ZEPHYR COVE -- U.S. Sen. John Ensign had a lot to say about preserving Lake Tahoe on Thursday, but refused to answer any questions from reporters about his affair with Cindy Hampton, the wife of one of his best friends.

"I have nothing left to say," the Nevada Republican said as he left a Lake Tahoe beach where he served as host of the 13th annual Tahoe Summit. He walked away from reporters as they started asking him more questions.

Ensign said he had said all he was going to say about the affair, which he talked about during a Chamber of Commerce luncheon Wednesday in Fernley.

The summit featured numerous public officials and environmentalists giving a report card on their efforts to preserve the alpine lake along the Nevada-California border.

The summits began in 1997 when President Bill Clinton announced a long-term federal, state and local effort to save the lake, whose clarity had been diminishing rapidly.

More than $1.4 billion has been spent on tree thinning, erosion control, fire prevention and other conservation efforts at the lake. Much of the money has come from sales of public land in Clark County.

At the Fernley luncheon, Ensign told The Associated Press he had done nothing "legally wrong" by his affair, in contrast to Clinton who he accused of committing perjury and lying to the American people in 1998 about his sexual relationship with a young intern.

Ensign, then a member of the House of Representatives, had called on Clinton to resign after he admitted the relationship with intern Monica Lewinsky.

But Ensign refused to resign after he announced in a June press conference in Las Vegas that he had an affair with Hampton between December 2007 and August 2008. She is the wife of Doug Hampton, who had been Ensign's administrative assistant.

The senator's comments Wednesday about the affair were the first he has made in public since his admission of the affair.

Ensign hosted the summit at the Round Hill Pines Beach & Marina, just a few feet from Lake Tahoe's eastern shore and a few miles from where he was reared and attended school. He said he has spent the last eight days vacationing at the lake.

Both U.S. Sen. Dianne Feinstein, D-Calif., and Ensign announced that they and other members of their delegations will reintroduce a bill in Congress to provide $390 million for additional preservation projects at Lake Tahoe.

Ensign said some have called the summits "publicity gimmicks," but they are an important way to focus at what still needs to be done.

He said he has noticed how the dense forest around the Nevada side of the lake has been thinned dramatically in an effort to prevent forest fires. Feinstein praised Nevada for its efforts to stop fires, adding she wishes she saw the same results in California. Unlike other officials, Feinstein blamed global warming for the degradation of Lake Tahoe.

"The real culprit in my mind is global warming," she said.

Since 1970, the water temperature of the lake has risen by about three degrees, according to scientists.

Feinstein said even more than the potential fire danger around the lake, Lake Tahoe faces a new danger from non-native Asian clams and mussels. About 3,000 of the clams now are found on each square yard of the lake near where she and Ensign spoke.

"If we don't get a stranglehold on them, then will get a stranglehold on this lake," Feinstein said.

Gov. Jim Gibbons and California officials signed an aquatic invasive species management plan to take steps to reduce the non-native species. Officials already are inspecting boats to remove mussels that attach to them.

Contact Capital Bureau Chief Ed Vogel at evogel@reviewjournal.com or 775-687-3901.