Tuesday, July 15, 2008

Scouring Cleburne County, Alabama, For Fundulus bifax

Last Friday four of us spent the day driving around the southern tier of Cleburne County, Alabama, SE of Anniston, AL. The Tallapoosa River enters the state from Georgia here, flowing south into Randolph County and other counties where we've already found bifax. To my knowledge no one has ever collected the species in Cleburne County, which represents a gap between the known populations to the south and populations that used to exist upstream in Georgia. So I thought it was worth trying to connect these two areas by somewhat randomly visiting sites that looked good on the map and see what we found. In short, we found no bifax, but I also now realize that we found no good habitat; in our experience the species is found in clean, clear water running over algae-free sand and we didn't find any such sites in Cleburne County.

Our first stop was the Tallapoosa River itself, where Highway 46 crosses it. GoogleEarth images looked good, showing a boat ramp leading into the river and sandy/gravelly habitat upstream. And the river did look good at first, as shown in the first photo. But, the substrate had lots of hair-like green algae, and other macroalgaes growing off of rocks. We found lots of fish, but too many centrarchids like redbreast sunfish and Coosa bass. The Tallapoosa is reported to be eutrophic coming out of nearby Georgia, and that's what we found. And that's not good for bifax.


Our next site was Dynne Creek, a branching stream coming off of Turkey Heaven Mountain (no, really!). The county road was unpaved leading up to it, which is usually a good sign since it implies little traffic. Below is a picture of Charlie peering into the creek before we sampled.


It was a good-looking creek, with rock cobble, some gravel, and some puffy sediments for substrate (see photo below). We caught lots of Tallapoosa shiners here, including beautiful breeding males. We also caught a single streamline chub, a rare species in Alabama, which I didn't ID until I had it back in the lab. And, we found a subadult bluehead chub, a species I usually don't encounter. But, once again, we found no bifax. My impression is that the species was never in this creek, since again it was a wrong microenvironment rather than significantly polluted or altered (although we encountered a cattle excluding fence across the creek as we worked upstream).


And the last creek we sampled that day was Lockhelooge Creek, in some ways similar to Dynne Creek, but with more exposed bedrock forming a series of descending pools, runs and small falls with little sand. It was a striking creek, and the picture below doesn't really do it justice. The interesting species we found here was the bandfin shiner, Luxilus zonistius. They look a lot like their relative the striped shiner at first, but with a golden brown body color and more color in their dorsal fin (hence the name). The bandfins were apparently the most common shiner in this creek, along with a few pretty and Tallapoosa shiners. But, no bifax were caught or seen, and like Dynne Creek I don't think the species was ever here; it's the wrong microhabitat with almost no sand, much less exposed sand bars alongside slow moving pools.

Several other creeks we visited near Highway 431, the main road leading to Anniston, were badly degraded by typical stupid land uses; one entire creek branch was gone, with the water impounded for a pond next to a church and the streambed now a covered drainage culvert. We stopped at one creek that looked OK at first until we noticed several big fat carp swimming through the channel under the bridge, and the heavily drifted-in garbage along the banks. A guy driving by stopped and engaged us in an incoherent chat about fishing for carp, I'm still not clear if he liked it or thought the carp were too tough to eat or something. More than anything else he probably wondered who the hell we were, four guys staring intently into a dirty creek from a bridge with no guard rails.
So Cleburne County is apparently a big gap in the historic distribution of bifax, and the species may not have been present in the smaller creeks in the area (or at least is long gone from the damaged creeks). Maybe the Tallapoosa was historically a connector between various scattered tributary creeks, and maybe parts of the river were suitable breeding habitat for bifax. The Tallapoosa site we saw was definitely not a good breeding site, with all of the heavy algae growth that would smother any eggs deposited in sand as bifax do when breeding. So with the species apparently extirpated in Georgia, and not present just downstream in Cleburne County, the six creek populations we've identified might be the only remaining populations now separated by alterations in the Tallapoosa. It's a stark thought, but the evidence supports it at the moment.



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