Apparently new restrictions on ballast-pumping by oceangoing ships are having an effect, with no new invasive species being found in the Great Lakes recently (but don't celebrate just yet.) On the other hand, we're dealing with multiple possible causes. Seven years into the era of hope and change, there hasn't been the kind of worldwide economic recovery to keep the ships at sea.
Furthermore, here's fear from seven years ago about the absence of a bad flood being all that's keeping the Asian carp out of the Great Lakes.
The problem is the carp also have recently migrated up the adjacent Des Plaines River, and that river has a history of flooding its banks and spilling into the sanitary and ship canal. The distance between the two waterways is, in places, only a matter of yards.That the Des Plaines River and the Root River, which drains into Lake Michigan, share a common marsh in Wisconsin suggests there's more than one way for those fish to find a new habitat.
Those fish are in the Mississippi River system in part because a government experiment went wrong.
[Environmental Protection Agency official Judy] Beck told the [2009 "State of the Lake" conference] that the fish escaped Southern fish farms during the 1993 floods in the Mississippi River.No doubt, four of five experts were confident there was minimal, or no, risk, of experimental fish going rogue.
That's not the whole story.
A 2006 Journal Sentinel investigation revealed the EPA played a role in their release.
Three decades ago, it funded programs in Arkansas that used the fish in sewage treatment experiments, and those fish were among the first known to have escaped into the wild.