SOUTH LAKE TAHOE, Calif. — Clams beware — the scientists are out to get you; consider the Fourth of July your judgment day.

This summer Tahoe scientists will continue to eradicate portions of the Asian clam population in Lake Tahoe by putting rubber tarps over areas of their nesting grounds. As proven by tests last summer, the tarps suffocate the clams and can kill off small populations. After the Fourth of July, scientists will test the method on larger areas — two half-acre plots near Lakeside Marina and Marla Bay.

“We don't have a day nailed down yet; we need to make sure we are operating in a manner that works for the water purveyors,” said Ted Thayer, Tahoe Regional Planning Agency Aquatic Invasive Species Program manager.

The thumbnail-size clams were discovered in small groups in 2002. Since then, they have grown in population and cover many areas along Tahoe's southeast shore.

A bloom of algae in Marla Bay in 2008 was linked to clam excretions. The clams could also alter water chemistry and increase the level of calcium in Tahoe, making it easier for invasive quagga or zebra mussels to grow in the lake, scientists said.

Last summer scientists put six 10 by 10 foot sheets of rubber on Asian clam population in the same area near Marla Bay and right outside Lakeside Marina. For the next two months they tracked how many clams died.

After 28 days at peak summer temperatures, 100 percent of the clams were dead. Warmer temperatures increase the clams' need for oxygen and therefore kill them faster, said Marion Wittmann, a UC-Davis scientist.

This year's project will cost $412,000, funded by Southern Nevada Public Land Management Act through the U.S. Fish and Wildlife Service and funds from the Nevada Division of State Lands.