THE RECRUITMENT PATTERNS OF AN ESTUARINE COPEPOD - A BIOLOGICAL-PHYSICAL MODEL

A biological-physical model was developed to study the population grow th of Coullana candensis (Willey), a meroplanktonic copepod, in the Sa co River estuary, Maine. The biological processes were derived from ex tensive laboratory and field data, and the physical processes were bas ed on a comprehensive estuarine hydrodynamic model. The study found th at the physical environment significantly altered the seasonal pattern of population growth from that predicted from the biological model. N auplii were lost from the estuary due to flushing in spring and early summer, and thus, the timing of the peak in copepod recruitment was de layed until late summer. A low river flux during late summer resulted in less mass exchange at the mouth of the estuary, that apparently was necessary for the viability of the population within the estuary.