Amphipod Crustaceans of the Indian River Lagoon: Current Status and Threats to Biodiversity

Sixty-nine species of amphipods have been collected from within the Indian River Lagoon. There are no known endemic amphipods in the Indian River Lagoon. Reanalysis of the relationship between number of species of seagrass amphipods and latitude demonstrated that amphipod diversity is comparable to seagrass sites at similar latitudes, contradicting an earlier study (Virnstein et al., 1984). The amphipod crustaceans of the IRL are best known from seagrass habitats. A continuous record of the population dynamics of seagrass associated amphipods is available for 1974–1979 from study sites at Haulover Canal, Link Port and St. Lucie Inlet. Mean abundances of seagrass amphipods did not differ significantly among the three sites. Amphipod abundance increased significantly over time at Haulover Canal, but not at the other two sites. These data suggest that various regions of the Indian River Lagoon are not closely coupled biologically. Little published information on amphipods from other habitats (unvegetated bottom, mangrove, marshes) is available. Principal threats to amphipod populations of the IRL are decreases in cover of submerged aquatic vegetation and increased pollution. Decreased amphipod populations would negatively affect the food supply of juvenile fishes. Amphipod biodiversity may be maintained by a management strategy which minimizes habitat loss and degradation of water quality.