Friday, February 22, 2002 By Christian Heuss
Overfishing and overuse of coastal regions have severely damaged marine habitats. New socioeconomic and ecological strategies are urgently needed to manage fisheries sustainably and to preserve marine resources, Stanford scientists say. Only such action can ensure the long-term survival of marine ecosystems and the profitability of fisheries.
"Reserves should set aside at least 30 percent of the habitat of a given species to have any serious assurance of long-term profitability as well as to guard against risk of extinction," said Stanford professor Joan Roughgarden, an ecologist who presented her model for sustainability of marine resources Feb. 15 during the annual meeting of the American Association for the Advancement of Science (AAAS) in Boston.
Roughgarden, who presented her research at a symposium titled "Community-Based Marine Resource Management: Incentives for Sustainable Management and Conservation," is a pioneer in applying economic theories to ecological problems. The "30 percent set-aside rule" is the result of a new model that computes the best strategy that small-scale sustainable fisheries can employ to optimize profit and social welfare. To determine the best strategy for managing fisheries, Roughgarden's model includes for the first time ever the risk of extinction.
"It is a fundamental thing to take risk of extinction into account, which until now hasn't been done in economic theories," Roughgarden said.
In her role as a scientific adviser for the establishment of the Channel Islands National Marine Sanctuary near Santa Barbara, Calif., Roughgarden applied her model to define the size of no-fishing zones. In these protected areas, fish stocks can recuperate and refill harvest zones through spillover.
For a sustainable harvest aimed at maximizing long-term welfare of the fishery, at least one-third of the fish habitat has to be protected, Roughgarden's model demonstrates. Smaller habitat size will not ensure the survival of marine resources or fisheries, which may eventually lead to extinction of the fishing grounds.
"We don't want to convey a false sense of security to people who valuably try to establish smaller reserves, only to see these efforts lost when everything collapses," Roughgarden said.
In 2000, the United Nations' Food and Agriculture Organization warned that about one-quarter of the world's marine resources were either overexploited or already depleted. About half of the marine fishing grounds were classified as "fully exploited," meaning that increased fish production from these regions is unattainable. Therefore, only about one-quarter of the world's fishing grounds can boost fish production to satisfy the growing global demand for fish.
For sustainable fisheries and successful establishment of marine protection programs, Roughgarden recommends that the immediate and long-term economic benefits for the fisheries be secured through incentives. They should encourage and reward fisheries in their effort to sustainably manage marine resources.
The fishery industry has more than doubled in the last 30 years. Ninety-five percent of the world's fishers are from developing countries and work in traditional artisan fisheries whose combined catches amount to about 50 percent of the 125 million metric tons of fish harvested worldwide each year. For that reason, implementation of no-fishing zones has met with tremendous resistance among people economically dependent on fishing.
Comanagement of marine resources by governments, private fisheries, and communities only recently has been recognized as an effective way for sustainable management programs to gain acceptance.
"The focus must be on understanding the connectivity between people and the ocean," said Assistant Professor Fiorenza Micheli of Stanford's Hopkins Marine Station in Pacific Grove, Calif. "Often there has been a tradition and a culture of using marine resources with a conservation perspective in mind." Together with biologist Rafe Sagarin, a postdoctoral scholar at Hopkins, Micheli initiated and organized the AAAS symposium.
Partnerships between local communities and scientists in the central islands of the Philippines, for example, resulted in implementation of marine reserves as a tool to manage overexploited fisheries. The establishment of no-fishing zones has increased catches in adjacent fishing grounds. "This is a good example where political will to support conservation was reinforced by ecologists who showed that there was an effect," Micheli said.
A more consumer-driven approach to conservation is the certification process initiated by the Marine Stewardship Council (MSC) that Julia Novy-Hildesley from the World Wildlife Fund (WWF) presented at the AAAS symposium. This program promotes sustainability of fisheries by rewarding local communities for sound management practices. The MSC in collaboration with Unilever, one of the world largest makers of fish products, and the WWF has established a label that tells consumers that fish products came from fisheries certified as sustainable. "The idea behind certification of marine fisheries is that you can use the power of the market to force and encourage sustainable catching practices," Micheli said.
Other speakers at the symposium included anthropologist Richard Stoffle, University of Arizona, and ecologist James Acheson, University of Maine. Three successful examples of sustainably managed, community-based fisheries in Chile, Mexico, and the Philippines were presented by Miriam Fernandez, Pontificia Universidad Catolica de Chile; Mario Ramade Villanueva, Federacion Regional de Sociedades Cooperativas de Mexico; and Angel C. Alcala, Silliman University-Philippines.
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