a alabama bass

Alabama Bass

Alabama Bass Micropterus henshalli is an invasive fish species and an imminent threat to native black bass fisheries throughout the southeasten United States.

Alabama Bass are referred to by most anglers as Spotted Bass. They are very similar in appearance to Spotted Bass and were originally considered to be a subspecies of Spotted Bass. But after more detailed analysis of their morphometry and genetics, they are now recognized as a completely separate species. 

True Spotted Bass are native to the mountain drainages of southwestern North Carolina and have been introduced into the Cape Fear River basin, W. Kerr Scott Reservoir, and the Yadkin River above High Rock Lake. Everyplace else in the state, any fish anglers have been catching that looks like a Spotted Bass is actually an Alabama Bass. 

Distribution of Alabama Bass in North Carolina

Black Bass Identification

Below is a comparison of the Alabama Bass, Bartram's Bass, Largemouth Bass, Smallmouth Bass, and Spotted Bass. Images courtesy of Black Bass iNaturalist.

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description of Alabama bass olive green top lighter on sides scales rougher than largemouth bass horizontal band blotches on tail jaw does not extend beyond back of eye rows of spots on sides

description of Bartrams bass olive bronze on top with vertical bars splotches on side second dorsal, caudal and anal fins are green to yellow with pale margins; may have tooth patch jaw does not extend beyond eye when mouth closed

description of largemouth bass darker green on top, lighter on sides; jaw extends beyond back of eye with mouth closed, no tooth patch on tongue. notch between dorsal fin deeper than most other bass species

description of smallmouth bass bronze to brownish green often with vertical bars, usually no tongue patch,jaw does not extend beyond back of eye with jaw fully closed

description of spotted bass olive green on top lighter on sides tooth patch on tongue jaw does not extend beyond back of eye rows of spots on sides scales rougher than largemouth bass horizontal band on tail

 

Alabama Bass History

How Did Alabama Bass Get Here?

Alabama Bass are not native to any part of North Carolina and were originally found in the Mobile River drainage, which is located primarily in Alabama but also extends into Georgia, Mississippi, and Tennessee. They were illegally introduced into North Carolina by anglers and were not stocked by the NCWRC.

The earliest known observations of Alabama Bass in North Carolina occurred in Lake Chatuge along the North Carolina-Georgia border in the early 1980s. After becoming established in Lake Chatuge, no additional Alabama Bass introductions were documented until they were found in Lake Norman in 2001. Lake Chatuge and Lake Norman likely are sources for the continued spread of Alabama Bass across North Carolina. 

How Can Alabama Bass Affect Existing Bass Fisheries?

The ultimate result of Alabama Bass introductions is that the original bass species present are replaced to varying extents with smaller, less desirable Alabama Bass through a combination of direct competition and interbreeding.

Lakes

When introduced into Largemouth Bass fisheries, Alabama Bass affect Largemouth Bass primarily through direct competition and displacement, with the competitive advantage of Alabama Bass being greatest in less productive lakes with higher water clarities. Where Alabama Bass coexist with Largemouth Bass in lakes within their native range, Alabama Bass dominate bass populations in less fertile lakes with clear water, while Largemouth Bass dominate in more productive lakes with murkier water. So far, the same pattern seems to be occurring in North Carolina, with Alabama Bass taking over rapidly in less fertile lakes and spreading more slowly in more productive lakes. As Alabama Bass become established in new lakes across the state, biologists will monitor bass populations to determine if the same relationship between productivity and the extent to which Alabama Bass impact Largemouth Bass populations continues.

While Alabama Bass primarily harm Largemouth Bass populations through direct competition, they also interbreed at low levels with Largemouth Bass. Hybridization with Largemouth Bass occurs most often during the early stages of an Alabama Bass invasion when Alabama Bass numbers are still low and it is difficult for Alabama Bass to find other Alabama Bass to spawn with. These Alabama Bass x Largemouth Bass hybrids resemble pure Alabama Bass and often grow much larger than pure Alabama Bass due to their hybrid vigor. As the Alabama Bass population expands, hybridization with Largemouth Bass occurs less frequently and does not impact the overall genetic composition of the Largemouth Bass population.

In lakes with Smallmouth Bass or Spotted Bass populations, Alabama Bass primarily harm the original bass populations through interbreeding. While Alabama Bass do not interbreed extensively with Largemouth Bass, they aggressively hybridize with both Smallmouth Bass and Spotted Bass. Alabama Bass genes begin appearing in populations of Smallmouth Bass and Spotted Bass shortly after Alabama Bass are introduced. Over time, the proportion of Alabama Bass genes continues to increase, until so few Smallmouth Bass and Spotted Bass genes remain that the fish essentially become pure Alabama Bass.

The “Alabama Bass Impacts in North Carolina Reservoirs” document contains specific examples of how Alabama Bass are impacting bass fisheries across North Carolina.

Progression of Changes to Bass Populations in Lakes

Lakes may experience a brief boom period shortly after colonization by Alabama Bass that gives anglers the impression that Alabama Bass will improve the fishery. The first generations of Alabama Bass that colonize a lake grow rapidly and the average-sized Alabama Bass caught by anglers is initially satisfactory. To complement the satisfactory size of the average Alabama Bass, a wave of trophy-sized hybrid bass is also frequently produced during the initial rounds of interbreeding between Alabama Bass and the original bass species in the lake. Additionally, angler catches of the original bass species present are largely unaffected during the first few years following Alabama Bass colonization because the impacts Alabama Bass ultimately have on other bass populations have not yet progressed to the point that they are noticed by anglers.

Over time, as Alabama Bass numbers increase, their growth rates decline and their average size decreases. While larger specimens will still be present, their populations become dominated by smaller fish averaging under one pound. The number of trophy-sized hybrid bass being caught by anglers in the early years after Alabama Bass colonization began also declines as the initial waves of hybridization between Alabama Bass and the existing bass populations subside. And as the impacts of the competition and hybridization between Alabama Bass and the original bass populations have more time to develop, abundance of Largemouth Bass declines while Smallmouth Bass and Spotted Bass are ultimately eliminated from the fishery.

Rivers

While all known introductions of Alabama Bass by anglers in North Carolina have seemingly occurred in lakes, Alabama Bass are now starting to migrate from their original stocking locations into adjacent river systems where they threaten riverine fisheries for Smallmouth Bass in the mountains and foothills and Largemouth Bass in the Piedmont and coastal plain. Although Alabama Bass have not been present in North Carolina rivers long enough to determine how extensively they might impact existing bass populations, Alabama Bass thrive in riverine environments within their native range and there is concern that they will adapt and thrive in North Carolina rivers as well.

What Should Anglers Do?

It is illegal to stock any species of fish into public waters without a permit from the Wildlife Resources Commission. DO NOT MOVE ALABAMA BASS OR ANY OTHER SPECIES OF FISH INTO NEW WATERBODIES! If you observe or have knowledge of Alabama Bass stockings, report it by calling 1-800-662-7137.

Harvest all Alabama Bass they catch. It is not possible to eradicate Alabama Bass where they have become established, but reducing their numbers as much as possible will minimize the impacts they have on other bass species. While catch & release for other bass species has been instrumental in maintaining the quality of our fisheries given how much fishing pressure they receive, releasing Alabama Bass will only make our bass fisheries worse.

If you catch an Alabama Bass in a waterbody where they have not been previously documented, report it at PublicInquiry-FishWildlife@ncwildlife.org.

What is the NCWRC Doing?

The size and creel limits for Alabama Bass have been removed as of August 1, 2020, and anglers may harvest unlimited numbers of Alabama Bass of any size. This summer, NCWRC will be posting signs at boating and fishing access areas across the state to remind anglers to harvest any Alabama Bass they catch.

Although it is not feasible to stock bass in every lake impacted by Alabama Bass, experimental stockings are being investigated to help maintain the Smallmouth Bass populations in Lake James and Lake Fontana and the Largemouth Bass populations in Lake Norman, Lake Gaston and Jordan Lake. 

Learn more about these experimental stockings on Lake Norman.

Reports, Summaries & Publications

Reports, Summaries & Publications

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Management Reports


2023 - Effects of Introduced Alabama Bass on an Existing Largemouth Bass Fishery in Moss Lake, North Carolina (2008-2021)

2022 - Lake Hickory Black Bass Surveys (2008–2018)

2016 - Changes in Black Bass Population Characteristics After the Introduction of Alabama Bass in Lake Norman (1993-2013)

2011- Moss Lake Black Bass Survey (2008-2010)

 

Summaries


2022 – Lake Gaston Black Bass Survey (2022)

2022 – Mountain Island Lake Black Bass Survey (2022)

2021 - Alabama Bass Impacts in North Carolina Reservoirs 

 

Publications


The Changing Landscape of Black Bass Fisheries in NC (video)


2023 - Unwelcome Visitors (Wildlife in North Carolina - May/June)

2023 - Alabama Bass Alter Reservoir Black Bass Species Assemblages When Introduced Outside Their Native Range (external website)

2021- Failure of Phenotypic Markers to Accurately Identify Black Bass Species and their Hybrids in the Mobile River Basin (external website)

2021 - Factors Relating to Hybridization Between Bartram's Bass and Invasive Alabama Bass (external website)

2019 - Conservation of Black Bass Diversity - An Emerging Management Paradigm (external website)

2018 - Genetic Impacts to Bartram's Bass in Savannah River Reservoirs Following Alabama Bass Introduction (external website)

2017 - Fact Sheet: Black Bass Population Changes in Lake Norman After the Introduction of Alabama Bass

2015 - Alabama Bass Life History (external website)

2014 - Genetic Confirmation and Assessment of an Unauthorized Fish Introduction into Parksville Reservoir (external website)

2011 - Hybridization Between Smallmouth Bass and Introduced Alabama Bass in Reservoirs (external website)

2008 -  Alabama Bass Species Description (external website)

2006 - Genetic Impacts to Lake Keowee Redeye Bass following Alabama Bass Introduction (external website)

1997 - Genetic Impacts to Lake Chatuge Smallmouth Bass Following Alabama Bass Introduction (external website)

1995 - Factors Related to Growth and Condition of Alabama Bass in Reservoirs (external website)

Related Links

Aquatic Nuisance Species - Learn more about aquatic nuisance species in North Carolina, how they got here, and what the NCWRC is doing to protect your waters. 

N.C. Stream Conditions - a list of websites that provide information on current stream flow conditions and projected release schedules from hydro power stations.

North Carolina Fishing Records and Angler Recognition Program - North Carolina has four programs that officially recognize anglers who have caught large fish. 

Where to Fish - Interactive map of publicly accessible fishing opportunities in western North Carolina streams, rivers, and reservoirs.

NC Fishes - more information and photos of fishes in North Carolina. (External website)

Protect Your Waters From Aquatic Hitchhikers - Learn how to prevent the spread of aquatic nuisance species through basic gear care procedures.  (External website)

Lake Levels and Flow Releases Management Authorities - links to various agencies, managed lakes, and lake level information sites.  (External website)

Bass Anglers Sportsman Society Conservation News – links to Keeping Bass Alive Guides, Bassmaster Conservation Directors, and aquatic conservation news (External website)

Major League Fishing Fish Management Division – links to the Fish Management Division of the Major League Fishing tournament circuit and more (External website)

Photos

alabama bass lying on a measuring tape above a largemouth bass

One-year-old Alabama Bass (top) and Largemouth Bass (bottom). Alabama Bass often grow faster than Largemouth Bass during early life stages, which helps them outcompete and displace Largemouth Bass. (Photo: NCWRC)  Enlarge image

 

alabama bass tooth patch

Tooth patch on the tongue of an Alabama Bass. Tooth patches on Alabama Bass are often smaller and fainter than those on Spotted Bass. (Photo: NCWRC) Enlarge image

 

jaw close up of Alabama bass

Jaw of Alabama Bass, which does not extend well past the back of the eye as it does on Largemouth Bass. (Photo: NCWRC) Enlarge image

 

red arrow pointing at alabama bass white text box that reads average number of scales along lateral line equals 75 with a range of 68-84

Lateral line scale counts on Alabama Bass, which are higher than those on Spotted Bass (average = 65, range = 60–71). (Photo: NCWRC) Enlarge image

 

hand holding an alabama bass

Alabama Bass readily interbreed with Smallmouth Bass, as demonstrated by this Alabama Bass x Smallmouth Bass hybrid caught in W. Kerr Scott Reservoir. (Photo: NCWRC) Enlarge image