Anything but a Snail's Pace
South Carolina works hard to lure visitors to the state's many attractions. Tourism helps drive our economy, and friendly guests are always welcomed to enjoy our scenic mountain vistas, warm beaches and picturesque lakes. Despite all of that, one visitor has most certainly overstayed its welcome and attracted the attention of Clemson biologists. Its name is Bellamya japonica.
B. japonica, commonly referred to as the Japanese mystery snail, is exactly that: a mystery. There is plenty of research available about this organism's taxonomy and genetics, but there is a surprising lack of information detailing the snail's ecology. Beyond that, nobody has explored the potential risks B. japonica poses to industry and human health. These dangers range from economic damage incurred when the snails clog industrial heat exchangers to the potential spread of parasites capable of infecting humans.
This void of knowledge is slowly being filled by the research and experiments of Clemson students led by Dr. John Hains, an associate professor of biological sciences. Since the snails were discovered in Lake Hartwell in 2006, Hains's classes have been learning as much as possible about them. Hains's teams have made headway so far, investigating the behavior, habitat preferences, fecundity and dispersal of the snails.
B. japonica is native to Asia and Japan and thrives in a wide variety of environments. The exact reason behind their sudden presence in the Savannah River Basin remains unclear, but there is strong evidence that the snails were originally brought to America as part of the Asian food market or for use in home aquariums.
One of the main problems facing Hains and his Creative Inquiry team involves the fecundity of the snails. Fecundity simply refers to the capacity and rate of reproduction attributed to the organisms. "One of the papers we read said that a single female could start an entire population," said Mark Chestnut, a senior biological sciences major working on the team. According to Chestnut and others in the class, there can be anywhere from 20 to 150 offspring in a single female at any time.
Because the fecundity of B. japonica is still relatively unknown, it is hard to estimate how many snails are currently present in Lake Hartwell. Additionally, these snails possess a particular aptitude for camouflaging themselves on top of mud and sediment, burrowing under the lake floor or hiding under rocks. Add rising lake water levels to the equation and Hains says it is all but impossible to determine an exact figure for the population of these snails.
"Checking once a week, they would have twenty babies sometimes," said Colleen Milsted, another senior member of the team. Tests from the team will eventually determine fecundity as well as any effects of seasonality or correlation to other factors such as water temperature.
The reproductive potential of B. japonica presents three serious issues for lake-goers and other South Carolina residents. First, the sudden proliferation of these snails introduces the threat of displacement for other species. Secondly, snails may get sucked into underwater intakes, which causes clogging and may result in the costly shut down of whole systems until they can be cleaned out. Perhaps most importantly, these snails have the potential to act as alternate hosts for parasites capable of infecting humans. So far, there is no evidence of such parasites and no indication that any of the snails have been infected. If that were to happen, Lake Hartwell would be ripe with hosts for these parasites to inhabit, making the potential for human infections much higher. Hains and his team are working diligently to find ways to manage these issues.
Hains's current team includes Hristos Stamatopolous, Amy Justice, Joey Farmer, Joe Catoe and Mark Chestnut. Past members include Colleen Milsted, Gregory Ricalde, Evan Meadows and Chaney Hiers. These students enjoy their research because it provides them an opportunity to contribute to the knowledge base of an area that is uncharted.
After more conclusive results are obtained, the team hopes others will apply their new discoveries as well. There are currently no similar previous studies of this new invasive species, which means that every discovery made by the team related to B. japonica is new.
This project provides fantastic experiences for all students who participate. Joe Catoe, a senior natural resource management major studying woodland environments is particularly invested. "I want to apply what I learn here to more terrestrial species. I know it will help me out a lot in my future career," says Catoe.