Cooperative Research Units
Education, Research And Technical Assistance For Managing Our Natural Resources
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Restoring Aquatic Habitats through Dam Removal


July 2018 - June 2019


There are thousands of small dams in Massachusetts that fragment and impair nearly every stream
and river throughout the state, altering fish passage, flow, sediment, and nutrient movement, and making
these ecosystems less resilient to natural and anthropogenic disturbances. To date, nearly 60 dams have
been removed in the state, yet only a fraction of these streams have been monitored to assess water
quality, habitat, and biotic responses to dam removal. Information on the benefits of dam removal,
including the watershed and long-term impacts of these changes, are critical for the public to understand
expectations following dam removal and to gain support for future dam removals. We also need a better
understanding of ecological changes following dam removal in order to better answer questions from
local, regional, and national regulatory community that impact our ability to advance projects. Over the
last three years, extensive pre-removal data has been collected on temperature, dissolved oxygen, and
macroinvertebrates at 12 dam removal sites across Massachusetts through a partnership with researchers
at the University of Massachusetts (UMass) and the Massachusetts Division of Ecological Restoration
(MDER). These data showed that most sites had significant warming downstream of dams, highlighting
the potential for extensive consequences of dams on biota, particularly coldwater fishes. However, the
magnitude and extent of effects of dams are highly variable across sites and raise additional questions.
Here, we propose to continue sampling these 12 sites plus 3 additional coldwater streams to quantify
water quality, macroinvertebrate, and fish responses to dam removal. We will use the extensive fish
database for Massachusetts and collaborate with UMass, MDER, and the Massachusetts Division of
Fisheries and Wildlife (MassWildlife) to add additional sites for a broader assessment of fish responses.
The results will be used to model the collective ecological benefits of dam removal statewide and will be
synthesized into outreach materials highlighting these benefits to promote future dam removal toward
increasing the quality and resilience of stream ecosystems.

Research Products and Activities


  • Zaidel, P.A., A.H. Roy, K.H. Nislow, C.R. Smith, and B.H. Letcher. 2016. Impacts of small, surface-release dams on stream temperature. New England Association of Environmental Biologists, 23-25 March 2016, Rockland, ME.
  • Zaidel, P.A., A.H. Roy, K.H. Nislow, B.H. Letcher, and C.R. Smith. 2016. Small dam impacts to stream temperature and potential consequences for aquatic biota. Northeast Natural History Conference, 22-24 April 2016, Springfield, MA.
  • Zaidel, P.A., A.H. Roy, K.H. Nislow, C.R. Smith, and B.H. Letcher. 2016. Impacts of small, surface-release dams on stream temperature. Annual Meeting of the Society for Freshwater Science, 21-25 May 2016, Sacramento, CA.
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Current Staff

Federal Staff: 3

Masters Students: 5

Phd Students: 11

Post Docs: 2

University Staff: 1

5 Year Summary

Students graduated: 69

Scientific Publications: 35

Presentations: 148



  • Allison RoyPrincipal Investigator
  • Keith NislowCo-Principal Investigator
  • Erin RodgersCo-Principal Investigator
  • Kris HouleNon-PI Collaborator
  • Beth LambertNon-PI Collaborator
  • Steven MattocksNon-PI Collaborator
  • Rebecca QuinonesNon-PI Collaborator
  • Todd RichardsNon-PI Collaborator
  • Sam SillenStaff
  • Eli LagacyStudent

Funding Agencies

  • Massachusetts Division of Ecological Restoration
  • Massachusetts Environmental Trust


Massachusetts Cooperative Fish and Wildlife Research Unit Cooperators

  1. Massachusetts Division of Fisheries and Wildlife
  2. Massachusetts Division of Marine Fisheries
  3. U.S. Fish and Wildlife Service
  4. U.S. Geological Survey
  5. University of Massachusetts
  6. Wildlife Management Institute