Donald M. AndersonPurpose This website is intended to provide background information as well as current observations and commentary on the status of Paralytic Shellfish Poisoning (PSP) outbreaks in the northeast United States. The content is provided for informational purposes only, and should not be used to guide recreational or commercial decisions regarding the harvesting of shellfish or other fisheries products within the region. History of PSP in New England Prior to 1972, PSP toxicity was historically restricted to the far eastern sections of Maine near the Canadian border, with the first documented PSP in Maine in 1958. In 1972, a massive, visible red tide of Alexandrium fundyense stretched from southern Maine through New Hampshire and into Massachusetts, causing toxicity in southern areas for the first time. Virtually every year since the 1972 outbreak, western Maine has experienced PSP outbreaks, and on a less-frequent basis, New Hampshire and Massachusetts have as well. This pattern has been viewed as a direct result of Alexandrium cysts being retained in western Gulf of Maine waters once introduced there by the 1972 bloom. Between 1994 and 2004 there was virtually no toxicity in Massachusetts Bay (see figure). Significant regional-scale Alexandrium fundyense blooms occurred in both 2005 and 2006. The 2005 event was longer, extended further to the south and had higher cell concentrations and shellfish toxicities. In 2007, toxicity was restricted to sections of Eastern and Western Maine. A large, offshore bloom was documented on Georges Bank as well. Details on these bloom events are provided in separate sections, accessed through the navigation buttons to the left. Current Status May 30, 2008 As of this writing, the 2008 bloom of Alexandrium fundyense is proceeding in a manner strikingly similar to that observed at the onset of the 2005 event. In 2005, for example, the first areas to become toxic were in western Maine and New Hampshire, during the first week of May. This year, during that same interval, those areas again became toxic and were closed for shellfish harvesting (see comparison maps). In itself, this pattern is not that unusual, but in 2005, the toxicity subsequently spread to the south (Massachusetts) and to eastern Maine in subsequent weeks. This has also occurred in 2008 with toxicity extending further to the east in Maine, as well as along the coast of Massachusetts as far as the Cape Cod canal. We have conducted cruise operations to sample for Alexandrium cell abundance, and these observations are entirely consistent with the patterns of shellfish toxicity. During our first GOMTOX cruise in 2008, funded by the NOAA NCCOS program called ECOHAB with leverage from the NSF/NIEHS Centers for Oceans and Human Health, a large offshore bloom of Alexandrium fundyense was documented, along with the beginnings of the 2008 coastal bloom of this organism in western Maine. The offshore toxicity is significant, as Georges Bank and Nantucket Shoals are important resources for surfclams, ocean quahogs, and sea scallops, all of which can be affected by PSP toxins. Note that the portion of the scallop eaten in U.S. markets (the adductor muscle) is not affected by PSP toxins. Our second GOMTOX cruise is well underway and we are finding a significant number of Alexandrium cells along the outer Cape, Massachusetts Bay and the western Gulf of Maine. This distribution is again strikingly similar to Alexandrium abundances mapped out at this point in time during the 2005 bloom event. Note that we have been able to modestly extend our survey efforts with event response funds from the NOAA Center for Sponsored Coastal Ocean Research (CSCOR), and that the MWRA has also been running Alexandrium surveys in Massachusetts Bay. Looking ahead, the outlook is for continued PSP toxicity in the western Gulf of Maine, including NH, northern MA, and Massachusetts Bay, with the potential that toxicity might reach closure levels on outer Cape Cod, or even on the islands of Martha’s Vineyard and Nantucket. We know that Alexandrium has reached the outer Cape in reasonable cell abundances, but whether those levels are high enough to cause closures there, and high enough to persist during the southerly transport to the Islands remains to be seen. The winds over the next week or two will be important in determining the extent to which the toxicity in the western region persists and spreads. Sustained winds out of the southwest may stall the southward progression of the bloom and reduce its magnitude, whereas strong northeasterly winds may increase toxicity and spread the problem further. Furthermore, our experience also tells us that the progression of toxicity in Maine is generally from west to east, and as the 2008 bloom season progresses, we expect that the coast of Maine will have more closures in eastern waters over the next month or two. (For the April 24, 2008 WHOI press release, please click here.) Last updated: May 30, 2008 | |||||||||||||||||||||||
Copyright ©2007 Woods Hole Oceanographic Institution, All Rights Reserved, Privacy Policy. | |||||||||||||||||||||||
