Skip to main content
U.S. flag

An official website of the United States government

Effects of Habitat Characteristics and Water Quality on Macroinvertebrate Communities along the Neversink Riverin Southeastern New York, 1991-2001

May 16, 2008

The Neversink River, in the Catskill Mountains of southeastern New York State, feeds the Neversink Reservoir, which diverts 85 percent of the river?s flow to New York City. Acidification of several headwater reaches has affected macroinvertebrate assemblages throughout the river system above the reservoir, and the alteration of flow conditions below the reservoir dam has affected macroinvertebrate assemblages for at least 10 kilometers downstream from the reservoir. In 1999, the U.S. Geological Survey, in cooperation with The Nature Conservancy, compiled data from 30 stream reaches to quantify the effects of acidification and of the reservoir on the structure and function of macroinvertebrate assemblages throughout the Neversink River.

Acidic headwater reaches supported greater numbers of acid-tolerant chironomid taxa and fewer numbers of acid-sensitive Ephemeroptera and Trichoptera than neutral reaches, and fewer scraper individuals and more shredder individuals. The 14 reaches below the reservoir, with sharply decreased flows and altered flow patterns compared to reaches above the reservoir, supported more Chironomidae and fewer Ephemeroptera and Trichoptera than the upper reaches; they also had greater numbers of shredder individuals and fewer scraper and filterer individuals than reaches above the reservoir. Water-quality variables such as pH and aluminum concentration appear to have affected macroinvertebrate assemblages more strongly in the headwaters than below the reservoir, whereas physical-habitat variables such as mean channel width and water temperature have affected these assemblages more strongly downstream from the reservoir than in the headwaters. The water-quality changes due to acidification, combined with the decreased flows and lowered water temperatures below the reservoir, have disrupted downstream continuum of macroinvertebrate communities that would normally be observed from the headwaters to the mouth. The information presented herein provides a basis for further evaluation of the Neversink and similar river systems, and for assessment of the effectiveness of future conservation efforts.

Citation Information

Publication Year 2008
Title Effects of Habitat Characteristics and Water Quality on Macroinvertebrate Communities along the Neversink Riverin Southeastern New York, 1991-2001
DOI 10.3133/sir20085024
Authors Anne G. Ernst, Barry P. Baldigo, George E. Schuler, Colin D. Apse, James L. Carter, Gary T. Lester
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Scientific Investigations Report
Series Number 2008-5024
Index ID sir20085024
Record Source USGS Publications Warehouse
USGS Organization New York Water Science Center

Related Content