Researchers are making progress toward understanding why some Great Lakes trout die after eating an invasive prey fish called alewife.
Alewife contains an enzyme that destroys thiamine, an essential vitamin for fish. Hatchery operators in the region bathe young trout and salmon in thiamine solutions before releasing them into the wild, but many still don't survive after they begin eating alewife.
A study released Wednesday by the U.S. Geological Survey says those fish appear to be experiencing changes in their immune systems that resemble those of humans with inflammatory diseases.
Lead researcher Christopher Ottinger says the finding will help scientists and resource managers who are trying to restore lake trout populations in the Great Lakes. Lake trout were decimated by the invasion of parasitic sea lamprey in the mid-1900s.