Motile Suspension-Feeders in Estuarine and Marine Ecosystems

Abstract

Motile suspension-feeders are defined as macroinvertebrates, fishes, and mammals that strain multiple small particles from the water column during each feeding event. Motile suspension-feeders include some of the most economically and ecologically important species in estuarine, coastal, and open ocean ecosystems. Major fisheries are based on fishes such as anchovies, herrings, and mackerels that feed either mainly or partially on plankton. A variety of mechanisms are used to procure, extract, and select food particles, but particles are not selected and targeted individually. Selectivity for certain-size particles coupled with pulses of high abundance can have major effects on food web and ecosystem structure. Although benthic and motile suspension-feeders share many characteristics, two major distinctions can be identified. Unlike benthic species, water column based forms do not create the kind of stable structures that provide habitat and affect hydrography. A unique character of the motile forms is the ability to migrate, often over long distances, effectively transferring nutrients and energy and otherwise impacting multiple ecosystems.