By Gary Polakovic
One day in a rooftop laboratory at San Diego State University, ecologist Stuart Hurlbert filled a series of big aquariums with various grades of salty water and tossed in barnacles, worms, microscopic animals and a passel of other Salton Sea creatures.
The Tanks simulated higher and higher salt levels at the Salton Sea. The experiment showed which animals will live and which will die.
The early results are unsettling.
Under the best conditions, salt toxicity will rip huge holes in the sea's intricate web of life in about 10 years, according to Hurlbert. Serious damage has already begun.
Tiny invertebrates, including pile worms and shrimp-like crustaceans called amphipods, mainstays at the bottom of the food chain, will perish. Populations of tilapia and croaker, scrappy little fish and dietary staples for bigger game fish and birds, will go belly up. And, in the end, a veritable air show of fish-eating birds may vanish.
The deaths of these and other species at the sea could come swiftly. The sea is already 30 percent saltier than the Pacific Ocean. Aggressive water conservation goals being considered for the Imperial Valley will steal fresh water that would enter the sea and in several years push salt to lethal levels for many species living there today, scientists say.
"We're running out of time. Even if we started a project today, we might not get the salinity back down to ocean water for 20 years from now and the longer we wait the more difficult it would be to turn it around," said Phil Gruenberg, executive director for the state Colorado River Basin Regional Water Quality Control Board.
The remarkable biological diversity evident at the Salton Sea today will gradually give way to a more rudimentary ecosystem. the environment will become so harsh only the hardiest of creatures will survive, scientists say.
When it is all gone, California will have lost a legendary fisher and much of the wildlife in the state's biggest lake. Tourism, which pumps millions of dollars into the local economy and requires a healthy sea environment for visitors, will tumble.
Toxic pollution poses a long-term risk to wildlife at the Salton Sea, but salinity is an unmistakably clear and present threat.
The sea is nature's perfect salt trap.
It has no outlet, so it can never cleanse itself of contaminants. Evaporation sucks away the water, but leaves salt behind, the same way mineral deposits accumulate in a steam iron.
"So long as the Salton Sea is configured the way it is as an evaporation pond, it is inexorably going to get saltier and saltier over time," said Henry Vaux, director of the University of California Water Resources Center at the Riverside campus.
Natural and man-made sources put approximately 5 million tons of salts and minerals into the sea each year. About 400 million tons of salts are believed dissolved in its waters.
Since the 1960s, numerous remedies have been put forward to slow the salt buildup. But they have been left to gather dust in government files.
Some of the solutions are expensive, for instance a $500 million canal to carry brackish water from the sea to the Gulf of California. Other less costly remedies, including solar salt evaporation ponds or dikes to divide the sea into high and low saline zones, have not gotten off the drawing board.
"They've all died the same death... A lack of funds," Gruenberg said.
Smothered by salinity, the sea has reached a critical turning point.
Stephen Sedam-Stone/The Press Enterprise
Neglect has squandered so many years that experts say only swift action can save the sea. It is so late in the game that some optimistic assessments concede only a fraction of the sea's recreational and wildlife values may be saved. The rest will go to ruin.
"There's no question in anybody's mind that as salinity continues to increase, there will be a gradual diminution and extinction of life in the sea," said Phil Meyer, former consultant to the Salton Sea Task Force, a coalition of 17 agencies organized by the state Resources Agency. "My own guess is that certainly we would see that in the decade.
Profound changes under way in the immense desert lake are cause for alarm.
After an 11-year stretch in which salinity in the Salton Sea fell sharply, the trend has reversed and salt is now accumulating at a record pace.
Up until seven years ago, the sea swelled as plenty of fresh water flowed in, albeit flooding marinas and farms and driving the shoreline up nearly 14 feet. The added water diluted the salt, and salinity fell by about 5 percent between 1969 and 1980.
But California's six-year drought, as well as vigorous farm water conservation practices and lawsuits to lower the lake level, has caused Salton Sea salinity to leap by 20 percent in the past 10 years. Evaporation now pulls more water from the sea than the rivers put in, reducing the amount of fresh water available for dilution.
Brine in the sea has started to kill wildlife.
Fish were the first casualties. Only a few years ago the Salton Sea was one of California's premier fisheries. Now it is collapsing.
Sport fish will perish in a decade, said Kimberly Nicol, fisheries biologist at the state Department of fish and Game's Indio office.
Salt concentrations in the Salton Sea now hover around 45,000 parts per million (ppm) -- a level the state acknowledges impairs reproduction in Salton Sea fish and some aquatic animals they consume.
Embryos from two of the dominant Salton Sea fish species -- corvina and sargo -- die before they grow into juvenile fish when water contains 45,000 ppm of salt, Nicol said.
Sargo and croaker will likely cease to reproduce when salt concentration hit 50,000 ppm expected in about seven years, according to a 1988 study for the Salton Sea Task Force. Both fish species are an important food source for countless birds and corvina.
Corvina are more salt-tolerant but no less threatened. Their numbers will plummet as smaller forage fish disappear not later than around 2008, scientists estimate.
In corvina, reproduction failure can occur at 45,000 ppm salt; young likely will not mature to adult fish at 50,000 ppm; and only a remnant of the once abundant species will remain at 55,000 ppm. The sea's salinity level reached 45,000 ppm last year, and is expected to reach the next two levels in 1999 and 2008, respectively.
Even tilapia, the most salt tolerant of the four dominant fish species at the sea, are dwindling. The risk of reproductive failure for this species is high when salt reaches about 50,000 ppm, according to the study prepared for the Salton Sea Task Force.
"There were times in 1981-1982 when the talapia were so dense in the water they'd stop the boat propeller," recalled Norm Hogg, biologist at Santa Monica College who has studied the sea's ecology since 1969. "The water literally boiled, the fish were that thick in the water. You'd have to turn the motor off and paddle out of the middle of them with your oar. It was unreal."
Long before salt kills the fish, it will spoil their food. Enough salt is already present to threaten reproduction of pile worms, amphipods and barnacles, although scientists have not quantified the loss.
As go the fish, so go many birds.
Seventy-four of the 380 species of birds at the Salton Sea rely on the fish and other organisms found in the sea, according to the U.S. Fish and Wildlife Service.
White pelicans, double-crested cormorants, herons, several species of egrets and brown pelicans, an endangered species, will be most affected. Some of those species are already in sharp decline at the Salton Sea.
Some fish-eating birds will shift and try to feed in the thousands of miles of canals and drains that lace the Coachella and Imperial valleys. However, biologist say there is not enough food in those waterways to sustain the large number of birds found at the sea. And water in some drains is significantly more polluted than the sea.
But the sea will not die. It will change. A stark, less diverse ecosystem will emerge. It will become a southern version of Mono Lake, the super-saline basin of the Eastern Sierra.
Salt-resistant desert pupfish, the only native fish in the sea, will flourish early in the next century after salt has wiped out the fish that prey on them. Though once rare, pupfish are now found in 79 percent of the agricultural drains and most of the sea's coastal pools, said Nicol, the Fish and Game department biologist.
Water boatmen, swimming bugs once held in check by fish and birds, are multiplying. Brine shrimp now locked in coastal pools will migrate to the sea where their populations should explode when salinity hits about 70,000 ppm some 35 years hence, Hurlbert said.
Eared grebes, if they survive the selenium poisoning (150,000 mysteriously died at the sea one year ago), would be one of the avian benefactors. The birds gobble up brine shrimp and water boatmen and the future Salton Sea will provided plenty of both, Hogg explained.
Migratory ducks and geese will be largely unaffected, since they mainly feed on grains and plants and use the sea for lounging. The exceptions are the thousands of diving ducks, including redheads and scarps. Deep-water pile worms they crave will be gone. Food may be present in the agricultural drains, but the birds avoid cramped canals, preferring the safety of open water bodies, Hogg said.
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