The Star Tribune’s Sept. 12 editorial (“Lock closure to fight carp is within reach”) claimed that 240,000 jobs and Minnesota’s entire water-based recreational economy are threatened by invasive Asian carp accessing the state’s waters from the main stem of the Mississippi River.
The implication that Asian carp can swim into central and northern heartland lakes and the Mississippi River headwaters is incorrect. Misstating the direct threat to these areas is a disservice to the residents, businesses and visitors who enjoy the environmental and recreational opportunities found there.
The U.S. Army Corps of Engineers operates six Mississippi Headwaters reservoir lakes — at Leech Lake, Gull Lake, Cross Lake, Sandy Lake, Lake Winnibigoshish and Pokegama Lake — that are managed primarily for recreational benefits. There are an estimated 2 million visitors to these headwaters reservoirs each year, so we at the Corps share concerns related to the adverse impacts that an established population of Asian carp could have on Minnesota’s northern waters.
However, these popular headwaters recreation destinations are currently protected from free-swimming Asian carp by a series of dams between the Twin Cities and Brainerd. These dams include the 46-foot-high, privately owned Blanchard hydropower dam near Royalton and the Coon Rapids dam (which is being modified so that it is an even more effective fish barrier than at present).
Additionally, other valuable recreational waters in the state of Minnesota, such as the Boundary Waters Canoe Area Wilderness in the Rainy River Basin and the Detroit Lakes area in the Red River of the North system, are not connected to the Upper Mississippi River watershed.
It is unfortunate that the benefits of the dams on the Mississippi River have been left out of recent discussions and news reports about the Asian carp threat. While it might offer environmental benefits to native fish to remove these dams, they do also serve as effective barriers to Asian carp.
Nothing here is meant to diminish concerns regarding the threat to the Mississippi River south of the Coon Rapids dam, or to the Minnesota River and lower St. Croix River basins, all of which are accessible to invasive species swimming from lower reaches of the Mississippi River.
While federal and state agencies have increased the science base of Asian carp significantly over the past five years, much remains to be learned about the fish and its habits. We need to continue to work together, share information and collaborate on cost-effective solutions. Yet one thing is clear from the historical record of invasive-species control: There’s seldom a single solution that’s 100 percent effective.
It is hoped that relevant facts and good science do not get lost in the effort to raise public awareness and influence decisionmakers. All of us have a right to the best information and science available in working toward collaborative solutions to the many issues in natural-resource management.
Judy DesHarnais is deputy for programs and project management in the St. Paul District of the U.S. Army Corps of Engineers.