scientific chapter | Proc Gulf Caribb Fish Inst | open access
Bryan DR, Arena PT, Spieler RE
Offshore of Broward County, Florida, below conventional SCUBA diving depths lies a deep escarpment between 70-95m that is relatively unexplored by research scientists. This escarpment is characterized by patchy sand and lowrelief rubble substrate. Ten derelict vessels have been deployed as artificial reefs below 70m with the goals of increasing fish habitat and enhancing recreational fishing. Although reports from local fishers are positive, little quantitative data exists. Previous studies on vessel-reefs in 20m reported greater fish abundance and species richness than surrounding natural reefs. We hypothesized that a similar situation would exist on vessel-reefs in deeper waters. A remotely operated vehicle (ROV) was used to survey three deepwater vessel-reefs and the surrounding natural substrate using a combination of point-counts and timed transects to record fish on digital video. Preliminary results support findings from shallow vessel-reef research, and suggest that deep-water vessel-reefs also harbor greater abundance and species richness than the surrounding natural substrate. However, the deep-water vessel-reefs appear to support a different fish assemblage characterized by a lack of herbivores, lower diversity of haemulids, and the occurrence of several deepwater species such as Prognathodes aya and Equetus iwamotoi. Despite these differences, several species are common to vessel-reefs at both depths. A few species, such as Lutjanus buccanella, Mycteroperca phenax, and Seriola dumerili appear to undergo an ontogenetic shift in habitat with larger individuals found on the vessel-reefs in 70-95m. The lack of fishes on surrounding natural substrates, as well as the higher abundance and species richness on the vessel-reefs may be due to a paucity of suitable deep-water natural habitat off Broward County and thus may indicate an important role for vessel-reefs in resource management at these depths.
Remotely Operated Vehicle (ROV)