St. Croix River Alewife Issue

Graph of Alewife Numbers & St. Croix Map

The St. Croix River is for 165 km. the international boundary between the U.S. and Canada, and on a more local level, between Maine and New Brunswick.

Traditionally action within this river's watershed is seen as affecting both countries, and thus should be dealt with on a consensus basis through such organizations as the St. Croix Board of the International Joint Commission (IJC).

However, with no scientific basis to its decision, the Maine Legislature in 1995 enacted "emergency" legislation, thus stifling debate, to close fish passages to an important native species, the alewife, also known as the gaspereau. They did this at the instigation of bass fishing guides on the St. Croix's lakes, who quite erroneously believed the alewives were impacting the introduced species of smallmouth bass, an important game fish for them.

No consultation occurred with either the Canadian government or with the IJC.

Grand Falls Dam - blocks alewivesFor 18 years the fishways remained closed to the alewives, despite strong representations by the U.S. Federal Government, the Canadian Department of Fisheries and Oceans (DFO), and the IJC. In some years the number of alewives dropped to as few as 900 fish.

Beginning in 2003, DFO began trucking alewives from the Milltown Dam fishway trap to above Woodland Dam, since the fishways for both the Woodland and Grand Falls Dams were on the Maine side of the border.

In 2008, science made a bit of a comeback, and Maine was persuaded to open the Woodland Dam fishway, allowing alewives to access a small portion of the habitat.

Alewives are important in the food web of both fresh and salt water.

Beginning at that time there was also an increasingly vocal group of 50 conservation, First Nations and other marine commercial groups that wanted the alewives restored to their historic role as an important species in the St. Croix.

In July 2012, the U.S. Environmental Protection Agency ruled that blocking alewives from ascending the St. Croix River made Maine in breach of the Clean Water Act.

Finally, in April 2013, both houses of the Maine Legislature voted overwhelmingly to open the St. Croix River to its native alewife population.

See News Story on Opening of St. Croix River to Alewives read more

Background on Alewives & St. Croix


  • Alewife eggs laid in St. Croix in June; the adults leave soon after; the young leave as juveniles in September; then spend four or five years at sea before returning
  • Alewives bring marine-derived nutrients to fresh water
  • Buffer predation on Atlantic smolt moving out and adult Atlantic salmon migrating upriver
  • Also buffer for shad and smelt
  • Nutrients from alewives very important in contributing to the bacterial breakdown of leaf litter - Durbin et al, 1979
  • Alewives food in freshwater for otter, mink, ospreys, eagles, snapping turtles
  • In saltwater, alewives appear important in supporting populations of groundfish, striped bass, and cormorants
  • Alewives in the St. Croix are the only known host for a freshwater mussel species known as the Alewife floater
  • Less than 2% of the St. Croix alewife production area of 40,147ha/99,200 acres was open to alewives before Apr. 2013

  • The St. Croix is an international boundary river between the United States and Canada, where a change in policy and watershed management has international impacts. The St. Croix is also the boundary between the Maine, and New Brunswick
  • Alewife bones found at an archaeological site at Mud Lake Stream on Spednic Lake, dated 4,000 years BP, showing alewives have traditionally been an ecological part of the entire St. Croix River system, and the fish has status as a native species
  • Up to 1825, 100-ton Rhode Island vessels would arrive at Calais, and leave full with barrels of alewives
  • 19th century exports of 1,500 to 2,000 barrels of alewives from St. Croix in 1870s
  • Dams took a toll on alewife numbers in 19th century
    • 1825 Union Dam - major blockage until 1869. Dam breached 1923
    • 1881 Milltown Dam
    • 1906 Woodland Dam
    • 1915 Grand Falls Dam
  • 1995 - Maine Legislature, via emergency legislation that stifled debate, arbitrarily and unilaterally blocked passage at Grand Falls and Woodland fishways in this international river
  • 2001-2007 DFO trucks alewives from Milltown Dam to above Woodland, while US Fish and Wildlife officials find their hands are tied due to ownership of the fishways at Woodland and Grand Falls
  • 2002 - Only 900 alewives in total return to the St. Croix, almost complete destruction of a native species that averaged about 250,000 returns in the 1980s
  • 2000s - Maine Rivers study of alewives and smallmouth bass showed that alewives do not reduce the number of bass
  • 2008 - Alewife passage opened at Woodland, but not Grand Falls
  • 2009 - ASF and 23 other conservation organizations make presentations to the International Joint Commission to intervene. IJC sends a letter to Maine's Governor Baldacci, but there is no further progress in reopening fishways for alewives
  • Apr 2013 - Reacting to concerted pressure from conservation organizations, First Nations, and user groups, both houses of the Maine legislature voted to reopen ALL of the St. Croix River watershed to alewives.