Lake Tahoe, Stateline, NV — Divers are mobilizing at the mouth of Emerald Bay to start removing 5 acres of rubber mats that were laid on the lake bottom two years ago for a pilot project to control Asian clam populations in the area.

Divers are anticipated to be working in the water through November, so boaters are asked to exercise caution when entering and exiting Emerald Bay and obey a no-wake zone that extends 600 feet from shore at Lake Tahoe.

Divers will remove the thin rubber mats that were laid down, each measuring 10-feet-wide by 100-feet-long and weighing 300 pounds, and then sample the Emerald Bay site to evaluate the project’s effectiveness at killing Asian clams, a non-native and invasive species in Lake Tahoe.

The mats were used to smother and kill the Asian clam infestation by starving it of oxygen. Early sampling has indicated at least a 90 percent mortality rate among the Asian clams in the treated area.

The Emerald Bay Asian Clam Control Project started with two main goals: To evaluate the effectiveness of the mats as a way to control Asian clam populations on a large scale at Lake Tahoe and to manage an infestation at an iconic and heavily-visited recreation site. It represents the largest Asian clam control project ever done at Lake Tahoe and is one of the first Asian clam control projects on the West Coast.

“Emerald Bay is an iconic place in Lake Tahoe and when we found this satellite patch of Asian clams we thought implementing a control project there was our best opportunity to protect the bay from a variety of environmental impacts that can arise from Asian clam infestations,” said Dan Shaw, an environmental scientist with the California Department of Parks and Recreation, Sierra District.

Asian clams can stimulate algae growth with the higher nutrient levels created around their clam beds. They displace a variety of native species, and increase the potential for other invasive species such as quagga mussels to establish in Lake Tahoe by increasing calcium concentrations in the water. Dead clam shells washing ashore can negatively impact recreational experiences.

Funding for the Emerald Bay Asian Clam Control Project was provided by the Lahontan Regional Water Quality Control Board, as well as through the Southern Nevada Public Land Management Act, California Department of Parks and Recreation, and Tahoe Fund.

The collaborative project was spearheaded by the Lake Tahoe Aquatic Invasive Species Program, a group of 40 public and private partners that are working to keep new invasive species out of Lake Tahoe with mandatory watercraft inspections and control populations of invasive species that are already in Tahoe.

The Lahontan Regional Water Quality Control Board, U.S. Fish and Wildlife Service, California Department of State Parks and Recreation, and Tahoe Regional Planning Agency led the effort to control Asian clams in Emerald Bay. The U.S. Forest Service Pacific Southwest Research Station is funding ongoing research on the invasive clam infestation to monitor the effectiveness of this control effort. Other project partners include the Tahoe Resource Conservation District, California State Lands Commission, Nevada Division of State Lands, and researchers from the University of Nevada, Reno, and University of California, Davis Tahoe Environmental Research Center.

The Lake Tahoe Aquatic Invasive Species and Watercraft Inspection Programs are implemented by 40 public and private partner organizations including federal, state and local jurisdictions, research partners, public utility districts, and private marinas. The Tahoe Regional Planning Agency and the Tahoe Resource Conservation District lead the inspection program through the collaborative framework of the Lake Tahoe Aquatic Invasive Species Coordinating Committee chaired by TRPA and the U.S. Fish and Wildlife Service. The Committee provides the leadership, direction, and resources to fulfill this program’s mission of prevention, detection and control of aquatic invasive species in the Lake Tahoe Region.

The Tahoe Regional Planning Agency leads the cooperative effort to preserve, restore, and enhance the unique natural and human environment of the Lake Tahoe Region, while improving local communities, and people’s interactions with our irreplaceable environment. For additional information, call Tom Lotshaw, Public Information Officer, at 775-589-5278.