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Images: Red Tide—Gone for Now, But Back Next Year?

At the height of the potent 2005 bloom of Alexandrium fundyense, coastal resource managers closed shellfish beds from Maine to Martha?s Vineyard. This map was compiled from information provided by the Massachusetts Division of Marine Fisheries, the New Hampshire Department of Environmental Services, and the Maine Department of Marine Resources. Individuals should consult local shellfish wardens regarding up-to-date closures.

From left: physical oceanographer Dennis McGillicuddy, research assistant Kerry Norton, and biological oceanographer Bruce Keafer draw samples from a CTD rosette, which measures conductivity, temperature, and depth while collecting water. During several expeditions on the WHOI coastal vessel Tioga, the researchers examined coastal waters for Alexandrium cells and for the water-borne nutrients that allow them to flourish.

Research associate Bruce Keafer looks for Alexandrium cells with a microscope during a research cruise on Tioga.

A computer model shows how the pattern of northeasterly winds?which dominated in spring 2005?can push Alexandrium cells down from the Gulf of Maine into Massachusetts Bay and Cape Cod Bay. In typical years, prevailing breezes from the southwest usually blow the cells out to sea before they can flow into Massachusetts Bay. Reds and oranges show areas of highest concentration. (Don Anderson Laboratory, WHOI)

Researchers from WHOI use fluorescent microscopy to positively identify and count Alexandrium fundyense cells in the laboratory in Woods Hole. Visual identification of cells was also done under a microscope at sea.