With data from last year's cyst counts, the WHOI and NCSU team ran their computer model through a range of scenarios, using the predominant regional wind patterns and ocean conditions from each year since 2004. (See figure......)
According to He and McGillicuddy, the simulations suggest a moderately large regional bloom of Alexandrium, falling in the mid range of those that have occurred over the last five years. Red tides during those years have ranged from very large ones that stretched from the Canadian border to southern Massachusetts, including Cape Cod and the Islands, to small outbreaks that have only caused limited harvesting closures in Maine, New Hampshire, and northern Massachusetts.
The researchers have found that toxicity in near-shore shellfish is the highest for years in which northeasterly storms occur, which tend to drive Alexandrium cells toward the southern New England coast. When southwesterly winds dominate, the algae tend to remain offshore. So even when there are a lot of cells in the Gulf of Maine, toxicity can be confined to offshore waters if the winds and currents cooperate.
The Alexandrium cells can be expected to appear in surface waters in early April. By the end of that month, cells usually begin to appear in large numbers in the waters off coastal Maine and New Hampshire, which is when and where the first reports of toxicity typically appear. As the coastal bloom is transported to the south, the Massachusetts shoreline can be impacted as well. The severity of this year's outbreak along the coast will depend in large part on the wind patterns in May, June, and July.
The GOMTOX researchers regularly share their results with coastal resource and fisheries managers in six states and at the National Oceanic and Atmospheric Administration, the Environmental Protection Agency, and the Food and Drug Administration (which oversees the safety of offshore shellfish be
|Contact: Media Relations|
Woods Hole Oceanographic Institution