Fishy Business
The problems with fishery management are mounting—and time may be running out
- By Anne Sasso
- Smithsonian.com, September 24, 2007, Subscribe
(Page 2 of 3)
This effect is especially clear along the East Coast of the United States. A study published in Science in March by Dalhousie scientist Ransom Myers shows that the impact of declining great shark populations is cascading through the marine ecosystem. Since 1972, growing demand for shark fins and meat has devastated shark populations by as much as 87 percent for sandbar sharks and 99 percent for bull, dusky and hammerhead sharks. As the sharks have declined, the populations of some of their prey, especially cownose rays, have exploded. In turn, more rays feed on more mollusks; in 2004, this biodiversity shift effectively put an end to North Carolina's 100-year-old scallop fishery and now threatens seagrass habitat along the coast.
"We're more cognizant of the fact that the ocean is not just a cheap machine that produces fish," Worm says. Instead, he says, it's a very intricate world that impacts habitat, marine mammals and birds, and that acts as an enormous filter to maintain water quality.
Because all life in the ocean is interconnected, figuring out how to manage it scientifically and institutionally has been a major challenge—one some have said is insurmountable. Worm, for one, thinks it's doable. "The idea isn't to manage the ecosystem; it's to manage and restrain our impact on it," he says. "We know how to do that, and we have, in fact, started to do it in many different places."
Designating marine protected areas (MPAs), like the 140,000 square-mile stretch of the Pacific northwest of Hawaii that was made a national monument in June of 2006, is one technique that governments are using to safeguard ocean diversity. Some parties resent the idea of completely excluding parts of the marine environment from fishing and other uses, yet most scientists see MPAs as essential. Much like national parks on land, these areas preserve regions of ocean biodiversity and allow them to exist in a natural state.
Right now, MPAs encompass less than 1 percent of the total ocean. In 2003, the 5th World Parks Conference set a target of protecting 20 to 30 percent of marine habitat. But getting consensus on what parts of the ocean to preserve is time-consuming, and governments are not creating MPAs fast enough, Pauly says. At the current rate, it will take roughly 70 years to reach the 20 percent target.
The only answer, Pauly says, is to act fast. Real fast. Governments and international agencies should accelerate the creation of MPAs, end all subsidies, implement tight control on what species can be fished and transfer oversight to those "who care and will exploit [the ocean] reasonably and sustainably and keep it safe from the trawlers of the world," he says.
According to Worm's models, published in 2006, people will run out of seafood by 2048 if current trends of overfishing and stock collapse continue. Yet he remains more optimistic about reversing the trend and restoring ocean biodiversity. Even though studies have shown that species bounce back in marine reserves, they're not a panacea, Worm says. They must be combined with measures to limit bycatch, implement sustainable fisheries practices and reduce pollution.
"I think we're starting to wrap our head around the fact that there's a lot of water out there, and that it's an essential ecosystem that's very important to the earth's life support system," Worm says. "We ought to take better care of it."
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Comments (1)
This is an interesting article in that it opens new windows of thinking. Of particular interest is that we may not be able to manage marine complexity; but rather we may do better managing our impact on ecosystems. This is an extremely important conclusion that merits thoughtful thinking. By the same token is it better to manage projects (which are embedded with complexity), or better try to manage the impact of projects? Any manager realizes that the projects involve many balances and interactions. Intervention will result in only disturbing the natural balances and the consequences will be unknown. Like a marine ecosystem, which may revert to type upon the removal of its disturbance factor(s) people would rearrange naturally to produce their best. It is like administering a drug in a human body that can be sure of its all side effects? The universality of your conclusion deserves further discussions.
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