SREL Reprint #2030

Short-term recolonization by fishes of experimentally defaunated pools of a coastal plain stream

Andrew L. Sheldon1 and Gary K. Meffe2

1Division of Biological Sciences, University of Montana, Missoula, Montana 59812
2University of Georgia, Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina 29802

Abstract: Fishes were removed from pools in a South Carolina stream to observe subsequent recolonization patterns and development of community structure. Recolonization, measured between two and 32 days, was rapid; and downstream sites attained preexperimental density, richness, and proportional composition by day 32. However, recovery of upstream sites was incomplete in that time. Species colonized in proportion to abundance, and rare species returned later; both of these results are interpreted as simple proportional sampling of a mobile fauna. In a longer experiment, defaunated pools did not differ from controls; and density, richness, and composition showed no temporal trend over 31-63 days. Movement, measured by directional trapping, was dominated by spawning yellowfin shiners (Notropis lutipinnis), but 16 of 26 species present were trapped, demonstrating active movement by much of the fauna. Rapid recolonization of defaunated areas is plausibly explained by a combination of high mobility and equilibrium with source populations.

SREL Reprint #2030

Sheldon, A.L. and G.K. Meffe. 1995. Short-term recolonization by fishes of experimentally defaunated pools of a coastal plain stream. Copeia 1995:828-837.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).