SULLIVAN, Maine — The Gulf of Maine Council on the Marine Environment (GOMC) announced the successful replacement of the aging Thorne Road culvert crossing over Flanders Stream in Sullivan. The project used Stream-Smart design principles that made the crossing more resilient to storm flows, less maintenance-prone, and likely to boost the productivity of a commercially harvested alewife run on the stream. Just downstream, the project team also replaced a crumbling fish ladder with a series of rock weirs that act like a natural cascade, gradually helping migrating fish reach the elevation of the new culvert. A dedication of the new crossing will begin at 5:00 pm on July 17th at the Sullivan Town Office.
Project Leader and Sullivan resident Gary Edwards said, “This project has been a real success story. Through the efforts of many agencies, including GOMC, the Town of Sullivan has been able to replace a failing stream crossing and do it in such a way as to improve the Flanders Stream watershed by improving fish passage.”
The previous culvert on Thorne Road was perched above the stream, a condition that interferes with fish passage at about 40% of Maine’s road culverts over streams. An even larger proportion of culverts in Maine show signs that they are undersized, which can cause steam flow velocities that prevent fish and aquatic wildlife from accessing important, upstream habitats. Undersized culverts can also require more frequent maintenance, age prematurely, or fail due to blockages.
Each spring alewives initiate a migration that starts in the open ocean and brings them to Maine’s freshwater spawning grounds. After breeding in lakes, ponds and other still waters, alewives return to the marine environment. Newly hatched fish spend up to several months in their freshwater nurseries before heading to the ocean. After three or four years at-sea, grown alewife return to their natal waters in Maine to spawn for the first time.
The journey to and from freshwater habitats is perilous for alewives and important to the ecosystems through which they pass. Along the way, alewives nourish the surrounding environment as predators like marine fish, eagles, osprey, herons, mink, otters, and freshwater sportfish feast on the seasonal bounty.
Alewives also have economic value, most notably as an important seasonal bait source for Maine’s lobster fishery. As an important prey species, it’s also been suggested that alewife restoration may be crucial to rebuilding economically important groundfish stocks.
Alewife restoration is a high priority due to large-scale population declines that started when dam building, and more recently roads, blocked fish passage to upstream spawning habitats. Maine once supported numerous alewife runs that individually numbered in the millions of fish. Many historical runs were lost or degraded due to obstructed passage. Today only one run of over one million returning adult alewives is documented in Maine.
The town of Sullivan partnered with a variety of organizations to implement the Thorne Road project over several years of planning and fundraising. The Gulf of Maine Council, National Oceanographic and Atmospheric Administration, U.S. Fish and Wildlife Service, Maine Department of Marine Resources (DMR), Maine Natural Resources Conservation Program, and Corporate Wetlands Restoration Partnership provided funding and technical assistance for the project. The Maine Coastal Program and DMR coordinated pre and post-construction volunteer alewife monitoring that confirmed the project’s alewife restoration value.
GOMC’s mission is to maintain and enhance environmental quality in the Gulf of Maine to allow for sustainable resource use by existing and future generations. The Flanders Stream Alewife Restoration is one of 114 projects supported by the GOMC-NOAA Habitat Restoration Partnership, which provided technical assistance and over $3.5 million in funding since 2002. Information about GOMC’s programs can be accessed at www.gulfofmaine.org. For more information about the July 17th dedication of the new crossing or habitat restoration programs in Maine, contact Slade Moore by email (email@example.com) or phone (207-837-3805).