The Dry Tortugas are small islands surrounded by coral reefs located west of the Florida Keys. Areas with different fishing rules have been created there:

 

- No fishing is allowed in Tortugas North Ecological Reserve, a marine reserve established in 2001, or in an additional marine reserve created in 2007.

 

- Only recreational hook-and-line fishing is allowed in Dry Tortugas National Park, a fished MPA created in 1992.

 

- Many types of commercial and recreational fishing are allowed in other areas.

 

After an initial failed attempt to establish a marine reserve in 1996, commercial fishermen, dive-boat operators, and members of local environmental groups became involved in the discussion. This led to the successful establishment of the Tortugas North Ecological Reserve in 2001.

 

Scientific divers counted fishes in 1999-2000 and 2004—before and after establishment of the Tortugas North Ecological Reserve. As shown in the figure at left, the scientists found that three species of commercially important fishes differed in their response. Black grouper became significantly more abundant in the marine reserve (120% increase) and in the recreationally fished national park (128% increase), but a trend towards an increase in the fished area was not statistically significant. Red grouper increased by 38% in the marine reserve but declined in the fished areas outside. Mutton snapper increased by 303% in the marine reserve and by 142% in the national park, but its numbers did not change significantly in the fully fished area. Changes inside the recreationally fished national park were moderate during the study period when compared to the bigger changes in the marine reserve.

 

These findings demonstrate that the responses of different fish species can vary after the establishment of marine reserves and other marine protected areas.