LAKE TAHOE — Lake Tahoe scientists are pioneering new techniques to control the population growth of non-native freshwater mollusks.

Ted Thayer, manager for the Tahoe Regional Planning Agency Aquatic Invasive Species program, collaborated with local scientists including Marion Wittman, scientist at the Tahoe Environmental Research Center, to use bottom barriers to control the population growth of Asian clams, an invasive species that continues to spread in the near-shore zones throughout Lake Tahoe.

Bottom barriers are 100-foot by 10-foot long pond liners, 45 mil thick that suffocate any organisms underneath by significantly reducing the amount of dissolved oxygen.

“While the program does not accomplish eradication, it is a method of population reduction that can be used in specific near-shore areas to control population growth,” Wittman said.

Curtailing Asian clam populations is important for Lake Tahoe's clarity because algal blooms crop up near areas dense with clams, Wittman said.

“If you reduce the population of the clams, you reduce the associated algal blooms,” Wittman said.

Up to now, scientists have installed 100-square-inch barriers, but aim to experiment with larger scale barriers. This summer, Wittman and Thayer will oversee the installation of two half-acre barriers, one near Marla Bay and the other near Lakeside Marina.

Wittman stressed the program is still in the experimental phase and data needs to be collected and analyzed before widespread implementation can begin.