A Pacific oyster is shucked in this June 18, 2010 file photo. (Ted S. Warren / AP)

WA - Predicting Harmful Algal Blooms Using Molecular Detection

TACOMA, WASH. — Alexandrium catenella is a toxic species of microscopic, single-celled marine algae that produces saxitoxins, a group of potent neurotoxins that cause paralytic shellfish poisoning along the Pacific and Atlantic coastlines of the U.S. and Canada. Paralytic shellfish poisoning, or PSP, is a potentially fatal illness resulting from eating shellfish that have ingested Alexandrium cells and concentrated the saxitoxins in their tissue.

Alexandrium is most abundant during the summer and spends the winter in marine sediments on the floor of coastal bodies of water, such as Puget Sound, as a dormant resting cyst. When environmental conditions are favorable during the spring and summer, these cysts germinate to form swimming cells in the water column where they multiply and may be food for shellfish. (Life Cycle of dinoflagellate Alexandrium catenella.) The distribution and abundance of cysts in the sediment during the winter can be used to identify where there is greater potential for Alexandrium to bloom.

A bloom is a rapid increase in the amount of Alexandrium in a body of water. During these harmful algal blooms (HABs), commercial shellfish harvests are delayed or cancelled and public beaches are closed to protect human health. The Washington State Department of Health monitors shellfish for the presence of the saxitoxins produced by Alexandrium, ensuring the safety of shellfish consumers.

The National Centers for Coastal Ocean Science, a research office of the National Oceanic & Atmospheric Administration (NOAA), awarded a multi-year research grant of $560,000 to UW Tacoma and the University of Alaska Fairbanks as part of a nationwide effort to improve monitoring of and response to HABs along the U.S. coasts. This project is in partnership with NOAA’s Beaufort Laboratory in North Carolina.

Dr. Cheryl Greengrove of the Sciences & Mathematics Division in the School of Interdisciplinary Arts & Sciences (SIAS/SAM) and co-principal investigator Julie Masura, senior lecturer in SIAS/SAM and research affiliate faculty with the Center for Urban Waters, will be leading the effort. UW Tacoma’s Greengrove and Masura are at the forefront of Alexandrium detection in Puget Sound, using methods first developed at Woods Hole Oceanographic Institution. Masura is a world-class expert at identifying cysts in sediment samples using a microscope, a critical but labor-intensive and time-consuming process. UW Tacoma undergraduate researchers will also be involved in field sampling and lab work for this project.

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