ESTUARINE MICROPHYTE PRODUCTIVITY

Abstract

An estuary is an interface where mixing of river and sea water occurs, often within the confines of an embayment. The abrupt environmental changes between these two environments pose a multiplicity of stresses to the estuarine biota, placing a premium on the ability to adapt to a wide range of conditions.

Few species have sufficient adaptability to meet these conditions and so estuarine species diversity is low (Odum, 1970). Additionally, estuaries are "young" ecosystems in that pioneer species are always present because constant flushing by fresh water and the tides precludes a successional sequence from going to climax. Such "young," low diversity ecosystems are characterized by large standing crops of short lived species (resulting in short nutrient recycling times), and high primary productivity. Table l provides some net primary productivity values for various estuaries and other ecosystems. Microphytic net production plus macrophytic net production is often very high in estuaries, albeit less than tropical rain forests and many agricultural crops.