Stephen Coghlan
5755 Nutting Hall, Room 240
University of Maine
Orono, ME 04469
207.581.2880
Stephen.Coghlan@umit.maine.edu
http://www.wle.umaine.edu/faculty/coghlan_website3/coghlan.html

Kevin Simon
School of Biology & Ecology, University of Maine

Joseph Zydlewski
USGS Cooperative Research Unit

Maine’s rivers were once linked to the ocean by spawning migrations of diadromous fishes. These fish brought nutrients and energy from the marine realm hundreds of miles into upland, freshwater food webs. Dams, constructed to power mills and later generate electricity, blocked these fish migrations, resulting in decreased biodiversity and productivity. The Penobscot River Restoration Project will open potentially thousands of kilometers of historic fish habitat, with ecosystem-wide effects anticipated. However, scientists lack empirical data about how systems respond to dam removal at the species, community, and ecosystem levels.

Sedgeunkedunk Stream, a tributary of the lower Penobscot River estuary, is the subject of a restoration effort to reconnect the stream and its associated lakes to the sea, in advance of the larger project on the Penobscot. One dam has been removed and another bypassed with a rock-ramp fishway and monitoring programs are in place for fish and macroinvertebrates. Coghlan’s project focuses on the sea lamprey, an anadromous fish whose nest-building activity creates habitat for another anadromous fish, the endangered Atlantic salmon. “In Sedgeunkedunk Stream, we observe a spectacular summer ‘greening’ of the river bottom in late June, coincident with sea lamprey carcass decomposition. We wondered what impact marine nutrients delivered by the lampreys have on in-stream communities,” said Coghlan, who calls sea lamprey a sentinel species that both responds to dam removal and enhances the effects of dam removal on other species.

Two-year project, 2010-2012
Total Sea Grant Funds: $105,224