Evaluating the Ecological Effects of the Penobscot River Restoration Project

The Penobscot River Restoration Project (PRRP) is a unique and innovative aquatic restoration project that aims to increase connectivity by removing two mainstem dams and bypassing a third dam on an upstream tributary without a subsequent loss in hydro-electric generating capacity.  Project objectives include: providing unobstructed access to the entire historic riverine range for lower river diadromous species such as shortnose sturgeon; improving access to upstream habitat for upper river species such as Atlantic salmon; reconnecting trophic linkages between headwater areas and the Gulf of Maine; restoring natural fluvial processes to the former impoundments; improving recreational and Penobscot Nation cultural opportunities; and maintaining hydropower generation.  Dam removal is increasingly being used as a management tool to restore aquatic habitats and recover imperiled species.  However, many of the putative benefits of dam removal (e.g., fish community changes) remain untested hypotheses.  Given the large investments being made nationally in the field of aquatic restoration, as exemplified by the PRRP, the lack of rigorous monitoring and research to support the assertions of the beneficial effects of dam removal is surprising.  Investments from a number of partners including the Nature Conservancy, the Penobscot River Restoration Trust, NOAA’s Northeast Salmon Team, and over $1.3M in NOAA Restoration Center support through the American Recovery and Reinvestment Act of 2009 are now supporting rigorous ecosystem monitoring of physical, chemical, and biological parameters.  Thus, the PRRP provides an enormous opportunity for fisheries agencies, academia, and the general public to begin to learn and understand the true ecological effects of large scale dam removals and have accountability for the large public and private restoration investments.  These investments in monitoring and research will allow the public to make informed decisions regarding the costs and benefits of large scale restoration projects well into the future.