INVERTEBRATES AND OTHER BENTHIC FEATURES AS INDICATORS OF ENVIRONMENTAL-CHANGE IN JUDAY-CREEK, INDIANA

Spatial and temporal changes in benthic features, especially macroinve rtebrate community structure, were examined from 1981 to 1992 in Juday Creek, a northern Indiana stream subjected to habitat degradation due to changes in land use along its length and over time. Watershed land use in 1992 was dominated by agriculture (45%) and urbanization (31%) ; only about 7% of the basin remained as original woodland or prairie. Habitat quality and biodiversity improved with distance from the agri culturally impacted headwaters to the lower section of Juday Creek, wh ere the stream flows through a heavily wooded area. Organic matter ret ention, a process critical to stream energy flow, was related positive ly to stream heterogeneity and the abundance of large woody debris in the channel. Abundance and secondary production of several groups of b enthic macroinvertebrates declined after 1982 and have been a result o f increased sedimentation in Juday Creek associated with changes in la nd use. Possible sedimentation effects were best revealed by changes i n secondary production of functional feeding groups, especially collec tor-filters (86% decrease) and collector-gatherers (292% increase). Ju day Creek showed short-term longitudinal recovery from upstream waters hed disturbance but a long-term overall decline in habitat quality. Ca reful land use and proper riparian management are needed to restore th is Indiana stream to its previous habitat conditions and biological pr oductivity.