Listed Endangered on May
5, 2000 (65 FR 26437 26461).†
descriptions are from the Federal Register (1994, 1999, and 2000).
sturgeon is a member of the Acipenseridae family.† The species typically grows up to 80cm
(30inches) in length, weighs 1 to 2 kg (2 to 3lb.), and may live 15+
years.† The species is an opportunistic
feeder, preying primarily on aquatic insect larvae, as well as fish eggs,
snails, mussels, fish, and plant material.
little is known of the life history, habitat, or other ecological requirements
of the Alabama sturgeon.† However, it probably spawns in the
spring.† Spawning frequency of both sexes
is influenced by food supply and fish condition, and may occur every 1 to 3
RANGE AND POPULATION LEVEL:
The Alabama sturgeonís historic range once included about
1,600 kilometers (km) (1,000 miles (mi)) of the Mobile River system in Alabama (Black Warrior, Tombigbee, Alabama, Coosa, Tallapoosa, Mobile, Tensaw, and Cahaba Rivers) and Mississippi (Tombigbee River).
species is now restricted to a 216km (130mi) reach of the Alabama
River below Millerís Ferry Lock and Dam.† The Alabama
sturgeon currently inhabits only about 15 percent of its historic range.
species prefers relatively stable gravel and sand substrates in flowing river
channels (Burke and Ramsey 1985).†
Verified captures of Alabama
sturgeon have primarily occurred in large channels of big rivers; however, at
least two historic records were from oxbow lakes (Williams and Clemmer
1991).† Riverine (flowing water) habitats
are required by the Alabama
sturgeon to successfully complete its life cycle.
historic population decline of the Alabama
sturgeon was probably initiated by unrestricted harvesting near the run of the
century.† Although the Alabama
sturgeonís capture is currently prohibited, the species has and still is
affected by incidental capture from commercial and sport fishery.
than harvesting, and more importantly, the decline in the Alabama
sturgeonís range is the result of 100 years of cumulative impact to the rivers
of the Mobile River
Basin as they were developed for navigation,
especially during the last 50 years.† The
deepening and destruction of shoals and shallow runs or other historic feeding
and spawning sites as a result of navigation development likely contributed to
local and overall historic declines in range and abundance of the Alabama
sturgeon.† These modifications have also
caused siltation, creating an unsuitable habitat for spawning and foraging.
of dams and locks fragmented the range and created metapopulations between the
dams where migration was inhibited.†
Fragmentation created metapopulations where all the speciesí habitat
needs were not necessarily met, and where the species became more vulnerable to
local declines in water and habitat quality caused by riverine and land
management practices and/or polluting discharges.
species has continues to be affected by over-fishing, loss and fragmentation of
habitat as a result of navigation-related development and maintenance, and
water quality degradation.†
Fish and Wildlife Service. 1994. Withdrawal of Proposed Rule for Endangered
Status and Critical Habitat for the Alabama
Sturgeon. Federal Register (59) 240: 64794-64809.
Fish and Wildlife Service. 1999. Proposed Rule To List the Alabama
Sturgeon as Endangered. Federal Register (64) 58: 14676-14685.
Fish and Wildlife Service. 2000. Final Rule To List the Alabama
Sturgeon as Endangered. Federal Register (65) 88: 26437-26461.
J.D., and G.H. Clemmer. 1991. Scaphirhynchus suttkusi, a new sturgeon
(Pices: Acipenseridae) from the Mobile Basin of Alabama and Mississippi.
Bulletin of the Alabama Museum
of Natural History 10:17-31.