YANKTON, S.D.
An effort at a Yankton fish hatchery to preserve the endangered pallid sturgeon has reached a new milestone with the spawning of two female sturgeon held in captivity their entire lives. Their offspring are expected to begin hatching Wednesday. While other hatcheries capture pallid sturgeon from the wild and use an artificial spawning process, the Gavins Point National Fish Hatchery is the only one in the world that raises the fish from birth to adulthood and then helps them spawn. Hatchery Manager Keith McGilvray says the spawning success answers a lot of questions about captive pallid sturgeon reproduction. "We've been doing this for years with wild fish," said McGilvray. "But we're just finding (captive) pallid sturgeon in the last two years that are old enough and have levels of sexual maturity where they can spawn. Generally, the first-time spawn is not the greatest quality of eggs. But it's a start." Generally, female pallid sturgeon do not become sexually mature until they are approximately 15 years old. The older fish that spawned at Gavins Point produced approximately 44,000 eggs. Many of those hatchlings will go to research institutions because the Fish and Wildlife Service didn't have the tools 16 years ago to determine the genetic purity of the class of 1992's parents. McGilvray said there is a chance they had some shovelnose sturgeon genes, and the Fish and Wildlife Service doesn't want to risk releasing a hybrid pallid sturgeon into the wild. The surviving offspring from the approximately 23,000 eggs produced by the younger pallid sturgeon will be used to stock the Missouri River from above Gavins Point Dam to Montana. McGilvray said he is hoping 70 percent of the eggs result in live hatchlings much better than would be expected in the wild. The pallid sturgeon preservation project at the GavinsHatchery will now aim for another milestone, he said. "The next step is to be able to take the fish you have used in this captive program and reintroduce them back into the wild," McGilvray said. "That's a huge step, because you're taking fish that have been in the hatchery their whole lives. But at some point in time, you need to stock fish back out into river." Pallid sturgeon were listed as an endangered species in 1990, and their demise has been blamed largely on dams and other forms of river channeling, which isolated them and reduced their natural habitat. (AP) Point
