Science study provides new evidence that marine reserves can replenish nearby fisheries
A study in the November 30 issue of Science provides two key pieces of new evidence that fully protected marine reserves can replenish fisheries beyond their boundaries. This comes at a time when new data shows that the state of world fisheries is even worse than previously thought. A study published this week in Nature reports that globally, fisheries catches have been falling for over a decade — but mis-reporting by member countries to the United Nations’ Food and Agriculture Organization (FAO) has masked this surprising truth. (The FAO is the sole source of global fisheries statistics.) This alarming revelation creates an even greater urgency to find ways to help fisheries recover from years of overfishing.
Today’s study in Science points to new hope for the use of marine protected areas as an important tool to help replenish fisheries. The study reveals significant gains attributed to nearby marine reserves for both recreational and community-based fisheries in two very different marine systems. In Florida, sports fishers are catching an inordinate number of world record size fish in the waters adjacent to the US’s oldest fully protected marine reserve, while in St. Lucia in the Caribbean, subsistence fishers are enjoying doubled returns from a once floundering fishery.
Scientists have widely predicted that marine reserves could help fisheries rebound in waters near marine reserves by functioning like natural hatcheries spilling out offspring and adults that can restock surrounding areas. This “spillover effect,” however, has not been widely documented, causing the use of reserves as a management tool to be hotly contested and often prevented. The controversy surrounding marine reserves in both the U.S. and abroad has centered on the question of whether reserves will improve surrounding fisheries.
Currently, less than 1/100 of 1% of the seas are encompassed in fully protected reserves. “This is a classic catch 22 situation,” says the lead author of the study, Callum Roberts of the University of York. “ It’s difficult to study the effects of reserves when so few exist. No matter how many theoretical studies show that fisheries will benefit, and there are many, it is fish on the deck and the testimony of other fishers that count. Our new study should help remove a major logjam in the debate over marine reserves by showing that they really can support increased fish catches—and produce bigger fish.” Cape Canaveral, Florida
In Florida, reserves in Merritt Island National Wildlife Refuge, close to NASA’s Cape Canaveral rocket launch site have been protected from human access since1962. “Data from the International Game Fish Association show that for three of the most popularly fished sport species – black drum, red drum and spotted sea trout—more world record size fish have been caught in waters within 62 miles of the reserves than in all other areas of Florida combined,” says co-author Jim Bohnsack, a Miami-based fisheries biologist with the National Marine Fisheries Service. Ironically, the two marine reserves were established for reasons of security rather than intending to allow fish to attain record breaking size. Recreational fishers are reaping unforeseen rewards.
Before being set aside as a buffer zone for space launches, this estuarine area was subject to an intensive recreational fishery. It has taken years for long-lived species to rebound, but the results appear worth waiting for. While the rest of Florida has seen no new world records for black drum (which can live to 70 years) since 1985, areas near the reserve continue to produce bigger and bigger fish. Red drum and spotted sea trout show similar results, with a disproportionate number of Florida’s recent record breaking fish coming from waters near the reserves. This is good news for fishers and for fish populations. Bigger fish produce many times more eggs than small fish, enlarging the numbers of the next generation. “Cape Canaveral is a window to the past, and a vision for the future” says Bohnsack. “We had lost sight of how big these fish could get, or what we could hope for the future.”
St Lucia, Caribbean
In the second study, a network of reserves around the island nation of St. Lucia in the Caribbean fishery has benefited an entire community. Despite strong initial resistance on the part of some fishers, the people of Soufriere decided to take a big risk. They closed off 35% of their former fishing grounds to try to rehabilitate their severely depleted reef fish food fishery. In the first couple of years, times were harder. Yet within just five years, stocks have nearly doubled in nearby waters and local fishermen are catching 46-90% more fish.
“Things are better now,” says reef fisher Aglan Joseph, 63, who has fished these waters for 50 years. “The place with the best fish is on the north side of the bay because of the marine reserves.” The initial skepticism felt by these fishers has faded and, in fact, there is a nearly unanimous call for more reserves to be created, according to Elwin Mongroo, President of the Soufriere Fishermen’s Co-operative in St. Lucia.
These two case studies provide clear evidence that reserves can help adjacent fisheries. The results come from very different fisheries (recreational and community based), different habitats (estuarine and coral reef), and different types of fish (relatively mobile and relatively sedentary), suggesting that marine reserves can produce positive results in a variety of situations. While the two cases differ in many ways, their success is attributed to the same causes: relatively large percentage of habitat protected, resolute enforcement of regulations, and, in the Florida example, long-lasting protection.
“Marine reserves are like money in the bank for fishers,” says co-author Fiona Gell of the University of York. “They protect breeding stocks and supply adjacent fisheries with young fish, just like a bank account produces interest. There are many more fish, there are bigger fish, and species that had disappeared due to intensive fishing are making a comeback. If you want to keep a population going, you have to provide safe havens where fish and their habitats can flourish.”
Reserves could also address growing concerns about the environmental harm caused in our pursuit of fish. Problems include, for example, damage from trawlers dragging nets across the seabed and marine mammals becoming entangled in fishing gear. “Marine reserves can provide refuges from fishing impacts as well as better catches, keeping oceans healthy and fish on our plates,” said Roberts.
For additional information, please go to: http://www.seaweb.org/ScienceNovember30.html
Contact Information:
Dr. Callum Roberts
Environment Department
University of York
York Y010 5DD
United Kingdom
Phone: 44-1904-434066
Fax: 44-1904-432998
Cr10@york.ac.uk
Dr. James Bohnsack
Southeast Fisheries Science Centre
NOAA Fisheries
75 Virginia Beach Drive
Miami, FL 33149 United States
Phone: 305-361-4252
Fax: 305-361-4499
Jim.bohnsack@noaa.gov
Journal
Science