WASHINGTON, D.C. - Leading scientists report that marine reserves are a win-win for fishers, coastal communities, and environmentalists. Three U.S. states are among global success stories profiled in a study released this week, which is based on a more comprehensive World Wildlife Fund report on the important benefits marine reserves provide to fisheries and ocean wildlife.
Amid growing fears for the future of the world's fisheries, the new paper - published in the scientific journal Trends in Ecology and Evolution - finds that marine reserves can rapidly rebuild depleted populations of commercially important species of fish and shellfish.
"Stocks typically expand between two and five times in just five years of protection," said Dr. Fiona Gell, of the University of York. "Benefits continue to grow for decades as populations of long-lived species recover. Those increases support and enhance surrounding fisheries."
Building on recent research in Nature, that shows global fisheries are removing more than 90 percent of large fish from the oceans, the WWF report confirms that reserves can boost fish populations and help ensure sustainable fishing. "Fishers have nothing to fear from marine reserves," said Professor Callum Roberts, "but they should worry about a future without them." Gell and Roberts emphasize, however, that marine reserves will not solve fishery problems on their own. They will be most effective where they are used to complement other controls on gears, catch and fishing efforts.
In the study, Gell and Roberts examine the findings of 300 studies of more than 60 different marine protected areas around the world. "The best evidence we found for fishery benefits came from places where between 10 and 35 percent of the area had been closed to fishing for more than five years," said Roberts. "We have discovered that these reserves offer a double dividend, safeguarding species and their habitats and supplying fisheries beyond their boundaries."
According to Roberts, "marine reserves are the most powerful tool available to restore fishery productivity. While they were once believed to be of value only to sedentary species and fragile habitats like those of coral reefs, new evidence makes it clear that we can design effective reserves for almost anywhere that is fished. They are a near universal tool."
As fish in reserves become more numerous and grow in size, they produce many more offspring. Their eggs and larvae are transported from reserves to fishing grounds on ocean currents, replenishing exploited stocks. Adult and juvenile animals also 'spillover' from reserves to fishing grounds.
The report features 16 case studies from around the world illustrating the wide variety of fishery and habitat types that marine reserves can benefit. These examples show that from artisanal clam fisheries in Fiji to industrial fisheries in the northwest Atlantic, closing areas to fishing can have significant and long lasting benefits to nearby fisheries. Species benefiting from protection include a wide variety of fishes, lobsters and shellfish like scallops.
For example, in the Gulf of Maine at Georges Bank, researchers have seen improvements after five years of protection, including the rapid recovery of scallops and some of the fish species. At Merritt Island National Wildlife Refuge in Florida, recreational fishing records reveal that an unprecedented number of world record size fish are caught in the vicinity of the closed area. In Edmunds Underwater Park in Washington state, copper rockfish produced 100 times more eggs than their counterparts in fish areas, and lingcod produced 20 times more eggs inside the reserves.
Protected areas also provide refuges for species and habitats that are highly vulnerable to overfishing or to damage done by fishing gears like trawls. "Marine reserves can keep species off the endangered list while allowing us to continue fishing. Without them, entire fisheries might have to be shut down to prevent species from being driven extinct," said Roberts. For example, barndoor skate have nearly become extinct on the North American East Coast because of trawling, but juveniles have recently been discovered in large areas closed to trawling on Georges Bank.
The study also examined how much of the oceans we need to protect. In a synthesis of the evidence from 40 studies, the report makes a strong case for new marine reserves. "At present only around one ten thousandth of the sea is protected from all fishing," said Gell.