DISTRIBUTION OF RECENT BENTHIC FORAMINIFERA ON THE SOUTHEAST FLORIDA REEF TRACT

The purpose of this study is to provide baseline data of the distribution of benthic foraminifera off Pompano Beach, FL, a marginal shallow water reef system. The study area is a small segment of the southeast Florida reef tract that includes the nearshore ridge complex, inner reef, and middle reef. In contrast to the carbonate platform in the Florida Keys, the Pompano Beach area is heavily dominated by siliclastics and consists of a series of linear ridges parallel to shore.

A total of ten rubble samples were collected between January 2014 and April 2015 across 5 different benthic habitats as defined by NOAA’s classification scheme: (1) uncolonized rubble 10-17ft (2) colonized pavement/rubble 13ft (3) colonized pavement 12ft (4) uncolonized rubble 27ft and (5) linear reef 33ft. Using a stereomicroscope well preserved foraminifera were picked and identified with a total of 32 genera and 42 species. A qualitative assessment of coral coverage was also recorded in order to compare populations of foraminiferal functional groups. Dominant species include Archaias angulatus, Quinqueloculina spp. and Laevipeneroplis proteus. Overall, opportunistic taxa were scarce specifically Ammonia spp. Elphidium advenum, Elphidium discoidle, and Bolivina pulchella.

Differences between the concentrations of species found at each habitat are conceivably contingent upon benthic organisms and the substrates of their environments. Habitat 2 was found to have Acropora cervicornis and the highest concentration of total species and heterotrophic taxa. Habitat 3 had the second highest total concentration and an abundance of Gorgonia spp. and mixed Scleractinia such as Diploria spp. Oribicella spp. and Porites sp. These habitats also had the highest concentrations of symbiont-bearing taxa and consisted primarily of colonized pavement. Habitats in depths greater than 27ft approaching the middle reef had the lowest concentration of total species and low coral coverage. The habitats at shallower depths consisting of rubble are found with mats of macro algae and had moderate concentrations of both symbiont bearing and heterotrophic taxa. The results of this study can be used to estimate distributions of benthic foraminifera and their correlating habitats for future studies along the southeastern Florida reef tract.