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Biologists reeled in a 240-pound fish from the Detroit River that probably hatched a century ago

A member of the U.S. Fish and Wildlife Service survey crew lies beside a 240-pound lake sturgeon pulled from the Detroit River. (U.S. Fish and Wildlife Service) (U.S. Fish and Wildlife Service)

Jason Fischer was shocked at what his crew had just caught.

Fischer, a biologist who works with a Michigan-based Fish and Wildlife Service office, was on the water late last month, putting out setlines with hooks to catch and survey the lake sturgeon population in the Detroit River. It was his first setline survey with this three-person crew, and until then his research had focused on egg and larval stages — “we’re talking about a fish less than an inch.”

It was his teammates, fellow biologists Jenny Johnson and Paige Wigren, who took a look at the latest catch and said: “Oh man, that’s going to be a very big fish.”

“We thought it would be in the 100-pound range,” Fischer said. Typically, they may catch a 40- to 60-pound fish.

This time, the crew had reeled in a 240-pound lake sturgeon, a 6-foot 10-inch female they believe to be about 100 years old. It’s the biggest fish any of them had ever caught — the team’s previous record, before he joined the crew, was 123 pounds, Fischer said. It also may be one of the largest lake sturgeon ever recorded in the country.

In a post on Facebook announcing the “once in a lifetime catch,” the conservation office noted the 100-year-old sturgeon “likely hatched in the Detroit River around 1920, when Detroit became the 4th largest city in America.”

“When it’s in the water, you don’t have that great reference for size until you actually try to get the net on it,” Fischer said. “Our basket’s like four or five feet deep, and this fish wouldn’t fit in the net. … It only got bigger when we got it on the boat.”

It took all three of them to lift it up out of the water and get it on the boat, an effort that was “exhausting,” Fischer said.

The U.S. Fish and Wildlife team weighed the fish, measured her and snapped a photo of one of them lying next to the fish for scale. Then they tagged the fish — a process that will allow the fish to be identified if ever caught again — before releasing it back into the water.

Scott Koproski, project leader with the conservation office, said he was amazed this fish had not yet been tagged.

“That tells us this fish, greater than 100 years in age, has never been encountered before, at least by biologists working with fish in the Great Lakes,” said Koproski, who was not on the boat during the catch. “That’s pretty fascinating.”

An annual effort by U.S. Fish and Wildlife Service to survey the St. Clair-Detroit River system to better understand the lake sturgeon population began in 2001. The lake sturgeon, considered a threatened species in Michigan, has endured a lot — from a boom in commercial fishing that continued into the early 1900s, periods of over-harvesting, and habitat loss driven by shipping channel construction and the damming of tributaries. All of that contributed to declines in population, according to the U.S. Fish and Wildlife Service.

“Given the age of this fish, it was probably around when some of the larger commercial fisheries were going in the Great Lakes in the early 1990s,” Fischer said. “Being able to avoid that effort, I think, was probably the most impressive part.”

There are now more than 33,000 lake sturgeon in the St. Clair-Detroit River system, 6,500 of which come from the Detroit River, according to Alpena Fish and Wildlife Conservation Office, which describes that as a “fraction of its historic size.”

James Diana, a professor emeritus of fisheries and aquaculture at the University of Michigan, said sturgeon are “very hearty fish” that “can survive pretty stressful situations.”

He said they “continue to grow and live fairly long lives, but normally you’re looking at a life expectancy around 60 or 80 years typically.”

“Over 100 is unusual,” he said.

John Hartig, a Great Lakes scientist and conservationist, said the age of this fish “speaks volumes to the resiliency of the species.”

Hartig, now a visiting scholar at the Great Lakes Institute for Environmental Research at the University of Windsor in Ontario, ticked off some of the events a century-old fish may have experienced.

“The Detroit River during World War II was considered the arsenal of democracy, Detroit was. Oil pollution was rampant, and they discharged not only oil but other toxic substances,” he said. “She lived through that.”

Natasha Myhal, an enrolled citizen of the Sault Ste. Marie Tribe of Chippewa Indians, is a PhD candidate at the University of Colorado writing her dissertation on nmé, the name the Anishinaabe people use for lake sturgeon.

She said the fish is “one of the oldest fish species in the Great Lakes, and nmé is central to the cultural and spiritual practices and lifeways of the Anishinaabe.”

“When I think about the age of the fish that was caught, the lake sturgeon that was caught, I think of the perseverance of nmé,” she said. “Just as the Anishinaabe and Indigenous peoples have persevered colonial policies and intense environmental change, so have sturgeon.”

Hartig said while the Detroit River used to be seen as a “working river that supported industry and commerce,” environmental policies and river cleanup efforts in recent years have sought to improve the quality of the waters and the life living in them.

“We’re trying to change that, we’re trying to say this is an ecosystem,” Hartig said. “We are also part of that ecosystem. What we do to the ecosystem, we do to ourselves.”

Diana and Hartig also pointed to efforts to construct spawning reefs to help the lake sturgeon begin to bounce back as a species.

Fischer said multiple agencies and universities, including the Michigan Department of Natural Resources and Michigan Sea Grant, are involved with efforts to restore spawning habitats within the Detroit River and St. Claire River to “improve the number of fish being born.”

“It’s great to see these old, large fish,” Fischer said. “But one of the projects our office is involved in is tracking younger fish. Those are really going to give us an indication of, are fish surviving to an age where they can reproduce and contribute to future generations?”

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