Cooperative Fish and Wildlife Research Units Program: Maine
Education, Research and Technical Assistance for Managing Our Natural Resources

Maine Project

Passage of adult Atlantic salmon in the Penobscot River before and after dam removal

January 2005 - January 2022


Participating Agencies

  • CRU
  • West Enfield Fund
  • NOAA Fisheries
  • NOAA
  • SSP Program
  • ARRA
Adult Atlantic salmon tagging

The Penobscot River has experienced two main-stem dam removals and other engineering changes, including the installation of a fish lift at Milford Dam (the lowest dam in the system) with hopes of restoring Atlantic salmon. Efforts to restore these federally endangered fish will rely on safe and effective fish passage. We sought to use acoustic, radio telemetry and PIT tag technology are being used to characterize migration patterns and passage efficiency of adult Atlantic salmon. This work in the Penobscot River, Maine, necessitating effective collaboration with USFWS, NOAA, Penobsot Nation, Maine Department of Marine Resources, Brookfield Power, TNC and the Penobscot River Restoration Trust. Characterizing migration patterns and passage efficiency in the Penobscot River, Maine can inform restoration strategies into the future.

Research Publications Publication Date
Sigourney, D., Zydlewski, J., Hughes, E., Cox, O. (2015) Transport, dam passage and size selection of adult Atlantic Salmon in the Penobscot River, Maine. North American Journal of Fisheries Management. 35:1164-1176 | Download January 2015
Maynard, G.A., Kinnison, M.T., and Zydlewski, J. (2017) Size Selection from Fishways and Potential Evolutionary Responses in a Threatened Atlantic Salmon Population. River Research and Applications. 2017;1–12 DOI: 10.1002/rra.3155 | Download March 2017
Maynard, G., Izzo, L., and Zydlewski, J. (2018) The fate of hatchery-spawned Atlantic Salmon kelts released into the Penobscot River, Maine. Fishery Bulletin 116:281-290. DOI: 10.7755/FB.116.3-4.6 | Download October 2018
Izzo, L., Maynard, G.A., and Zydlewski, J. (2016) Upstream movements of Atlantic Salmon in the lower Penobscot River, Maine following two dam removals and fish passage modifications. Marine and Coastal Fisheries, 8(1): 448-461. DOI: 10.1080/19425120.2016.1185063 | Download July 2016
Holbrook, C., J. Zydlewski, M. Kinnison, Gorsky, D., and S. Shephard (2009) Movements of pre-spawn adult Atlantic salmon near hydroelectric dams in the lower Penobscot River, Maine. North American Journal of Fisheries Management. April 2009
Gorsky, D., J. Trial, J. Zydlewski, J. McCleave (2009) The Effects of Smolt Stocking Strategies on Migratory Path Selection of Adult Atlantic Salmon in the Penobscot River, Maine. North American Journal of Fisheries Management 29:949-957. | Download June 2009
Theses and Dissertations Publication Date
Izzo, L. K. 2016. Exploring the threats of dams and ocean conditions: In-river movements and ocean growth of Atlantic salmon (Salmo salar) from Maine's rivers. Weaver 2017. Ph.D. Sea lamprey (Petromyzon marinus) as a functional link between marine and freshwater ecosystems. August 2016
Holbrook, C. 2007. MS Thesis: Behavior and survival of Migrating Atlantic salmon (Salmo salar) in the Penobscot River and Estuary Maine: Acoustic Telemetry Studies of Smolts and Adults. March 2007