| Long-lived Deep-sea Fishes Imperiled by Technology, Overfishing; 'We Shouldn't Eat Grandmother' | |
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Source: Underwatertimes |
2/18/2007 |
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Many commercially prized fish from the depths of the world's oceans are severely threatened by over-fishing and the species' ability to recover is constrained by the fishes' long lifespans and low reproductive success, a panel of experts said today at the annual meeting of the American Association of the Advancement of Science. Some of the fish species living at depths greater than 500 meters take decades to reach breeding maturity, so there are no quick-fix remedies available to replenish the population, said Selina Heppell, a fisheries biologist from Oregon State University.
"The harvest of deep-sea fishes is a lot like the harvest of old-growth timber," Heppell said, "except we don't ‘replant' the fish. We have to depend on the fish to replenish themselves. And the habitat that used to provide them protection – the deep ocean – is now accessible to fishing because of new technologies." |
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Among the most recognized deep-sea species at-risk are orange roughy and Patagonian toothfish, better known as Chilean sea bass. In the deep ocean off the Pacific Northwest, sablefish – also known as black cod – are another depleted species. Deep-sea fishes grow slowly because of limited food sources and slower metabolisms and many don't reach sexual maturity for 30 to 40 years, Heppell said. The harvest of older fish may have an even greater impact on these threatened populations because older fish are more likely to breed successfully than younger fish.
"When you buy orange roughy at the store, you are probably purchasing a filet from a fish that is at least 50 years old," Heppell said. "Most people don't think of the implications of that. Perhaps we need a guideline that says we shouldn't eat fish that are as old as our grandmothers." |
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