Using field experimentation to evaluate benthic macroinvertebrate recovery in a highly disturbed lake (Onondaga Lake, NY)

Onondaga Lake is a highly disturbed system undergoing a large scale remediation effort. Recent surveys of the macroinvertebrate community show Onondaga Lake is dominated by pollution-tolerant taxa. To assess potential recovery of the macroinvertebrate community in Onondaga Lake, I compared dispersal of macroinvertebrates to artificial substrates in Onondaga Lake with those in a reference lake (Otisco Lake). Fewer families (19 vs. 24) were collected on substrates in Onondaga Lake than in Otisco Lake. Some taxa dispersed exclusively to one lake, including two mayfly families (Heptageniidae and Caenidae) that only dispersed to Otisco Lake. The exotic quagga mussel was exclusively found in Onondaga Lake; exotic zebra mussels dominated community composition in Onondaga Lake. Crustacea-Mollusca taxa, Percent Exotic Dreissenidae, and Percent Non-insects showed differences between lakes most often. Length of deployment of artificial substrates should be considered in sampling design when monitoring recovery in lentic systems. Stenonema femoratum may not be able to survive in current Onondaga Lake conditions; a combination of both sediment and water quality may be inhibiting survival of this species.;Keywords: Benthic macroinvertebrates, remediation, dispersal, artificial substrates, bioassessment metrics, survivorship.