Coral Reef Fish Assemblage Shifts and Declines in Biscayne National Park, Florida, USA

Abstract

Reef fish assemblage structure was assessed in 2006-2007 (recent period) in Biscayne National Park, Florida, USA, and compared with data collected from 1977 to 1981 (historical period) from the same location. Substantial differences were observed in reef fish assemblage structure between periods. Sixty-four percent of species were observed less frequently in the recent period. Mean species richness per survey declined at all sites, with declines ranging from 9% to 27%. Declines of fishery-targeted species were also observed and were consistent with but not greater than those observed for the reef fish assemblage as a whole. The observed declines appeared to be assemblage-wide, as a majority of species within all trophic guilds examined (spongivores, planktivores, herbivores, omnivores, invertivores, generalist carnivores, and piscivores) declined in frequency of occurrence between periods, with declines ranging from 55% of species for piscivores to 75% for omnivores. Mean number of species per survey declined for all guilds but herbivores, and ranged from a 14% decline for piscivores to 67% for planktivores. The declines observed in the present study are conceptually consistent with, but more extensive than, those recently documented for the Caribbean region as a whole and with those expected in coral reef systems that are heavily utilized by humans.