On a comfortable day in late September 2024 about a dozen anglers from the Ashokan-Pepacton Watershed Chapter of Trout Unlimited (APWC-TU) and the Region 3 Fisheries Unit of the NYS Department of Environmental Conservation (NYSDEC) gathered to obtain tiny clips from the fins of native Brook Trout. The volunteer anglers from APWC-TU initiated the citizen science study to determine if local Brook Trout are genetically distinct from other native and stocked populations in New York State. Fin samples would later be processed through a genetics laboratory and analyzed by a geneticist.
Brook Trout are the only native trout that inhabits the cold, clear streams of much of the eastern United States and are prized by anglers. They are found in a limited number of streams spread throughout the Adirondacks, Catskills, and several other areas of New York State. The APWC-TU similarly sampled local Brook Trout in the Esopus Creek watershed in 2019, 2020, and 2023.
In February of this year, the genetic analysis for the 2023 samples came back. The genetics report developed by Dr. Spencer Bruce, the current Director of the Bioinformatics Core at the Wadsworth Center for NYS Department of Health, compared the genetic composition of sampled Catskills population Brook Trout to the genetics of populations native to the Adirondacks and to current stocking strains.
Dr. Bruce’s findings indicate the stream sampled in 2023 harbors a Brook Trout population with unique genetics. There was little indication the Brook Trout have had genetic connectivity or gene interaction with Adirondacks populations or strains currently used for stocking in the Catskills.
The 2023 study results repeat findings of genetically distinct Brook Trout populations in small streams that were sampled in 2019 and 2020. All streams sampled by the collaborators between 2019 and 2024 were tributaries to the upper Esopus Creek and Bushkill streams located in northwest Ulster County. The studies were funded by APWC-TU with small matching research grants from the Ashokan Watershed Stream Management Program (AWSMP). Dr. Bruce has largely donated his time to conduct the genetic analyses.
Similar genetic studies have been completed on Brook Trout taken from the upper Delaware River and Schoharie Creek. Intriguingly, Brook Trout populations from the upper Schoharie Creek were also genetically isolated from fish sampled in the immediately adjacent Stony Clove Creek watershed. Stony Clove Creek is a tributary to the upper Esopus Creek. The fish populations showed no signs of mixing over the thousands of years Brook Trout have inhabited the Catskills region. Collectively, the findings strongly suggest that Catskill populations of Brook Trout are genetically adapted to their specific regional habitat, and careful consideration must be given to protecting and improving their local habitats to support healthy populations.
Data from these studies is shared with the Eastern Brook Trout Joint Venture (EBTJV), a fish habitat partnership with the goal of maintaining “healthy coldwater systems with fishable Brook Trout populations throughout their historic range.” While Brook Trout are resilient fish – they have thrived in cold waters of the Appalachian Mountains for several million years – landscape changes have greatly diminished the presence of wild Brook Tout throughout their native range.
According to the EBTJV, Brook Trout are impacted by habitat modification, non-native species, and other population-level threats like climate change. One way to support robust wild Brook Trout populations is to restore Brook Trout habitat where it’s been degraded and improve connectivity between suitable habitats.
Access to new Brook Trout habitat might be restored through removing small dams and replacing undersized or perched road culverts; removing competing fish species; and restoring streamside vegetation and natural stream functions that create suitable habitats.
In some cases, restoration involves reintroducing Brook Trout to streams where habitat issues have been addressed. Fish reintroduction efforts should be informed by genetic studies like those conducted by APWC-TU and the AWSMP. According to the EBTJV on its website, “preserving genetic diversity is akin to protecting the Brook Trout ‘toolbox’, the sections of genetic code that might help brook trout populations survive and even thrive in a changing world.”
Several local agencies and organizations specialize in work that has the potential to conserve local and genetically distinct Brook Trout populations discovered by APWC-TU and collaborators in the Catskills region. The Ashokan Watershed Stream Management Program operating in the APWC-TU sampled watersheds, frequently works with county and local highway departments, and their hired consultants to incorporate fish-passage friendly design features into replacement bridges and culverts. The program implements large-scale stream restorations that restore natural stream function and revegetate stream corridors with genetically native Catskill plants that co-evolved with Brook Trout.
“The NYSDEC Bureau of Fisheries is grateful for the opportunity to assist the Ashokan-Pepacton Watershed Chapter of Trout Unlimited in their research of Catskill Mountain brook trout genetics. These studies demonstrate both the uniqueness and resilience of our local brook trout and bolster ongoing efforts to preserve these fish and their threatened habitats throughout the Catskills. We look forward to future collaborations with the APW-TU Chapter and commend their dedication to the conservation of our native trout populations,” said Robert Adams, an Aquatic Biologist with the NYSDEC Bureau of Fisheries responsible for fisheries resources in Ulster and Dutchess Counties.
“Historically, wild brook trout thrived throughout the Northeast, but due to human activities, they are now confined to the most pristine and remote streams. Often referred to as the “canaries in the coal mine,” their presence and health are indicators of the ecological well-being of our mountain streams. Our efforts align with the broader Eastern Brook Trout Venture, aiming to identify existing brook trout populations and develop management strategies to address habitat loss, ecosystem changes, and the impacts of climate change. The Ashokan-Pepacton Watershed Chapter of Trout Unlimited is honored and thrilled to be working in partnership with the Ashokan Watershed Stream Management Program, the New York State Department of Conservation, and Dr. Spencer Bruce in executing this important multi-agency, citizen-based scientific research, said Mark Loete, President of the Ashokan-Pepacton Watershed Chapter of Trout Unlimited.
To learn more about the APWC-TU, visit www.apwctu.org.
The AWSMP is a partnership between Cornell Cooperative Extension of Ulster County, Ulster County Soil and Water Conservation District, and NYC Department of Environmental Protection. Funding for the AWSMP’s Stream Management Implementation Program grants is provided the New York City Department of Environmental Protection. For more information on the AWSMP visit www.ashokanstreams.org.