. Critical trends in Illinois ecosystems. Ecological assessment (Biology); Environmental impact analysis; Nature; Pollution; Conservation of natural resources; Environmental quality. 88 Critical Trends in Illinois Ecosystems ECOSYSTEM MONITORING The 10 sites sampled by CTAP biologists scored below average for HBl and about average for habitat quality, but had the best scores for EPT and native fish species richness. Several sites were large streams in the Embarras drainage where a shifting sand bottom predominated. However, snags (wood debris) and undercut banks were plentiful, providing stabl
. Critical trends in Illinois ecosystems. Ecological assessment (Biology); Environmental impact analysis; Nature; Pollution; Conservation of natural resources; Environmental quality. 88 Critical Trends in Illinois Ecosystems ECOSYSTEM MONITORING The 10 sites sampled by CTAP biologists scored below average for HBl and about average for habitat quality, but had the best scores for EPT and native fish species richness. Several sites were large streams in the Embarras drainage where a shifting sand bottom predominated. However, snags (wood debris) and undercut banks were plentiful, providing stable habitat for a large number of EPT and fish species. Because the larger streams have a tendency to flood, row crops are kept further from their banks, allowing for meandering, wooded. H CTAP-INHS River Sites 0 RiverWatch Sites A ForestWalch Sites Figure 54. Monitoring sites riparian corridors. Smaller streams, however, have been cleared of trees, wood, and natural bimk struc- tures to facilitate drainage for row crops. The best site was the Embarras River at Fox Ridge State Park, where native fish and EPT richness and habitat scores were well above statewide and basin averages. An unnamed tributary of Freept)rt Creek near Oblong, channelized long ago but now heavily wooded, had EPT and native fish richness well below statewide and basin averages. This situation suggests a fairly recent spill event that was either toxic or depressed oxygen levels enough to kill sensitive insects. Table 42. Watershed Indicator Scorecard Indicator Value Watershed Value Statewide Ranking Watershfd Macioimertebrales HBI S,S 8 MBI ; 9 EPT richness 1 EPT taxa fRW) 4 Taxa richness 1 Taxa dominance S Fish Native fish I Darter richness 33 1 Exotic species 4 Habitat Habitat score 6 RiverWatch volimteers monitored 43 sites on 32 streams between 1995 and 1999. collecting a total of 86 samples. The watershed scored high in
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