Saturday, January 06, 2007

Our "Status Of The Flame Chub In Alabama" Summary

What follows is the current "Discussion" section of my developing paper on flame chub distribution across north Alabama. I still have to flesh it out somewhat, but this is the gist of our findings on the current status of the flame chub, Hemitremia flammea, in north Alabama:

A species like the flame chub that is a “narrow endemic” by definition has a patchy distribution. This makes it more difficult to determine if such a species is in decline. The results of this survey show that the flame chub is in decline in Alabama, being found in 18 of 50 historic sites sampled. It is of course possible, maybe likely, that flame chubs were missed at one or more sites. Even if this was true for 7 sites, that would still leave flame chubs missing from a full half of the sampled historic sites.

There is a strong geographical pattern to the remaining flame chub populations in Alabama. There are two primary strongholds for the flame chub in north Alabama. The first is the central and eastern parts of the Cypress Creek system in Lauderdale County. Burcham Creek and Bruton Branch in the western part of this system seem to have lost flame chubs from human alterations of stream flow. The other flame chub stronghold is in the Flint River system in Madison County, comprising Mountain Fork of the Flint River and Acuff Spring. Flame chubs were easily seined in Mountain Fork just below a lowhead dam. Acuff Spring was the only sampled site where schools of flame chub were easily observed. But this site is under various stresses. The spring is on land that belongs to and is managed by a housing development. Recently the management has treated the spring run with herbicide to kill “unsightly” native aquatic vegetation, and a friend of the developer has repeatedly released koi into the spring run to “improve” it (Casper Cox, personal communication).

Other sites yielding flame chubs were erratically scattered with no easily discernible pattern. The only historic site in Marshall County, Eudy Cave, seems to have a healthy flame chub population and is relatively pristine in spite of being in the middle of a cattle farm. The one site of three visited in Morgan County that yielded a single flame chub, Dutton Creek, is also surrounded by cattle pasture with cows having access to the creek both above and below our sampling access.

Surprisingly, flame chubs were found in only one of five historic sites visited in the upper Paint Rock River system of Jackson County. Streams in this area show few obvious signs of any abuse, and support populations of other vulnerable fishes such as the blotchside logperch, Percina burtoni and palezone shiner, Notropis albizonatus. Two historic sites were sampled without success on Larkin Fork in June 2005. One of these sites produced a single flame chub as recently as 2001, and at the other nearby historic site downstream 8 flame chubs were collected in 1980. This population may have been in decline to the point where it’s now difficult to find any flame chubs.

Based on the dramatic reduction of historic sites in Alabama yielding even a single flame chub in this survey, it seems to be time to adjust the NatureServe conservation status of the flame chub in Alabama from a rank of S3, Vulnerable, to S2, Imperiled. The S2 rank would reflect an observed steep decline in populations across Alabama over the last 40 years. The global rank of the flame chub is currently G3, Vulnerable. Because Alabama is currently about half of the range of the flame chub, this ranking may be too optimistic and G2, Imperiled, may be more accurate. A similar survey needs to be done in Tennessee, the other half of the current range of the flame chub. For the same reasons, an argument can be made to change the IUCN category for the flame chub back to Rare from Data Deficient.

1 Comments:

At 4:22 PM, Blogger Andrew Adrian said...

Very nice and convincing article.

The part about Koi being introduced was rather disgusting.

 

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