AUTHORS: Jacob Zona, South Dakota State University; Tait Ronningen, US Fish & Wildlife Service; Christopher Cheek, South Dakota State University; Stephanie Webster, South Dakota State University
ABSTRACT: Habitat fragmentation is one of the most pressing issues in conservation biology. Restricting the movement of organisms can limit access to critical habitats during different life history stages, reduce population sizes, decrease genetic connectivity, and ultimately disrupt community structure. There has been a tremendous amount of research and management focused on the impact of large dams on aquatic ecosystems, particularly anadromous fishes. However, the removal or remediation of these structures is often socially unfeasible or financially restrictive. Work focusing on smaller, more abundant barriers to aquatic organism passage (e.g. culverts, low-head dams) has increased in recent years. Considering the wide geographic scope of this issue and the enormous number of potential barriers, careful consideration needs to be taken on where best to focus limited financial resources. As more stakeholders begin working in watershed connectivity, coordination between partners becomes increasingly important. Multiple resources available to managers have been recently developed to aid in this prioritization and coordination. We utilized the USFWS National Fish Passage Coordination Map and the SARP National Aquatic Barrier Inventory and Prioritization Tool to help us more effectively assess stream connectivity across the western Great Plains in partnership with the BLM. Using the NFPCM we prioritized 38 HUC10 watersheds across Eastern Montana based on percent BLM ownership, SGCN fish species richness, amount of stream habitat, and coverage by previous barrier survey projects. We also used the NFPCM combined with other GIS tools to identify, categorize, and prioritize potential barriers within each watershed prior to field surveys. Between July and September 2024, 329 potential barriers were assessed using the Stream Crossing Survey and the Dam and Diversions Survey through SARP. Each survey was uploaded to the NABI where managers can now use the prioritization tool to determine best candidates for remediation based on their specific connectivity goals.
