Today, the current kicks up sediment, clouding the water at depths not greater than two feet. If, however, a developing water quality improvement plan proves successful, that could be reversed.
As part of preliminary stages of that plan, biologists with a new unit of the Alabama Wildlife and Freshwater Fisheries Division placed 1,600 mollusks, one by one, onto the creek bed Thursday. The division is a part of the Alabama Department of Conservation and Natural Resources.
The plan is part of a larger effort by the new unit, called the Alabama Aquatic Biodiversity Center. Its director, Paul Johnson, has already released the tiny animals into the tributaries of the Mobile River basin, which the project aims to improve.
Mollusks, which include snails and mussels, are natural water filters and in some instances can filter several gallons of water per day. If the project is successful, the animals could restore the creek’s water quality — but first the scientists have to ensure that the species being asked to do the work, the Alabama rainbow mussel, can survive the environment.
If it does, more mollusk species might be released later, making it more likely that the water quality would improve.
“If these releases are successful, there are at least 20 species, if not more, that could go back here,” Johnson said. “The river bottoms used to be paved with these animals.”
As journalists and a couple of volunteers placed the rainbow mussels onto the creek’s floor Thursday, biologist Todd Fobian, in a wet suit and snorkel mask, swam in the chilly current between moss-covered rocks to examine the mussels’ habitat up close.
Fobian said the animals not only purify water and enhance biodiversity, but also serve as an indicator of the water’s quality. The more mollusks that can survive there, the better the water. Fobian has been working with Johnson to prepare for the release since last spring.
Back before strong chemical pollutants could be found in Choccolocco Creek, the water offered a clear view of the mussels and snails that covered its bed, but when the scientists checked earlier this year, few could be found.
Prior to Alabama Power’s damming of the Coosa River Basin, there were 40 species of mussels and 30 species of snails in the Choccolocco Creek Basin. They were all but wiped out in the decades that followed as the water flow was disrupted and chemical pollutants began to affect the creek.
Today, only about a dozen mussel species remain in the creek and about 15 species of snails cling to the rocks that line the creek’s bed. It’s not known how many could be reintroduced to the creek, but Johnson said it is unlikely it will be restored to its pre-development conditions. Organizers of the species introduction have been pleased to see that a test sample of Alabama rainbow mussels, placed in the creek in small cages, has survived.
The latest release has new challenges for the animals, however. They will have to survive in the polluted creek bed, which the test samples were protected from.
However, a simple examination of the underside of a wet rock pulled from the creek bed indicates that the animal’s chances are good. Johnson pointed to a number of more sensitive snail species that were thriving in the creek, and said if they could survive the new mussels would have a fair chance of doing likewise.
Calhoun County Commissioner Robert Downing, who dressed in waders and helped with the project Thursday, said it’s the first part of a process he hopes improves both biodiversity and water quality at the creek.
“This is the first effort to turn back the clock so to start to restore the natural quality of the water that we’ve historically enjoyed,” Downing said. “It’s great that what we’re doing now in our back yard is going to benefit all the back yards downstream.”
Contact staff writer Laura Johnson at 256-235-3544.