Prehistoric fish can spawn in Georgia: first time in 50 years

Scientists and students embarking on a census of Lake Georgia’s sturgeon have found three females with mature eggs, an indication that armored “living fossils” may be breeding in that state for the first time in half a century.

“It’s exciting because it’s confirmation that they are maturing and trying to spawn,” Martin J. Hamel, an associate professor at the University of Georgia Warnell School of Forestry and Natural Resources, said in a recent news release.

Fossils indicate that the shovelnose fish with a bottom mounted vacuum hose instead of jaws has existed for more than 136 million years, according to scientists.

one of nine sturgeon species and subspecies found in the U.S., lake sturgeon live in 18 states and five Canadian provinces in the St. Lawrence, Hudson Bay, Great Lakes, and Mississippi River watersheds, according to the Water Service. US Fish and Wildlife

Pollution, habitat destruction, and harvesting for meat and caviar have diminished their numbers so much that the US Fish and Wildlife Service is considering federal protection for the species.

The bone-covered carcasses of sturgeons caused so much damage to fishing nets that commercial fishermen scooped up large numbers in the 19th century and left them on the banks of rivers and lakes, the Minnesota Department of Natural Resources account on your website.

Dams, which prevent large fish from migrating from lakes to rivers where they spawn, also reduced their numbers. Lake sturgeon are now at less than 1% of historical levels.

State protections such as fishing limits and stocking programs, some run by Native American tribes, have helped the sturgeon.

By the 1970s, lake sturgeon had disappeared from the Coosa River watershed in northwestern Georgia, the only place they were found in Georgia.

The state Department of Natural Resources began reintroducing lake sturgeon 20 years ago, after the Clean Water Act cleaned up the river, Hamel said.

It takes 20 to 25 years for females to mature and produce the shiny, black eggs that people love to eat, according to Michigan Sea Grant. So until those eggs appeared this year in females implanted with radio telemetry tags to track their movement, no one knew whether the Georgia sturgeon survived long enough to reproduce.

“Because lake sturgeon take a long time to mature and then reproduce intermittently, every two to three years, we really need a robust population of different sizes and age classes,” Hamel said.

The current population assessment is the largest since Georgia first collected fish eggs in Wisconsin, raised them in a hatchery, and released them in Coosa in 2002. State natural resources staff, in collaboration with their counterparts from Wisconsin has done it almost every year since then.

“It’s a huge investment because you don’t even know if the fish in storage are going to survive, let alone grow and reproduce,” Hamel said.

Some 330,000 fish, most about 6 inches (15 centimeters) long, have been released since 2002, Hamel said in an email to The Associated Press.

“While that sounds like a lot of sturgeon, the survival rate of fish that are released at that size is probably 1-10%,” he wrote.

Students catch as many lake sturgeon as they can to estimate population size, survival, and growth rates. The project started in the spring. It will run through this summer and next spring and summer, ending in the winter of 2023, Hamel wrote.

Radio telemetry tags will give a better picture of where sturgeons tend to live in the river basin.

“We have implanted 28 telemetry-tagged fish so far and plan to implant 12 more in the coming months,” Hamel wrote.

Scientists have implanted tiny PIT tags, like those used to identify pets, into hundreds of fish over the past two decades. The tags let researchers know when and where scientists previously caught the fish.

Hamel said that 15% to 20% of the fish caught have PIT tags, and one goes to each untagged fish.

Five adults and five juveniles will also receive a tag that records depth and temperature every 10 seconds, he said.

Information from the first three years of repopulation suggested that the juveniles were surviving.

“There have been a lot of questions about long-term survival, growth rates, and when these fish would reach sexual maturity, and we are about to determine if these fish will reproduce successfully,” Hamel said.

The oldest recorded lake sturgeon was 152 years old, according to the Fish and Wildlife Service. The agency says the fish can reach up to 9 feet (2.7 meters) in length and 310 pounds (140 kilograms).

The largest caught so far by the Georgia group was 52 inches (1.3 meters) long and weighed 24 pounds (11 kilograms).

“This is the largest fish anyone has ever documented in the Coosa River,” Hamel wrote.

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McConnaughey reported from New Orleans.

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