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June 2003



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Harbor Porpoise Rescue




By Bill Curtsinger
An odd thing happens when a harbor porpoise swims into a net. It doesn't spin like a shark or fight like a tuna. It calmly and quietly gives up. That's not what I expected from a marine mammal that, in the wild, seems as highly strung as an Irish setter. But the North Atlantic's smallest and least studied cetacean is full of surprises. Hard to spot with their hand-size black dorsal fins, harbor porpoises are also fearful of boats and divers, making research and photography difficult. No underwater images exist of harbor porpoises in their natural habitat, though pictures of dead ones abound. In the early 1990s up to 3,000 a year drowned in the Gulf of Maine region, mostly in gill nets. A hundred or so also died in herring seines. That prompted Duke University biologist Andy Read to work with herring fishermen on Grand Manan Island to rescue the animals—and learn something about them in the bargain.

"Where there are herring, you're gonna find those little porpoises," Grand Manan fisherman Herbert Lambert told me, dispensing a bit of local knowledge that has endured around the Bay of Fundy for centuries. Passamaquoddy and Micmac Indians caught herring in brush weirs and also ate harbor porpoises that preyed on the herring. Today's porpoises are merely by catch, a nuisance in modern weirs  and gill nets. Fence-like weirs can hold 20,000 dollars' worth of herring and often a dozen porpoises or more. As fishermen seine out the catch, herring and porpoises jam into a roiling ball. "It's a frightening environment for them," says Andy Read, who started the rescue program in 1991. "There's a lot of noise, and it's the first time in their lives they've been restrained." A decade ago most harbor porpoises trapped with the herring died. Now fishermen call Read's team when they spot a porpoise in their weirs and head out in their boats to help free it. Fishermen are paid for their time, scientists get valuable data, and the survival rate has hit 95 percent. Thanks to such conservation efforts—and to a steep decline in gillnetting—population estimates in the Gulf of Maine have doubled in the past decade to nearly 90,000.

At one weir we found more porpoises than the divers could handle. I shed my cameras and dove to one caught in the seine's folds, grabbed it, and hauled it over to the scientists' skiff. Working as smoothly as an Indy 500 pit crew, the researchers measured the length, weight, and girth, constantly bathing the porpoise in cold seawater. Most animals were tagged, and on some Read attached satellite-linked transmitters that recorded the porpoises' travels and dives for several months. One of these they named Owen, after my youngest son. I watched with pride as he darted off into the green water, and later I followed his progress on the Internet until his transmitter gave out. I imagine him making deep dives in the dark Atlantic, chasing silver walls of herring. I wonder what perils he'll encounter and if he'll enjoy a long and fruitful life, just as I wonder about my own 16-year-old son as he makes his first tentative tracks down Maine's highways with his new driver's license. Now if only I could stick a satellite tag on him. . . .

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