LAKE SUPERIOR, Mich. — Researchers on Lake Superior have "rediscovered" the shortnose cisco, a Great Lakes fish species thought to have been extinct for decades.
Before the usual suspects — overfishing and invasive species — wiped out the freshwater whitefish, the shortnose cisco swam in Lakes Michigan, Huron and Ontario.
Belonging to a class of fish called coregonines, they likely went extinct in the '80s, most experts in the field thought.
Life found a way.
During a public presentation in front of the Lake Superior Technical Committee (a branch of the Great Lakes Fishery Commission) this spring, the U.S. Geological Survey (USGS) revealed they had "rediscovered" the shortnose cisco while conducting a larger fish survey.
“No one was expecting for us to find this,” Owen Gorman, a fisheries biologist, said at the time. “Apparently, there it is.”
As part of a study spanning several years, researchers with the USGS sampled 602 adult fish at 60 locations on Lake Superior, attempting to determine the genetic and morphological differences between them. During that time, they not only identified four distinct cisco species but found enough evidence to believe the shortnose cisco was one of them.
“If that is indeed the case, then what do we do with that information?” asked Dave Caroffino, Lake Superior basin coordinator for the Michigan DNR.
While Caroffino has seen the USGS presentation, he has not been able to read its research on the ciscoes, including the shortnose cisco. The agency, he says, typically does not talk publicly about their findings until peer-reviewed research is published.
“We don't know distribution. We don't know population structure,” Caroffino said. “There are still a lot of questions you would need answered before you could take management action.”
Still, he says the mere presence of the fish species in Lake Superior — a body of water that many believed it never lived in to begin with — speaks well of the lake’s health and ability to sustain life.
“It's not terribly surprising that we could find something like that there, because it's been untouched, per se, compared to the lower lakes,” said Caroffino, referencing invasive species like quagga mussels and sea lamprey that have rapidly spread in recent decades in Lakes Michigan and Huron.
Like other cisco species, the shortnose cisco fills an “intermediate” link in the Great Lakes food chain. Their survival is connected to the success of the state’s multibillion-dollar fishery.
“People who want to go out and catch lake trout, they want to make sure lake trout have something to eat. Lake trout are eating ciscoes," said Caroffino. “Every fish species has a role they play in the ecosystem.”
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