The King of Fishes: Sturgeon 1955

by Constance Riggins

ñThe sturgeon population in Georgia may be the largest left in the world. It is doing better that anyone expected.î That is the preliminary prediction of a study by Douglas Peterson, Professor of Fisheries at the Warnell School of Forest Resources at UGA. The study is evaluating the status of the shortnose and Atlantic sturgeon in the Altamaha River from the ocean to the lower Oconee and Ocmulgee Rivers. The study began in the spring of 2003 and will go through next summer. Peterson says he is encouraged because his preliminary results show a much larger population of both species than previously predicted. Prior 1993 studies indicated there were only about 466 of the federally endangered shortnose sturgeon left in Georgia's waters. The current study shows the population is at least 10 times higher.

The shortnose sturgeon is federally protected as a threatened species under the Endangered Species Act and has been since the act was passed in 1973. The shortnose sturgeon's average weight is 8-12 pounds. The Atlantic sturgeon is listed as a candidate for threatened under the National Endangered Species Act, although the fishery for this species was not banned until 1998. The Atlantic sturgeon typically weighs between 100 to 300 pounds. Both species have been known to live for over 60 years.

Some species (27 species world wide) of these passive, slow-moving bottom feeders can live more than a century. Dating from the time of the dinosaurs, sturgeons lack scales, instead having ridged bony plates along their back called scutes. They also lack teeth and feed using their rubbery protrusible lips like hoses to vacuum up mollusks, worms, and other food from the mud. The Atlantic sturgeon is ñanadromousî meaning it spawns in the rivers but spends the majority of its life in coastal waters at the mouth of rivers ranging from Canada to Florida. The shortnose is considered ñamphidromousî meaning it completes its entire life cycle within the river and estuary.

Sturgeons, including both shortnose and Atlantic, were slaughtered for their eggs (roe) during a craze for caviar during the late 1800's. They were caught primarily by commercial fishermen using large gill nets and were particularly vulnerable because they congregate in high densities in their spawning areas at predictable times each year. They are also extremely vulnerable to gill nets because their sharp scutes are easily entangled in these nets.

The fish were also used commercially. Isinglass, a gelatin made from the inner lining of the surgeon's air bladder was used to clarify wine, cement pottery, stiffen cloth, thicken jams and jellies, and provide waterproofing. Sturgeon skins were tanned for leather, as well. Not only was sturgeon over fished, its decline was exacerbated because it is slow to mature and only spawns every two to six years. Since the ban on Atlantic sturgeon fishing, virtually all caviar production has shifted to Russia, which is now decimating its sturgeon population in the Caspian Sea.

For the past two years, in conjunction with Peterson's study, graduate student, Rob DeVries, has been collecting information on the life history and population dynamics of both Atlantic and shortnose sturgeon by netting, tagging, and tracking the fish in the Altamaha River, near Darien. DeVries is doing the work as part of his Masters Degree in the world-renowned fisheries program at UGA's Warnell School of Forest Resources. The netting process consists of stretching a heavy-duty mesh net, 100-200 feet long, across the river. One end of the net is tied to shore while the other end is anchored in the river. The bottom of the net is weighted to the bottom with the top of the net extending up through the water to within about 2Æ3 feet of the surface. DeVries and his coworkers check the net for sturgeon four times daily, at each change of the tide. To monitor the migration movements of the large Atlantic sturgeon, DeVries attaches a small radio transmitter to the back of several adult fish before releasing them. He also clips a small section of the pectoral fin from each fish captured to determine the age of the fish. A similar process is used to study the movements and preferred habitat of shortnose sturgeon.

Rob says ñsightings of the local sea monster, the Altamahaha, were probably Atlantic sturgeon. The largest Atlantic we caught was 282 pounds and 8 feet long. When the fish mate they resemble a submerged dragon, yet they can jump completely out of the water.î Local fishermen tell stories about how the huge fish have jumped right into their boats almost capsizing their craft.

The current study is being conducted in collaboration with the Georgia Department of Natural Resources and according to Peterson, it is the one of most thorough studies of a sturgeon population ever conducted in Georgia. He says the study is evaluating the status of the shortnose and Atlantic sturgeon in the Altamaha because fishery scientists are concerned about world-wide declines in sturgeon that have continued throughout the past century. Peterson hopes the study results will provide up to date information to help protect the population.

It is good to know that the species that existed since the Cretaceous period, more than 120 million years ago, is alive and well in Georgia.