Lake Trout Making 

A Comeback in Niagara River

New research findings are advancing efforts to restore the Niagara River lake trout population.


Lake trout were a top fish predator in the Great Lakes for thousands of years, until invasive sea lamprey spread throughout the lakes in the 1940s.  Sea lamprey, an eel-like fish that clings to lake trout and sucks their blood and bodily fluids, decimated lake trout populations throughout the Great Lakes. The Great Lakes Fishery Commission has spent $20 million annually since the 1960s to control sea lamprey populations, which has helped lake trout restoration efforts. The New York Department of Environmental Conservation began stocking lake trout in Lake Ontario in the 1970s in an attempt to rebuild the population. Naturally reproduced lake trout have been collected in the Niagara River since 1994, during population assessments. Lake trout are normally reef spawners, and spawn in lakes, but in 2005 researchers confirmed that lake trout were spawning in the lower Niagara River. That discovery led researchers to tag and track 18 lake trout to identify a suitable spawning site for the fish. In 2011, researchers collected live lake trout larvae in nets in the Niagara River, near Lewiston. The discovery was the first confirmation of successful lake trout spawning in the Niagara River. The finding will help researchers determine where more lake trout could spawn in the river and advance efforts to bolster the lake trout population. Great Lakes Restoration Initiative funds are funding similar research on lake sturgeon in the Niagara River. Scientists are working to identify suitable sturgeon spawning areas in the river, which would bolster efforts to restore the sturgeon population.

Resource Challenges Addressed

  • Loss of fish habitat
  • Depressed populations of Lake Trout and Lake Sturgeon
  • Invasive species
  • Pollution


A U.S. Fish and Wildlife Service intern shows off a lake trout caught in Lake Ontario. Photo credit: U.S. Fish and Wildlife Service.

Results and Accomplishments

Scientists identified the first lake trout spawning site in the Niagara River and natural reproduction by the imperiled fish. The discovery will bolster efforts to restore the lake trout and lake sturgeon populations in the Niagara River.