Alabama sturgeon (Scaphirhynchus suttkusi)
Where Listed: WHEREVER FOUND
The Alabama sturgeon (Scaphirhyncus suttkusi) was listed as an endangered species on May 5, 2000 (65 FR 26438). Its historic range encompassed all major rivers in the Mobile Basin, below the Fall Line, including the Alabama, Tombigbee, and Cahaba River systems. Recent collections are restricted to the lower Alabama River below Millers Ferry Lock and Dam to the confluence of the Tombigbee River and in the lower Cahaba River near its confluence with the Alabama River; however, records are extremely rare. The last capture of an Alabama sturgeon was on April 3, 2007 by the biologists at the Alabama Department of Conservation and Natural Resources (ADCNR). The Alabama sturgeon is one of the rarest and most endangered fish in the nation and may be close to extinction.
- States/US Territories in which the Alabama sturgeon, is known to or is believed to occur: Alabama
- US Counties in which the Alabama sturgeon, is known to or is believed to occur: View All
|Status||Date Listed||Lead Region||Where Listed|
|05/05/2000||Southeast Region (Region 4)|
» Federal Register Documents
|Date||Title||Plan Action Status||Plan Status|
|07/08/2013||Recovery Plan for the Alabama Sturgeon (Scaphirhynchus suttkusi)||Recovery efforts in progress, but no implementation information yet to display||Final|
|Date||Citation Page||Title||Document Type|
|04/12/2012||77 FR 21993 21994||Notice of Availability of a Technical/Agency Draft Recovery Plan for Alabama Sturgeon||
|07/06/2009||74 FR 31972 31973||Initiation of 5-Year Status Reviews of 23 Southeastern Species||
|08/06/2013||78 FR 47722 47723||Endangered and Threatened Wildlife and Plants; Notice of Availability of the Recovery Plan for Alabama Sturgeon||
|11/09/2010||Alabama Sturgeon 5-Year Review|
» Critical Habitat
|Date||Citation Page||Title||Document Type||Status|
|06/02/2009||74 FR 26488 26510||Designation of Critical Habitat for Alabama Sturgeon (Scaphirhynchus suttkusi)||Final Rule||Final designated|
|05/27/2008||73 FR 30361 30374||Designation of Critical Habitat for Alabama Sturgeon (Scaphirhynchus suttkusi): Proposed rule.||Proposed Rule||Not Required|
|06/15/1993||58 FR 33148 33154||ETWP; Proposed Endangered Status and Designation of Critical Habitat for the Alabama Sturgeon (Scaphirhynchus suttkusi)||Proposed Rule||Not Required|
To learn more about critical habitat please see http://ecos.fws.gov/crithab
» Conservation Plans
No conservation plans have been created for Alabama sturgeon.
» Life History
Very little is known of the habitat requirements of the Alabama sturgeon. Based on capture data, it inhabits the main channel of large coastal plain rivers of the Mobile River Basin. Most specimens have been taken in moderate to swift current at depths of 6 to 14 m, over sand, gravel or mud bottom (Williams and Clemmer 1991). Similar preferences have also observed in shovelnose sturgeon (Hurley et al., 1987; Curtis et al. 1997). The COE identified 30 locations on the Alabama River where 58 Alabama sturgeon were reportedly captured between 1950 and 1998, and documented channel morphology and substrate types at 12 of the capture locations during low flow conditions. Substrates correlated with these capture sites included sand, gravel and limestone outcrops. All capture locations downstream of Claiborne Lock and Dam (L&D) were either on or within 300 meters of a sandbar. Most historical and recent sturgeon capture sites are at or near features presumably associated with feeding, reproduction, or refugia and include, rock walls, channel training devices, deep pools, mussel beds, confluence with tributaries, and/or stable sand and gravel bottoms (Burke and Ramsey 1985; Mayden and Kuhajda 1996; Hartfield and Garner 1998; and Rider et al., 2009). The presence of mussel beds represents stable channel habitats with high aquatic invertebrate diversity and density that are likely important feeding areas for sturgeon; deeper holes and lower reaches of tributary streams may be used as thermal refugia during times of low flow (Hartfield and Garner 1998; Rider et al., 2009). Data collected from a radio-tagged Alabama sturgeon released in 1985 near Millers Ferry L&D on the Alabama River and tracked for four months, showed that its preferred position was in swift current at 7.7 to 12.3 m (25 to 40 ft), but never at the deepest part at any location except where bottom contour was uniform (Burke and Ramsey, 1985). Irwin (2005) and Kynard (2000) found that adult shovelnose sturgeon are more active at night, but their habitat preferences did not vary from day to night. This type of behavior was also observed in juvenile shovelnose sturgeon (Kynard et al., 2002). According to Rider et al. (2009), the Alabama Sturgeon collected in 2007 that was sonic tagged and tracked between April 2007 and June 2008, displayed varied movement patterns. During the summer months, the fish was stationary and resided around the confluence of a small spring-fed creek (Sizemore Creek) in the lower Alabama River. Water temperatures in Sizemore Creek were typically 4-50C cooler than the Alabama River, which suggest the area was being used as a thermal refuge. Movement was greatest during the spring as the fish was presumably attempting to make an upstream spawning run. The greatest movement was associated with water temperatures between 16 and 210C, and no clear correlations were made between upstream movement and increased river discharge
The examination of stomach contents of museum and captured specimens indicate that sturgeons feed in a broad range of habitat, including shallow water in swift currents, and maybe even in the water column. However, they generally tend to be opportunistic bottom feeders primarily preying on aquatic insects, plant material, and mollusks (Mayden and Kuhajda, 1996; Williams and Clemmer, 1991; Burke and Ramsey, 1985; Haynes et al., 2005; and Keevin et al., 2007); however, commercial fisherman report that sturgeon have been taken on trotlines using a variety of bait, including poultry parts, fish, and commercially prepared bait (Williams and Clemmer 1991). Taylor (2004) found that juvenile shovelnose sturgeon overwhelmingly preferred feeding in sandy substrates and actively avoided gravel areas. This behavior may also be displayed by Alabama sturgeon (Keevin et al., 2007). Post-spawning downstream movements of shovelnose sturgeon have also been documented (Delonay, 2005). Adult Alabama sturgeon may exhibit seasonal downstream migrations in search of feeding and summer refugia. Burke and Ramsey (1995) determined that Alabama sturgeon were rare or absent from the free-flowing sections of the Mobile Delta and the lower Tombigbee River during the early 1980s, due to factors such as low flow and salt water intrusion. Therefore, downstream movements may currently be limited to the lower Alabama River.
Movement / Home Range
River sturgeons (Scaphirhynchus spp.) require extensive areas of flowing water habitats to complete their life cycle. The decline of collection records and anecdotal accounts of captures of Alabama sturgeon over the past century coincides with construction of dams and the cumulative loss and fragmentation of riverine habitat in the Mobile River Basin over time. These habitat changes, coupled with what is known about life history requirements and life span of other species of river sturgeon, suggest that the Alabama sturgeon may be close to extinction.
Sexual maturity of the Alabama sturgeon is believed to occur between 5 to 7 years of age. Spawning frequency of both sexes is likely influenced by food supply and fish condition, and presumably like other shovelnose sturgeon, may only occur at 2-3 year intervals (Mayden and Kuhajda 1996). Life span of the Alabama sturgeon is unknown. Although few individuals probably exceed 12 to 15 years of age (Mayden and Kuhajda 1996), it is possible the species may live longer. Age determination was attempted on three preserved specimens by three different examiners using pectoral fin ray analysis; however, while all examiners agreed that the smallest sturgeon examined was two years old, no clear consensus on aging the larger specimens was attained. A 0.9 kg gravid female was at least 7 years old, and a 1.6 kg sturgeon was at least 10 years old (Burke and Ramsey, 1985). The individual collected in 2007 by the ADCNR was the second largest specimen ever collected (72 cm total length, 28.3 inches). As with most riverine sturgeon, spawning is likely initiated by environmental cues such as, temperature, photoperiod, and an increase in river discharge during the late winter and early spring. The development of numerous large-river impoundments in the Mobile Basin may influence these cues (Mayden and Kuhajda 1996). Following spawning, Scaphirhynchus species larvae require highly oxygenated, flowing water for development. The larvae are planktonic, drifting with river currents for 12 to 13 days after hatching, and exhibit a swim-up and drift behavior while floating in currents (Kynard et al., 2005). Research indicates that pallid sturgeon larvae (Scaphirhynchus albus) can drift more than 200 km (125 mi) during the first 11 days of the larval life stage, depending on water velocities, before settling to a benthic existence (Braaten and Fuller 2005). This information suggests that Alabama sturgeon may require some minimum distance of flowing river conditions for development of larval to juvenile stage, and for sustainable recruitment of the species.
» Other Resources
NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.
ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.
FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.