Opportunities for Barrier Removal and Fish Passage Improvements for Atlantic Salmon Recovery

In 2009, the expanded Federal listing of Atlantic salmon identified dams as one of the greatest threats to the recovery of the species.  As agencies responsible for implementing the Endangered Species Act (ESA), the NMFS and the USFWS are responsible for not only identifying threats to the recovery of Atlantic salmon, but also to identifying actions that will contribute to its recovery.  Repairing, removing and retrofitting barriers (e.g., installing fish ladders) are seen as some of the most effective and cost-efficient means of habitat restoration available.  However, in spite of the potential benefits, surprisingly little has been done with regard to the development of quantitative/analytic planning methods for prioritizing barrier repair and removal decisions.  The objective of this project was to develop a systematic method for prioritizing the repair or removal of fish passage barriers for Atlantic salmon.  Working with a variety of partners, we have developed GIS tools and budget-constrained optimization models for deciding which barriers to repair or remove in order to maximize habitat availability.  We then used these metrics to rank and compare individual barriers for benefits to Atlantic salmon recovery efforts.  This list of barriers will aid the USFWS and NMFS in their decision making as it relates to implementing the ESA and providing funding assistance for project proposals.  Furthermore, we hope the attributes used in this prioritization effort provide conservation partners with important information to aid in their own efforts as they relate to barriers or the restoration of other diadromous fish species.