Distribution, abundance and habitat utilization of adult and juvenile jewfish, Epinephelus itajara, in southwest Florida, USA

Anne-Marie Eklund
National Marine Fisheries Service, Southeast Fisheries Science Center, Miami, Florida 33149; Voice 305-361-4271, FAX 305-361-4478, email anne.marie.eklund@noaa.gov

Christopher C. Koenig and Felicia C. Coleman
NOAA/FSU Institute for Fishery Resource Ecology, Department of Biological Science, Florida State University, Tallahassee, FL 32306-1100; Voice 850-644-2019, FAX 850 644-2019, email coleman@bio.fsu.edu, koenig@bio.fsu.edu

Jewfish, Epinephelus itajara, are large, long-lived groupers that were severely overfished on their spawning aggregations and have, subsequently, been protected from all harvest in U.S. waters since 1990. The species is now a candidate for the US threatened/endangered species list. To assess the recovery of this species, we have been monitoring the density of adult spawning aggregations and the distribution and habitat requirements of juveniles. Our censuses on four aggregation sites show a precipitous decline in abundance in 1980's, followed by a gradual increase in abundance through 1998. The size structure of the aggregations suggest, however, that these adult fish are not new recruits to the population. In June 1997 we began tagging juveniles and quantifying significant features of their habitat in the Ten Thousand Islands area of southwest Florida. We have processed scales and dorsal fin rays for age determination in juveniles. Using acoustic tags, we have been able to monitor the movements of juvenile fish in the mangrove habitat and have found that they live among island undercuts and deep holes in tidal passes throughout the year. We are continuing to tag the juveniles, in order to estimate absolute abundance, survival, degree of site fidelity, and growth rates.