Waconia councilman makes his case

In Saturday morning's StarTribune, on the editorial page, is an opinion piece by a Waconia city councilman, Jim Sanborn. It is about -- you guessed it -- Double-crested Cormorants. Mr. Sanborn is long on opinion, long on exaggeration, long on supposition, and short on fact.

Let's follow along as he writes.

"The economic, environmental, and wildlife impact of these birds is staggering," says Mr. Sanborn.

The fact is: There have been many, many research projects done in several states by state wildlife agencies, several university research teams, and by government agencies in two countries. Very little conclusive evidence has been found showing that cormorants have a harmful impact on game fish, the economy, the environment, or other wildlife. Studies in Minnesota show no problem meriting solution.

Mr. Sanborn uses "simple math" to tell us that the cormorants remove 100,000 pounds of fish from the lake in a typical summer. That's too many pounds, he says.

How many pounds of fish are in the lake to begin with? How many pounds are removed by fishermen, disease, turtles, herons, egrets, gulls, etc.? What is the recruitment rate of the lake (rate of replacement)? The fish breed. Each year fish are naturally added to the population. (Plus, the DNR stocks walleyes). So, how does the removal rate stack up with the recruitment rate? Is there a net gain or loss or is fish population stable? Mr. Sanborn does not tell us.

He also fails to mention the DNR fisheries survey in summer 2010 of the game fish population in the lake. This was 2010, remember, several years after cormorant complaints began. The DNR in effect gave Lake Waconia a grade of A: No shortage of game fish of any species. Great place to fish.

Mr. Sanborn mentions the supposed cormorant problem at Leech Lake a few years ago. Research that involved shooting something over 3,000 cormorants, and examining the stomach contents of many of those dead birds, failed to show significant impact on game fish by cormorants. Leech Lake fishermen and some residents of Walker found this result difficult to accept, but that doesn't change the facts.

(Leech Lake does have a problem that affects fish. The lake is heavily infested with an invasive species known as the Rusty Crawfish. Following a study of Rusty Crawfish by the Minnesota Sea Grant, a research body located in Duluth, a report had this to say:

("Rusty Crayfish are probably spread by non-resident anglers who bring them along to use as fishing bait. …. Invading Rusty Crayfish frequently displace native crayfish, reduce the amount and kinds of aquatic plants, decrease the density and variety of invertebrates (animals lacking a backbone), and, reduce some fish populations.")

Back to Mr. Sanborn. He mentions supposed problem at other lakes, mentioning several by name. He does not mention Lake of the Woods. A 2007 DNR study there is summarized with this statement: "There is no evidence in the year class strength (number of young fish produced in year) indices to suggest that cormorants have been causing additive mortality to the walleye and sauger year classes on the Minnesota portion of Lake of the Woods."

The cormorants nest on an island in Lake Waconia. Mr. Sanborn describes "tens of thousands of pounds of bird poop" deposited each month by cormorants and other nesting birds. Tens of thousands of pounds. Each month. Sounds like a lot of bird poop to me.

Fewer cormorants? For sure. They've shot about 1,400 at Lake Waconia in the past four years. He doesn't mention that either as he tries to rebut newspaper stories with "screaming" headlines and this blog and others.

He says Waconia is a great place. It is. He says you should come out and see for yourself. You should. He says they don't want to shoot all of the cormorants. He says, "We just want the freedom to manage our beautiful lake …."