It’s a fish that has inhabited the Earth for at least 150 million years — including 85 million spent alongside the dinosaurs -— and this weekend Toledoans will take the next step in advance the return of this prehistoric species.
The second annual release of iconic lake sturgeon into the Maumee River will take place on Saturday from the city of Toledo’s boat launch near Walbridge Park.
Children and adults of all ages are expected to participate in the event, which is from 10 a.m. to 2 p.m. It is free and open to the public.
Lake sturgeon are a large, pug-nosed species of fish that is older than dinosaurs.
They are the Great Lakes region’s biggest fish and can grow up to 12 feet long and weigh up to 300 pounds. With all of their muscle and attitude, they are capable of knocking down grown men like bowling pins. They are also one of 27 species of sturgeon worldwide but one of only three that spend their entire life in fresh water. Most others live at sea, seeking out fresh water to spawn.
As many as 1.1 million sturgeon were believed to be in Lake Erie during the 1800s, so plentiful they were used as fuel for Great Lakes steamships back then. Caviar made from their eggs was sold to Europe, where it was relabeled and sold back to the United States as Russian caviar. Their numbers plummeted because of financial losses incurred by the commercial fishing industry. When the sturgeon got trapped in fishing nets, they used their strength and their thrashing, bull-like demeanor to tear them up.
By the early 1900s, lake sturgeon were nearly extinct.
Despite their size and strength, the fish are sensitive to changes in water quality and hydrology. Many succumbed to dams built along Great Lakes tributaries during the Industrial Revolution. Lake Erie once had 19 tributaries spawning them. Now it has only two: the Detroit River-Lake St. Clair corridor and the Niagara River.
Last fall’s inaugural release drew about 1,000 people, Matt Cross, Toledo Zoo conservation biologist, said. This year, the zoo and its partner organizations will have attendees release about 3,000 lake sturgeon, including 1,300 the zoo has reared from eggs collected in U.S. and Canadian waters earlier this year. The fish are reared in a specially outfitted trailer along Broadway. The other 1,700 lake sturgeon were raised at a U.S. Fish and Wildlife Service’s Genoa National Fish Hatchery in Genoa, Wis.
That’s the same number as last year, although the 2018 breakdown consisted of 600 from streamside rearing and 2,400 from that hatchery.
Fish are more expensive to raise in streamside rearing facilities. But scientists are trying to see if there’s a difference in success rates between the two types, and if fish raised at a conventional fish hatchery are less likely to return to the Maumee River to spawn once they reach adulthood in about 15 years, Mr. Cross said.
“That’s going to be our stocking strategy for the next few years,” he said.
Juvenile fish from last year that were equipped with tracking devices prior to their release have done what was expected of them by swimming out into Lake Erie after acclimating to the river for a few months, Mr. Cross said.
That is a sign the restocking program is on track, he said.
This year’s fish are about six months old and seven inches long. They will be monitored for years by state and federal biologists, as well as the Great Lakes Acoustic Telemetry Observation System.
“In addition to creating a self-sustaining lake sturgeon population in the Maumee River, there is a research component associated with this work,” according to Justin Chiotti, a U.S. Fish and Wildlife fisheries biologist involved in lake sturgeon recovery efforts across the Great Lakes region. “We are comparing survival, movement, and eventually return rates between the two stocking strategies. Results from the stocking events will be compared over time to determine the success of each strategy to share with other lake sturgeon restoration programs in the Great Lakes.”
Forty fingerlings from last year were equipped with acoustic transmitters. They have been detected more than 35,000 times over the past year, Mr. Chiotti said, explaining that the battery life of each tag is about a year.
“These 35,000 detections have provided us with movement and survival information,” he said. “Some of the lake sturgeon that were released traveled nearly 40 miles and were detected on stationary receivers throughout the western basin of Lake Erie.”
In addition, every fish released in the Maumee gets equipped with a small microchip called a “PIT tag,” which identifies them. If they are ever caught, the sturgeon can be scanned with information sent back to researchers. Several commercial fishermen have been provided microchip readers to do that, Mr. Chiotti said.
The zoo is selling sponsorships to the public for the PIT tags, starting at $25 for online orders and $30 at the event. Under that program, zoo staff will notify sponsors if their individual fish are ever caught. All sponsors are invited to release their fish at the event.
Males don’t mature until they’re 15. Females don’t spawn until age 20 and hold as many as 60 pounds of eggs.
Both sexes reproduce once every four or five years. But it’s not uncommon for them to live 100 years or more, and they reproduce until they die.
First Published October 4, 2019, 12:00 p.m.
