COLUMN ONE : Slime Turns Bays Into Cesspools : Toxic algae is choking marine life and thickening crystal waters into pea soup. Spawned by sewage and fertilizer runoff, the problem could swell into a global epidemic.

The attack of the phantom killers came on a warm September night in 1991.

Schools of menhaden, a herring-like fish, were swimming down the Neuse River on their annual migration to the sea when they suddenly began battling an invisible foe. By the time the massacre ended six weeks later, millions of corpses were piled along three miles of beach, and it took a caravan of bulldozers to clear the sand of rotting carcasses.

The mysterious fish kill--the worst in state history--was traced to a microorganism that dwells in the phosphate-laced waters of Pamlico Estuary, a bay along the Atlantic seashore overlooking the Outer Banks. The killer algae, which since has been detected in six states from Delaware to Florida, is the prime suspect in dozens of unsolved attacks on fish and shellfish.

Algae blooms are not new; they probably date back to biblical times. The first plague visited upon Egypt--a “bloody” river, dead fish, stinking water--was almost certainly what is known today as a red tide.

But in recent years, algae slimes dense enough to suffocate marine life have been swelling around the world, especially in coastal bays such as Pamlico Estuary. They are largely caused by fertilizing pollutants called nutrients in human sewage and farm runoff.

Some marine experts call this “fertilization” a silent, global epidemic that if unabated could destroy America’s most scenic and commercially valuable waters.

Despite a few high-profile success stories, most notably Lake Erie, nutrient pollution is worsening. One of America’s premier environmental laws--the 1972 Clean Water Act--has failed to cure the most insidious threat to bays, rivers and lakes.

“Nutrient loading is probably the single biggest problem to coastal ecosystems in the U.S. right now, and it will continue to get worse before it gets better,” said Brian Howes, a scientist at Woods Hole Oceanographic Institution in Massachusetts who has researched the problem for 20 years.

“People are upset about oil spills, and they should be, but the thing with nutrients is that it is happening every day, all day, and in many, many areas it is widely spread and causing declines in coastal water quality and shellfish harvests,” he said. “Whole fisheries have collapsed. It can bring wholesale mass destruction or more subtle impacts on marine animal communities.”

Nationally, the U.S. Environmental Protection Agency says that at least 3.2 million acres of lakes, 4,700 square miles of estuaries and 82,000 miles of streams are impaired by nutrients, which means they cannot fully support fishing, swimming and other uses.

From Long Island, N.Y., to the Florida Keys, nutrients have devastated many of the East Coast’s popular fishing spots and shellfish beds. Many coastal bays have turned the hue of pea soup, and some have regressed to “dead zones”--water so depleted of oxygen that only primitive creatures such as bacteria and algae can survive.

Meanwhile, an unexplained surge of bizarre, poisonous forms of algae is occurring around the world; scientists suspect excessive nutrients could be a primary cause. Ten toxic species--which do not just suffocate fish, but poison them--have been discovered since the mid-1980s.

Most of the 127 coastal estuaries in the United States suffer some symptoms of nutrient overload, although the damage varies greatly, according to government data and interviews with scientists.

* At Long Island, a dense bloom as dark as coffee appears every summer and has wiped out bay scallops by smothering the eelgrass that fish use when nursing.

* In the Florida Keys, a deep bay that a decade ago was as transparent as gin is covered with thick green scum. Coral beds are dying and the shrimping industry has virtually collapsed.

* At Chesapeake Bay, the nation’s largest estuary, the oyster industry has declined 90% in 35 years because of nutrient buildup, overfishing and disease; striped bass and other fish also have declined dramatically.

* Near Cape Cod, Mass., Waquoit Bay is covered with thick carpets of green algae that resemble steel wool; once-abundant oysters and scallops are disappearing.

* About 70 miles of Gulf waters at the mouth of the Mississippi River are virtually without oxygen. The problem could stem from a variety of pollutants, but the river has a serious nutrient problem largely because more than 600 sewage plants dump into it.

The brunt of the damage, both economic and environmental, has hit bays along the Atlantic and Gulf of Mexico. These poorly flushed, slow-moving waters are more vulnerable to vast volumes of sewage and farm runoff than the deep, churning Pacific.

“The East Coast estuaries are typically quite shallow and they drain very large rivers. The combination of the two makes the coastal zone a target,” said Raymond Alden, director of the Applied Marine Research Laboratory at Old Dominion University in Norfolk, Va.

Cleaning up such widespread pollution is a massive challenge because nutrients--nitrogen and phosphorus--come from many sources, mainly sewage plants, septic tanks, livestock farms and fertilizer used on crops and yards.

New research also shows that large volumes of fertilizing nitrogen are falling from the air, mostly from car exhaust. In some urban areas, one-third of nutrients polluting waterways are linked to air pollution.

But whether it is sewage, farms or cars, the problem mainly stems from burgeoning populations.

“The nutrient load has been increasing exponentially with the population. Anywhere you have a growing population you have a problem,” said James T. Hollibaugh, director of San Francisco State University’s marine laboratory.

Called nutrients because they nourish plants, phosphorus and nitrates are beneficial to marine ecosystems in small quantities. But such large volumes of human waste and farm fertilizer carried into streams can trigger a phenomenon called eutrophication--algae blooms so dense that oxygen levels drop to zero near the bottom.

Without oxygen, many fish suffocate and sea grasses, where fish and shellfish breed and nurse, die.

Melvin Shepard, a commercial fisherman in North Carolina for 35 years, said finding enough fish to make a living has become harder. He said he is absolutely certain the nutrients from farms and sewage are to blame.

“The pollution in our rivers in North Carolina is absolutely terrible,” said Shepard, 60. “In some of our rivers, there are areas two-thirds of the way down where not even clams live. They have gradually died. There are less fish of all kinds.”

Marine scientists suspect such fishermen’s tales are true because they believe nutrients are forcing subtle shifts in the food chain of coastal waters.

“It can change everything, the whole dynamics of an area, because there are such delicate threads among species,” said Karen Steidinger, a senior scientist at Florida Marine Research Institute in St. Petersburg who is known for her work with algae. “What happens with high nutrients, you get different species compositions, different species dominating. What you wind up with is a blue-green algae that nothing wants to eat and spits out. You’re short-circuiting the ecological efficiency of an area.”

Coastal waters also contain lots of bacteria, which come hand-in-hand with nutrients in sewage and farm waste. In nearly every coastal bay in the nation, shellfish beds that are critical to local economies and recreation have been shut down by the human disease threat posed by contamination, according to the National Oceanic and Atmospheric Administration.

Harvesting of shellfish has been banned or restricted in 37% of the nation’s waters--more than 6 million acres--and experts predict that more beds will be shut down.

“Although declines in any given year are not dramatic, an almost inexorable trend that threatens to destroy the harvest of wild or natural shellfish continues throughout the nation’s coastal areas,” according to the 1990 National Shellfish Register, a five-year study by the NOAA.

Southern California streams have the dubious distinction of carrying the nation’s heftiest volumes of both nitrogen and phosphorus because of the region’s enormous volumes of urban runoff, sewage and farm waste, according to U.S. Geological Survey measurements taken at about 400 sites.

As a result, a few California estuaries, including Newport Bay in Orange County and Elkhorn Slough near Monterey, have murky, algae-prone waters and the state’s once-productive shellfish industry has been virtually wiped out by bacteria contamination.

But the impact on aquatic life in California is much more discreet than in the East Coast, where waters routinely are discolored and millions of fish smothered.

“We typically have deeper, colder waters that assimilate nutrients much better than East Coast waters,” said Craig Wilson, chief of bays and estuaries at the California Water Resources Control Board. “We just haven’t had the same kind of depressions in oxygen concentrations that kill fish.”

Progress has been made in tackling some of the most visible symptoms of nutrient overload. Twenty-five years ago, Lake Erie was loaded with so much phosphate that soap bubbles piled up on its surface in 15-foot heaps.

As a result, phosphates were banned nationwide in laundry detergents and industries were regulated. Congress passed the Clean Water Act, setting a lofty goal of making waterways safe for fish and people by 1983.

Many freshwater lakes, including Erie, did improve in the 1970s. But the nutrient problem began to re-emerge in the mid-1980s, this time in coastal estuaries, primarily because more people were moving to the coast and bringing sewage and runoff.

“There are places where it is really bad, there are places where it is getting worse, but there are only a few places where it has gotten better,” said Suzanne Bricker of NOAA, which launched a project in 1992 to assess the nation’s estuaries.

The problem’s persistence is a main reason environmental groups are pushing to strengthen the Clean Water Act. The debate, heating up in Congress this year, centers mostly on the cost. Who should pay to cleanse the dirty waterways? Farmers, home builders and small municipalities all fear the burden will fall on them.

Sewage plants are the leading cause of pollution in the nation’s coastal bays, with agriculture and urban runoff close behind, according to the EPA.

Many coastal communities conduct no sewage treatment--they still rely on septic tanks where raw waste seeps into the ground and eventually into streams and bays. Most cities and counties with treatment plants have not installed expensive technology that removes nutrients.

“One of the real quiet crises is when we put sewage in our estuaries and it’s gone--out of sight, out of mind. Very, very small concentrations are causing dramatic changes,” said JoAnn Burkholder, a North Carolina State aquatic botanist who identified the toxic algae in the Pamlico Estuary.

At Cape Cod, the number of homes has risen dramatically along Waquoit Bay since World War II, yet all sewage is handled by septic tanks. Nitrogen in the waste filters rapidly through the sandy soil and seeps into the bay.

“It slowly builds up over time. We’re mainly just documenting a resource that is degrading,” said Charlene D’Avanzo, a marine ecologist at Hampshire College in Massachusetts.

The transformation of Florida Bay, a deep estuary nestled between the tip of the Everglades and the Keys, is one of the most alarming examples. The waters appeared turquoise crystal until 10 years ago, when algal blooms started appearing and turned the water greenish-brown. Algal blooms now occur year-round and stretch over hundreds of square miles, said Brian La Pointe of Harbor Branch Oceanographic Institution.

As the algal blooms started, coral beds and sea grasses began dying and shrimp populations declined dramatically. Fishermen report fewer grouper, snapper and other popular fish.

“And it’s going to get greener and greener,” La Pointe said. “The reason we are going to eclipse places like Chesapeake Bay, Boston Harbor and Lake Erie (in damage) is because tropical ecosystems like this have exceedingly low thresholds for die-offs. They are the most sensitive ecosystems in the world’s oceans.”

Some researchers say nitrogen from sugar farms and phosphate flowing into the Gulf from a mine near Tampa are to blame, although there is no conclusive proof.

La Pointe said the connection is unmistakable, and he blames the state and federal governments for allowing increased volumes of farm runoff to flow through the Everglades into the bay.

“I sounded this alarm way back in ’84 and ’85 and it (has) fallen on deaf ears. The denial of the problem has continued up to present,” he said. “Nobody wants to believe that Florida Bay, which is surrounded by one of the world’s most famous wetlands, could possibly be polluted because of its remoteness.”

Other coastal areas have had obvious problems for years. Since the 1980s, Peconic Bay on the east end of Long Island has had a devastating series of summertime brown tides that kill shellfish. Researchers believe the problem is tied to massive sewage plants serving the New York City area.

“It grows very rapidly and shades out the light so that eelgrass, which is essential for scallops and other marine organisms to use as a nursery area, dies. This (algae) has caused many, many millions of dollars in damage,” said Edward Carpenter, a professor of biological oceanography at State University of New York who wrote a book on nitrogen pollution in 1981.

Chesapeake Bay, the nation’s largest estuary, is perhaps the most famous case of nitrogen overload. It has pea-soup water, no grasses where fish spawn and suffers periodic fish kills.

Making matters worse, there is no single cause such as a sewage plant. The huge bay catches the urban waste, air pollution and farm runoff that flows from one-quarter of the Eastern Seaboard.

An agreement drawn up by four states surrounding the Chesapeake calls for a 40% reduction in phosphorus and nitrogen by 2000, including efforts to build advanced sewage plants.

Other areas also are starting to search for solutions. In Pennsylvania, dairy farms are installing costly systems to contain cow manure. In Delaware, a municipal sewage plant is spending $12 million to remove nutrients discharged into Rehoboth Bay.

“It is next to impossible to find who to regulate because the problem is essentially the citizenry,” said Alden of Old Dominion.

“The best we can do is implement some controls and slow the decline,” he said. “There are a lot of people who want to turn the Chesapeake Bay back to when (colonist) John Smith first floated in on it. I don’t want to say I’m pessimistic, but I’m not a starry-eyed optimist either.”

Next: Scientists look at the link between poisonous algae and human health.

Portrait of a Troubled Bay

Many bays along the Atlantic Coast have been devastated by a buildup of pollutants from the nutrients nitrogen and phosphorous, which come mainly from human sewage and farms. Here is an example, based on Delaware’s Inland Bays, of how such damage occurs in shallow estuaries along the ocean.

1) Waste from farms, dairies, sewage treatment plants and household septic tanks flows into creeks that empty into a coastal bay.

2) Waste flowing toward the coast meets ocean tides. The salt water is held underneath the waste, forming a nutrient trap.

3) Nutrients become concentrated on the water surface and begin nourishing phytoplankton, causing thick algae blooms.

4) Algae take in oxygen from the bottom of the bay and block sunlight.

5) Without sufficient oxygen and light, the bay bottom becomes a dark dead zone that smothers areas of submerged sea grasses where marine life spawns. Fish, oysters, clams and other species start to die. The entire food chain can be affected, including birds that feed on fish.

Life in an Estuary

Here are some examples of sealife found in estuaries, the places where freshwater streams meet the sea:

A) Eelgrass: This submerged, ribbon-like plant, once common along the East Coast, has been virtually wiped out by pollution and development.

B) Striped bass: These fish, which grow to six feet, live mostly in or near estuaries, moving between fresh and salt water. The species was in severe decline along the Atlantic coast, but is on its way back because of fishing restrictions.

C) Blue crab: These tasty crabs, an important commercial species, reach a width of nine inches. They are common in estuaries and seem to be doing well despite pollution.

D) Shrimp: Found in shallow waters along the Atlantic coast that are vulnerable to pollution, these crustaceans have been depleted in many areas.

E) Oysters: These shellfish have been decimated on both coasts. Chesapeake Bay’s harvest, 32 million pounds per year in the 1950s, dropped to 3.7 million pounds in 1990.

F) Soft-shelled clams: These whitish clams with gaping shells are found in water depths to 30 feet. Waters off New Jersey are the biggest source of harvested clams.

G) Winter flounder: Adult flounder spend summers in the ocean but move into estuaries in winter to spawn. They are declining because of estuary pollution.