Survey of fish assemblages in the upper Neversink River and upper Rondout Creek, New York, 2017–19
Streams in the Catskill Mountains region of New York provide many important ecological and economic services, including recreational angling and serving as a drinking water supply to New York City. Many streams in this region were adversely affected by acid deposition during the late 20th century, impairing water quality and aquatic ecosystems. More recently, the level of acid deposition has declined while changes in climate have become more pronounced. As a result, biological and chemical data are needed to determine the current condition of stream ecosystems in the Catskill Mountains region. The U.S. Geological Survey, in cooperation with the Rondout Neversink Stream Program, surveyed fish communities and water chemistry annually between 2017 and 2019 at 23 sites in the upper Neversink River and upper Rondout Creek watersheds to compile a contemporary baseline dataset and assess potential biological recovery from reduced acidification. The resulting data indicated that brook trout ( Salvelinus fontinalis ) were present at every study site, although slimy sculpin ( Cottus cognatus ) was the most abundant species at most sites. Stream pH ranged from 4.8 to 7.0 across all sites and generally increased from upstream to downstream. Similarly, the number of species present and the ratio of brown trout ( Salmo trutta ) to brook trout increased at sites in each subwatershed from upstream to downstream.