Development of micro-scale frequency distributions of plankton for inclusion in foraging models of larval fish, results from a Video Plankton Recorder

Abstract

A self-contained, analog Video Plankton Recorder (VPR) mounted on a 1-m2 MOCNESS sampling system was used to obtain data on micro-scale (<10 m) distributions of zooplankton as prey for larval cod and haddock during May 1997 and May 1999 on Georges Bank. The negative binomial frequency distribution was selected to best describe the more abundant plankton categories in 10-second bins for 10-m depth intervals. Most of the strata had asymmetrical frequency distributions with low means and low k values indicating a clumped distribution. Water-column stratification was especially important in structuring micro-scale high-density layers of phytoplankton and copepods. The most symmetrical Poisson-like distributions with high means and high k values occurred in the upper 30 m above the base of the thermocline.