reduce coho deaths through a combination of stormwater filtration and eventually source control. 
Citation:
Using High-Resolution Mass Spectrometry to Identify Organic Contaminants Linked to Urban Stormwater Mortality Syndrome in Coho Salmon. Katherine T. Peter, Zhenyu Tian, Christopher Wu, Peter Lin, Sarah White, Bowen Du, Jenifer K. McIntyre, Nathaniel L. Scholz, and Edward P. Kolodziej. Environmental Science & Technology. DOI: 10.1021/acs.est.8b03287
 

University of Washington associate professor Ed Kolodziej

PSI collaborator receives NSF grant to study coho deaths

PSI collaborator Ed Kolodziej has received a $330,000 National Science Foundation grant to expand his research on toxic pollutants in Puget Sound. Kolodziej’s project will identify chemicals in stormwater that are killing coho salmon and endangering some spawning runs. The project includes a collaboration with citizen scientists who will alert project members to salmon die-offs as they are happening. Kolodziej’s team will then collect water and tissue samples from these sites that they will analyze at the labs of PSI’s parent group the Center for Urban Waters.
Project summary
In rapidly urbanizing areas of the Unites States, stormwater runoff is a major water quality and treatment problem because it accumulates many harmful chemicals from our homes, roads, and cities as it flows downstream. However, the chemical make-up of urban stormwater runoff is poorly understood although it is known to be harmful to fish and aquatic ecosystems (often called “urban stream syndrome”). This project will focus on identifying toxic chemicals in urban stormwater, especially focusing on understanding the link between stormwater pollution and observations of acute mortality in adult coho salmon in the Pacific Northwest. This project will measure harmful pollutants in stormwater so we can better manage urban water quality and protect fish such as the economically and culturally important coho salmon. Citizen scientists will help monitor watersheds for salmon mortality as it happens, and alert project researchers to collect water and tissue samples during acute mortality events. The project will work with citizen science groups, regional agencies, and the Center for Urban Waters (Tacoma, WA) to collaborate with local, regional, state, and tribal communities who are very interested in protecting salmon for economic and cultural reasons.
Relative to well-studied urban pollutant sources such as municipal wastewater effluent, very little is known about the chemical composition of urban stormwater runoff despite its importance as a major source of chemical pollutants to receiving waters.In fact, in the Pacific Northwest, an unexplained acute mortality phenomena occurs widely in urbanized watersheds where 50-100% of adult coho salmon quickly (1-4 h) perish after urban stormwater exposure.Because salmon mortality occurs prior to spawning and severely compromises reproductive output, local extinctions and failed stream restoration efforts focused on salmon habitat and health are expected. This project will focus on characterizing the identity and quantity of novel contaminants in urban stormwater using high-resolution mass spectrometry, especially seeking to identify stormwater contaminants with problematic structures (e.g. metabolic poisons that inhibit mitochondrial electron transport and induce cellular hypoxia).Water and tissue samples collected by citizen scientists will be screened using broad spectrum, suspect and non-target analyses to identify novel pollutants in urban stormwater. Chemical bioactivity will be selectively screening via in-silico receptor docking to detect novel bioactivity from high interest detections. Collaborating with ongoing ecotoxicology efforts, selective fractionation and chemical screening will be used to identify toxicant candidates in toxicologically active samples and link toxicant chemical characteristics to typical stormwater runoff treatment systems mechanistically. Project outputs will be broadly disseminated through collaboration and outreach efforts to local and regional citizen science programs. Through the project affiliation with the Center for Urban Waters, additional outreach to local, regional, state, and tribal stakeholders, many of them very interested in salmonid health for economic and cultural reasons, will occur.Project collaborations will include regional municipalities and agencies such as the Puget Sound Partnership, a Washington state agency dedicated to protecting the Puget Sound ecosystem, as well as NOAA-NMFS researchers and regulators focused on the health of economically important salmon populations. Via project characterization efforts, the management of urban stormwater quality can be improved by improved capabilities for chemical source control and optimization of treatment technologies.
Related story in Salish Sea Currents: What is killing the coho? 

University of Washington associate professor Ed Kolodziej

PSI collaborator receives NSF grant to study coho deaths

PSI collaborator Ed Kolodziej has received a $330,000 National Science Foundation grant to expand his research on toxic pollutants in Puget Sound. Kolodziej’s project will identify chemicals in stormwater that are killing coho salmon and endangering some spawning runs. The project includes a collaboration with citizen scientists who will alert project members to salmon die-offs as they are happening. Kolodziej’s team will then collect water and tissue samples from these sites that they will analyze at the labs of PSI’s parent group the Center for Urban Waters.
Project summary
In rapidly urbanizing areas of the Unites States, stormwater runoff is a major water quality and treatment problem because it accumulates many harmful chemicals from our homes, roads, and cities as it flows downstream. However, the chemical make-up of urban stormwater runoff is poorly understood although it is known to be harmful to fish and aquatic ecosystems (often called “urban stream syndrome”). This project will focus on identifying toxic chemicals in urban stormwater, especially focusing on understanding the link between stormwater pollution and observations of acute mortality in adult coho salmon in the Pacific Northwest. This project will measure harmful pollutants in stormwater so we can better manage urban water quality and protect fish such as the economically and culturally important coho salmon. Citizen scientists will help monitor watersheds for salmon mortality as it happens, and alert project researchers to collect water and tissue samples during acute mortality events. The project will work with citizen science groups, regional agencies, and the Center for Urban Waters (Tacoma, WA) to collaborate with local, regional, state, and tribal communities who are very interested in protecting salmon for economic and cultural reasons.
Relative to well-studied urban pollutant sources such as municipal wastewater effluent, very little is known about the chemical composition of urban stormwater runoff despite its importance as a major source of chemical pollutants to receiving waters.In fact, in the Pacific Northwest, an unexplained acute mortality phenomena occurs widely in urbanized watersheds where 50-100% of adult coho salmon quickly (1-4 h) perish after urban stormwater exposure.Because salmon mortality occurs prior to spawning and severely compromises reproductive output, local extinctions and failed stream restoration efforts focused on salmon habitat and health are expected. This project will focus on characterizing the identity and quantity of novel contaminants in urban stormwater using high-resolution mass spectrometry, especially seeking to identify stormwater contaminants with problematic structures (e.g. metabolic poisons that inhibit mitochondrial electron transport and induce cellular hypoxia).Water and tissue samples collected by citizen scientists will be screened using broad spectrum, suspect and non-target analyses to identify novel pollutants in urban stormwater. Chemical bioactivity will be selectively screening via in-silico receptor docking to detect novel bioactivity from high interest detections. Collaborating with ongoing ecotoxicology efforts, selective fractionation and chemical screening will be used to identify toxicant candidates in toxicologically active samples and link toxicant chemical characteristics to typical stormwater runoff treatment systems mechanistically. Project outputs will be broadly disseminated through collaboration and outreach efforts to local and regional citizen science programs. Through the project affiliation with the Center for Urban Waters, additional outreach to local, regional, state, and tribal stakeholders, many of them very interested in salmonid health for economic and cultural reasons, will occur.Project collaborations will include regional municipalities and agencies such as the Puget Sound Partnership, a Washington state agency dedicated to protecting the Puget Sound ecosystem, as well as NOAA-NMFS researchers and regulators focused on the health of economically important salmon populations. Via project characterization efforts, the management of urban stormwater quality can be improved by improved capabilities for chemical source control and optimization of treatment technologies.
Related story in Salish Sea Currents: What is killing the coho?