(AP) -- Two more water samples from near Lake Michigan have been found to contain genetic material from invasive Asian carp.
Federal officials tell The Associated Press the samples were taken from Chicago's Lake Calumet, where the Army Corps of Engineers reported seven other positive DNA hits earlier this week.
The DNA came from silver carp, one of two Asian varieties that have migrated up the Mississippi River and its tributaries for decades and are threatening to enter the Great Lakes.
The latest positive hits turned up during a second round of tests in Lake Calumet triggered by the earlier findings. Samples from a third round are being analyzed. If they also reveal carp DNA, officials will decide whether to take rapid-response measures such as spreading fish poison or intensifying commercial netting.
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