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Can Fewer Traps And Lines Help Whales And Overall Catch?
Whether that finding applies coastwide is a matter of further research. But Department of Marine Resources biologist Carl Wilson said the initial results of the Monhegan Island trap study offer food for thought, particularly at a time when fishermen are struggling with whale-conserving gear restrictions as well as seeing a drop in landings. Adjusted figures put landings for 2003 at 90 million pounds. Landings in 2007 represented a 40 percent decline, to 56 million pounds. “Things are changing,” said Wilson. “The big bang is starting to fizzle a little bit. Certain things aren’t working that well.” The state has seen a boom in the number of traps in the water; in 2007, 3.2-3.4 million tags were sold. Fishermen are also leaving their traps to set longer; last year, the average soak time was five days. Despite these efforts, fishermen are seeing their lowest catch rates per trap haul since the 1990s, and the lowest catch rate per trap haul per day since the 1980s, Wilson said. That rate averages 1.2 pounds per trap. Two times more lobsters are caught on hard, versus soft, bottom. The density of traps coastwide is 2,000 traps per square mile; midcoast Maine sees the greatest density. “There isn’t much of the coast of Maine that isn’t covered by traps at some time in the year,” Wilson said. Monhegan Island was selected as the study area due to its unique characteristic as a conservation area, formerly closed six months per year to fishing and fishing 600 traps, and now closed four months per year and fishing 300 traps. The closure is a tradition among that island’s fishermen going back a century. “It’s the only area you can go to set a trap and not see another trap in sight,” Wilson said. “It’s a very interesting area to study.” The two experiments, performed by seven fishermen with Mr. Wilson, were conducted from September-October 2005 and August-September 2007. In 2005, eight study areas of the same depth and bottom architecture were selected. Two areas each were set with 500 traps, 167 traps, and 50 traps. Two more areas were set to look at random soak times. The 500-trap areas had the lowest catch rates. In those areas, the highest rates were found around the edge, with the rate dropping toward the middle. In 5,000 hauls, 5,500 lobsters were caught, which conformed to the average state catch rate of one lobster per trap. In areas with 167 traps, 2,000 hauls took in 4,500 lobsters. The 75 percent decrease in the number of traps resulted in only a 15 percent drop in catch. However, there was a threshold to these results. In those areas with 50 traps, the catch dropped by 80 percent. This showed that there is a point when a decrease in trap numbers cannot be compensated for. The 2007 study was designed to follow up on the 2005’s random soak time work. The results were phenomenal, Wilson said. Over 3,500 hauls, 14,000 legal-size lobsters were caught, an average of four legal lobsters per trap. Eighty percent of the hauls had four legals or more. One haul teemed with about 40 lobsters. “Food for thought,” said Wilson, who stressed that he is not advocating for any particular action as a result of the studies. “I wanted to start a conversation about how this might translate to our fishery.” Wilson presented several scenarios that showed how the experiment might extrapolate to fishing practices, during a period from May-December. • In the first, a fisherman would set 800 traps, each left in the water for six days at a time, using 1,197 bushels of bait. There would be 32,000 traps hauls, averaging nine-tenths of a pound per haul. The bait bill would come to $30,000. • The second scenario showed 400 traps with six days soak time, using 598 bushels of bait. There would be 16,000 trap hauls, averaging 1.9 pounds per haul. Bait would cost $15,000. • The third scenario showed 200 traps with three days soak time, using 470 bushels of bait. In this scenario, because the soak time is halved, there would also be 16,000 trap hauls, averaging 1.9 pounds per haul. The bait bill would be $12,000. The three scenarios ultimately become a discussion that shows how money can be saved on bait. As far as any biological discussion is concerned, he said, the study of trap soaks shows that those in the water for longer periods of time come up with more dead lobsters. Traps soaked for six days average one dead lobster per 100 hauls; those in for three days average half that number. The studies show, at least, that there can be local and direct impacts on catch rates, Wilson said. There was some skepticism among fishermen as to whether the findings could be extended beyond Monhegan. One Swans Island fisherman said that, from the economic standpoint, shorter soakings meant more frequency in the boat on the water, which meant higher fuel costs. But a Monhegan fisherman said that last year’s change in the number of traps, from 600 to 300, while scary at first, is turning out to work just fine. “I wouldn’t trade it back to 600,” he said. “I’m having my best year now with 300 traps.” Wilson noted that data continue to stream in from Monhegan, since every fisherman there keeps an electronic log. Data for this fishing year, for example, shows that fishing during the first four months of the season has already exceeded previous years’ landings, with half the number of traps and hauling more frequently. Wilson said experiments of this kind need to be done in other areas along the coast. The experiments, he said, are sobering in that they show that, at least in one area, reducing the trap numbers won’t affect the overall catch. |
