Sea Sick: Saving The Salton Sea
[Second of two parts]
By Steve LaRue
The San Diego Union Tribune, July 1, 1998
SALTON SEA -- For now, its waters still bubble with life: Fish species such as corvina and tilapia thrive, forming the basis for a profitable sports fishery and attracting hundreds of thousands of migratory waterfowl and shore birds and their admiring eco-tourists.
But can the Salton Sea last? Already, parts of the root beer-colored lake appear dead, scenes of massive fish and bird die-offs. And some biologists fear that in as little as two decades the state's largest inland body of water could become little more than a poisoned pool occupied by brine shrimp, salt-loving worms and a handful of waterfowl species able to feed upon them.
Over the next 18 months, the fate of the sea, located in the Imperial Valley 120 miles east of San Diego, could be decided. More than $10 millio in federal and state funds will be spent to study environmental factor ranging from toxic chemicals in sediments to breeding areas of wading water birds.
The goal: to learn how the ecology of this 35-mile-long, 15-mile-wide inland ocean works, why it now appears to be failing and what can be done to reverse the decline.
"The magnitude and frequency of bird die-offs, the fact that one of the latest was the largest recorded die-off of an endangered species (brown pelicans) ever, has brought national attention to" the Salton Sea's condition, said U.S. Fish and Wildlife Service biologist Milton Friend.
Since 1975, when he helped create the National Wildlife Health Center here, Friend has witnessed first-hand the sea's ecological collapse. Last December, that experience prompted Interior Secretary Bruce Babbitt to ask Friend to step down as the center's director and head a multi-agency scientific committee that will direct research at the inland sea over the next year and a half.
"There have been a lot of studies but we are not in a position at this point to identify what the current (sea's) status is, relative to the flora and fauna. Our first major task will be to document what is out there,"Friend said.
"For example, where are the critical nurseries for desert pup fish and Yuma clapper rails?" Both species are listed as endangered and both call the sea home.
Actual work to restore and revive the sea will begin only after these studies are complete, Friend said. Congressional leaders such as House Speaker Newt Gingrich, R-Georgia, have already vowed to try to save it, though the effort will likely cost hundreds of millions of dollars.
In but not out
The sea's basic problem is that it has no exit. Every fluid-borne mineral, nutrient or toxin that flows into it stays there. Only water can escape -- through evaporation. And with 380 square miles of surface area situated under a blazing desert sun, the relatively shallow sea is a virtual evaporation machine: About 1.3 million acre feet of water evaporates annually, roughly twice as much fresh water as San Diego County consumes each year.
At the same time, approximately the same amount of runoff water from Imperial Valley farm fields, and agricultural and urban waste water from Mexicali, flows into the sea, more to less maintaining its level. This water, though fresher than that found in the sea, is laced with fertilizer nutrients and pesticides, sewage and industrial wastes.
These tailwaters also carry dissolved minerals and salts, which do not evaporate.
"We are assuming that within 10 to 15 years we will lose the fishery," said Tom Kirk, executive director of the Salton Sea Authority, a partnership of Imperial and Riverside counties and the Imperial and Coachella Valley water districts.
"The sea would not be dead, but it would be a drastically different ecosystem. Without the fish, you would lose the fish-eating birds."
Early in the sea's history, fresh-water fish like trout were introduced but did not survive. Other saltwater species were then tried, including halibut and anchovies, but they, too, could not endure the sea's ever-increasing saltiness.
The salinity of the sea's water these days has risen to about 44,000 parts per million, about 25 percent saltier than the ocean. Only the most saline-adapted fish, like corvina and tilapia, survive here now. Studies over the next year and a half are expected to determine whether, as some scientists fear, the rising salinity has begun to interfere with their reproduction.
Kirk calculated that about 4.5 million tons of salts -- including sodium chloride but also calcium and magnesium chloride -- entered the sea last year and remained. That is about as much salt, he said, as would be delivered if a one-mile salt train dumped its cargo in the Salton Sea every day for a year.
Many ideas have been proposed to stop the sea's ever-increasing salinity, and perhaps even reduce it. None are cheap.
Perhaps the most frequently discussed idea calls for damming off a portion of the sea with gates that would allow water to enter the diked area, but not exit. This could involve dumping tens of thousands of tons of rocks and soil to form wide earthen levees that would have rise at least 50 feet to clear the water surface.
Within the dams, salt would theoretically concentrate while inflows of relatively fresh water from surrounding sources would make the water outside of the diked area less salty. The plan would reduce the size of the usuable sea, but make it more environmentally stable. Advocates say this approach would be relatively low-tech and low-cost, though building miles of the earthen dikes would be no small endeavor.
Critics note, however, that salt accumulating in the dammed portion would eventually crystallize, requiring it to be removed and disposed of elsewhere.
"The bigger you make the diked-off area, the quicker you solve the salinity problem in the area outside the dike, and the longer you can wait to deal with the disposal problem," Kirk said.
"But when you have to deal with the disposal problem, you have quite a problem to deal with."
One suggested remedy to the salt-disposal problem would be to pump the highly saline water from the diked area into a nearby depression or dry lake where the salt would remain indefinitely.
That creates other complications, not the least of which is that the Salton Sea is 228 feet below sea level, and pumping the briny water would involve enormous power costs, along with right-of-way issues and pipe-construction expenses.
Another idea is to connect the Salton Sea to the Gulf of California through Mexico. Less saline ocean water would be pumped into the Salton Sea, while brinier water would be pumped out.
But this concept presents formidable international complications and undetermined but likely huge construction, pumping and maintenance costs. Moreover, no one has studied what effect the Salton Sea's brine would have on the shrimp, game fish and general ecology of the Gulf of California.
For the time being, the only consensus seems to be that a solution must to be found, and it is not likely to come cheap.
"It will cost hundreds of millions to fix (the sea)," said Friend. "It will be a long process."
Salt is not the Salton Sea's only ecological dilemma.
Before immigrating to the United States three years ago, Boris Kuperman and Victoria Matey made a career of studying the tiny creatures that inhabit Russia's vast lakes and rivers. Now, they have turned their scientific gaze on this desert lake, as adjunct professors at San Diego State University.
In 1996, Kuperman and Matey discovered an unusual parasite in the gills of the thousands of dead fish littering the lakeshore. Now, after only two seasons of field research on a shoestring budget, they are finding just how widespread that infestation has become.
In all, four kinds of parasites have been found to infest young tilapia and croaker, two of the lake's prime game fish. The parasites don't harm humans, but can weaken and kill fish. Invisible to the eye, they also suggest that the lake's ecosystem is out of whack.
During a two-day trip to the sea in May, the pair hunted for newly-hatched larval fish that school in protected pools along the northeast shoreline, and found nearly all the fish infested.
"For this age, it is not good," Kuperman said.
Meanwhile, SDSU graduate students Maryann Tiffany and James Watts are studying the microbiology of the sea. They believe its biggest problem may not be rising salt levels but something more difficult to measure: an overload of nutrients that is robbing the lake of its oxygen and causing toxic red tides.
The source of the problem, they say, is fertilizer nutrients -- mainly nitrogen and phosphorus -- draining into the sea from surrounding farm fields. These nutrients cause blooms of algae; when the algae die, they sink to the lake bottom where they are decomposed by oxygen-depleting bacteria.
When this happens, usually during the summer, oxygen levels in the sea become critically low and fish essentially suffocate.
"People say this is a dying lake," said Tiffany. "But that's really not true. There's plenty of life in the water. There's too much life."
She has found chattonella, a kind of alga that can form massive blooms the color of Astro turf, in the sea. Chattonella, which is toxic to fish, blooms only under certain conditions of water temperature and light, but it is common in the Salton Sea.
Another serious problem is the nonmetallic element selenium, which for years has leached out of the surrounding farmland, carried by excess irrigation waters into the lake where it accumulates on the bottom.
Worms and other small sea floor organisms absorb the selenium, as do the fish that eat them and the bigger fish that eat the smaller fish, and the birds that eat them all.
Selenium has been linked to birth defects and reproductive failure among birds at the Kesterson Wildlife Refuge in California's Central Valley, which also receives selenium-tainted agricultural drainage water.
Though levels of the metal are lower in fish and birds at the Salton Sea, some scientists worry that they are on the rise. Indeed, some studies have shown that selenium concentrations have already reached detectable levels in the eggs of some migratory birds at the sea.
The selenium issue also must be addressed if the Salton Sea's sports fishery is to be fully restored. Since 1986, the California Department of Health Services has warned children and pregnant woman not to consume the sea's game fish because of selenium buildup in fish tissues. The state also has warned other adult consumers to eat no more than four ounces of these fish per week. Somewhat contrarily, the state's Fish and Game Department continues to promote the sea as a fishing spot.
Public and government attention has been slow to turn toward the environmental problems here. Most of the state's powerful environmental groups did not consider the sea a priority, even in the midst of the great bird and fish die-offs in the late 1980s.
The National Audubon Society took closer notice after 1992, when roughly 150,000 eared grebes and ruddy ducks suddenly perished, a die-off that still has not been adequately explained.
"The reason the Salton Sea is important for birds is because so much similar habitat in Southern California has been destroyed," said Dan Taylor, executive director of Audubon California.
"It is now an absolutely essential stopover for the Pacific Flyway, which is the river of birds migrating north and south in the spring and fall."
The sea's accidental pedigree -- it was formed in 1904 when the Colorado River broke through an ill-conceived levee system -- is one reason given for the lack of environmental groups' concern until now.
But geologists and archaeologists now say the sea has a much longer history as the basin once forming the bed of the prehistoric Lake Cahuilla.
"There have been three occurrences of Lake Cahuilla in the past 1,000 years and, even when there has not been a lake, there have been marshes there," said Tom Kirk, of the Salton Sea Authority.
"There are also remains of Indian fishing sites. It was a part of the biology and economy of this region for the past 1,000 years."
More than 14,000 additional birds expired in a 1997 die-off, including about 1,400 endangered brown pelicans. The cause was linked to a form of botulism carried by tens of thousands of tilapia fish, which also perished.
As these and smaller die-offs occurred, Rep. Duncan Hunter, R-San Diego, the late Rep. Sonny Bono, R-Palm Springs, and other area legislators joined in an informal Congressional task force to develop support for addressing the sea's problems.
Bono's death in a skiing accident earlier this year focused new attention on his concerns for the declining sea. With his widow, Mary, succeeding him in Congress, House Speaker Gingrich has vowed to support legislation to make restoration of the sea a top priority.
Whether that restoration actually happens -- and whether it will happen in time to save this place -- remains to be seen.
See Part I
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