What’s Up Down East?

On the assumption you have a taste for lobster, have you found it difficult to obtain at your local seafood restaurant? Does lobster seem more expensive than usual? If you read the dire predictions contained in Michael Powell’s article in the November 30, 2003 edition of The Washington Post, you can be forgiven for believing the waters off the coast of Maine are teeming with tropical fish and yield fewer lobsters because of global warming. On the contrary, in the 1970s, Maine’s annual lobster catch averaged 20 million pounds. By 1995, it had nearly doubled at 38 million pounds. In 2002, the lobster harvest ran to more than 61 million pounds, which was slightly less than 2001’s banner year. As they might say Down East, “Ah, yep, our lobster harvest has tripled in thirty years.”
     The increased availability of lobster is the result of three things: (1) a decline in the lobsters’ natural predators such as sea bass and cod, (2) higher water temperatures, and (3) more bait in the lobster traps providing juvenile lobsters a healthy and readily available diet. However, this is supposed to be a climate change story, so the Post’s staff writer casually dismisses all of these meddlesome realities and predicts the imminent decline of Crustaceanea. According to Powell:

Eventually, however, these same conditions that have proved so favorable for Maine’s lobsters could put them at risk. Warmer waters in southern New England already have attracted semitropical fish, which are aggressive about stalking lobsters... Warm water, too, may carry many pathogens and could account for the disfiguring shell disease found on lobsters in southern New England... Finally, scientists speculate that global warming could short-circuit the North Atlantic oscillation, the vast conveyor belt that brings warm ocean water north along the Gulf Current before it cools, sinks and rolls back south. That would result in a sharp drop in temperatures in the North Atlantic and would dramatically slow lobster growth. Lobsters cannot live in waters cooler than 30 degrees. Ocean temperatures dropped sharply last winter.

Space permits us an opportunity to point out only a few of the logical inconsistencies in Powell’s coverage.
     If semitropical fish are so aggressive, why does Maine report record lobster harvests? If increasing water temperatures are responsible for the increased catch, why haven’t warm-water pathogens been an issue during the last fifteen years, the time when global warming is supposed to have been most rampant? Finally, disruption of the oceanic conveyor belt (not the North Atlantic Oscillation, which is something completely different) appears to be little more than a ploy to work global warming into the story. It’s one of those “climate surprises” we hear about from time to time despite the lack of evidence for them.
     If you are willing to suspend disbelief, however, and assume the disruption of the Atlantic conveyor belt, how would that lower water temperatures off Maine? And, wouldn’t it be the antidote to the terrible effects of global warming if it did? We are compelled to offer this discomfiting fact: While ocean temperatures plunged dramatically last winter, the lobster harvest was spectacular. If it has been getting warmer, despite evidence to the contrary, then maybe, just maybe, a lobster isn’t as sensitive to changes in ocean temperature as the article implies.
     But don’t take our word for it. According to marine biology professor Diane Cason, the founder of the Lobster Conservancy, “Honestly, at this point, I don’t see much to worry about down there.” Sorry, Michael.