Baseline Data for Evaluating Reef Fish Populations in the Florida keys, 1979-1998

Bohnsack, James; Mcclellan, David; Harper, Douglas; Davenport, Guy; Konoval, George; Eklund, Anne-Marie; Contillo, Joseph; Bolden, Stephania; Fischel, Peter; Sandorf, G. Scott; Javech, Joaquin; White, Michael; Pickett, Mathhew; Hulsbeck, mark; Tobias, James; Ault, Jerald; Meester, Geoffrey; Smith, Steven; Luo, Jiangang

Reef fishes are an essential and conspicuous component of the South Florida Marine Ecosystem that support important commercial, recreational, and aesthetic fisheries. Fishes are the ultimate downstream integrators of environmental conditions and human activities. Factors that increase mortality, such as fishing, loss of habitat, and pollution are eventually reflected in adult population abundance, individual size and condition. Over the last two decades, the Florida reef tract ecosystems and Florida Bay have undergone dramatic environmental changes from human and natural forces. These changes are a general concern and the focus of an intensive effort to restore the ecosystem by altering the hydrology to a more natural condition. Fishes are a direct public concern and obvious measure of restoration success. Success of restoration and management changes should be reflected in reef fish communities in terms of the species composition, the size/age structure of fishes, and in fisheries. Fishery resources are regulated by several state and federal agencies under different levels of spatial protection. Understanding and modeling the dynamics of physical and biological processes of Florida Bay and the Florida reef tract requires a good database on fish composition by habitat. The Florida Keys National Marine Sanctuary (FKNMS) final management plan became effective on 1 July 1997 creating the first planned network of 'no-take' marine reserves in North America. These reserves included 18 'no-take' Sanctuary Protected Areas (SPAs) and one large 'no-take' ecological reserve. This action provides a unique research opportunity to examine the processes and effects of reserve protection at replicated sites of different size. An important goal of the FKNMS management plan is to evaluate changes resulting from establishing no-take marine reserves five 1 years after they became established. In addition, new ecological reserves are being proposed for the Tortugas region. Biological data on reef fish biodiversity have been collected continuously since 1979 by highly trained and experienced divers using open circuit SCUBA and visual methods. Visual methods are ideal for assessing reef fishes in the Florida Keys because of prevailing good visibility and management concerns requiring the use of nondestructive assessment methods. Data were collected from randomly selected 7.5 m radius plots using a standard fishery independent, stationary plot method (Bohnsack and Bannerot 1986). Data collected show reef fish species composition, abundance (density per plot), frequency-of occurrence, and individual sizes of fishes at reef sites extending from Miami through the Tortugas. These data can be used to assess changes in reef fish communities in the Florida Keys as the result of changes in zoning, regional fishery management practices, and restoration efforts in Florida Bay. This report provides a summary of a 20 year historical data base that will form the baseline for assessing future changes in reef fish communities in the FKNMS. A total of 263 fish taxa from 54 families were observed from 118. sites in the Florida Keys from 6,673 visual stationary plot samples from 1979 through 1998. The ten most abundant species accounted for 59% of all individuals observed. Ten species had a frequency-ofoccurrence in samples greater than 50% and only ten species accounted for 55% of the total observed biomass.

Baseline Data for Evaluating Reef Fish Populations in the Florida keys, 1979-1998

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