Article Author:
Associated Press
Janet McConaughey
Scientists and students embarked on a census of sturgeon in Lake Georgia and found three females with mature eggs. That state for the first time in half a century.
"We are thrilled to have confirmed that they are maturing and about to spawn," said Martin J. Hamel, an associate professor in the Department of Forestry and Natural Resources at the University of Georgia Warnell University, recently. news said in his release.
Fossils indicate that spade-nosed fish, which have vacuum hoses attached to the bottom instead of jaws, have existed for over 136 million years, according to scientists. 24}
One of nine species of sturgeon and their subspecies found in the United States, the lake sturgeon, is found in 18 states and five provinces of Canada in St. Lawrence, Hudson Bay, the Great Lakes, It lives in the Mississippi River basin. According to the U.S. Fish and Wildlife Service.
Pollution, habitat destruction, and meat and caviar harvesting have decimated their numbers so much that the U.S. Fish and Wildlife Service is considering protecting the species for federal protection.
} The Minnesota Department of Natural Resources says on its website that sturgeon's bone-covered carcasses caused so much damage to fishing nets that commercial fishermen harvested them in large numbers in the 1800s and left them on the banks of rivers and lakes. ing.
Dams that prevent large fish from migrating from lakes to spawning rivers have also reduced their numbers. Lake sturgeon are now at less than 1% of their historical levels.
Some state protections, such as fishing restrictions, and grazing programs, run by Native American tribes, have helped the sturgeon.
By the 1970s, sturgeon had been wiped out of the Coosa River basin in northwestern Georgia. It is the only place in Georgia where sturgeon are found.
The State Department of Natural Resources began reintroducing Sturgeon Lake 20 years ago after the Clean Water Act cleaned the river, Hamel said.
According to the Michigan Sea Grant, it takes a female 20 to 25 years to reach maturity and lay the shiny black eggs that people love to eat. So until such eggs emerge this year with radio her telemetry her tags implanted to track the movements of the female, who knows if the Georgia sturgeon will survive long enough to breed. I didn't understand either.
"Since lake sturgeon take a long time to mature and reproduce intermittently, every 2-3 years, robust individuals of various sizes and age classes are found. We really need a herd," said Hamel.
The current population assessment is the largest since Georgia first collected eggs from fish in Wisconsin, reared them in hatcheries, and released them into Coosa in 2002. Almost every year since then.
"It's a big investment because we don't even know if the fish in captivity will survive, let alone grow and reproduce," Hamel said.
About 330,000 fish have been released since 2002, mostly about six inches (15 centimeters) long, Hamel said in an email to his AP.
"While this appears to be a high sturgeon population, the survival rate for fish released at this size he is likely to be 1-10%." he wrote.
Students are catching as many sturgeons as possible to estimate sturgeon populations, survival rates, and growth rates. A project that started in the spring. Following this summer and next spring and summer, it will end in the winter of 2023, Hamel writes.
Radio He uses telemetry his tags to find out where sturgeon live in river basins. You can get a more accurate picture of trends.
"So far telemetry he has tagged. He has transplanted 28 fish. In the next few months he plans to transplant 12 more," Hamel wrote. I'm here.
Scientists have implanted tiny his PIT tags, such as those used to identify pets, into hundreds of fish over the past two decades. The tags let researchers know when and where scientists have previously caught fish.
Hamel found that about 15% to 20% of the fish caught were PIT-tagged, and all untagged fish were PIT-tagged. said to be attached.
Five adults and his five juveniles also get tags that record depth and temperature every 10 seconds, he said.
Information from his first three-year re-breeding suggested that the juveniles survived.
"There have been many questions about long-term survival, growth rates, and when these fish reach sexual maturity. We are trying to determine whether these fish will succeed in breeding." said Hamel.
According to the Fish and Wildlife Service, the oldest sturgeon on record he was 152 years old. According to the agency, the fish can grow up to 2.7 meters long and weigh 140 kilograms.
The largest captured so far by the Georgian group was 52 inches (1.3 meters) long and weighed 24 pounds (11 kilograms).
"This is the largest fish recorded in the Cootsa River," wrote Hamel.
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McConaughey reported from New Orleans. Follow his AP coverage on climate and environment at
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https://apnews.com/hub/climate.
