Gulf Sturgeon

U.S. Fish & Wildlife Service Gulf Sturgeon A “Living Dinosaur,” that’s the Gulf (bristle worms), and other marine worms. sturgeon! The Gulf sturgeon, Acipenser oxyrinchus desotoi,traces its ancestry Adult and sub-adult Gulf sturgeon have back 200 million years and little has few natural predators other than large ©Paul A. Lang ©Paul changed with the appearance of this fish alligators in rivers and sharks in the boy scouts holding sturgeon since. marine waters. Gulf sturgeon eggs, hatchlings, and young juveniles fall prey This prehistoric fish reaches lengths of to a variety of predators, including up to nine feet can weigh up to 300 catfish, bass, sunfish, and suckers. pounds. It is well armored with rows of heavy plates that make it look menacing, Among the 25 different sturgeons but it is actually not an aggressive throughout the world, the Gulf sturgeon species, preferring to linger near the inhabits the most southern ranges of the bottom of riverbeds and oceans. With a sturgeons and is unique to the Southeast. tail like a shark, whiskers like a catfish, Gulf sturgeons, once common in river and a tube-like mouth that projects from systems from Tampa Bay, Florida to the the bottom of its head…the sturgeon has Mississippi River, occupy only a portion been called both ugly and yet beautiful. of their original habitat and are now found only in a number of large fresh The Gulf sturgeon is an anadromous fish, water coastal rivers from the Suwannee meaning that it migrates from the marine River in Florida to the Pearl River in environment to the fresh water river Louisiana. systems in the spring to spawn. It has a very strong homing instinct, and As with most sturgeons worldwide, Gulf individuals generally return to the river sturgeons were exploited for their meat of its birth. Gulf sturgeons live up to 40 and caviar. Commercial landings of years and mature late in life. Males will sturgeons in Florida alone approached mature at about seven years while 400,000 pounds in the early 1900s. Gulf females reach maturity at 12 to 15 years. sturgeon populations decreased The females, which spawn only every dramatically. The species was further aul A. Lang/USFWS three to five years, will migrate upriver in impacted by the construction of dams on P intern measuring sturgeon the spring, sometimes over 100 miles, the fresh water rivers, which blocked seeking limestone bedrock, cobble, and them from reaching their historical coarse gravel to deposit from 200,000 to spawning sites. Water pollution and loss 500,000 black eggs, also called roe, and of habitat have also had an adverse about the size of a BB. The eggs, which impact on this prehistoric survivor. are sticky, adhere to the rocks and crevices and hatch in two to three days. The Apalachicola River in Florida had a The hatchlings remain in the river for long history of sturgeon fishing dating about a year, feeding on small organisms. back to the late 1800s and early 1900s. It supported the most economically Spawning and non-spawning adult and important sturgeon fishery in the state. sub-adult Gulf sturgeons migrate into the Thirty-two families commercially fished freshwater rivers in the spring and stay for Gulf sturgeon in the Apalachicola aul A. Lang/USFWS in the rivers until fall when they return to River from the middle 1940s until the P weighing sturgeon the marine environment. Adult and sub- 1970s, when sturgeon harvest levels were adult Gulf sturgeons have an unusual life greatly reduced and competition from the history trait — they do not eat during Russian imports increased. their six to eight month fresh water residency. A limited recreational fishery developed in the late 1950s in the Apalachicola River Their weight loss is quickly gained back below the Jim Woodruff Lock and Dam — and then some — when the fish return when it was built. Gulf sturgeons would to the marine waters to overwinter and congregate below the dam, which blocked feed on a variety of bottom dwelling upstream movement to historical marine organisms, including amphipods spawning sites, and anglers would “snag” Jake Osborne/USFWS (small shrimp-like crustaceans), isopods or “snatch” the fish using heavy fishing USFWS biologist, holds a young Gulf (small crustaceans), lancelets (sediment- tackle. This fishery only lasted a few sturgeon in his hands dwelling worm-like animals), polychaetes years. U.S. Fish & Wildlife Service Scientists have also used unknown if once a population is ultrasonic transmitters to eliminated from a system that it will be determine that Gulf sturgeons able to recover by individuals straying feed and grow mainly in the into that river from other watersheds. marine environment. Gulf sturgeons were found in the In 2003, the Apalachicola River was bays, estuarine areas and Gulf of designated as “Critical Habitat” for Gulf Mexico during the overwintering sturgeon due to its documented suitable period. While in the bays, the spawning habitat, active summer resting fish showed a preference for the areas, and availability of food for juvenile sandy shoreline habitats with and young-of-year fish. The designation water depths less than 11 feet. of critical habitat requires that each aul A. Lang/USFWS P Gulf sturgeons overwintering in federal agency shall, in consultation with USFWS biologist and intern holding sturgeon the Gulf of Mexico were the Fish and Wildlife Service, insure that generally located in near-shore any action authorized, funded or carried The Gulf sturgeon was listed as a areas, from one-half to two miles from out by the federal agency is not likely to threatened species in 1991 under the shore at water depths of 15 to 40 feet. adversely modify critical habitat. Critical Endangered Species Act. As a result of habitat is adversely modified if it no the listing, a multi-agency team Suitable Gulf sturgeon spawning habitat longer provides the essential conservation developed a comprehensive plan to consisting of limestone bedrock and needs of the species for which it is recover and manage the Gulf cobble is limited in the Apalachicola designated. sturgeon. Prior to the Gulf sturgeon’s listing, very little The Gulf sturgeon was known about the life population in the history of the fish. Apalachicola River was Consequently, researchers had estimated in 2004 to be to start from scratch to under 400 fish. At that time, address recovery action items the Gulf sturgeon population addressed in the newly was increasing slightly. developed Gulf Sturgeon Further studies are Recovery/Management Plan. necessary to determine the current Gulf sturgeon Scientists from Florida and population. However, lack of Georgia have studied the Gulf personnel and funding are sturgeon population in the the primary reasons why Apalachicola River researchers have not done periodically for the last 30 more to recover the Gulf years. Much of the work was sturgeon in the Apalachicola directed toward solving some River. of the unknown life history characteristics of the Gulf The Gulf sturgeon is an sturgeon, and the work still excellent indicator of the continues. health of the aquatic system. range map for the sturgeon It is found in a wide Early collection and tagging studies were River. Researchers have identified diversity of habitats and has persisted in able to prove that a small population of several good spawning sites, and recent less than optimal conditions. Continued reproducing Gulf sturgeon still existed in studies documented successful Gulf existence of the Gulf sturgeon in the the river. sturgeon spawning at several of the sites. Apalachicola River depends on our Efforts are now being directed toward maintaining and protecting important Scientists attached radio transmitters to determining potential threats to the riverine and marine habitats. a number of sturgeons and monitored spawning habitat and finding solutions to them while in the river to study their ensure protection that will save the vital movement and learn more about where spawning habitat. they live. Juvenile, sub adult, and adult Gulf sturgeons show a preference for Scientists documented that the Gulf specific holding areas in the Apalachicola sturgeon in the Apalachicola River River system referred to as “summer possessed as unique genetic makeup, resting” sites. The resting areas, ranging different from Gulf sturgeon populations in depth from six to 60 feet, are described located in river systems to the west but as moderate to deep holes, and sometimes identical to sturgeons found in river shallow areas along straight stretches of systems to the east. Although, some the river. straying and exchange exists among Gulf Coast river sturgeon population, it is.

Load more