Marine Biology

Grazing by zooplankton

The grazing rate of zooplankton is one of the major factors influencing the size of the standing crop of phytoplankton and thereby rate of production. The grazing rate of herbivorous zooplankton, consisting mainly of copepod species, euphausids, pteropods, cladocerans, appendicularians, salps and many meroplanktonic larvae have a remarkable influence on the density of phytoplankton. The inverse relationship in the distribution of phytoplankton and zooplanktons is usually common, where phytoplankters are abundant, zooplankters are few and where zooplankters are abundant, phytoplankters are few. Thus, an explosion in algal production will mean that it is also due to the scarcity of zooplankton. Hence, herbivorous zooplankton affects primary production to a greater extent.