Idled lobster traps at Cape Cod. Regulators say warmer seas are the reason traps in Buzzards Bay have come up increasingly empty in the last decade. Cape Cod Times File / Steve Heaslip

By Doug Fraser
dfraser@capecodonline.com
June 13, 2010 Too hot for a lobster? The imagination leaps to boiling water, followed by lots of melted butter. But the water temperatures that are killing off far more lobsters than make it into a cooking pot are of a much lower order. In what could be the first major economic blow to local fisheries pinned on global warming, regulators are contemplating shutting down the lobster industry from Buzzards Bay to Long Island Sound for five years due to a drastic population drop brought on by temperature changes of just a few degrees in inshore waters. Lobstermen south of Cape Cod have seen their catches nosedive for the past decade, from more than 20 million pounds in 1997 to less than 5 million last year. In the past, overfishing, water pollution, pesticides and an outbreak of shell disease were blamed for the failure of the fishery. But tough fishing regulations have done nothing to reverse the trend, and some scientists now believe water temperature may be the primary obstacle to recovery. “(The lobster decline) is a combination of factors that are all related back to changes in water temperature,” said Robert Glenn, a senior marine fisheries biologist with the state Division of Marine Fisheries. Glenn is also in charge of the Coastal Lobster Investigations arm of the fisheries division and is on the Atlantic States Marine Fisheries Commission’s technical committee for lobsters. It’s called trophic shift — when the environment changes so dramatically that the least tolerant resident species move out, and ones more adapted to live under those new conditions move in. As the ocean warms, even small increments mean big changes especially for cold-water species like lobster that are at the southern limit of their range in the waters off the Cape, said Michael Fogarty, the chief of the ecosystem assessment program at the Northeast Fisheries Science Center in Woods Hole. Fogarty was one of many scientists who worked on a 2007 report by the Union of Concerned Scientists that predicted that signature species like lobster would disappear from the waters south of the Cape as one of the many impacts of global warming. He pointed to research now under way at the fisheries science center that tracked three dozen marine species and found that two-thirds of them had shifted north due to warming water temperatures. The future doesn’t promise any relief. “We’ll definitely see ups and downs (in average water temperatures) related to other factors,” said Fogarty. “But the projections are that the overall trend will still be up.” Despite drastic new regulations that ended overfishing, there has been no evidence of a turnaround in Southern New England lobster stocks. In fact, indicators of abundance, like the numbers of juvenile lobsters that become legal-sized each year, have been worsening. Last year, the Atlantic States commission’s tech committee, a confab of lobster scientists, began looking for answers. What surprised them, said Glenn, was the complete lack of lobsters in many inshore areas where they used to be caught. That included little to no evidence of egg-bearing females or the tiny lobsters that settle on the bottom after they mature from free-floating larvae. The marine fisheries’ own lobster surveys showed that, in Buzzards Bay, for instance, many lobsters were found in locations all over the bay by research cruises in 1999. Over the next decade, researchers caught few, if any lobsters in the bay. In a trend mirrored up and down the southern New England coastline, lobsters were found congregating in the deeper, cooler waters of Vineyard Sound. It appeared that the whole population had moved west to get away from what had become an intolerable heat in the bay. …

Cape lobster industry faces crisis