Scientists who’ve been tracking Lake Champlain’s fish populations say that, while lake trout are in ample supply, the surviving adults are exclusively hatchery-raised fish.
The fact that wild trout are not reaching adulthood is baffling researchers, because the trout are spawning, and the fry are hatching, successfully.
UVM Professor of Fisheries Ellen Marsden, who has been studying the Lake Champlain trout for a decade, has several theories.
"It could be predation. There are exotic species in the lake like alewife that will cheerfully eat a small fry. Or it could be starvation. We have changed the food web accessible to them in the lake such that they have no food once they leave the reef,"Marsden.
Currently, UVM is using a home-built remotely-operated vehicle that is equipped with a video camera to learn more about the lake trout’s behavior. Better technology, like acoustic tagging, could help future efforts.
Marsden says the ultimate objective is for the lake trout to become a self-sustaining population without the reliance on annual stocking.