San Francisco — Efforts to save Mono Lake, a unique natural wonder bequeathed by the ice age to the Sierra Nevada region of California, are receiving renewed attention because of recent developments -- some discouraging, and some positive.
The blue, saline lake, in dry hill country abutting 14,000-foot, snowclad peaks, is not nearly so well known as its resort-rimmed neighbor, Lake Tahoe. But is being cited by environmentalists as a classic example of how human society can, in a few years, dismantle nature's works of eons.
Formed some 12,000 years ago when glaciers receded, Mono Lake is salty, but not "dead" -- at least not yet. Its waters support a chain of life that begins with microscopic plants (phytoplankton) and takes wing with gulls, ducks, and other bird species.
Tourists who find their way to the lake marvel at the geological formations -- including two volcanic islands; the Mono craters, a recently formed chain of cones and lava flows; and "tufa towers" -- chalk-white, erosion-sculptured upthrusts of calcium carbonate which are in some cases delicate, in others grotesque.
What endangers Mono Lake is the thirst of Los Angeles. Since 1941, the metropolis to the south has diverted water from streams in the Mono basin to help meet its ever-growing need for water. At present, the city water and power department takes 101,000 acre-feet a year from the basin. Over the past 40 years the lake level has dropped at a rate of 1 to 2 feet a year. It was at 6, 417 feet (measured from sea level) in 1941; in June of this year it measured 6, 373 feet.
This summer it was discovered that, possibly because of increased salinity, the population of brine shrimp, a key part of the Mono Lake food chain, had dropped sharply. Researchers found that only 5 to 15 percent of shrimp eggs hatched in June.
One-fourth of the California gull population in the United States nests at Mono Lake, and the chicks are nurtured on brine shrimp. This summer, says biologist David Gaines, practically all the gull chicks have starved.If it happens again next year, he adds, that will be the end of the California gull colony at Mono Lake.
California gulls are not an endangered species; they breed at a nuber of other locations, including Utah's Great Salt Lake. But Mr. Gaines and others say that what is happening to the shrimp and gulls at the lake is dramatic evidence of how the whole system is slowly -- or perhaps not so slowly -- destroyed.
The answer, they say, is for Los Angeles to reduce the amount of water it diverts from the lake. In 1979 a state task force recommended several alternative plans for maintaining the lake level at 6,388 feet. The Mono Lake committee, of which Gaines is chairman, supports one of the plans.
But Los Angeles, which as a permanent state license to divert as much as 167, 000 acre- feet of water annually from the Mono basin, accepts none fo the alternatives.
Further, the city recently informed the US Department of the Interior that it would like to purchase 23,000 acres of federal land along the Mono Lake shore. This was in response to a letter sent out by Interior Secretary James G. Watt inviting state and local governments to apply for the right o purchase federal lands at $1.25 an acre.
Acquisition of this land would give the Los Angeles Water and Power Department control over much of Mono Lake's shoreline.
But there are countermoves afoot in California and Washington, D.C.
A bill to establish a Mono Lake state preserve was introduced this year in the Legislature. Passed 30 to 0 by the state Senate, it is expected soon to be approved by the Assembly.
Although this step would not affect the rate of water diversion by Los Angeles, Gaines says, it would at least give official status to the lake environs and help protect against vandalism, which is increasing.
US Rep. Norman D. Shumway (R) of California, whose district includes Mono County, has introduced two bills in Congress. One would grant national monument status to the immediate Mono Lake area and provide for a study of ways to reduce water diversion. The other bill would repeal the 1936 federal law under which purchase of federally owned land at $1.25 an acre is authorized.
Both bills have been sent to the House Subcommittee on Public Lands, and Gaines says hearings are expected in October.
He says the effort to preserve Mono Lake has gained support among state legislators and California congressmen. There is a good deal of support among officials of state resources agencies, he adds, but Gov. Edmund G. Brown Jr. has taken no position. The governor, who plans to run for the US Senate in 1982, is treading a fine line on water issues, always politically dangerous here.
Perhaps more than anything else, Gaines points out, the Mono Lake committee needs support in Los Angeles. The group maintains an office there and is circulating news letters and petitions. Response lately has been encouraging, the committee chairman says.