James Q. Lynch, CR Gazette –
In the war against Eurasian milfoil, zebra mussels and silver carp, Kim Bogenschutz is fighting for time.
Bogenschutz, the Iowa Department of Natural Resources Aquatic Nuisance Species coordinator, concedes her firepower is limited at this point in the battle against invasive species. Despite the efforts of her mostly seasonal, part-time army, zebra mussels continue to move upstream in Iowa rivers, Eurasian milfoil still is being spread lake-to-lake on boats and trailers, and Asian carp were found in natural lakes in northwest Iowa after flooding on the Missouri and Little Sioux rivers last summer.
As a result of Iowa’s aquatic invasive species law, Bogenschutz, a biologist, a part-time technician and a part-time, seasonal staff of up to 20, armed with a $650,000 budget, concentrate their efforts on slowing the spread of invasive species rather than eradication. For the most part, the seasonal staff monitors Iowa waters and educates boaters about how to prevent the spread of invasive species.
While herbicides have been successfully used to eliminate Eurasian milfoil, there’s nothing Bogenschutz can use on zebra mussels and carp that won’t kill native aquatic species.
“But people are working on things,” she said Tuesday after a presentation to the House Natural Resources Committee. “So if they come up with something in the future, we’re better off to have (invasive species) under control in 10 lakes and rivers than 100.”
The bad news Bogenschutz told the committee is that zebra mussels, first identified in the Mississippi River on Iowa’s eastern border in 1992, have spread to Clear Lake, Lake Delhi – before the lake was destroyed by flooding in 2010 — and Lake Rathbun.
Eurasian milfoil, first identifies in Iowa in 1993, has now spread to at least 40 locations, she said. And the bighead, Asian and silver carp, first identified in Iowa in 1995, are spreading, too, swimming on their own until they reach an impediment.
Impediments, such as fish fences, electric and acoustic barriers, are among the strategies being employed to prevent carp movement. Bogenschutz can’t speak to the effectiveness of any of those weapons.
“Up in the Iowa Great Lakes to put in an electric barrier so should the Little Sioux flood again the Asian carp would not be able to move into the Iowa Great Lakes,” she said. In Minnesota, acoustic barriers that use sound to deter fish from moving upstream, have been tried.
“A lot of this is not well-developed science, but people are doing what they can to prevent the spread of these things,” she said.
