DNA sampling of Indiana ports and harbors near Lake Michigan by researchers from the University of Notre Dame has found no evidence of Asian carp making it into those areas.

Court action, however, continues based on the DNA evidence that has been found.

Two species of Asian carp–bighead and silver—are now considered a risk to the Great Lakes.

The voracious eaters consume plankton–algae and other microscopic organisms–thereby stripping the food web of a key source of food for small and big native fish.

The Asian carp are also known for their ability to jump out of the water, often into boats.

Asian carp were first detected in Indiana waters in 1995 and have worked their way up the Wabash River, into the East and West forks of the White River, the Patoka River, and the Ohio River and some of its tributaries.

Catfish farms originally imported bighead and silver carp to aquaculture facilities in the South. They escaped into the wild in the 1980s, and have been moving northward ever since.

The Notre Dame researchers collected 125 samples from five areas in northwest Indiana:

On Aug 6, Notre Dame collected 14 samples from the outflow of Lake George by kayak and by wading into the lower reaches of the Deep River.  One cooler blank was evaluated and also tested negative for bighead and silver carp DNA.

On Aug. 11, the researchers collected 25 samples from Burns Harbor and 21 from Burns Ditch.   All 46 samples and four cooler controls tested negative.

On Aug 18, the project collected 11 samples from the Gary Boat Slip and 54 samples from Indiana Harbor.  All 65 samples and five cooler controls tested negative.

The Asian carp is such a serious threat to the Great Lakes that both its $7 billion commercial and recreational fishing industry and its ecosystem are at risk.

Great Lakes states are now waiting for a decision from U.S. District Judge Robert M. Dow, who has been asked to permanently close the link between Lake Michigan and downstate rivers–the Chicago Sanitary and Ship Canal. 

Attorneys for Michigan told Dow that’s the only way to stop the invasive species from reaching the Great Lakes.   They pointed to DNA evidence in about 50 samples that has been collected beyond the electrical barriers in the canal.

With no predators, Asian carp are multiplying so rapidly that a Pearl, IL fish processor inked a deal to sell 30 million pounds of carp to China.

Judge Dow’s decision probably won’t come for several weeks.