Effects of flow alteration on ecological health of streams across the Atlantic Highlands Ecoregion

Problem: The Clean Water Act (PL 92-500) requires that the health of the Nation’s rivers and streams be assessed on a regular basis, and in the Northeast such assessments often use information from aquatic biological communities that live in the stream.  Biomonitoring programs implemented by individual states evaluate biological data to assess stream health on the premise that certain sensitive species that are native to the region cannot survive when water quality is poor.  The aquatic community data are typically condensed into a set of biological condition metrics that are scaled numerically to convey the relative degree of stream impairment (e.g., excellent, good, fair, poor).  However, biological condition metrics generally are interpreted as reflecting changes in the chemical characteristics of water quality, even though changes in the physical characteristics of stream flow and water temperature also affect stream health.  Therefore, an effort to establish a set biological condition metrics indicative of changing stream-flow and temperature regimes is important, especially regarding levels of uncertainty in the ecological effects of climate change. 

 

Project goals: Our goal is to develop a predicative model for forested streams in the northeast that will indicate how the ecological health of streams is affected when flow and temperature regimes are altered.  The use of streams in primarily forest watersheds reduces the likelihood that stream health will be impaired by poor water quality. This project makes use of on an existing network of about 75 USGS streamgaging stations in the Atlantic Highlands Ecoregion, which primarily includes watersheds in New York, Vermont, New Hampshire, Maine, Massachusetts, Connecticut, New Jersey, and Pennsylvania. Data from this study will also be synthesized on a national scale, along with data from similar studies in California, Colorado, and Utah to assess broad geographic and regional patterns.

Tasks: 

• Determine the hydrologic flow characteristics for each of the 75 streams in the network of USGS Stations, using records from USGS streamgages that have been active for 10 years or longer. 
• Calculate the extent that flows have been altered at each stream (such as from dams, controlled releases, and interbasin transfers), using methods that measure how flows have departure from a natural (undisturbed) system, such as described by Carlisle et al., 2012.
• Monitor the air and water temperatures at each station with the use of electronic data loggers programmed to record at hourly intervals; these data will be used to determine air and stream temperature characteristics for the stations.
• Collect macroinvertebrate and periphyton (attached algae) samples from each stream to evaluate the biological condition of streams based on the array of species in the macroinvertebrate and algal communities.  For macroinvertebrates, the ecological health of each stream will assessed relative to biologic condition metrics that have been established for state biomonitoring programs in streams of the respective areas (Barbour, et al., 1999). 
• The biological condition of streams will be related to the flow and temperature regimes to help establish how changes in stream flow and temperature can degrade the ecological health of streams in the northeast.  Results will be described in terms of the Biological Condition Gradient (BCG) framework, a descriptive model developed for the EPA, to evaluate region-specific characteristics of stream health and to communicate the results in terms easily understood by the general public (Davies and Jackson, 2006).        

Opportunities for collaboration: Linking the flow-ecology study with other assessment, monitoring, and research activities in the northeast is a high priority for the USGS. Partnerships with the USGS will help supplement resources to collect data, share information, and promote scientific understanding in the region. To facilitate collaborations, the USGS is soliciting input and cooperator support from interested parties (such as state and federal agencies, academic institutions, and non-governmental organizations) on issues of ecological importance associated with flow alteration and areas of complementary research.

References cited

Barbour, M.T., J. Gerritsen, B.D. Snyder, and J.B. Stribling. 1999. Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers: Periphyton, Benthic Macroinvertebrates and Fish, Second Edition. EPA 841-B-99-002. U.S. Environmental Protection Agency; Office of Water; Washington, D.C.

Carlisle, D.M., Nelson, S.M., and Eng, K. 2012. Macroinvertebrate community condition associated with the severity of streamflow alteration. River Research and Applications DOI: 10.1002/rra.2626

Davies, S.P., and Jackson, S.K., 2006, The biological condition gradient: a descriptive model for interpreting change in aquatic ecosystems: Ecological Applications, v. 16, no. 4, p. 1251–1266.

Project Location by County

Albany County, NY, Rensselaer County, NY, Comumbia County, NY, Greene County, NY, Dutchess County, NY, Putnam County, NY, Westchester County, NY, Rockland County, NY, Schoharie County, NY, Otsego County, NY, Delaware County, NY, Ulster County, NY, Sullivan County, NY, Orange County, NY, Wayne County, NY, Broome County, NY, Chenango County, NY, Oswego County, NY,  Adirondack Region: Clinton County, NY, Essex County, NY, Franklin County, NY, Fulton County, NY, Hamilton County, NY, Herkimer County, NY , Lewis County, NY, Oneida County, NY, Saint Lawrence County, NY, Saratoga County, NY, Warren County, NY, Washington County, NY