The Mast-Head: A Biotoxin’s Warning

   Shellfish fans in the Town of East Hampton got a reminder this week of just how lucky we are — for now. The State Department of Environmental Conservation ordered a huge swath of Shinnecock Bay closed on Tuesday until further notice after the detection of a powerful biotoxin there.

    According to a press release, the D.E.C. found saxitoxin in mollusk samples from Weesuck and Penniman Creek in Southampton at levels that could lead to paralytic shellfish poisoning. The ban covers 3,900 acres. Some 90 acres in Mattituck Creek were closed after the biotoxin was detected on April 3.

    Saxitoxin is dangerous, and can cause death in untreated and extreme cases. It gets into filter-feeding shellfish during some algae blooms. And when certain predatory fish, crabs, and snails feed on contaminated clams, mussels, or oysters, they accumulate it, too, and it can climb the marine food chain. In 1985, 14 humpback whales that died during a five-week period off Cape Cod were found to have symptoms associated with saxitoxin.

    Algae blooms of the sort that carry saxitoxin and other harmful single-cell organisms may or may not always be linked to excess nutrients in road and septic waste runoff into surface waters. It appears to researchers that weather changes that lead to temperature and/or salinity spikes could play a role.

    Shinnecock Bay is no great distance from East Hampton’s surface waters. While residential and commercial development there exceeds that development here, conditions are similar in some places, so we cannot assume we are not also in danger of harmful blooms. Saxitoxin can be detected only in a lab, and the D.E.C., which has suffered deep budget cuts, is really the only line of defense.

    Semi-stagnation, for example, othe sort that could occur if Napeague Harbor’s east inlet remains closed this spring, could be a risk as well. Lake Montauk, which is under tremendous environmental stress and has low rates of tidal exchange at its southern reaches, might be another place the toxin could emerge, particularly as the climate warms. This is something that regulators need to take very seriously.