Threat to fragile past

Little Salt Spring harbors magical ancient artifacts. But some fear tainted runoff could disrupt the water's delicate chemical balance.

The water in Little Salt Spring doesn't look like anything special. It seems like any other small Florida pond, ringed by thick stands of wild palms and gnarled oaks, where the only sound is the grunting of a mama alligator and her young.

But because it comes from deep underground, the water in the spring has a peculiar chemistry. The water has made the spring a treasure trove of well-preserved prehistoric artifacts. Archaeologists who have dived into the 220-foot-deep spring have found the remains of mastodons and sabertooth tigers, wooden implements and even human tissue from 10,000 years ago.

"It's one of the earliest indications we have of people being in this part of the world," said John Gifford, the University of Miami archaeologist who has been unearthing the spring's secrets.

The spring lies within the city limits of North Port, south of Sarasota, but when Gifford first began exploring it in the 1980s, the spring was "out in the middle of no place," he said.

Not any more.

North Port's population has nearly doubled in the past 10 years, to 21,000. New homes, schools, churches and a lush new golf course have encircled Little Salt Spring the way a doughnut surrounds a hole.

The boom has Gifford worried that North Port's future will obliterate its ancient past by monkeying with Little Salt Spring's magical water. He is worried that every time the spring's new neighbors fertilize their lawns or water the golf course, every time a septic tank springs a leak, pollutants seep into Little Salt Spring and alter its chemical balance.

"I've noticed every year that the average clarity of the water in the spring is decreasing," Gifford said. "Given the nature of the chemistry of the water, that could potentially have a major effect on the preservation of the material below the water's surface."

Christopher Dilley disagrees. Dilley, an engineer recently hired as North Port's stormwater manager, said the spring "in my opinion shouldn't be affected" by runoff from the city's new development.

The city channels its stormwater runoff into nearby Myakkahatchee Creek, which carries it into the Myakka River and out through Charlotte Harbor into the Gulf of Mexico, Dilley said.

That should not affect the underground aquifer that feeds Little Salt Spring, he contended.

But Scott Mitchell, in charge of the Florida archaeology collection at the state Museum of Natural History, said Gifford is right to be concerned. Underwater archaeological sites are notoriously fragile.

"If you alter anything, you can screw things up pretty quickly," he said.

State officials have in recent years found a host of contaminants in North Florida's springs, mostly nitrates from fertilizers used on farm fields, golf courses and lawns.

In North Florida, retention ponds designed to handle polluted urban runoff are actually harming springs, state officials found. As the polluted water collects in the pond, small fissures develop, sending the tainted water straight underground without the usual filtering through the soil.

The owners of North Port's better-known Warm Mineral Springs, a popular resort, are so concerned about the potential damage from stormwater runoff that they do not allow any pesticides, fertilizer or poisons anywhere near their spring. So far, they have seen no change in their water, which comes from a different source than Little Salt Spring.

Because it comes from so far underground, the water gushing up into Little Salt Spring has no dissolved oxygen in it, Gifford said. That means that the bacteria that would break down the ancient artifacts cannot exist. As a result, wood and other organic materials decay very slowly.

The spring is actually a sinkhole, shaped like an hourglass with the narrowest part forming a ledge about 80 feet down where many of the best artifacts are. Archaeologists have found bones of extinct animals, wooden tools and even weapons, including part of an oak boomerang similar to the ones used by Australia's aborigines.

Among the most dramatic finds in Little Salt Spring was the shell of a giant land tortoise. A pointed stick of raspberry wood had been driven through it. Carbon dating gauged the spear at 12,000 years old.

+ + +

The town now closing in on Little Salt Spring is younger than most of its inhabitants, but just barely. North Port is just 41, while its residents' average age is 48 and dropping steadily.

In the 1980s, the average age was 60 and the population slightly above 6,000 souls, mostly revolving around U.S. 41. They occupied an incorporated area so large that North Port was both the state's fourth-largest city and its emptiest.

The town's main feature was the vast grid of roads laid out by the original developer, roads that promised a neat suburban future but instead became an embarrassing joke when no houses materialized. Drug smugglers turned the roads into runways for delivering airborne contraband, leading to an occasional midnight gun battle.

Four years ago, an Arkansas developer, KEB Inc., looked at North Port and saw opportunity where everyone else saw emptiness. Malls, beaches and Interstate 75 were nearby. Impact fees were ridiculously low and city officials were hungry for development.

The developers said, "Why isn't anyone building here? Was there a bomb or something?" recalled KEB vice president Jonathan Baltuch.

Other companies have followed KEB's lead and created subdivisions close to I-75 such as Heron Creek, the country club development now wrapping itself around the 112-acre Little Salt Spring parcel owned by the University of Miami.

That has led to a string of new churches _ including several catering to the city's burgeoning population of Russian immigrants _ as well as new schools. One elementary school is next door to the spring, and the town's new high school is under construction directly across the street.

The new developments are pulling the center of town away from U.S. 41 and over to where prehistoric man first settled. Next to Heron Creek is a new fire department and community center, and sometime in the next decade city hall and police headquarters are expected to join them, according to Pat Foster, executive director of North Port's Chamber of Commerce.

Looking over the map of North Port's rapid growth, Foster noted the gap where the spring remains untouched. That may not last, she joked.

"The highest spot in North Port is one of the hills on the Heron Creek golf course," she said, chuckling. "That's the old landfill. They built on the landfill. So anything's possible."

_ Staff researcher Caryn Baird contributed to this report.