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Saving the Salton Sea

By Steve La Rue
The San Diego Union Tribune, February 8, 1999

The sun barely had pierced through the crags of the low Chocolate Mountains to the east one recent morning when four San Diego State University researchers piled into a 24-foot boat and guided it into the choppy waters of the Salton Sea.

The team headed by Stuart Hurlbert, director of SDSU's Center for Inland Waters, was not after game fish, which in the recent past have drawn more yearly visitors to this accidental ocean than had annually visited Yosemite National Park.

Plankton were the quarry. The simple plants and animals, though microscopic, will dictate much of the future for this environmentally declining inland sea about 150 miles east of downtown San Diego.

"The problems the sea has are fundamentally biological problems, and the last time any serious biological work was
done at the sea was in the 1950s," Hurlbert said.

"Now there is a tremendous impetus to go ahead with whatever engineering work is required (to save the sea), and people have discovered that they have engineering studies but nobody knows anything about the biology of the sea.

"The sun barely had pierced through the crags of the low Chocolate Mountains to the east one recent morning when four San Diego State University researchers piled into a 24-foot boat and guided it into the choppy waters of the Salton Sea.

The team headed by Stuart Hurlbert, director of SDSU's Center for Inland Waters, was not after game fish, which in the recent past have drawn more yearly visitors to this accidental ocean than had annually visited Yosemite National Park.


Gathering data: SDSU biology professor Stuart Hurlbert yanked up a Plexiglas box used to collect water at various depths. Assisting him was Mary Ann Tiffany, a research technician with the university's Center for Inland Waters.

SCOTT LINNETT / Union-Tribune


Information gathered and processed in the studies will guide decisions about what kinds of dams, dikes, canals or treatment plants could save the 380square-mile sea from what appears to be its headlong course toward environmental collapse.

The biological health of the Salton Sea is of more than distant curiosity to water officials in San Diego County, because they have contracted to buy conserved water from the Imperial Valley starting in 2003 or 2004.

Much of the farm runoff that will be conserved in order to sell water to San Diego County is relatively fresh and otherwise would flow into the Salton Sea and help dilute its rising salinity.

That makes the impact of this water-transfer contract the most formidable, and potentially most expensive, environmental stumbling block for the Salton Sea proposal.

Agricultural runoff water is much fresher than the dark, cloudy sea, but it still carries 4.5 million tons of salts into the sea each year. Because the sea has no outlet, and dissolved minerals do not evaporate, salinity has risen, reaching the level of ocean water in 1915.

Today, the Salton Sea at some points is 29 percent saltier than the ocean. If this continues, it could become a dead sea where even ocean fish and other species could not survive.

"We are looking at a range of consequences of water transfers out of the Salton Sea Basin," said Tom Kirk, executive director of the Salton Sea Authority.

"The sea has problems regardless of the water transfers, but there is no doubt that transfers make them more difficult. If you cannot solve the salinity problem, you might as well write off the sea's ecosystem."

The Salton Sea Authority is a 5-year-old partnership involving the Imperial and Coachella Valley irrigation districts and Imperial and Riverside counties.

The SDSU studies are part of a roughly 14-month, $2.2 million array of basic research that will set the stage for a second round of studies that will cost $4.5 million.

The money is coming from the authority via federal grants that reflect continuing interest in the sea among legislators, such as Rep. Duncan Hunter, R-El Cajon, and former House Speaker Newt Gingrich. The late Rep. Sonny Bono, R-Palm Springs, also was a strong supporter of the sea.

SDSU's studies of the sea's basic biology and fishery have the largest contract of the first round, for nearly $1 million.

Discoveries

The list of organisms known to live in the sea has tripled in the past few weeks because of the study, Hurlbert said.

"We are looking at everything from the fish down to tiny protozoa," he said.

Though sampling at the sea and studies of the results are incomplete, one conclusion has been reached. Among the plankton is a toxic algae called chattonella, which was identified by Mary Ann Tiffany, research technician for SDSU's Center for Inland Waters.

"It had never before been reported in the Salton Sea," she said.

"It is a type of algae that occurs in coastal marine areas in many parts of the world, and is often associated with massive fish kills -- off the coast of Australia and off the Japanese coast."

Toxic algae have been suspected as a cause for the sea's most catastrophic bird kill -- the still unexplained deaths of 150,000 eared grebes and ruddy ducks in 1992.

It was one of several ecological crises at the sea over the past decade that have mobilized scientists and legislators to come to its aid. Another was the August 1996 die-off of more than 14,000 birds, including more than 1,400 endangered brown pelicans. Bacterial infection and botulism are suspected in that incident.

There are other toxic algae in the Salton Sea, and more research is required to suggest a cause of the 1992 die-off.

Disease link?

A discovery by Deborah Dexter, an SDSU marine ecologist, may suggest how toxins from such algae can find their ways into birds' stomachs.

Dexter's sampling of bottom sediments has found that a common saltwater worm called the pile worm is abundant in various kinds of sediments across the sea's floor -- even though the sea's current salinity was thought to be fatal to the species.

"We knew that the worm was quite abundant along the shore but we had no idea how abundant it was in the middle of the lake bottom," she said.

The reddish-pink worm, about half an inch long, is a major food item for the sea's fish species -- including many of the fish that are eaten by the millions of birds that live at the sea or stop over on their migrations.

"If the dead toxic algae make their way to the bottom and the pile worm eats them and bio-accumulates their toxin, this could be one cause for the bird deaths," Dexter said.

Again, she said, more study is needed before researchers will know whether this is a mechanism that causes some bird deaths.

"This is a very exciting study," she said. "We have to know what is in there before anything can be done."

The Salton Sea, about 35 miles long and up to 15 miles wide, was created accidentally in 1905 when the Colorado River breached an agricultural irrigation diversion canal and poured into a sink in the middle of the Imperial Valley. The river had meandered into that same sink several times in the previous several thousand years, creating the prehistoric Lake Cahuilla.

The sea, which is 227 feet below sea level, is the largest inland body of water west of the Rockies. Its reputation as a major sportfishing destination in the 1970s was eroded by state warnings in the mid-1980s about eating too much of its fish. The fish were found to contain rising levels of the heavy metal selenium, which flows into the sea with irrigation runoff water.

Meanwhile, the sea remains a key stopover for millions of migrating geese, ducks and other waterfowl that ply the Pacific Flyway from summer habitats in the north to winter habitats to the south.

Other first-round contracts have been issued to the Point Reyes Bird Observatory, to study birds; the U.S. Geological Survey, to study disease organisms at the sea; and the U.S. Bureau of Reclamation, to study the sea's chemistry and physics, with help from UCSD's Scripps Institution of Oceanography.


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