Stream Health: biotic integrity variation in Owasco Lake watershed Susan F. Cushman Hobart and William Smith Colleges 2007 Finger Lakes Research Conference October 6 th, 2007

Background Owasco Lake was ranked with the worst water quality in Finger Lakes (Halfman, 2005). One of the smaller lakes, but largest watershed area to lake volume ratio. Research on stream water quality indicated subwatersheds supply varied concentrations of elevated nutrients and pollutants which may impact overall stream health.

Owasco Lake Watershed

Objectives a) To assess the biotic health of streams draining Owasco Lake watershed b) To examine relationships between water quality and biotic community

Sampling Methods Kicknet sample Disturbed sediment upstream of D-net for 5 mins moving across channel diagonally in riffle habitat

Laboratory Subsampling Samples preserved in 70% ethanol were rinsed in U.S. standard # 30 sieve Invertebrates were subsampled and sorted by order until 100 individuals were counted Insects were identified to family Data was analyzed using Percent Model Affinity (PMA) developed by Bode et al. (2002).

Richness EPT Family Richness

Model Community

Percent Model Affinity Watershed composition: Hemlock -57% Ag -42% Forest -1% Urban Veness -85% Ag -0% Forest -1% Urban -14% Wetlands Slightly impacted

Water quality and PMA Adj-r 2 = 0.35

Conclusions Both IBI’s indicate degradation along the southern end of the Inlet Benthic community in Hemlock is very healthy, compared to streams at northern end (Veness, Sucker, Dutch Hollow) Elevated stream nutrient concentrations appear in streams with high biotic integrity

Biotic impacts are evident along the Inlet, and are consistent with biological assessment by Bode et al. (2006). County line displays low IBI values, however the community seems to improve downstream before entering Owasco Lake. Future research on algal standing crop may indicate relationship between nutrients and benthic macroinvertebrate community. Conclusions cont’d

Acknowledgements John Halfman and Jim Ryan (HWS) Robert Bode and Gary Neuderfer (NYSDEC) Funding: Senator Michael Nozzolio