Macroinvertebrate response to stream flooding and restoration in the Mohawk River Basin, New York.

MIRIAN CALDERON; ALEXANDER SMITH; TED ENDRENY

Syracuse

Simposio; Mirian Calderon; 2014

State University of New York. College of Environmental Sciencia and Forestry

Floods constitute a major disturbance to streams, causing changes in ecosystem, community or population structure through the modification of their habitats and flow regime. Macroinvertebrates are critical to aquatic trophic systems but they are particularly susceptible to changes of flow, and their abundance and diversity has been shown to generally decline in response to increases or decreases in flow. The objective of this study is to assess the response and recovery of the macroinvertebrate community to the historic flooding in 13 streams in the Mohawk River Basin caused by Hurricane Irene in August 2011 and posterior flood mitigation efforts. Macroinvertebrate data were collected in July and October 2011 and two new sets of data will be collected in July and October 2014. Macroinvertebrate Biological Assessment Profile (BAP) for Riffle Habitats will be calculated using: SPP (species richness), HBI (Hilsenhoff Biotic Index), EPT (Ephemeroptera, Plecoptera and Trichoptera richness), PMA (Percent Model Affinity), and NBI-P (Nutrient Biotic Index ? Phosphorus). Values from the five indices are converted to a common 0-10 scale, with 10 corresponding to the higher water quality.Initial macroinvertebrates results show that the 13 river sites had variable macroinvertebrate community structure before the 2011 flooding, which could indicate that communities at these sites could be affected by different biophysical factors or be in various states of recovery from prior flooding events. This study aims to increase the understanding of the susceptibility of macroinvertebrate communities to severe flooding, and how recovery trajectories are affected by stream restoration and local biophysical controls.