Species Diversity

The Coosa Watershed is the largest and most biodiverse subwatershed of the Mobile River Basin in terms of overall number of fish, mussel and snail species. Historically the basin harbored 147 fish species, and 78 taxa of snail (60 species endemic to the Coosa). (State of Rivers)

Aquatic biodiversity has declined significantly as a result of riverine habitat loss, modification and fragmentation from impoundments, and water quality degradation. The remaining significant reaches of free-flowing riverine habitat on the mainstem Coosa River are limited to:

  1. An 8-mile reach downstream from Jordan Dam. This reach is affected by flucuating releases from Bouldin and Jordan dams and provides habitat for the endangered Tulotoma snail and the threatened fine-lined pocketbook. The shoal lily occurs occasionally on shoals in this reach. Paddlefish, a species of concern, is restricted to downstream of the Fall Line. (Corps)
  2. A 21-mile reach of bypassed river channel extends downstream from Weiss Dam, and is known as the Dead River.
  3. A 9-mile free-flowing reach extends downstream from Rome, GA to the headwaters of Weiss Lake. There is a fish consumption advisory for this section of river due to elevated PCB levels. Few mussel species persist in this reach.

Due to the construction of dams and limited free-flowing mainstem habitat, much of the remaining faunal diversity in the Coosa Basin is restricted to tributaries of the Coosa. (State of Rivers)

The upper Coosa supports the largest number of Federally listed species (6 fish and 7 mussels) compared to the lower Coosa system (2 fish and 4 mussels). Many of these species occur in the Conasauga, upper Etowah, and Coosawattee River systems, which contain the longest remaining reaches of free-flowing river in the Coosa Basin. (Corps)


Fish diversity in the Coosa Basin is extremely rich, ranking it ___ out of ____ total watersheds in Alabama. A total of 147 fish species have been documented from the Coosa River drainage. (Corps)

At this time 7 fish known from the Coosa drainage are listed as federally threatened or endangered. Only two of these occur in the Alabama portion of the basin.

The Blue shiner (Cyprinella caerulea), a threatened species, is found only in the upper Coosa River drainage in Georgia, and in Alabama in a 5.2 mile segment of the Little River, 18.4 mile segment of Choccolocco Creek / Calhoun Co., and a 22.4 segment of Weogufka Creek / Coosa Co. (Pierson, 1998) This shiner inhabits small to medium streams over rocky substrate with moderate to slow current. (Recently a new population of this shiner was found in Spring Creek which drains to Weiss Lake. This population is disconnected from the Little River population by an inundated section of Weiss Lake (Blanchard 2001).

The Pygmy sculpin (Cottus pygmaeus), a threatened species, is known only in Alabama at Coldwater Spring near Anniston, and its spring run to its confluence with Dry Creek in Calhoun County. (Corps) This fish is a mottled and banded bottom-dwelling species. Its colors allow it to blend perfectly with the gravel on the bottom of the spring. (Godwin)

The five remaining threatened and endangered species are found only in the Georgia portions of the Coosa watershed, or in other subwatersheds of the Mobile River Basin.

The Etowah darter (Etheostoma etowahae) is a federally listed endangered species that requires riverine or tributary watercourses with riffles and moderate to strong current. It is found only in the upper Etowah River system above Lake Allatoona in GA. (Corps)

The Cherokee darter (Etheostoma scotti), a threatened species, is present in the upper Coosa River system in GA. It is found in small to medium sized streams with gravel and cobble substrates. (Corps)

The Amber darter (Percina antesella) is an endangered species with designated critical habitat on the Conasauga River in Tennessee and in Murray and Whitfield Counties, Georgia. This darter is found in mainstream river and large tributary habitat with moderate to swift currents. (Corps)

The Goldline darter (Percina aurolineata), a threatened species, is presently found only in the Coosawattee River in Georgia and the Cahaba River. This darter inhabits rivers and large tributaries having swift current over gravel, cobble, bedrock, and boulder substrate. (Corps)

The Conasauga logperch (Percina jenkinsi), an endangered species, has designated critical habitat on the Conasauga River from Polk County, Tennessee, downstream to Murray County, Georgia. It is found only in 148 feet reach of the river, in association with riffles and runs of moderately deep water with swift current over coarse substrates. (Corps)

Many biologists and conservation agencies also evaluate fish species of concern that are showing signs of being at risk of extinction. According to ___________, there are ___ of these at-risk species in the Coosa Basin.

The Holiday Darter (Etheostoma brevirostrum) has the most distinctive coloration of all darters found in the subgenus Ulocentra. This species is only found in the Coosa River drainage where it prefers medium to large streams with fast current and a mixture of substrate including sand, gravel, small boulders, and river weed. Most populations, although disjunct are stable. This species is common in the Upper Conasauga River drainage that drains portions of the Cherokee and Chattahoochee National Forests in Georgia.

Fish status in Coosa Basin

Total species
# endemic
# extinct
# extirpated
# threatened or endangered 7
# imperiled
# special concern


There are 10 threatened and endangered mussels from the Coosa.

The Upland combshell (Epioblasma metastriata), an endangered species, is found in a small portion of the Conasauga River in Georgia and may be present in upper reaches of the Black Warrior and Cahaba River drainages in Alabama. Suitable habitat for this mussel is free-flowing rivers and large creeks with gravel and sandy gravel substrates.

The Southern acornshell (Epioblasma othcaloogensis) is an endangered mussel found in large creeks and small rivers with rock and gravel substrate. This species has been found in the Coosa River drainage of Georgia and the Cahaba River drainage of Alabama above the Fall Line.

The Fine-lined pocketbook (Lampsilis altilis) is a threatened species found in the Coosa River and Talladega Creek systems in Alabama and the Etowah and Conasauga Rivers in Georgia. Preferred habitat is free flowing rivers and creeks with gravel and sandy gravel substrate.

The Alabama moccasinshell (Medionidus acutissimus), a threatened species, is found in the upper Coosa River drainage of northwest Georgia. It occurs in rivers and large creeks where substrates are boulders, cobbles, gravel and sand.

The Coosa moccasinshell (Medionidus parvulus) mussel is endangered and is found in the Coosa River drainage of northeast Alabama and northwest GA where it occurs in association with free-flowing water over gravel and sandy-gravel substrates.

The Southern clubshell (Pleurobema decisum) is an endangered mussel found in scattered populations in the Coosa and Cahaba River systems and in the Coastal Plain tributaries of the Tallapoosa River. Preferred habitat is medium sized rivers with moderately high gradient and stable sand-gravel substrate. (Corps)

The Southern pigtoe mussel (Pleurobema georgianum), an endangered species, historically was found in the upper Coosa River drainage in GA, AL and TN, including Chattooga, Coosawatee, and Conasauga Rivers. Most recent records of the southern pigtoe are from the Conasauga above Dalton.

The Triangular kidneyshell (Ptychobranchus greeni) is an endangered species that occurs in the Coosa River drainage of north GA and the Cahaba River.

coosa mussels
Coosa River Mussels – Photo by M. Pierson

Mussel status in Coosa Basin

Total species
# endemic
# extinct
# extirpated
# threatened or endangered 10
# imperiled
# special concern


Recent surveys of aquatic gastropods in the Coosa basin have been described by scientists as “disturbing.” In ’92 Pierson and Bogan failed to find 29 species known to occur historically in the watershed.

Currently only 3 species of snail are listed as threatened or endangered. All are found only in the Alabama portions of the Coosa Basin.

The Lacy elimia (Elimia crenatella) is a threatened species found only in Cheaha (largest population), Emauhee, and Weewoka creeks in Talladega County. It is presumed extirpated from its former habitats of the Coosa mainstem, Big Will’s Creek, Kelley’s Creek, and Choccolocco and Tallaseehatchee creeks. (Pierson and Bogan)(Federal Register)

The Painted rocksnail (Leptoxis taeniata) is a threatened species found in only three tributaries of the Coosa Basin; the lower reaches of Choccolocco Creek (Talladega County), Buxahatchee Creek (Shelby County), and Ohatchee Creek (Calhoun County). The painted rocksnail has apparently been extirpated from the Coosa mainstem, as well as the Alabama and Cahaba rivers. (Federal Register)

The Tulatoma (Tulotoma magnifica) is found in Choccolocco Creek, the mainstem of the Coosa below Jordan Dam, Kelley Creek, Weogufka Creek, Hatchet Creek, Ohatchee Creek, and Yellowleaf Creek.

Snail status in Coosa Basin

Total species
# endemic
# extinct 23
# extirpated
# threatened or endangered 3
# imperiled
# special concern

There are 23 species of snail that are presumed to be extinct in the Coosa. (Corps)

The Cylindrical lioplax (Lioplax cyclostomaformis) was once known from the Coosa mainstem in Shelby and Elmore counties as well as the tributaries of Little Wills Creek (Etowah county), Choccolocco Creek (Talladega county), and Yellowleaf Creek (Shelby County). Currently found only in the Cahaba basin. (Federal Register)

The Flat pebblesnail (Lepyrium showalteri) was once known from the Coosa mainstem in Shelby and Talladega counties. It has been missing from this habitat since the construction of Lay and Logan Martin Dams. Currently found only in the Cahaba basin. (Federal Register)

The Round rocksnail (Leptoxis ampla) was once known form the Coosa mainstem in Elmore county as well as the tributaries of Canoe Creek and Kelly�s Creek (St. Clair county), Ohatchee Creek (Calhoun county), Yellowleaf Creek (Shelby County), and Waxahatchee Creek (Shelby and Chilton counties). It is currently isolated to the Cahaba River basin. (Federal Register)


There are two aquatic dependent plants that are protected by the endangered species act.

Kral’s water plaintain is a threatened species of perennial aquatic herb that grows in riverine habitat, on exposed shoals, or in sand, gravel and silt in quiet pools up to 3 feet in depth. (Corps) Its only remaining habitat is approximately 12 sites in the Little River drainage area in Georgia and Alabama stretching about 25 river miles.

Harperella is an endangered plant found in DeKalb county that may actually require intensive spring floods for its survival. (FWS)