Conservation officers are intensifying enforcement of regulations to combat the spread of invasive species by Minnesota boaters over the July 4th weekend.
The effort by the state Department of Natural Resources (DNR) comes as a new law took effect Thursday that requires boaters to drain all water — including live wells — before leaving any lake or river in Minnesota. Violations are misdemeanors.
Previously, boaters had only to drain their craft after boating on infested waters.
On the enforcement front, DNR Invasive Species Program coordinator Jay Rendall said there will be more inspections. Also, 31 billboards around the state address the invasive species threats, and grants are being given to local groups for prevention efforts, Rendall said.
Invasive species can be plants (Eurasian milfoil, curly-leaf pondweed, etc.) or aquatic life (zebra mussels and silver carp, among others). Zebra mussels and the Eurasian water milfoil have been of particular concern in the state.
Native to Eastern Europe and western Russia, zebra mussels were brought to the Great Lakes in ballast water of freighters. They were discovered in the Duluth harbor in 1989 and now infest at least 30 state lakes and rivers. They filter up to a quart of water daily and consume tiny plankton that provide food for various lake and river inhabitants, including fish. When they show up, water clarity increases dramatically.
In 2009, after discovery of a zebra mussel in Prior Lake, the DNR conducted 1,370 inspections of boats, which required 284 hours.
Eurasian milfoil stems weave into unsightly floating matts that discourage swimming and boating. They can become entangled in propellers and attached to keels and rudders.
The weed was accidentally introduced from Europe and spread to inland lakes primarily by boats and waterbirds. It reached Midwestern states between the 1950s and 1980s.