Publication Summary

Mill and Cameron Creeks′ benthic macroinvertebrate assemblages were sampled on September 23, 1997 to determine if there was evidence of toxic effects due to aluminum or other pollutants on the streams' biological community. No definitive signals were seen in the macroinvertebrates; however, the assemblage showed some degree of impact with lower than expected numbers of taxa and indicator species.

Mill and Cameron Creeks′ benthic macroinvertebrate assemblages were sampled on September 23, 1997 to determine if there was evidence of toxic effects due to aluminum or other pollutants on the streams' biological community. No definitive signals were seen in the macroinvertebrates; however, the assemblage showed some degree of impact with lower than expected numbers of taxa and indicator species.

The relative degree of metals tolerance in the sampled assemblage (as measured by the Metals Tolerance Index) was 1.6-1.7 for both streams. Values greater than 4 are considered impacted by metals, with 10 being the maximum. Of note, Mill Creek had low numbers of organisms (672/sq. meter) which is indicative of a moderate level of disturbance. Mill Creek also had moderate levels of substrate embeddedness (30%); however, the numbers of Oligochaeta, which can indicate finer sediment, were extremely low. This might suggest some toxic or other impact. Low numbers of gatherers and shredders were sampled which could indicate low system retention of leaves and other organics during high flows. Overall, the benthic macroinvertebrate assemblage indicated some degree of impact from watershed disturbance but there were no clear signals of toxic pollution.