Tulotoma, hornsnail nurtured back from dangerous plight
In knee-high waders, Cole Hetherington turns over rocks along the waterline of the Coosa River — occasionally stuffing what looks like small dark rocks in a bag attached to his belt. Turn, stuff, repeat — until he has turned over every rock between him and a wooden yardstick laying a foot up the bank. He then picks up the stick and moves it one length down the bank — starting again.
A couple of miles downstream, Angie Anderegg carefully scans a muddy bank as her yellow kayak slowly coasts in the current. Every now and again she reaches out with a small net attached to a 3-foot stick and gathers a small object barely discernable from the dark mud strewn with the tracks of clam-sized mussels following the dropping waterline. She, too, has a bag on her side where she places her finds.
With different tactics and tools, the two members of Alabama Power’s Environmental Affairs team are working toward the same goal — gathering threatened and endangered snails.
Partnering with the Alabama Department of Conservation and Natural Resources (ADCNR) and the U.S. Fish and Wildlife Service (USFWS), the Environmental Affairs team conducted studies observing the response of two federally listed snail species during drops in habitat water levels.
The four-day effort — manned largely by Alabama Power Environmental Affairs employees under the guidance of ADCNR and USFWS — surveyed populations of the tulotoma snail (Tulotoma magnifica) and rough hornsnail (Pleurocera foremani) along the waterline as water levels dropped a foot a day on Lay Lake. Using the final day as a control, biologists with the three groups hope to determine the two species’ ability to respond to water level fluctuations.
“Alabama Power is bringing the reservoir down — instead of three feet and holding it to do all the (shoreline) maintenance activities — they are bringing it down slowly to enable the snails to follow the waterline down,” said Jeff Powell, a USFWS aquatic species recovery biologist who is helping with the effort.
Working to create conditions to help snails thrive, the three organizations have previously conducted population surveys for the two species. In 2012, Alabama Power, USFWS and ADCNR surveyed rough hornsnail populations along the Yellowleaf Creek tributary of Lay Lake.
“The key take-home this week is the relationships we have with our regulatory agencies and all the folks within Alabama Power,” said Jason Carlee, APC Environmental Affairs supervisor. “It is certainly a group effort and would not have taken place without the support received from all these groups.”
In 2009, the three groups, along with Auburn University researchers, conducted similar surveys on clusters of the then-endangered tulotoma snail on Lay Lake and below Jordan Dam near Wetumpka. Those surveys helped lead to the first down-listing in 2011 of an endangered mollusk in North America, when the snail was reclassified as threatened at the request of ADCNR.
“Between the new discoveries in the Coosa tributaries, the new Alabama River populations and the improving populations in the Coosa River, the Fish and Wildlife Service actually down-listed the animal (tulotoma) from endangered to threatened in 2011,” said Paul Johnson, Alabama Aquatic Biodiversity Center supervisor with the ADCNR.
As part of relicensing its dams on the Coosa River with the Federal Energy Regulatory Commission (FERC), Alabama Power has worked with ADNCR and USFWS during the past decade to find ways to protect and improve habitat conditions for these and other aquatic species — providing best-management practices for shoreline development and management and installing equipment at the dams it operates to increase the oxygen levels downstream.
Because of its FERC-licensed operations, Lay Lake rarely sees water fluctuations like those during a planned drawdown — which gives residents of the lake the rare opportunity to repair or construct permitted projects below the normal waterline. The last scheduled drawdown on Lay Lake occurred in 2005.
Results from this survey will allow regulators to determine the impact of drawdowns on these species and help provide guidance for future water level drawdowns.