University of Florida researchers say a tiny native snail may make a big difference in Florida's fresh water spring cleanup.
North Florida has the world’s highest concentration of large freshwater springs. For decades, crystal-clear water bubbling from the ground has driven tourism in the form of scuba divers, canoeists, boaters and swimmers, but today, many of those springs don’t bubble like they used to; green scum often obliterates the view.
Although the blame for algae-choked springs is often pinned on excess nitrate, the scientists say the absence of algae-eating native freshwater snails known as Elimia -- which UF researcher Dina Liebowitz calls the “little janitor of the springs” -- may be a key factor.
Nitrate, which has gotten the lion’s share of attention in springs-health discussions, enters the aquifer and emerges at the springs from municipal sewage treatment and disposal, agricultural and residential fertilizer use, livestock farms and residential septic systems.
Matthew Cohen, a UF associate professor and Institute of Food and Agricultural Sciences faculty member who specializes in ecohydrology, says while controlling nitrate is a worthy goal, doing that alone “will not be enough to restore springs ecology.”
Cohen’s former doctoral student, Liebowitz, spent nearly six years studying the springs. Among her findings: Where they found more snails, in general, there was less algae.
And later experiments found that the snails could keep algae from accumulating in the springs.
Liebowitz found that snail populations are down compared with previous years. Studies suggest pesticides, herbicides and pumping water out of the springs may all be to partly to blame.
That doesn’t mean that other factors aren’t part of the equation, she said, “but it suggests pretty strongly that snails are an important factor in keeping algae levels down.”