Puget Sound’s growing nutrient problem

An algae bloom covers a huge section of Lake Erie. Photo courtesy of NASA.

An algae bloom covers a huge section of Lake Erie. Photo courtesy of NASA.

First there was “The Blob” that fed last year’s massive algae bloom in the Pacific Ocean. Now there is another monster getting our attention. You might call it “The slime that ate Lake Erie.”

The incredible images of Lake Erie’s expanding blanket of green show the familiar effect of nutrient pollution. Nutrients such as phosphorous and nitrogen have been flowing into the giant lake primarily from sources like agricultural fertilizer and wastewater. This has led to a 700-square-mile algae slick, alarming officials worried about potential buildups of dangerous algal toxins or areas of low oxygen known as “dead zones.”

This sort of thing is well-known in the Pacific Northwest. Decades ago, Lake Washington faced a similar problem due to unchecked dumping of human waste that made the lake un-swimmable and prone to green slime and bacteria. At one point, an estimated 20 million gallons of sewage per day flowed directly into Lake Washington. Then, in the 1960s the city of Seattle initiated tighter pollution controls that diverted sewage to treatment plants, cutting the amount of raw sewage entering the lake to virtually zero.

Lake Washington is often touted as a pollution control success story, and other water bodies like Puget Sound have followed suit. Despite occasional high profile overflows like last year’s massive sewage spill at the West Point Treatment Plant, most of the wastewater that flows into Puget Sound is now treated in some way. (The state is also taking comments on a rule that would make it illegal for boats to discharge treated or untreated waste into Puget Sound.) Parts of Canada still release raw sewage into our shared waters to the north, although Victoria, B.C. finally approved development of a tertiary sewage treatment plant last year.

Scientists will be quick to tell you that, at the very least, some sewage treatment is better than no treatment. It filters many of the potential pathogens that can come with raw sewage, and a whole lot more. But what about those nutrients?

What most of Puget Sound’s sewage treatment plants don’t remove — at least to a significant degree — are nutrients. At most normal levels, these nutrients are natural and essential for the health of the ecosystem. However, when there are too many of them, problems can occur not unlike the situation in Lake Erie.

Image from the Salish Sea Model. Courtesy of the Pacific Northwest National Lab, the Washington State Department of Ecology and U.S. Environmental Protection Agency.

Image from the Salish Sea Model. Courtesy of the Pacific Northwest National Lab, the Washington State Department of Ecology and U.S. Environmental Protection Agency.

For a long time, Puget Sound was thought to be big enough to handle the nutrient load from its wastewater treatment plants and other sources. Now, a new mathematical model shows that we are coming up against the limits of the system. The region is expected to grow by more than 1.5 million residents within the next two decades, putting huge strains on wastewater infrastructure. Add to that climate change that may lower stream flows that normally help to circulate and mix the water in Puget Sound. The model says these two factors will contribute to nutrient build-up and will likely mean increasing problems with water clarity and dissolved oxygen throughout the Sound.

The region is once again at a turning point. Officials say current levels of sewage treatment are not enough.

“Puget Sound’s health is degrading due to increasing levels of nutrients that are adversely affecting water quality,” reports the Washington Department of Ecology on its website. “We are finding that nutrients in Puget Sound are out of balance altering some of its fundamental physical, chemical, and biological functions.” The imbalance could affect sensitive plants like eelgrass as well as salmon and forage fish sensitive to low oxygen, Ecology says.

Ecology is now working on a nutrient source reduction project, and in 2018 is expected to use that research to help guide a collaborative “implementation strategy” related to the state’s Marine Water Quality “Vital Sign”. Watch for more coverage of nutrients here and in our online Encyclopedia of Puget Sound as the story develops.

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New project searches for contaminants of emerging concern

PSI research scientist Andy James

PSI research scientist Andy James

PSI research scientist Andy James has been funded by the Environmental Protection Agency’s National Estuary Program to identify contaminants of emerging concern (CECs) in the waters of Puget Sound.

There are literally thousands of man-made chemicals known as CECs circulating in local waters, but very little is known about their impacts on wildlife. They are often found in tiny concentrations and can include residuals from pharmaceuticals and personal care products that are flushed through treated wastewater.

James’ project will extend through May 2019 and will focus on the non-targeted sampling of marine waters and shellfish, as well as selected streams in Puget Sound. James will use mass spectrometry to analyze samples with an eye toward identifying CECs that might have the potential to cause risk to aquatic organisms.

Collaborators include researchers at the University of Washington Center for Urban Waters, the Department of Ecology and the Washington Department of Fish and Wildlife.

Funding Amount: $200,000.

Project duration: Now through May 2019.

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Healthy stream, healthy bugs

Benthic invertebrates range in size from those easily seen with the naked eye to those that cannot be spotted without the use of a microscope. Photo: Christopher Dunagan

Benthic invertebrates range in size from those easily seen with the naked eye to those that cannot be spotted without the use of a microscope. Photo: Christopher Dunagan

Many groups have been formed around the goal of saving salmon, but few people talk about a concerted effort to save microscopic creatures. Whether or not a pro-bug movement catches on, future strategies to save salmon are likely to incorporate ideas for restoring streambound creatures known as benthic invertebrates. Read our latest story in Salish Sea Currents. 

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Marine Waters report provides overview of 2015 conditions in Puget Sound

Marine Waters 2015 report cover

Marine Waters 2015 report cover

The Puget Sound Ecosystem Monitoring Program released its fifth annual Marine Waters Report today. The report provides an assessment of marine conditions for the year 2015 and includes updates on water quality as well as status reports for select plankton, seabirds, fish and marine mammals.

According to the report, water temperatures broke records throughout Puget Sound. The year was also the worst on record for two distinct stocks of Pacific herring. You can read the full report on the Puget Sound Partnership website. 

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New theory rethinks spread of PCBs and other toxics in Puget Sound

Puget Sound's orcas are among the most contaminated marine mammals in the world. Photo: Minette Layne (CC-BY-2.0) https://en.wikipedia.org/wiki/Killer_whale#/media/File:Orca_porpoising.jpg

Puget Sound’s orcas are among the most contaminated marine mammals in the world. A new theory rethinks how PCBs and other toxics enter the food web.Photo: Minette Layne (CC-BY-2.0)

Last month, more than 1100 scientists and researchers converged on Vancouver, B.C. to attend the Salish Sea Ecosystem Conference. The biennial conference is the region’s largest gathering on the state of the ecosystem, and we sent a group of reporters to bring back some of the highlights. Over the next several months, we’ll be collecting those highlights into a new series on the Encyclopedia of Puget Sound. We kick things off today with a must-read story from Christopher Dunagan. He reports that scientists may be changing their view of how PCBs and other toxics enter the Puget Sound food web. Read the story in Salish Sea Currents.

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