“Invasive species are often thought of as species that take over wherever they get in,” says Jake Vander Zanden, a UW limnology professor who directed the research. “But, in our experience studying lakes and rivers, in most places they weren’t all that abundant. It was only in a few places where they got out of hand.”

In Wisconsin, for example, research has shown that lakefront property owners see the value of their property plummet if it’s discovered that an invasive aquatic plant, Eurasian water milfoil, is in their lake. But, says Vander Zanden, that’s “only a reaction to the presence of the plant, not a reflection of its impact on that specific lake.”

Vander Zanden argues that if scientists can identify characteristics of the sites where a specific invasive species will flourish or determine what level of abundance constitutes an “invasion,” then the countless hours and millions of dollars spent on invasive species control each year could be better allocated.

Read More https://phys.org/news/2013-10-prevailing-view-invasive-species.html