Assessing and Prioritizing Barriers to Aquatic Connectivity in the Eastern United States

Abstract

AbstractThere are tens of thousands of dams and millions of road‐stream crossings in the eastern United States (U.S.) which can prevent fish and other aquatic organisms from accessing key habitats. There is growing momentum in the eastern U.S., and throughout the country, to remove dams which no longer serve their intended purpose, provide improved fish passage facilities at those dams that cannot feasibly be removed, and upgrade road‐stream crossings to benefit aquatic organism passage (AOP). However, these projects are expensive and given the extensive scope of the problem and the limited resources available to address it, it is imperative to be strategic in deciding which barriers are removed or upgraded. The Nature Conservancy, in conjunction with several partners, has conducted a suite of analyses which assess and prioritize barriers to AOP for the potential ecological gains that could be realized if they were removed or upgraded. The results of these analyses have been used both proactively and reactively by managers throughout the eastern U.S. to identify potential connectivity restoration projects, support funding requests, and help inform funding allocation decisions by providing a common evaluation system for the many thousands of potential projects. In contrast to more prescriptive barrier removal optimizations, their flexibility of use provides managers with a practical framework for planning aquatic connectivity restoration while remaining open to the element of opportunity.