The effect of substrate resource level on the colonization and emigration rates of several taxa of drifting invertebrates.

Abstract

The purpose of this study was to investigate the effect of substrate resource level on emigration rates of the drift community as a whole by evaluating the response of several taxa to an increase in food (algae) abundance. The effects of food abundance were tested using channels placed in a natural stream through which invertebrates could drift freely. Half of the channels contained stones with normal algal levels and half contained stones with augmented algae levels in order to test the response of drifting invertebrates to differences in substrate resource levels.