A picture postcard from Wisconsin features a lone fisherman in his boat on a beautiful lake, loons swimming, with a lovely sunset framing the surrounding pines. To Bill Provencher
and his research colleagues this man is a vector.
Recreational boaters are largely responsible for spreading aquatic invasive species (AIS) across Wisconsin’s 15,000 lakes. The state currently spends $4.3 million a year to combat non-natives like zebra mussels and Eurasian watermilfoil, the weed that tangles in boat propellers and swimmers legs in many lakes.
In the Great Lakes ecosystem a more frightening invader, the giant Asian carp that can sink small boats and wipe out native fish species, is making its way up the Mississippi toward Lake Michigan’s shipping locks.
Globally, invasive species rank as a leading threat to native species and biodiversity. Lakes are especially vulnerable because their discreet boundaries create closed ecosystems. In the U.S. alone, economic damages from invasive species cost $120 billion each year, yet few researchers have studied the economics of aquatic invasives.
A major grant from the National Science Foundation will help Bill Provencher and his colleagues in limnology examine the ecological and economic connections between AIS dispersal in order
Eurasian water milfoil has spoiled many Wisconsin lakes
to design control and prevention strategies. Using a complex modeling scheme, they hope to answer questions about boater behavior. How, when and why do boaters decide to visit a particular lake? If they live on an invaded lake, will they be more likely to use a cleaner lake for fishing and recreation? If their boats carry invasive weeds, insects or crustaceans, how will those pests’ life cycles dictate control strategies? What would be the regional effects of a launch fee designed to pay for
an eradication campaign on a single lake? Would it speed dispersal to surrounding clean lakes?
The project is unique in its approach to analyzing the dynamic nature of the research problems. Past ecological studies of species invasions have focused on the cost of such occurrences, without calculating the actual benefits of effective management. Yet people affected by these policies are demanding proof that the costs are worth the benefits.
Provencher and his colleagues are betting that being able to predict the economic benefits accruing from certain policies could convince shoreline property owners and boaters to adopt better practices. For example, a 2008 study by former AAE professor Dave Lewis
and graduate student Eric Horsch
found that property values for homes on lakes invaded by Eurasian watermilfoil were 13% lower than homes on clean lakes.
Milfoil will be targeted for the study because it has not yet colonized the vast majority of lakes and is viewed as highly noxious by lake users. So a control strategy to prevent milfoil invasions would not only be publicly popular but also economically and ecologically compelling.
Steve Carpenter in Lake Mendota holding native pondweed, an important fish habitat
By looking at boater uptake of pests, how they are transported to a clean lake, and whether the weed or animal will become established in the new lake, the researchers hope to design effective control and prevention interventions, such as boat inspections, fines and educational campaigns.
Provencher and his team, which includes Dave Lewis and limnologists Steve Carpenter
and Jake Vander Zanden
, will share their findings with homeowner’s groups and county officials to guide local decision-making. They also hope legislators and other state policy-makers will use the research results to craft new laws. But ultimately, the residents and tourists who live on and use Wisconsin’s lakes will play the biggest role in maintaining the water quality, good fishing habitats and biodiversity that draw so many to the picture postcard scenery of Wisconsin’s northern counties.
See the websites: http://limnology.wisc.edu/personnel/jakevz/ais/http://lter.limnology.wisc.edu/
Related story: http://www.news.wisc.edu/19045