AUTHORS: Teresa Newton, US Geological Survey, Upper Midwest Environmental Sciences Center; Jeff Cole, US Geological Survey, Pennsylvania Water Science Center; John Young, US Geological Survey, Eastern Ecological Science Center; Jordan Allison, Pennsylvania Fish and Boat Commission; Nate Welker, US Forest Service; Kristi Dobra, US Army Corps of Engineers; Molly Reif, US Army Engineer Research and Development Center
ABSTRACT: The Sustainable Rivers Program, a national partnership between The Nature Conservancy and the U.S. Army Corps of Engineers, was created to modernize water infrastructure to maximize ecological benefits. In the Allegheny River (PA), resource managers are considering modifying flows at the Kinzua Dam but are concerned about effects of altered flows on sensitive species, such as native freshwater mussels. Prior to implementing a revised flow regime, resource managers requested baseline data on existing mussel resources. We developed a robust sampling design to (1) understand how mussels are spatially distributed across the riverscape, (2) estimate density, population size, and recruitment strength of mussels, and (3) obtain remotely-sensed habitat data across a 135 km reach of the Allegheny River downstream of the Kinzua Dam. In June 2024, divers obtained data on mussels from 300 systemically placed quadrats across the reach. From the quadrat data, multiple metrics of the relative health of mussels will be estimated (e.g., species richness, mortality, age and length demography, recruitment). From high-resolution aerial and boat-borne sensors (e.g., bathymetric lidar, hyperspectral imagery, sonar), characterization of in-channel mussel habitat will be obtained and used to create hydrodynamic and habitat models to explain patterns of mussel distribution at a variety of flows. Currently, resource managers rely on data obtained from project-specific studies to make management decisions. The addition of systemic baseline data on mussels across an entire reach of the Allegheny River will facilitate more informed decisions about how mussels may respond to proposed changes in river flows.
