Statewide: January 13, 2012 Archive
MPR Photo/Dan Gunderson
Aquatic invasive species are drawing a lot of attention in Minnesota. Invasive plants like Eurasian milfoil have been common in Minnesota lakes for years. But new invasive species like zebra mussels and Asian carp are causing a higher level of anxiety about their effects on Minnesota's beloved lakes.
Many invasive species arrived via Great Lakes shipping. The U.S. Geological Survey has identified more than 136 exotic species that have established populations in the Great Lakes.
That's how the zebra mussel arrived. This animation created by the U.S. Geological Survey shows how the invasive invertebrate spread.
Geological Survey officials say once an exotic species is established, control efforts are very expensive and rarely successful. Just one invasive, the zebra mussel, is expected to cause billions of dollars in economic effects over the next decade.
Invasive species often have a variety of impacts on the ecosystem.
The zebra mussel, for example, is a filter feeder. That means each mussel filters up to a gallon of water a day, eating the plankton at the bottom of the food chain.
That means less food for some species of fish.
It also means increased water clarity in lakes. In Lake Erie for example, water clarity increased from a few inches to 30 feet as a result of zebra mussel filtering.
Light then penetrates deeper, and aquatic plants grow much larger. That's good for some species of fish like the northern pike, or bass, but all that weed growth hampers boating or swimming in lakes, and can reduce the lakes ability to support fish populations over time.
I often hear people say zebra mussels have no natural predators in Minnesota. That's not the case — Geological Survey officials say there is evidence migrating waterfowl have changed their flight patterns to feed on zebra mussel colonies.
Fish like sturgeon, catfish, freshwater drum and sunfish all eat the tiny zebra mussels.
But the mussel is so prolific, its population generally grows rapidly, despite predators.
Scientists say preventing the spread of zebra mussels is the only effective control. There are chemicals that will kill zebra mussels, but they're mostly used in small areas such as around water intake pipes.They have not successfully been used to treat an entire lake.
The state Department Natural Resources has experimented with pesticides to control an early infestation of zebra mussels. But the verdict on that approach is not in.
Minnesota officials are focusing on prevention with expanded boat inspection and decontamination. The state is also requiring workers who move equipment like docks and boat lifts to be trained to recognize aquatic invasive species.
Zebra mussels are commonly thought to hitch a ride from lake to lake on boats, but can just as easily travel on the boots of someone who goes from lake to lake installing or repairing docks, or on the gear of scuba divers or swimmers.
Listen to my report on how Minnesota lake associations hope to spur action against invasive species on today's All Things Considered.
Posted at 7:30 AM on January 13, 2012
by Michael Olson
Filed under: Around MN
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More Minnesota lakes, rivers added to impaired list
MPR News: "Minnesota is adding another 500 lakes and stretches of river to its list of impaired waters.
"This new list brings the total number of impaired rivers and lakes to more than 3,600. Impaired means the waters have excess nitrogen, phosphorus, mercury, bacteria or other pollutant to support activities like swimming or fishing, or even to provide healthy habitats for fish and wildlife.
"Listing these lakes and rivers is the first step in attempts to fix them. But some critics say the state isn't doing what it takes to clean up the pollution. Once they're on the list, the state works with local governments and citizen groups to design clean-up plans.
"So far, researchers have found that about 40 percent of Minnesota's waters are impaired."
Northland sites among top Minnesota emitters of greenhouse gases
Duluth News Tribune: "Coal-fired powerplants and taconite processing are the largest sources of greenhouse gas emissions in Northeastern Minnesota, according to a new list of the nation's largest sources of carbon dioxide, methane and other gases."
Map: Largest producers of greenhouse gases in Minnesota [pdf]
USDA: Minnesota fall crop yields down
Pioneer Press: "Minnesota farmers already knew it, but today the USDA made it official: The fall harvest was disappointing."
Ikea's rooftop solar array will be the largest in Minnesota
Star Tribune: "The project, to be built this summer, is one of five solar power projects in four states that Ikea announced Thursday. The new projects and others now underway will put solar arrays atop 37 of its 44 U.S. locations, Ikea said."
Dayton names panel to map fixes for ailing transportation system
Pioneer Press: "Saying Minnesota's transportation system is deteriorating, Gov. Mark Dayton on Thursday announced a task force to look for ways to reverse that trend."
Dayton to mull over competing stadium plans
KARE: "Governor Mark Dayton said Thursday he'll spend the next week pondering three competing Vikings stadium options, in anticipation of recommending a single plan to lawmakers when they return to the Capitol January 24."
Referee report riles Privette parents
Fox: "Jenna Privette's parents say they are livid after seeing a report from the referees who were on the ice when the 18-year-old suffered an injury. An incident report obtained by FOX 9 News on Wednesday afternoon says the teen was not checked behind, despite what her family says they saw."
Bill Janklow, a four-term governor of South Dakota, dies at 72
New York Times: "Bill Janklow, a four-term governor of South Dakota with a colorful and brash persona whose political career ended abruptly when, as a congressman, he was convicted of manslaughter for killing a motorcyclist while speeding, died on Thursday in Sioux Falls, S.D. He was 72."