Island Creek, a tributary of the Northeast Cape Fear River in Duplin County, North Carolina, was modified through excavation and snagging during 1977 and 1978. To evaluate the effects on resident fish populations, rotenone samples were taken before alteration in 1977 and after the project in 1981 and 1982. Mean standing crop of fish increased from 27.5 to 38.3 kg/ha after the project and total number of fish captured increased from 424 to 1,058. Significantly greater (P < 0.05) centrarchid and total game fish biomass were found after the project. No statistically significant differences could be detected between biomass and numbers of nongame fish or numbers of game fish before and after the project.