Dying Lobsters: Preview of Future?
Jim King witnessed the mass death of lobsters in Long Island Sound in 1999.
Lobsters are part of Jim King's life. His father was a fisherman in Long Island Sound, off New York and Connecticut, and Jim has been a lobsterman himself for more than 40 years. He appreciates the mysteries and charms of lobsters: "You see trends over time in the fishery, but every time you think you've got the lobsters figured out, they do something different. They're a unique animal."
Jim has seen good and bad years since he started trapping. But in 1999, lobsters in the area began dying in record numbers. In parts of the sound, nearly all the lobsters died. Jim remembers the horror stories: Fellow lobstermen pulled up traps filled with dead lobsters.
Financial disaster follows lobster die-off
"A lot of folks in the western part of the sound depended on the fall molt," says King, referring to the period just after lobsters shed their shells and lay low until their new shells become hard. After this waiting period, they voraciously go for food in the traps. The two major molts—in June and early fall—are the lobstermen's biggest payday. In 1999, the lobsters never showed after the fall molt, and many lobstermen were plunged into financial ruin.
Trapping on the less-affected eastern part of the sound spared lobsterman King most of the economic misfortune. But the area where he traps still felt the after-effects: "It took its toll a few years later in terms of the number of stock."
The summer of 1999 was one of the hottest summers on record. The heat most likely contributed to the mass deaths and made the lobsters more susceptible to disease. It's a clear warning of how higher temperatures around the globe can disrupt ecosytems that people depend on for their livelihood.
In 2000 the U.S. Secretary of Commerce declared the Long Island Sound area a "resource disaster." The value of the lobster fishery fell from $42 million in 1998 to $10 million in 2002. Over $7 million dollars was allocated to assist the hard-pressed lobstermen.
Long decline started with bad year
By 2003, lobster populations were down 70 percent from 1998 levels. The die-off made 1999 more than just a bad year. King says, "All the bad things that can happen to a lobster resource happened in that one year. High water temperatures, hurricanes and on top of that we had mosquito spraying."
"It was a perfect storm," agrees Environmental Defense scientist Jake Kritzer. "Hot water drove the lobsters down into deeper waters to try to get where it was cooler and in the process it exposed them to toxic sediment and more crowded conditions that promote spread of disease."
Higher temperatures put lobsters at risk
Lobsters are cold-blooded (or poikilothermic). This means a lobster's body temperature is determined by the temperature of the water it lives in. Studies show that lethal temperatures for lobsters range from 75 to 86 degrees Fahrenheit.
Coastal bottom waters off the Long Island sound fall within the upper limit of the lobsters' tolerance, reaching an average of about 71.6 degrees Fahrenheit during the summer months. (CT DEP Water Quality Monitoring Program) Because the water in the western sound is shallow and doesn't mix much with the deep Atlantic Ocean waters, its temperature depends on the air above it. If air temperatures are high, the bottom waters, where lobsters live, can also warm up.
The summers of 1999 and 2002 were the fourth and fifth hottest in 108 years of record-keeping in Connecticut. New York City recorded its highest summer temperatures in 1999 and 2002. (National Climatic Data Center) That meant the sound was also unusually warm. The record-breaking heat most likely contributed to the mass deaths and helped make lobsters more vulnerable to disease.
An insecure future for lobsters and lobstermen
"This is my 43rd season," says King. "It's been up and down." It will take several more years for the lobster population to rebound from the 1999 die-off. But the lobster's long-term survival in the sound remains in question. Scientists predict that global warming could raise the average global temperature by four to 10 degrees Fahrenheit in the next hundred years. If global warming continues unchecked, Long Island Sound water temperatures—especially in the shallow western part—could become too high to support the lobsters.
A combination of limiting polluted runoff and slowing global warming can reduce stress on the lobster population. That would give lobstermen like Jim King a better chance of passing on the tradition. "I think the stocks are starting to come back now since the die-off," says King.
What You Can Do
Small changes to your daily routine can add up to big differences in helping to stop global warming.
Sources
CT DEP Water Quality Monitoring Program. This is an average for 1991-2002 from 6 axial stations running the length of the Sound.
D.W. McLeese. "Effects of Temperature, Salinity and Oxygen on the Survival of the American Lobster." Journal of the Fisheries Research Board of Canada. 1956, 13: 247–272.
Gornitz, Vivien; Hale, Steve; Larsen, Kate; Levine, Naomi; Rosenzweig, Cynthia; Sacks, Lauren. Bracing for Climate Change in the Constitution State. Environmental Defense. 2004. 32-33.
LoBue, C.; Howell, P. "Fishery Dependent Monitoring of the Long Island Sound Lobster Fishery" in the Third Long Island Sound Lobster Health Symposium Programs and Abstracts. 2003.
National Climatic Data Center. Climate of 2001 and 1998 Annual Assessments. www.ncdc.noaa.gov/oa/climate/research/monitoring.html.