Feds battle Asian carp invasion in the Great Lakes

Invasive Silver carp caught by the USFWS Credit: USFWS

In another attempt to locate the potential threat of Asian carp in the Great Lakes, officials began dumping approximately 2,000 gallons of the organic fish poison Rotenone yesterday into a two-mile stretch of the Calumet-Sag Channel, about seven miles west of Lake Michigan. The aim is to kill and count any invasive carp potentially lurking in the waterway as proof that these fish are spreading into Lake Michigan.

Previously, DNA samples of the water revealed the likely presence of the Bighead and Silver carp, invasive fish introduced in 1973 to improve the water quality of aquaculture ponds primarily in Arkansas and notorious for their voracious appetite and tendency to jump at and onto boats. Due in large part to flooding, these particular species of carp escaped the ponds and spread to the Upper Mississippi River System in the late 1970s where they currently threaten to invade the Great Lakes via the ship canal connecting the Mississippi River to Lake Michigan.

At least that is what Michigan state officials are claiming after a previous mass fish poisoning turned up one Asian carp in the canal. This second mass fish kill is being funded by the federal government in an attempt to take action after a failed lawsuit. Last month, the U.S. Supreme Court rejected a lawsuit by Michigan that would have forced Chicago to shut down its shipping locks. The Supreme Court sided with Illinois and declined to close the locks over concerns of endangering the $7-billion fishing industry; the Court also barred the states from pursuing the matter further.

In the meantime, biologists will be searching the Calumet-Sag Channel in the next couple of weeks in search of dead Asian carp, among likely thousands of other fish which will also be killed, and as the vital shipping corridor is shut down for about a week.

Results from the mass fish kill, which is being funded by the federal government with an estimated $1.5 million price tag, could stir further debate. That is, if the fish turn up, then Michigan and partnering states would have ammunition to revisit the lawsuit of closing the Chicago-area locks. If no Asian carp are found, then the validity of DNA testing as confirmation of biodiversity in aquatic ecosystems will likely be called into question.

According to a Chicago Tribune article, if no Asian carp turn up, “it would also bolster claims by the Illinois Department of Natural Resources, the Army Corps of Engineers and others that say methods to control the fish’s movement are working.” No proof of Asian carp would also mean thousands of dead fish as a result of a stalled issue.

However as Charlie Wooley, the Midwest deputy director for the U.S. Fish and Wildlife Service, pointed out in the article, the economic and ecological costs of this last ditch effort reveals the urgency of this issue. If action is not taken and Asian carp invade Lake Michigan, the costs for the fishing industry and ecosystem damage of the Great Lakes would be far-reaching. Wooley said in the article:

“This is as good as an effort as we could possibly come up with. If we don’t find any Asian carp through this sampling I can assure you we’ve given it our best shot.”