Feeding the River

Abstract

Abstract The stream invertebrate community is nourished by both dissolved and particulate carbon, the latter of various size ranges, both living organisms and decaying matter. The invertebrate communities conform to the geomorphic and hydrologic conditions of the river as it transforms from small headwaters streams to large river channels far downstream. The River Continuum Concept is a unifying concept that details these relationships and is valid in many types of rivers. Exceptions would be in nonforested headwaters regions and in the abundant blackwater river systems in the US Southeast. The flood-pulse concept describes how, at least in relatively unaltered rivers, there are annual, natural floods that fish evolutionarily take advantage of to access the rich food resources of the floodplain, where younger and smaller fish can find refuge from larger, channel-based predatory fish. Unfortunately, the flood pulse is diminished or absent in dammed or otherwise fragmented river systems, which are now found worldwide.