Today National Public Radio‘s All Things Considered featured a good piece on the Asian Carp problem entitled “White House ‘Asian Carp Czar’ Outlines His Strategy For Eradicating Species“. The story explains how two human actions — the importation of carp for aquaculture and the reversal of the Chicago River by a massive engineering project — have created the potential for this foreign predator to travel all the way into the Great Lakes.
The story makes a lot of the fact that the Chicago River was re-engineered to run in reverse, a change that also reverses the connection between the Great Lakes and the Mississippi River systems. This is certainly an evolutionary jolt, because it changes the way in which two somewhat-separate ecosystems interact. Of course the Asian Carp is foreign to both of these freshwater ecosystems, so the degree to which the reversal really represents an evolutionary affront is somewhat debatable. What seems less debatable is the potential for the Asian Carp to have a major impact on the fish populations native to the Great Lakes. To prevent the carp from making it this far, state and federal officials have erected several electric barriers and even dumped poison into waterways. But carp continue to be caught further and further up the river, and tests that look for their DNA find evidence of their presence even further up from where they have been caught.
With other solutions failing, some are calling for the “ultimate solution”, which would be to re-reverse the flow of the Chicago River. This would have massive economic consequences, so this single invasive species has set up an interesting requirement for accounting: we need to compare the potential economic losses associated with an Asian Carp invasion of the Great Lakes to the losses associated with changing the flow of an essential Chicago-area waterway. Science and politics blend in strange ways on this one.
Perhaps the most precious feature of this segment is the picture of Asian Carp appearing at a congressional hearing in 2010 shown on the web version of the segment. Funny, until you realize that congress is finally coming to understand the tremendous threats to ecosystem services posed by invasive species.
There are also other recent NPR stories on the Asian Carp that discuss the general strategy used to prevent these fish from spreading and the poisoning of waterways in more detail.Coevolution, Freshwater Ecosystems, Invasive Species, Predation, Public Policy, Radio & Podcasts, Urban Ecology