The prehistoric-looking Lake Sturgeon is a pretty amazing fish. They can become river giants, growing to lengths of more than nine feet and weighing up to 275 pounds. Lake Sturgeon are also long-lived, with some known to reach over 100 years of age.
Once abundant in the Tennessee River, Lake Sturgeon were extirpated, or disappeared from this part of its historic range, by 1961. This ancient species fell victim to overfishing, pollution, and habitat destruction. Today, Lake Sturgeon are listed as endangered in Tennessee. This species is considered vulnerable worldwide.
Fifteen years ago, the Tennessee Aquarium Conservation Institute (TNACI) and its partners began the Saving the Sturgeon program to restore this species. The working group has released more than 150,000 Lake Sturgeon to the Tennessee River through captive rearing and reintroduction. (Another 30,000 have been reintroduced to the Cumberland River.)
Annual fish surveys and reports from anglers give researchers a few clues about these sturgeon, but until recently, scientists have struggled to establish a rigorous monitoring program to measure the success of reintroduction.
Last week, eight Lake Sturgeon, approximately 20 inches in length, were released into the Tennessee River in downtown Chattanooga. These fish were surgically implanted with sonic tags that broadcast unique signals, allowing researchers to see what sturgeon do when no one is looking.
“Fifty-seven sonic-tagged Lake Sturgeon are now swimming between Knoxville and Chattanooga,” said TNACI biologist Dr. Bernie Kuhajda. “In addition to tracking movement, some of these tags provide data about the depth and water temperature, giving us a more complete picture of their lives.”
A network of 29 receivers has been established from Knoxville to the Nickajack Dam downstream from Chattanooga. In addition, a sonic receiver was installed on a Serodino Barge towboat that makes weekly trips to Knoxville, detecting Lake Sturgeon between the stationary receivers.
TNACI received a grant from the Association of Zoos and Aquariums (AZA) for more than $17,000 to further expand the tracking capabilities by implanting more tags and installing a sonic tag receiver aboard the Aquarium’s boat, the River Gorge Explorer.
TNACI has developed a classroom program to help demonstrate this type of research to high school students. Aquarium naturalists will also share information about tracking sturgeon during daily cruises.
For more information about the Aquarium’s conservation efforts, go to www.tnaqua.org/AZA-SAFE.
Source: Tennessee Aquarium