Michigan and Ohio crews are surveying several Lake Erie bays and river mouths this summer in search of invasive grass carp.
They're hoping to capture some of the fish and install transmitters enabling researchers to track their movements.
A network of receivers across portions of western Lake Erie helps the Grass Carp Response Team to follow the fish and determine when they're grouping to spawn or feed.
Grass carp are among several varieties of Asian carp that scientists say could extensively damage the Great Lakes by competing with native species for food.
Officials say grass carp have been captured in Lake Erie since the 1980s, probably after escaping from private ponds.
All the states and Canadian provinces in the Great Lakes region now prohibit possession of live, fertile grass carp.