Vertical zooplankton distribution on the northeastern Florida shelf and its relation to temperature and food abundance

Abstract

The vertical distribution of abundant zooplankton on the northeastern (NE) Florida shelf was measured and related to depth, temperature and concentration of particulate matter. High particle concentrations were observed in low-temperature near-bottom intrusions of upwelled Gulf Stream water. Patterns of vertical distribution differed among the abundant zooplankton taxa. Abundances of the calanoids Eucalanus pileatus and Temora turbinata , late copepodids and adults of the cyclopoid Oncaea sp., the cladcceran Penilia avirostris and larvae of the cephalochordate Branchiostoma sp. generally increased with increasing depth. E. pileatus, T. turbinata, Oncaea sp. and P. avirostris increased with increasing concentration of paniculate matter. Abundances of young specimens of the tunicate Oikopleura , the calanoid Centropages furcatus and during one period, the cyclopoid Oithona sp. were greatest in the upper mixed layer and the thermocline. The abundance of Eucalanus, T. turbinata and the late copepodids/adults of Oncaea showed a significantly positive conelation to the abundance of paniculate matter.