Alewife Confirmed in Lake Champlain

Grand Isle, VT - In the past three years, sampling throughout Lake Champlain conducted by state, provincial and federal agencies has confirmed the presence of alewives, a non-native invasive fish, in several sections of Lake Champlain.

In 2003, Québec Ministry of Wildlife and Parks biologists made the first discovery of the species in Lake Champlain when they found several adult alewives in the Québec portion of Missisquoi Bay. This was followed by the collection of a single adult alewife by fisheries biologists with the Vermont Fish & Wildlife Department in 2004 in Vermont waters of northern Champlain. As a result of these discoveries, coordinated sampling efforts were expanded throughout Lake Champlain in 2005 by the Vermont Fish & Wildlife Department and the U.S. Fish & Wildlife Service. These efforts resulted in the collection of an additional three young-of-the-year alewives in the main lake and one adult alewife in the Inland Sea. A class from the University of Vermont added another young-of-the-year alewife to the Inland Sea collection.

Vermont fisheries biologist Bernie Pientka believes these catches indicate that a new population may be forming in Lake Champlain. "The collection of both juvenile and adult individuals from different areas of Champlain suggests that alewives are now reproducing in the Lake," said Pientka, who led most of the sampling for Vermont.

The alewife, a member of the herring or "shad" family, is native to the Atlantic Ocean but migrates to freshwater rivers and lakes to spawn. They are able to adapt to live their entire lives in freshwater and have done so in the Great Lakes and many other inland waters across the United States. In some areas, they are often used as bait and have become established in many lakes following intentional introductions or accidental bait-bucket releases. Once established in a new waterbody, alewives can cause tremendous changes to a lake ecosystem.

"An alewife invasion could potentially cause significant ecological and economic disruption in Lake Champlain," said Dave Tilton, director of the U.S. Fish and Wildlife Service's Lake Champlain Complex and Chairman of the Lake Champlain Basin Program's Aquatic Nuisance Species subcommittee. "It is now important for natural resource agencies to 'gear up' to address the threats," said Tilton.

Shawn Good, a fisheries biologist with Vermont's Fish & Wildlife Department, wrote an extensive report in 2004 predicting potential impacts alewives may have to Lake Champlain and other Vermont waters. Good says that Lake Champlain's aquatic ecosystem may be in for a big change. "Looking at case studies from across the U.S. and Canada where alewives have been introduced to new waters, we can make predictions about what may happen to Lake Champlain and its fisheries," said Good. "For starters, we are likely to see the alewife replace smelt as the dominant forage fish. Other fish species such as cisco, whitefish, shiners, and yellow perch may decline in numbers as well. Alewives restructure a lake's food web, leaving less food for native fish. They can also eat a lot of young fish, such as newly hatched perch, walleye and lake trout, for example." It has been shown that salmon and lake trout in certain lakes can experience a disease known as early mortality syndrome directly associated with a diet comprised mostly of alewives. Good's report on alewives and their impacts can be found on the Vermont Fish & Wildlife Department's website at (http://www.vtfishandwildlife.com) in the Library section under "Reports and Documents."

Although the potential impacts of a widespread alewife infestation in Lake Champlain have been documented in detail, learning from resource managers having first-hand experiences with alewives may prove useful. The Lake Champlain Basin Program is sponsoring a public workshop scheduled for this winter, organized by the Lake Champlain Sea Grant Program staff. Invited experts from other regions will provide specific information on their experiences with alewife invasions. Experts will explore the range of potential changes to expect in Lake Champlain, and discuss how they altered fisheries management practices in their respective systems to respond to the changes brought on by alewives.

"Great Lakes fishery managers and researchers have a long history of trying to understand alewife impacts and then implementing management strategies that could mitigate some of those impacts," said Mark Malchoff, Lake Champlain Sea Grant Specialist at SUNY Plattsburgh. "We can't turn back the clock on the alewife invasion of Lake Champlain, but we can use some of the outside expertise to help us predict changes in the lake's ecology should this apparent invasion produce nuisance level alewife populations in the lake." Malchoff added that, "There is no substitute for meeting face to face with scientists who have been down this road ahead of us."

Although the source of the alewives in Lake Champlain is unknown, most invading species spread through human activities. Citizens, resource managers, policy-makers, and others all have a role in preventing the spread of non-native aquatic invasive species into new lakes, rivers, and ponds. Both Vermont and New York have regulations in place that restrict the possession and use of several fish species as bait and in both states it is illegal to use alewives as bait in Lake Champlain.

The Vermont Fish & Wildlife Department recently produced an informative booklet describing acceptable and non-native baitfish species and the pertinent regulations in Vermont, New York, and Québec relating to baitfish use and collection. The booklet is an excellent identification guide to baitfish species.

To receive a copy of the baitfish booklet, contact the Vermont Fish and Wildlife Department at (802) 241-3700 or the Lake Champlain Basin Program at (800) 468-5227 or (802) 372-3213. For further information on the alewife workshop, contact Mark Malchoff, Lake Champlain Sea Grant, (518) 564-3037 or Lisa Windhausen, Lake Champlain Basin Program, (800) 468-5227 or (802) 372-3213.

The Lake Champlain Basin Program is a partnership among the State of Vermont, the State of New York, the Province of Québec, and several federal and local organizations working to implement Opportunities for Action, a restoration and management plan for the Lake Champlain Basin.

Photo Text : Photo showing a rainbow smelt (top) and the first alewife ever collected by Bernie Pientka in the Vermont portion of Lake Champlain (bottom).
Photo Credit : Bernie Pientka, VTFWD

                 -30-

For Further Information please contact:
Shawn Good at 802-786-3863 or email to shawn.good@state.vt.us

Click Here To Return To The Previous Page