FEMAR

Coral reefs in the Florida Keys are impacted by fishing and indirectly by habitat degradation from other human activities including coastal development, altered freshwater flow, and changes in water quality from pollution, sedimentation, and excess nutrients (CERP 1999; Cowie-Haskell and Delaney, 2003). Human impacts have grown as a result of Florida’s tenfold population growth from 1.5 million people. Human population growth and vessel registrations in Florida. (A) Florida’s population from 1840–2000. (B) Growth of commercial and recreational fleets in southern Florida (Palm Beach, Broward, Miami-Dade, Monroe, and Collier Counties) from 1964–2002. Source: Florida Statistical Abstracts (2002). BULLETIN OF MARINE SCIENCE, VOL. 604 . 76, NO. 2, 2005 in 1930 to 16 million in 2000. In 2000, over 5 million residents, nearly a third of Florida’s population, lived in the five southern counties adjacent to coral reefs (Palm Beach, Broward, Miami-Dade, Monroe, and Collier). In addition, over three million tourists visit the Keys annually (Leeworthy and Vanasse, 1999).

Precise data on coral reef fishing effort trends do not exist, but are reflected by state-wide fishing statistics and numbers of registered boats. In 2001, for example, an estimated 6.7 million recreational fishers took 28.9 million marine fishing trips in Florida and caught 171.6 million fish, of which 89.5 million (52%) were released or discarded (U.S. Department of Commerce, 2002). From 1964–2002 the number of registered recreational boats in southern Florida grew by more than 500%, while the number of commercial vessels grew at a much lower rate, about 150%. Many of these vessels are used for fishing and for non-extractive activities, such as sailing, sightseeing, transportation, snorkeling, and SCUBA diving. Increased fishing fleet size has been accompanied by a number of technological advances that have been estimated to have quadrupled average fishing power (Mace, 1997), i.e., the proportion of stock removed per unit of fishing effort (Gulland, 1983). These advances include improvements in fishing tackle, hydroacoustics (depth sounders and fish finders), navigation (charts and global positioning systems), communication, and inexpensive, efficient, and more reliable vessel and propulsion unit designs (Bohnsack and Ault, 1996; Ault et al., 1997, 1998). These fishing trends have thus become an obvious concern to the fishery sustainability and persistence of the coral reef ecosystem.

Fisheries in southern Florida are complex (Bannerot, 1990; Chiappone and Sluka, 1996). Adult reef fishes are caught for food and sport around bridges and on offshore patch and barrier reefs. Commercial and sport fisheries also target spiny lobster, marine aquarium fishes and invertebrates, inshore and offshore. Pink shrimp, a principal prey item of the snapper-grouper complex, are intensively exploited. Offshore, a substantial commercial food fishery targets adult pink shrimp inhabiting softbottoms near coral reefs. In coastal bays and near barrier islands, juvenile pink shrimp are commercially targeted as live bait for the recreational fishery. Both food and sport fisheries target pre-spawning subadult pink shrimp as they emigrate from coastal bay nursery grounds to offshore spawning grounds. Inshore, sport fisheries pursue highly prized game fishes, including spotted seatrout, sheepshead, black and red drum, snook, tarpon, bonefish, and permit, while commercial fisheries primarily target sponges and crabs. Offshore of the deep margin of the barrier reef, commercial and sport fisheries capture an assortment of species including amberjack, king and spanish mackerel, barracuda, sharks and small bait fishes (e.g., Exocoetidae, Mullidae, Carangidae, Clupeidae, and Engraulidae). Farther offshore (seaward of the 40 m isobath), commercial and sport fisheries catch dolphinfish, tunas, and swordfish, and sport fishers target sailfish, wahoo, and white and blue marlin.

The principal factors influencing the dynamics and sustainability of snapper-grouper populations are illustrated in the conceptual diagram. Besides exploitation, other factors can affect reef fish populations including: (1) fishery removal of key prey (e.g., shrimps, baitfish) and predators (e.g., barracuda, sharks), (2) alterations to benthic habitats (e.g., loss of mangroves and seagrasses to shoreline development, channel dredging, and ship groundings), and (3) alterations to water quality (e.g., pollution, nutrification, and turbidity), quantity, and timing of freshwater inflows. Other environmental issues facing the Keys include coral declines from diseases and bleaching, invasion of exotic species, shifts to algal dominance, and damage from contact by anchors,

Human population growth and vessel registrations in Florida. (A) Florida’s population from 1840–2000. (B) Growth of commercial and recreational fleets in southern Florida (Palm Beach, Broward, Miami-Dade, Monroe, and Collier Counties) from 1964–2002. Source: Florida Statistical Abstracts (2002).

Conceptual diagram of reef ecosystem and fishery processes that influence sustainability of exploited reef fishes. Principal biotic components and human impacts (boxes and solid arrows) are shown distributed over cross-shelf habitats of the Florida Keys. Dotted arrows denote predator-prey relationships. The dashed box denotes components and impacts that are the traditional focus of fishery science and management.