A federal official outlined for an audience in Milwaukee the government's efforts to protect endangered freshwater fisheries from the invasive Asian carp.

The hearing Tuesday was part of the U.S. Army Corps of Engineers study examining ways to stop the spread of unwanted species from the Mississippi River basin into the Great Lakes, the Milwaukee Journal Sentinel reported Wednesday.

The study is expected to take years, but the administration's carp chief, John Goss, said the federal government hasn't stopped its fight to keep the ecosystem-ravaging Asian carp from invading Lake Michigan.

"We've all learned to live with different waves of invasions," said Goss of the White House Council on Environmental Quality.

Goss noted the electric fish barrier system on the Chicago Sanitary and Ship Canal blocks a man-made link between Lake Michigan and the Asian carp-infested Mississippi River basin. The barrier system includes two fences built to prevent Asian carp from infested Mississippi basin rivers from swimming into Lake Michigan and an aggressive fish-sampling operation on the canal above the barrier.

The Army Corps of Engineers is studying options to "prevent or reduce the risk" of species invasions between the two basins, as well as what's needed to build a permanent, physical barrier, Goss said. The barrier is opposed by Chicago-area barge operators and businesses dependent on the canal to move cargo, and tour boat operators and recreational boat owners.

Conservationists said they believe the only long-term solution to the Asian carp is to rebuild the natural separation between Lake Michigan and the Mississippi River basin that the Chicago canal destroyed nearly a century ago, the Journal Sentinel reported.