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Extension Volunteers Work to Stem the Tide

A network of trained citizen volunteers is monitoring Maine's coast and looking for invaders from the sea. Every summer, tiny marine algae, a type of phytoplankton also known popularly as red tide, appear in Maine's coastal waters where they can turn shellfish from a valued resource to a potential poison.

"It was generally a low toxin year. Our volunteers try to monitor twice a week near locations where the Department of Marine Resources monitors shellfish for red tide. They gather water samples off docks and bridges and from boats, and conduct their analyses in the field," says network coordinator Wendy Norden of the Waldoboro office of University of Maine Cooperative Extension.

The volunteers in the Phytoplankton Monitoring Program have just completed their second year of activity. Their mission is to provide an early warning system to detect the plankton which can cause paralytic shellfish poisoning (PSP) and other problems for consumers of shellfish. Red tide is a bit of a misnomer, Norden notes, because most toxic algae do not turn the water red.

"If the volunteers find toxic algae in the water, they inform the Department of Marine Resources," says Norden. Participants from Wells to Eastport are working with Extension and the DMR with financial support from the Maine Outdoor Heritage Fund.

In one case last summer at Eastport, says Norden, volunteers identified Alexandrium, a red tide plankton, in the water nine days before evidence of toxins showed up in harvested clams. To ensure food safety, DMR officials harvest a small number of clams, grind the meat and inject mice with an extract. If present, the toxin produced by the algae is strong enough to kill a mouse within 15 minutes of injection.

The volunteers also found possible indications of another toxic algal species, Dinophysis. Scientists have been aware of its presence in Maine waters, but until now, they have had little knowledge of its abundance. Further testing revealed that the species was not present. Dinophysis causes diarrhetic shellfish poisoning.

A graduate of the University of Rhode Island, Norden conducts training sessions for volunteers and presents data collected by the network to organizations concerned with the quality of Maine's marine environment.

At present, more than 80 volunteers participate through 18 distinct monitoring groups at specific coastal locations. They look for four potentially toxic algae species, as well as non-toxic species.

Norden arranges twice-a-year training workshops in which volunteers receive information on how to collect samples, record data and report the results. In addition to the plankton, the volunteers collect information about salinity, water temperature and wind speed.

"The volunteers have microscopes for examining water samples and identifying different types of plankton," says Norden. "After they collect a water sample, they put it under the microscope and classify the potentially toxic algae as rare, common or abundant."

Scientists and government officials have known for many years that the Gulf of Maine harbors a toxic species, Alexandrium, which causes PSP. Researchers from universities in New England, private research labs and government agencies launched a five-year research project last spring to understand what conditions favor the growth and spread of Alexandrium plankton.