Sanctuary No-Take Zone Performance
bhaskell at ocean.nos.noaa.gov
Thu Mar 4 14:08:09 EST 1999
For immediate release
March 4, 1999
U.S. Department of Commerce
National Oceanic and Atmospheric Administration
National Ocean Service
Marine Sanctuaries Division
Florida Keys National Marine Sanctuary
CONTACT: Cheva Heck Ben Haskell
(305) 292-0311 (305)743-2437, ext. 25
First-Year Results Show Sanctuary No-Take Zones Beginning to Change Fish and Lobster Populations
Marathon -- After their first full year of protection, the Florida Keys National Marine Sanctuary's 23 no-take zones are showing signs of restoring spiny lobster (Panulirus argus) and fish populations, according to results from the long-term zone monitoring program.
In July of 1997, the sanctuary established a pioneering marine zoning program that includes three types of no-take zones: eighteen small sanctuary preservation areas, four special use areas and an ecological reserve. The zones comprise less than one percent of the sanctuary but protect much of its critical coral reef habitat. That same year, the sanctuary initiated a five-year zone monitoring program looking at changes in ecosystem function and populations of key species.
"We are surprised how quickly animal populations are responding to these no-take zones. It's probably a good indication of the intense exploitation pressure they are under. We're looking forward to many more surprises from these zones over the coming years," said Ben Haskell, sanctuary science coordinator.
Carrollyn Cox and John Hunt of the Florida Department of Environmental Protection used teams of divers to compare lobster populations in fifteen sanctuary no-take areas with reference sites open to fishing. The divers found significantly more legal lobsters (carapace length greater than 76 millimeters) in no-take areas during both study years, 1997 and 1998.
In 1997, Cox and Hunt found that the size of legal lobsters was the same in no-take areas and reference sites. But by 1998, lobsters in the no-take areas that exceeded legal size were significantly larger than legal lobsters in reference sites.
First-year results from a second lobster study provide additional evidence of increased abundance and size in the no-take areas. The sentinel lobster fishery project used a commercial fisherman fishing traditional trap gear to compare lobster populations in Western Sambo Ecological Reserve with populations in Middle Sambo and Pelican Shoal, nearby areas that are open to fishing. Results from 1998 indicate that lobsters were significantly larger and more abundant in the reserve compared to outside reference sites.
The average annual abundance of economically important reef fish (yellowtail snapper, hogfish, and grouper) were compared to a long-term baseline and between no-take zones and comparable reference sites. Grouper analysis excluded two small rarely targeted species: graysby and coney. In all cases, the highest average abundances were observed in no-take zones in 1998, the first full year of no-take protection, according to a preliminary analysis under the direction of Dr. Jim Bohnsack with the National Marine Fisheries Service. Grouper in the remote Tortugas region were more abundant than in the rest of the Florida Keys.
Rates of fish herbivory in the zones compared to reference sites provide another intriguing indication that the zones may be beginning to restore the natural food chain. Dr. Margaret Miller of the National Marine Fisheries Service found that herbivory was higher in the no-take zones during 1997 compared to outside reference sites, but declined in the largest zone in 1998. This points to a potential trophic cascade effect, in which herbivorous fish populations initially increase, but then decline as predatory fish populations rebound from overfishing.
The monitoring program also looks at other key species, such as coral, queen conch (Strombus gigas), fish and urchins. Coral community dynamics are being intensively monitored in 3 zones and reference sites by Drs. John Ogden, Richard Aronson, and Struan R. Smith. The response time for coral is expected to be much longer than that of heavily exploited and faster growing species such as lobster or fish.
The Florida Keys National Marine Sanctuary, designated in 1990, protects 2,800 square nautical miles of critical marine habitat, including coral reef, hardbottom, seagrass meadows, mangrove communities and sand flats. In addition to the marine zoning program, key sanctuary initiatives include a water quality protection program, extensive education and volunteer programs, channel marking initiatives, and installing and maintaining mooring buoys to prevent damage to the reef.
If you would like a copy of the first year Zone Performance Report please email Ben Haskell at bhaskell at ocean.nos.noaa.gov.
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