Florida Bay Ecosystem on Verge of Collapse; Experts Differ on Cause : Environment: Some blame diversion of fresh water for farming; others say pollution runoff is upsetting the balance of life.

It was a sunny Florida Keys morning, the kind of day when death should have been on vacation.

Charter fishing guide John Kipp revved up his 17-foot skiff and joked with his two passengers as they glided through flat bay water and headed for Rabbit Key. They were after big game: tarpon, which they would cut loose after capture to allow the silver monsters to fight again another day.

Kipp saw the dead fish about eight miles out. Hundreds, perhaps thousands, of them were lying on their sides, motionless but for the rocking caused by the boat’s bow wave as he throttled back for a better look. Each button eye was staring into the sun, as if in shock.

“They were not small fish,” Kipp recalled. “These were large snappers, barracudas. It certainly wasn’t a good sign.”

The fish devastation Kipp saw last August has become a distressingly common sight in Florida Bay, a 1,000-square-mile wedge of water between the Florida Keys and the Gulf of Mexico, once haunted by the likes of Zane Grey and Ernest Hemingway.

Everyone agrees that Florida Bay is dying. The question is how to bring it back to life.

As it expires, it threatens to take with it much of south Florida’s sport and commercial fishing industry. Floridians also fear harm to other natural assets, including almost 500,000 acres of mangroves that line the shores and islands, and the chain of coral reefs just offshore in the Atlantic Ocean that annually draw hordes of scuba divers and snorkelers.

Dusky blooms of algae sometimes stain as much as half of the bay. The brown and green smudges suck up oxygen that fish need for life and choke off beds of sea grass and sponges that lobsters, stone crabs and other species call home.

“No one wants to swim in dark green water, and nobody wants to go fishing if the fish aren’t there,” said stone crabber and lobsterman Karl Lessard of Marathon, Fla. “I’ve seen dive boats just bring the people back to the dock and give them their money back because the visibility was down to zero.”

“This is an ecosystem on the verge of collapse,” said Michael Collins, an Islamorada charter boat owner who used to help run fishing expeditions for President George Bush and his friends.

“Just five years ago you could read a newspaper lying on the bottom through eight feet of water,” Collins said. “Now, sometimes the visibility is less than six inches.”

Commercial fishermen and marine scientists report declines of 80% in catches of pink shrimp and 30% in juvenile spiny lobsters. Average lobster catches on the east side of the bay are down 40%, and commercial catches of pompano and mackerel have plummeted by 75%.

The damage is all the more remarkable because it has occurred in an area nominally protected by the federal government. The bay is part of Everglades National Park.

For years, environmentalists, along with fishermen and others who depend on Florida Bay for a living, have argued that the chief culprit has been the diversion of fresh water that once flowed into the bay from the Everglades.

That view is now disputed by scientists who blame high nitrogen levels caused by pesticides and other chemicals.

Since early in the century, water has been siphoned off from the vast wetlands to the north to create farmland, control flooding and provide drinking water for cities on both of Florida’s coasts.

The freshwater diversions have intensified over the last decade. Today, 1,400 miles of canals drain off 970 billion gallons of water a year. Park hydrologists estimate that the bay receives as little as 10% of the fresh water it once did.

These diversions, the environmentalists say, have upset the delicate balance between fresh water and salt water that sustains Florida Bay’s diverse plant and animal life, elevating salinity levels and setting off chains of destruction.

All this has produced a bitter struggle between the bay advocates and the farmers whose livelihoods depend on the diverted water.

After years of controversy and delay, state and federal agencies have agreed that the way to save the bay is to restore the flow of fresh water.

The Army Corps of Engineers recently proposed that the federal government buy a belt of farmland north of the bay to act as a buffer zone between the Everglades and other farmland. The immense plumbing system would be redesigned to restore much of the freshwater flow into the bay. The initial estimated cost of the whole project is $100 million.

Other scientists argue that the biggest problem isn’t salinity, but pollution. Some say that chemical runoff from farms and cities raises the levels of nitrogen in bay waters, sustaining the death-producing algae. Others attribute the high nitrogen content to decaying sea grasses.

Principal proponent of the runoff view is marine biologist Brian LaPointe, who operates an independent laboratory at Florida’s Big Pine Key. “Nutrient pollution is the No. 1 threat to water quality in Florida Bay,” he said. “Adding more water is like adding fuel to the fire.”

Bruce Rosendahl, dean of the University of Miami’s Rosenstiel School of Marine and Atmospheric Science, advocates a federally financed two-year study of the bay’s ecosystem.

“We think lack of water flow into the bay is certainly a problem,” he said. “But it’s probably a complex series of issues, including pollution. I would like to know what the entire problem is before I start dumping money into any one part of it.”

In the meantime, veteran fisherman John Kipp doubts that anything will be done soon. “We’ll probably all be dead before it’s cleaned up,” he said.