Plan proposed to reduce cormorant population along Lake Michigan and Green Bay
Three public meetings set on proposed management plan
MADISON – Breeding populations of double-crested cormorants – a once rare colonial nesting water bird that is now common along the Great Lakes and other costal areas – would be reduced by half along Green Bay and Lake Michigan, under a proposed management plan that will be the subject of three upcoming public meetings.
Staff from the Department of Natural Resources wildlife, endangered resources, and fisheries programs have prepared a management plan to reduce breeding populations of cormorants on islands of Green Bay and Lake Michigan, which currently are home to more than 12,000 nesting pairs. The colonies account for about 90 percent of the state’s breeding populations of cormorants.
“Double-crested cormorant numbers have expanded tremendously across the North American continent over the past 20 years,” says Jeff Pritzl, regional DNR wildlife supervisor at Green Bay.
The population growth has raised concerns among commercial fishermen and recreational anglers that cormorants are excessively preying on yellow perch and other fish in Green Bay and Lake Michigan. Biologists are also concerned that the large cormorant colonies may have a negative affect on the vegetation and other water bird populations on the islands where the colonies are located.
Cormorants historically occupied large, isolated lakes and wetlands in northern Wisconsin, but by the mid 1960s, pesticide contamination, habitat loss and human persecution had reduced their numbers statewide to about 30 in four colonies. In 1972 the double-crested cormorant joined the bald eagle and osprey as the state’s first officially listed endangered birds. With the banning of the pesticide DDT in 1970 and efforts to restore the species by establishing nesting platforms, the species began increasing significantly. Cormorants were taken off the state endangered species list when the population reached nearly 3,000 nests in 1986.
The U.S. Fish and Wildlife Service allows federal, state, and tribal agencies to take action to control cormorants where public resource damage can be documented and cormorant management can be shown to abate damage to the resource. Pritzl says most other states in the region have conducted Environmental Assessments of cormorant management that have demonstrated a need to take action to control populations.
“Wisconsin has not conducted this Environmental Assessment, and in order to do so, we must first establish management objectives for cormorants in Wisconsin,” he says.
The management plan is directed at reducing cormorant breeding numbers without causing the birds to abandon the colonies, which may increase the likelihood that cormorants would pioneer new breeding sites. It recommends that the population objective for four distinct colonies with 10,000 nests on Northern Door County Islands be reduced to 5,000 nests, with no less than 500 nests at any one of the colonies, and that the current colony of about 2,100 nests at Cat Island on Lower Green Bay be reduced to 1,000 nests.
Cormorant numbers in the remainder of the state are stable to declining, so recommended management objectives are directed only at the Lake Michigan breeding colonies. Management techniques may include egg oiling, nest destruction, and shooting cormorants.
At the public meetings, DNR staff will present information on the history of cormorant breeding numbers in Wisconsin, potential impacts to public resources due to cormorant population expansion, and Wisconsin's role in the Great Lakes regional management of cormorants. The public will be invited to comment on the proposed population objectives after several short presentations. There will also be the opportunity to submit written comments.
The meetings will all begin at 7 p.m. on the following dates at the locations listed:
* October 30, Sturgeon Bay - Crossroads at Big Creek, 2041 Michigan St.
* November 1, Madison - Lussier Family Heritage Center, 3101 Lake Farm Road.
* November 5, Green Bay - UW-Extension Service Center, 1150 Bellevue St.
FOR MORE INFORMATION CONTACT: Paul Peeters, DNR fisheries team supervisor - (920) 746-2865; Sumner Matteson, DNR endangered resources ecologist - (608) 266-1571; or (after Oct. 22) Jeff Pritzl, DNR wildlife supervisor – (920) 662-5127
