FOOD WEB MODELING TO ASSESS INTERACTIONS BETWEEN ARTIFICIAL REEFS AND NATURAL REEFS

The effect of artificial reefs on natural reefs is poorly understood. This study focused on Aquarius Reef Base (ARB), an underwater habitat offshore of Key Largo, Florida, and 14 natural reef sites spanning 4 habitats, on the surrounding Conch Reef. Food web models were created for ARB and natural reef habitats. Biomass at each habitat was quantified by fish surveys. Using Ecopath, species were organized into functional groups with supporting data from previous research for other inputs. ARB’s food web was found to have a large predator biomass with insufficient prey biomass to sustain the population, suggesting that these predators must forage on nearby natural reefs where the predator/prey ratio is smaller. Between 0.57km2 and 1.79km2 of natural reef is estimated to be a sufficient spatial subsidy for the large predatory biomass at ARB when the biomass is added as determined by the seascape around the artificial reef.