QUEEN CONCH, STROMBUS GIGAS, IN FISHED AND UNFISHED LOCATIONS OF THE BAHAMAS - EFFECTS OF A MARINE FISHERY RESERVE ON ADULTS, JUVENILES, AND LARVAL PRODUCTION

摘要

Marine fishery reserves (MFR's) have been set aside in coastal areas throughout the world with the hope of reversing population decreases commonly observed in many marine resources. In this study, a comparison of population structure of the commercially important gastropod Strombus gigas, queen conch, was made between a fished area and an MFR in the Exuma Gays, central Bahamas. There were 31 times more adult couch on the shallow (<5 m) Great Bahama Bank in the MFR, and in a survey at 7 depth intervals (to 30 m) on the island shelf in the Exuma Sound, mean adult density was always higher in the MFR, by as much as 15 times. Shell length and lip-thickness measurements indicated that adults in the MFR migrate with age from bank nursery sites into deeper sound water, whereas those on the bank in the fished area were harvested before reaching water sufficiently deep to protect them from free-diving fishermen. Although sparsely distributed juveniles in shallow-water (<15 m) habitats of the sound were the primary source of adults in the fished area, large juvenile aggregations on the bank also contributed to the deep-water adult stock in the MFR.