Between the head of tide above Bangor to where it widens into the bay at Searsport, the Penobscot River shifts from a flowing freshwater waterway banked by cedar and pine to a brackish, wave-lapped marsh with a rocky shoreline. In this estuary, salt concentrations fluctuate as the winds and tides push sea water and sediments back and forth.
The estuary and the river that feeds it have taken on a new character recently, and have become an international example of watershed restoration. Sea Grant researchers are among those studying the impacts of dam removal on the river's fish populations and ecology. This article, in the Winter 2016 issue of Maine Boats, Homes & Harbors Magazine, describes the preliminary findings in the few years since dam removal, including an estuary filled with small, silvery fishes, and a series of surprises for scientists like University of Southern Maine's Karen Wilson.