Distribution and Habitat Use of the Golden Crab Chaceon fenneri off Eastern Florida Based on in situ Submersible and ROV Observations and Potential for Impacts to Deep Water Coral/Sponge Habitat

Abstract

A bstrAct : This study documents the distribution and habitat use of the golden crab (Chaceon fenneri) , a commercially fished species, in relation to deep—sea coral/sponge ecosystems (DSCEs) at 200—900 m depths off eastern Florida. A total of 386 h of videotapes from 94 submersible and remotely operated vehicle (ROV) dives from 1999 to 2009, covering a total distance of 376 km, were reviewed and characterized for habitat type and presence of crabs. The DSCEs surveyed included Lophelia coral mounds, Miami Terrace, Pourtalès Terrace, and Tortugas Valleys. Video transect data also included environmental surveys of proposed deepwater routes for Liquid Natural Gas (LNG) pipelines, LNG port, and telecommunications fiber—optic cable. A total of 351 golden crab was counted and observed on a wide variety of habitat types, including coral thickets, rock escarpments, rock pavement, boulders, and soft bottom. The mean density of golden crabs was greater on soft bottom than on hard bottom habitat (0.342±0.234 vs 0.190±0.121 crabs /1000 m 2 ); within the hard bottom regions, mean density was greater on rock substrate than coral substrate (0.206±0.120 and 0.040±0.035 crabs /1000 m 2 ). The current golden crab fishery operates off eastern Florida in Allowable Crab Fishing Areas (ACFAs) within the deepwater Coral Habitat Areas of Particular Concern (CHAPCs); however, we have documented at least 8 regions within the CHAPCs where the ACFAs overlap probable DSCE habitat. Resource managers should adjust the boundaries of the ACFAs to protect and preserve vulnerable DSCE habitat while allowing benthic fisheries to operate in areas of soft bottom habitat.