STONY BROOK, NY - Another outbreak of lobster mortalities hit Long Island Sound this summer.
    Reports of weak, sluggish, dying, and dead lobsters started coming in around mid-August, right after bottom temperatures in the sound peaked at around 73°F, according to Carl LoBue, a biologist working with the New York State Department of Environmental Conservation.
    LoBue said that the affected lobsters had a distinct orange coloring to their "blood," or hemolymph, that showed through on the undersides of their tails and in their leg joints.
    Although there may be a correlation with the massive mortalities of 1999-2000 that devastated the sound's lobster industry, LoBue and others are leaning towards a theory that these current deaths may be linked to unusually high water temperatures that pushed the lobsters to the edge of their temperature tolerance range.
    Al Dove is the Cornell University representative and senior research associate in the Marine Disease and Pathology Consortium that is studying recent Long Island Sound lobster mortalities.
    Dove said the affected lobsters were found throughout much of the sound, from Mattituck in the east to Oyster Bay in the west.
    When he cut the animals open he found that their antennal glands, and sometimes their gills, were clogged with clumps of what turned out to be calcium carbonate. The antennal glands are located under the lobsters' eyes and filter out impurities from the blood, excreting urine and functioning much like our kidneys.

    Dove stressed that no scientific studies have yet been carried out, but he has formed a working hypothesis that he hopes to test soon.
    One possible explanation for the phenomenon goes something like this: The abnormally high water temperatures increased the tendency of the calcium carbonate to come out of solution and form crystals in the blood of the lobsters, resulting in a type of "ectopic shell deposit."
    In other words, these lobsters are laying down "shell" in places where it doesn't belong.
    Entire books have been written on the complex equilibrium that determines when the calcium carbonate stays dissolved in seawater and when it comes out of solution to form a solid. One of the many factors affecting that delicate balance is temperature.
    To grossly oversimplify the chemistry, dissolved calcium carbonate more easily precipitates out of solution at higher temperatures to form solid crystals. That's one reason why you find more coral reefs in warmer waters than in colder waters.
    Dove theorized that when the crystals of calcium carbonate circulating in the lobsters blood started to build up in the antennal glands, they may have triggered an inflammatory response, causing the lobsters' cells to engulf the crystals and leading to the large amorphous clumps that he found.

    When the antennal glands became so clogged with these "stones" that they could no longer function, Dove speculated that the animals suffered a type of "kidney failure" and the gills were called into service to try to clear the blood of excess calcium carbonate.
    Because lobsters' gills consist of hollow filaments lined up like a toothbrush, they too became quickly clogged, causing the tissue to die. Since the lobsters' clogged gill surfaces could no longer extract oxygen from seawater, the animals' respiratory efficiency plunged and they eventually suffocated and died.
    This drop in the lobsters' ability to get enough oxygen to live may have been exacerbated by hypoxia in Long Island Sound, a condition of drastically reduced oxygen concentrations in the water brought on by high temperatures, poor mixing, and high levels of decomposition.
    Dove pointed out that lobsters are designed to function best in water temperatures of around 55°F. Since they cannot regulate their body temperature as mammals do, the excessive heat this summer sped up their metabolism to double its normal rate.