Symposium Abstract: Spatial Distribution and Benthic Impacts from Hook-and-Line Fishing Gear in the Florida Keys National Marine Sanctuary
M. Chiappone, D. W. Swanson, and S. L. Miller
The spatial distribution and impacts to coral reef benthos from hook-and-line fishing gear were assessed at 117 sites spanning 2000 km in the Florida Keys National Marine Sanctuary during the summers of 2000 and 2001. Sites were stratified random with respect to habitat type and fishing protection. Surveys encompassed patch reef, spur and groove, and hard-bottom habitat types from 3 m to 12 m depth within and adjacent to 13 of the Sanctuary’s 23 no-fishing zones. Diver surveys using transects were performed to document the type, length, and number of biota impacted by hook-and-line gear. From surveys of 34,000 m2 of benthic habitat, 361 incidences of gear totaling nearly 465 m were documented, yielding a domain-wide density of 1.06 incidences/100 m2. Gear densities ranged from 0.82 to 1.35 incidences/100 m2 among the habitat types. In patch reef and spur and groove habitats, no significant differences were detected in the distribution of gear between protected and fished sites, while protected areas in the hard-bottom habitat yielded more gear than expected. Hook-and-line gear caused partial mortality or complete mortality to 434 sessile invertebrates. Organisms with upright morphologies such as gorgonians (47%), sponges (18%), and milleporid hydrocorals (18%) were the most frequently affected. Organism density, gear density, and gear length are some of the factors influencing gear impacts. For the habitats surveyed, hook-andline gear is spatially pervasive in the Florida Keys, indicates a pattern of non-compliance with nofishing regulations, and represents a low-level stressor to sessile reef invertebrates.