Lake Sturgeon Reintroduction to the Coosa River Basin
The Process of Reintroducing Lake Sturgeon to the Coosa River Basin
Why DNR is Reintroducing Lake Sturgeon to the Coosa River
Following six years of study, the Georgia Department of Natural Resources, Wildlife Resources Division (WRD) initiated a long-term effort in 2002 to restore lake sturgeon to the Coosa River system in Northwest Georgia. An ancient fish dating back to the era of the dinosaurs, lake sturgeon once occurred from the Great Lakes down the Mississippi into the Missouri and the Tennessee and Coosa drainages. Today, the species is listed as threatened throughout the U.S. and has disappeared completely from much of its original range, including the Coosa River. Through collaborative efforts between several state and federal agencies, WRD has released more than 85,000 fingerlings to the Coosa River since December 2002 in an effort to return the lake sturgeon to a healthy, self-sustained population in the river.
WRD's desire to reintroduce lake sturgeon is two-fold. One reason for stocking lake sturgeon is to re-establish a native sport fish to Georgia waters. Anglers reported good harvests of lake sturgeon in Georgia waters as recently as the early 1960s. However, the fish suddenly disappeared. Considering the longevity of lake sturgeon and the heavy harvests reported by some anglers, over-harvest was likely a factor in the disappearance of the Coosa River fish. DNR believes the species can once again be part of the river ecosystem and provide some harvest if monitored and managed carefully.
The second reason for restoring the species addresses the conservation of Georgia's rare species. In a recent survey completed by WRD, 72 percent of Georgians supported the allocation of financial and personnel resources for managing and conserving imperiled species. This is an excellent example of how WRD is working to conserve and protect Georgia's native species. By reintroducing lake sturgeon, Georgians are contributing to the conservation of a fascinating species.
Scientists believe pollution, over fishing and other factors have contributed to the decline of the species nationwide. Thanks to the efforts of concerned citizens and a variety of government agencies, much of the pollution in the Coosa system has been eliminated and the Coosa can once again support lake sturgeon.
The reintroduction of Lake Sturgeon to the Coosa River will serve as a major milestone in Georgia's conservation efforts. The reintroduction of a native species to an area is a difficult task that takes the cooperation of state agencies and citizens working together for a common good. It will take several years before lake sturgeon are a common species in the Coosa. Research indicates it will take more than a decade of annual stockings before the species can reach adequate numbers to reproduce on their own. It will take an estimated 25-30 years before the fish are large enough and mature enough to support a controlled harvest.
In recent years, WRD biologists concentrated on three main areas of research in preparation for the reintroduction. First, they wanted to determine if any lake sturgeon still existed in the Coosa River system. Second, they needed to refine hatching and rearing techniques to produce the fingerlings necessary to restock the river. Third, they wanted to know if lake sturgeon would impact other species in the river system.
Several methods were used to determine if any lake sturgeon still existed in the river. WRD consulted with staff of other agencies and the University of Georgia to determine if they had any data indicating the presence of lake sturgeon in Georgia. WRD biologists also reviewed 40+ years of their own fish sampling data to determine if any sturgeon had been collected and to determine how much sampling had been conducted that potentially could have collected sturgeon. Some additional sampling effort was directed specifically toward catching sturgeon in their last known locations using techniques provided by older anglers who caught them many years ago. Finally, DNR actively sought information from the general public using posters and newspaper articles that requested anyone with information on recent sturgeon sightings to contact DNR. The result of these efforts indicated that no lake sturgeon had been verified from the river since 1959 and it was very unlikely that any original lake sturgeon existed in the river.
The potential for lake sturgeon to impact other species is extremely small for several reasons. Lake sturgeon are opportunistic feeders that feed primarily on soft-bodied invertebrates, which live on the stream bottom. They feed almost entirely by feel using the barbels located around their mouth, making them inefficient predators on other fish. Because individual females spawn infrequently, their reproductive potential is very low and overpopulation of sturgeon, which could cause competition with other fish species, is unlikely. In fact, throughout its range, inadequate reproduction is a problem, whereas over abundant populations have not been documented. Not only is the potential for over production very low, but the potential for reducing a population, if necessary, is very high. This is because sturgeon are valued not only for their meat but also for their eggs, which are used to make caviar. Thus, large numbers of fish can easily be reduced using harvest regulations.
Rearing experiments were conducted at the WRD's Summerville Fish Hatchery beginning in 1999 using eggs obtained from Wisconsin. Rearing lake sturgeon is not a simple process, but the hatchery staff has been able to raise them with increasing success. In fact, the current production rate of the past few years has approached that of more experienced hatcheries in the upper Midwest.
Beginning in April 2002, Wisconsin DNR began shipping 40,000 lake sturgeon eggs yearly to Georgia. The eggs hatch out in about seven days. From March through September, the sturgeon are fed a variety of natural and commercial foods. Once the sturgeon reach four inches, they are released into the Coosa River system at several locations. Sturgeon are raised primarily at the WRD's Summerville Fish Hatchery with additional production occurring at the U.S. Fish and Wildlife Service Warm Springs Hatchery and the University of Georgia Cohutta Hatchery.
Current Status of Lake Sturgeon in Georgia
Funded by Federal Sportfish Restoration Funds granted to WRD, the University of Georgia, Warnell School of Forest Resources monitored the initial success of the lake sturgeon reintroduction using radio telemetry and population assessment techniques. University researchers recaptured some stocked fish and surgically implanted miniature radio transmitters through small incisions in the belly of each sturgeon. After allowing the fish to heal for about two weeks, the sturgeon was released back into the river near where it was captured. A total of 20 sturgeon were outfitted with transmitters. Since each transmitter gave off a unique radio signal, individual fish movement and behavior could be monitored. Study results indicated that the lake sturgeon are utilizing the Coosa River from Rome downstream into, and throughout, Lake Weiss. The sturgeon move seasonally, ranging throughout the lake and river in the winter and moving upstream in mid to late summer.
Various types of sampling gear are used to determine the survival, size distribution, and growth of the lake sturgeon. Over 350-lake sturgeon from the 2002 through 2004 releases were captured, measured (length and weight), and released. Lake sturgeon survival has been higher than expected. Initial growth of the lake sturgeon was good with fish from 11 to 36 inches long being caught and released. Lake sturgeon of over 40 inches long and weighing up to 15 pounds have been reported in 2009 by anglers who caught and released sturgeon. Based on angler reports, the fish have moved further downstream in the Coosa system including Neely Henry and Logan Martin reservoirs in Alabama.
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