A Population Study of the Benthonic Foraminiferida in Northern Biscayne Bay, Florida

Abstract

A portion of northern Biscayne Bay, Dade County, Florida, was investigated to determine the distribution of its benthonic foraminiferal assemblage. Percentages were calculated for the standing crop and total population from a count of all specimens present in aliquots of 26 samples taken from 15 stations. One hundred fifty-two species belonging to 75 genera and 35 families have been identified. Although the primary interest is the description of the fauna and its distribution, additional information on depth, temperature, and bottom condition was obtained to facilitate discussion of ecologic factors as they pertain to the patterns of distribution. The area is a complex positive estuarine bay, with influx of fresh waters from the west (inland) side and open ocean waters mixing on the east. The presence of barriers, natural and man-made, further complicates the water circulation and water quality, in addition to the effects of tides, weather, and hydrologic factors. Areal distribution and abundance of certain species can be correlated with the grain-size distribution of the sediments. The distribution of specimens illustrates areas of mixing or foraminiferal assemblages and the association of certain faunal assemblages with particular environmental conditions. The presence of several species not known to South Florida waters are noted herein. The species recognized are recorded in the section on systematics