Macroinvertebrate sampling was conducted in February to coincide with the period of maximum larval abundance in low order streams of southeastern Pennsylvania. Preliminary results suggest that forested reaches have slightly greater species diversity than open reaches. The EPT index was lower and Chiromonid Dominance was significantly higher in urban watersheds than in non-urban watersheds. Selected sites were sampled in late fall 2000, as well. Fish sampling was conducted in late fall in order to survey a full season's production and to avoid sampling during low-flow periods.
Preliminary results suggest a greater abundance of fish in most non-intermittent meadow reaches.
Food Web Linkages. Samples of leaf litter, algae, macroinvertebrates from various feeding niches, and fishes from various feeding niches were collected and analyzed for carbon and nitrogen isotopic composition to determine food web linkages. The carbon and nitrogen isotopic composition of the various producers and consumers suggest that the peripyton is a dominant source of carbon to macroinvertebrates and most fish during the summer. Further analysis of winter samples at selected reaches is ongoing. The influence of riparian vegetation on channel morphology and lateral migration.