THE PRINCIPLE OF BIOLOGICAL ATTRACTION, DEMONSTRATED BY THE BIO-CONTINUUM THEORY OF ZOOPLANKTON PATCH DYNAMICS

A theory of zooplankton and micronekton patch dynamics is developed th at expressly includes animal behavior. This represents a departure fro m traditional models of patch dynamics, which generally treat animals as Lagrangian particles whose distributions are determined solely by p rocesses of advection and diffusion. The ''bio-continuum'' theory is b ased on principles of statistical mechanics, and describes animal aggr egations in terms of mean motion, random motion, random kinetic energy , distribution and abundance. The forces on an animal aggregation act both upon the aggregation as a whole (external forces) or between indi viduals (internal forces). We demonstrate here that the internal force s which serve to maintain autocoherence are, in essence, a force of bi ological attraction that can be quantified in Newtons. A coefficient o f biological attraction is defined, and its magnitude evaluated in agg regations of Antarctic euphausiids (Euphausia superba). We hypothesize that the coefficient of biological attraction may be constant for all organisms in the sea. A method for measuring all key variables with a coustic Doppler technology is presented, with specific attention to ap plication of the Acoustic Doppler Current Profiler (ADCP). We conclude that bio-continuum theory, coupled with acoustic Doppler observations , provides a practical approach for studying animal aggregation dynami cs in the sea.