Marine reserves: A promising tool to protect oceans
he ocean is one of the Earth's great "commons." Coral reefs, kelp forests, and other ecosystems of the sea not only support dolphins, sea turtles, albatrosses and other marvelous creatures. They also provide essential "goods and services," such as fish, minerals, waste conversion and even the moderation of our climate.
Creating sustainable fisheries and reducing overfishing, which scientists have identified as the most serious threat to marine biodiversity, are key priorities in protecting the world's oceans. Some fisheries have been managed sustainably, but many others have not. About 70 percent of the world's major fisheries are either fully exploited, depleted, or recovering from depletion. In the United States, overfishing and habitat degradation have left many fish populations unable to produce maximal yields. Thousands of jobs and millions in revenue are lost as a result.
In relatively well-managed fisheries there is often a poor understanding of fishing's effects on marine biodiversity and ecosystem health. Fish are vital components of marine ecosystems. Overfishing can have profound unintended effects, ranging from algal blooms that can destroy coral reefs to the starvation of seabird chicks that depend on fish for survival.
To halt and prevent overfishing, we need continued advances in the scientific understanding of fishery management and improved conservation goals and we must hold resource managers accountable to these goals. We must also replace the strong existing incentives to overexploit with equally strong incentives to conserve.
Managing fisheries will always be an uncertain art, despite such exciting advances as the ability to predict El Niño events, the discovery of long-term cycles in ocean circulation and productivity and better understanding of how marine ecosystems function. Because of the complexity of these ecosystems, the high level of natural variation of the ocean, and limited funds for research, uncertainty will remain.
EDF is advancing a promising hedge against uncertainty: the idea of "no-take" marine reserves, in which fishing is banned a kind of underwater wildlife refuge. No-take reserves reduce economic pressures to overfish, protect marine ecosystems and, ultimately, increase fishery yields. Stock assessments and projections of fishing effort are often wrong, but no-take reserves will protect fish populations and habitats. Models and catch limits protect "paper" fish; marine reserves protect real fish.
The critical need is for networks of no-take marine reserves, analogous to wildlife corridors on land. No-take marine reserves can yield dramatic benefits, including increased fish abundance, often by several-fold and sometimes within just a few years. No-take reserves also tend to contain more large fish, because in areas that are open to fishing, fishermen often target the largest fish first. Having a diversity of ages and sizes, including plenty of older, larger fish, appears to be critically important for many fish species. Big fish produce many more eggs than small fish; for example, it takes about 200 small adult snappers (typical of a heavily fished population) to produce as many eggs as one large snapper. Well-designed marine reserves should enhance fisheries in adjacent waters by exporting both baby fish and older fish.
Effective no-take marine reserves are also needed on the high seas and in the territorial waters of other countries. Although there are more than 4,500 protected marine areas, they cover far less than 1 percent of the ocean's surface, and most are relatively ineffective because of lax enforcement and weak public support. Few are closed to fishing; in fact, to win fishing industry support, many so-called marine sanctuaries were set up under implicit or explicit agreements to impose few limits on fishing.
EDF is working with fishermen, other environmental organizations, scientists, SCUBA divers, and community leaders of all types to build support for creating networks of no-take marine reserves. This scientific concept is ready for prime time.
The authors of this article are leaders in the effort to establish no-take marine reserves.
As President of the American Association for the Advancement of Science at the 1997 AAAS meetings, Lubchenco called for setting aside 20 percent of the world's ocean areas as permanent biological preserves.
Fujita has advocated marine reserves in the United States since 1990 and helped establish a no-take reserve in the Florida Keys National Marine Sanctuary. He is working with a broad coalition in California to develop and pass legislation that would mandate the creation of a network of marine reserves.
EDF recently organized a series of marine reserve workshops in major coastal areas of the United States. Dr. Bill Ballantine, who pioneered the establishment of marine reserves in New Zealand, led the workshops, which were hosted by local environmental groups, dive organizations, business associations, and others in New England, Newfoundland, Florida, California, and Oregon.
Ballantine, who is professor of marine ecology at the Leigh Marine Laboratory, University of Auckland, New Zealand, won the prestigious Goldman Award for his work on marine reserves.
Dr. Rod Fujita is a marine ecologist with Environmental Defense Fund's Oceans program, and EDF Trustee Dr. Jane Lubchenco is professor of marine biology at Oregon State University.
A subscription to the bimonthly EDF LETTER (an 8-page newsletter with photographs and postage-free Member Response Form) is included with annual membership. (Regular membership is $24 per year; student, senior, and limited income rate: $10 per year. Outside USA: $35 per year. Contact EDF Membership at 257 Park Avenue South, New York, NY 10010; (202) 387-3525; fax: (202) 234-6049; email: membersedf.org; www.edf.org