Fish and Wildlife Passage Barriers: A Web-based Tool Identifying Opportunities for Improved Ecosystem Connectivity

Shannon Crossen, ICF
Jon Walker, ICF; Martin Fisher, ICF

Habitat connectivity is essential to fish and wildlife species ecology, movement, and conservation, and for many species movement is substantially impacted by impassable roadway culverts. Methods to remediate fish and wildlife movement barriers along roadways have been implemented globally for decades. Fish passage barrier remediation typically involves engineering culverts and bridges with appropriate size, slope, velocity, and substrate to accommodate fish passage. Wildlife barrier remediation typically involves constructing a combination of wildlife crossings (in the form of culverts, bridges, or stand-alone wildlife crossings), combined with wildlife fencing. These measures ensure fish and wildlife can access historical habitats and allow safe movement across roadways. For both fish and wildlife this remediation results in improved access to feeding, breeding, and shelter and constitute important conservation actions. Interestingly, fish and wildlife barrier remediation efforts have largely been conducted within separate disciplines and largely uncoordinated with one another. Further, there are few systems in place to ensure that wildlife passage assessments are conducted on fish passage barrier remediation projects. Many fish passage barriers, both remediated and existing barriers, also experience adjacent wildlife-vehicle collisions and are in locations which warrant wildlife passage assessments and wildlife crossing design considerations. This will be demonstrated with our pilot web-based planning tool which identifies fish passage barriers that warrant consideration of wildlife movement design considerations. The tool identifies locations where fish movement is impeded and where wildlife movement, wildlife-vehicle collisions (WVCs), and public safety are also a concern. These can be easily located within the tool's viewer, and design considerations for wildlife and WVC reductions can be considered if feasible and warranted. The tool is malleable to allow the objectives and priorities of the user to be integrated. Such tools provide a simple and cost-effective way to identify and prioritize opportunities early in the planning process to facilitate connectivity for a larger suite of species, improve road safety, and prevent further lost opportunities in restoring habitat connectivity.

Abstract Keywords
fish passage
Wildlife Crossing
Tranportation Planning
habitat connectivity