Sea Sick?

Some scientists believe the levels of disease-causing pollutants in the ocean might be higher than normal this year after the winter’s heavy storm runoff created a layer of polluted freshwater so large and deep that it depressed salinity levels in the ocean surface.

“There is a large mass of freshwater floating on the surface from one month to the next and it won’t go away,” said Charles McGee, a microbiologist with the Orange County Sanitation Districts. “The sea is really dynamic out there and it should have gone away, but there’s just been so much rain.”

Each winter, rains wash pollutants off streets and fields and down streams into the ocean. The lighter freshwater floats atop the heavier saltwater until time and tides mix the two and allow the marine salt to kill many of the microbes that have been washed into the ocean. Ultraviolet light from the sun kills more.

But this winter’s epic El Nino storms have washed off so many pollutants that scientists such as McGee fear that the waters remain more polluted than usual at the beginning of beach season.

Bolstering such fears are the signs posted by the county warning swimmers away from the water at some spots, long after such signs are usually gone. Usually, the county closes a beach area for 72 hours after it finds bacteria levels above the allowable standard, said Monica Mazur, an environmental health specialist for Orange County.

Because of the rains that sputtered through the spring, “we pretty much had the standard advisory going from Dec. 6 to into May,” she said.

There were 37 beach closures in Orange County because of pollution levels that exceeded safety standards, the most ever in recent years, Mazur said. El Nino-generated storms also contributed to unauthorized discharges of raw or untreated sewage--25 million gallons--that were responsible for many of the closures, she said. Portions of Doheny State Beach have been closed since a December spill there.

“The 25 million gallons of sewage represents the biggest year we’ve had for sewage discharges that I can recall,” she said.

In Los Angeles County, beaches were closed 13 times for a total of 50 days during a winter when more than 120 million gallons of urban runoff entered the ocean from Los Angeles and Ventura counties alone.

In May, the environmental group Heal the Bay in Santa Monica in its annual report warned that contaminated ground water from the Santa Monica Mountains is expected to pollute Santa Monica Bay well into the summer, affecting some of the most popular beaches in Los Angeles County, including Will Rogers, Sunset and Surfrider.

Ocean’s Health Woes

McGee said that even as summer opens, he still has concerns about water safety, especially at storm drains and river mouths, where he said bacteria levels have remained high and salinity levels low. He supervises the sanitation district’s microbiology laboratory in Fountain Valley, which takes ocean samples at 19 locations in northern Orange County; other sanitation districts and the county health department cover the rest of the county.

“I wouldn’t go in the water now, and I wouldn’t let my kids go in the water,” McGee said.

A USC researcher also has been monitoring the lower salt levels caused by the larger-than-usual layer of polluted freshwater in the ocean.

After normal rainstorms of 1 to 2 inches in Southern California, the plume of brownish freshwater extends 2 to 3 miles from shore and is about 16 feet deep, said Burton Jones, a USC biology professor.

In a special El Nino study he conducted in Santa Monica Bay in February, Jones found the plume extended more than 6 miles out and was more than 130 feet deep.

“It was the largest volume we’ve seen in three years of testing,” Jones said.

What does the large offshore plume mean to the health of the ocean and for ocean users? No one really knows. But generally speaking, more runoff from rains means more polluted water entering the ocean. With the rains spattering into June, many creeks continue to flow long past the point where they typically dry up, said Larry Honeybourne, a spokesman for the Orange County Health Care Agency.

Risk Is Uncertain

In addition, the large amount of freshwater means that there is less salt in the topmost layer of the ocean to kill off dangerous microbes. Water samples gathered by the Orange County Sanitation Districts in April nearly made McGee fall off his chair. Normal is 33.8 parts salt per thousand, he said; some samples showed 30.8.

Beyond that concern, Jones said, potentially harmful microbes in the lower reaches of the plume can live longer because ultraviolet rays from sunlight cannot penetrate that much water to kill them, Jones said.

Health officials are noncommittal about whether there is a heightened risk for swimmers in areas that are not near rivers and storm drains.

The data on those areas shows water meeting state standards, Honeybourne said.

Mazur said the issue is more complicated than simple measurements can show.

“Safety depends on how much the flow is from a river mouth or creek,” she said, as well as the speed and direction of ocean currents.

Most county health departments test the ocean regularly where people swim for fecal coliform, which is an indicator of sewage and waste from warm-blooded animals. But McGee said his concerns go beyond that bacterium, which has been linked to higher levels of respiratory ailments and other illnesses among beach users. Typically, storm drains, creeks and rivers carry runoff that includes such pollutants as decomposing vegetation, motor oil, fertilizer and pesticides. There is no coordinated effort among agencies to test for such pollutants.

Honeybourne agreed: “We aren’t measuring for disease-causing organisms. We are using indicators [such as fecal coliform] as a sentinel or surrogate for those diseases because it’s difficult measuring the viruses, bacteria and protozoa.”

And no one knows how much of the freshwater plume is left. County health agencies limit themselves to monitoring the surf area.

“We don’t track the plume,” Honeybourne said. “You can use the depressed salinity as an indication of the ocean water’s condition. But in terms of regulatory standpoint, it’s beyond our responsibility.”

Scientists expect to have more information on the damage El Nino might have done to the ocean environment, as well as on coastal pollution in general, after a large-scale coastal study in August, said Stephen B. Weisberg, executive director for the Southern California Coastal Water Research Project. More than two dozen agencies from Santa Barbara to the Mexican border will conduct five weeks of testing after they meet Aug. 3.

“For the most part,” Weisberg said, “these agencies don’t talk to one another. But we will be sharing information on testing, and monitoring the beaches during a five-week survey beginning in August.”

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

A More Polluted Ocean

A thick layer of polluted freshwater from El Nino-related storm runoff has created a higher concentration of microbes in the ocean, according to scientists at the University of Southern California.

After a normal storm:

* Plume extends 2--3 miles from shore, is about 16 feet deep, 32 feet at most.

* Freshwater layer is thin, easily penetrated by ultraviolet light, that kills bacteria, viruses.

After El Nino Storms:

* Plume extends at least 6 miles and is 100 to 130 feet deep.

* Because freshwater layer is deep, UV rays can’t reach and kill bacteria and viruses in the layer’s lower levels.

Beach Closures

In Orange County there were 37 beach closures during the 1997-98 rain season, when concentrations of polluted runoff exceeded safety standards. More than 25 million gallons of sewage from unauthorized discharges forced many closures.

In Los Angeles County, authorities closed beaches 13 times for a total of 50 days. Rainstorms dumped more than double the average precipitation in Los Angeles and Ventura counties, flushing urban runoff into the ocean and 120 million gallons of raw sewage along with it.

*

Biggest Orange County events included:

* A 21-million-gallon sewage spill from the East Valley Water District in San Bernardino County. The spill traveled into Prado Dam in Riverside County and then down the Santa Ana River and into the ocean off Newport Beach.

* A 3-million-gallon sewage spill by the Moulton Niguel Water District in Orange County when a large pipeline under Trabuco Creek washed away.

* Closure of a portion of Doheny State Beach north of San Juan Creek in the area known as North Beach. The beach has been closed since Dec. 6 because of coliform counts from sewage and bird waste that persistently exceed safety standards.

Sources: Orange County Health Care Agency; Los Angeles Department of Health Services; Santa Monica-based Heal the Bay; Burton Jones, University of Southern California

Graphics reporting by DAVID REYES / Los Angeles Times