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Keeping Seafood Safe

PULLMAN, Wash. – Ellen Preece wants to know if microcystins, liver-damaging toxins produced by algal blooms in freshwater lakes, accumulate in Puget Sound seafood.

She’s not the only one who wants to know. Preece, a doctoral student in the WSU School of the Environment, is helping the Washington Department of Health determine whether seafood accumulates enough microsystins to be a health concern for populations who rely on locally harvested seafood to meet their protein needs.

Measuring contaminants in mussels. Photo courtesy of Pacific Northwest National Laboratory
Measuring contaminants in mussels. Photo courtesy of Pacific Northwest National Laboratory

Microcystins are a group of amino acids produced by cyanobacteria, or blue-green algae, which thrive in freshwater lakes with high water temperatures and excess nutrients such as nitrogen and phosphorous. The problems have been traced to sewage, fertilizer, detergent, and animal waste. Previously found only in freshwater lakes, microsystins are now showing up in saltwater.

Lessons from the California Coast

News that recent sea otter fatalities on the California coast have been attributed to microcystins coming from freshwater lakes alerted regional scientists to the possibility that the same toxins could show up in Puget Sound shellfish.

“The Washington Department of Health is very interested in understanding this potential exposure pathway,” said Joan Hardy, a toxicologist with the state agency. The Department of Health has partially funded Preece’s research because of concerns that lakes in Kitsap and Pierce Counties could be contributing to the growing risk.

Recent immigrants (often from Asia) regularly depend on shellfish they harvest from the shores of Puget Sound as a protein source. A USGS Western Ecological Research Center study suggests that consuming saltwater shellfish harvested near river mouths could pose a risk to people because of the freshwater toxins.

Preece is also investigating microsystins on the Colville Indian Reservation, where tribal members fish for rainbow trout in lakes with poor water quality.

A Matter of Detection

Preece’s research focuses on refining methods for detecting microsystins in seafood. Using mussels collected from Puget Sound, she is developing protocols for a technique that can determine which variants of the microcystins are present at what concentrations. She is also developing standard methods for health agencies to use a more common, less expensive tool to screen for microsystins in fish and shellfish.

Both techniques provide information that is critical for assessing whether seafood poses a potential health risk. “We’re counting on Ellen’s interest in the analytical issues associated with this problem so that the Department of Health can give sound advice to the public,” Hardy said.

The Climate Change Factor

According to Preece, if a changing climate results in higher lake temperatures, we could see increases in these toxic algal blooms in freshwater lakes. Hardy agrees that climate change may be at play and that monitoring is warranted. “We’re really just beginning to look at climate change and whether it’s a factor in freshwater toxic algal blooms. We need to carefully monitor lakes over time to see if there is a trend in toxicity linked to changing temperatures or other environmental factors.”

Preece conducts her research in the limnology lab of Dr. Barry Moore in the WSU School of the Environment. Her work relies on partnerships with the Washington State Departments of Health and Ecology, departments of health in Kitsap and Pierce Counties, the King County Environmental Laboratory, and the Colville Confederated Tribes.

A recent recipient of a grant from the Natural Resource Conservation Endowment Fund at WSU and past recipient of an EPA STAR graduate fellowship, Preece expects to complete her doctoral work in 2014.

For more information about freshwater cyanobacteria blooms in Washington, go to https://www.nwtoxicalgae.org

Media Contacts

Ellen Preece, Research Assistant, 509-335-8560