For the past 2½ years, Matt Aresco has been a lone force in an effort to save Lake Jackson turtles migrating across U.S. Highway 27.

But Aresco, a biological science doctoral student at Florida State University, is looking for help in saving the turtles, which he said are killed in greater numbers crossing the highway than on any other road in North America.

On Tuesday, Aresco will ask Leon County commissioners for help in finding money for a permanent ecopassage that would help not only turtles but also alligators, frogs, snakes, mammals and other critters cross the road.

"They're all moving back and forth because this highway was built over the lake bottom," said Aresco, an ecologist and turtle biologist. "They wander into the road, and they get hammered. It's just a cruel way for a turtle to die."

The turtles cross the highway between Lake Jackson, a 4,000-acre sinkhole seven miles north of Tallahassee, and Little Lake Jackson, a much smaller lake created when the road was built in the 1950s.

Some turtles cross the highway looking for a mate or a place to nest and lay eggs. Others cross during annual migrations in the spring and summer. Still others leave the main lake during dry periods in search of water, Aresco said.

In February 2000, a friend called Aresco to tell him about dead turtles along the highway. Aresco was stunned when he walked along a stretch of the highway and counted 90 dead turtles that had been struck by vehicles.

By April of that year, Aresco counted 439 dead turtles along the highway. So, on his own time and with his own money, Aresco built a series of temporary fences along the highway shoulders to direct turtles and other wildlife to an underground culvert connecting the two lakes.

Aresco didn't stop there. Using containers and a green sack, Aresco carried more than 8,000 turtles, mostly yellow-bellied sliders and Florida cooters, across the highway over more than two years. He estimated that 90 percent of those would have been killed without the fences.

"He single-handedly initiated this project," said one of Aresco's professors, Frances James. "It's really very remarkable."

But the fences, about a foot high and made out of woven vinyl, are designed to break down over time. They're also too small to prevent large turtles or alligators from climbing over and wandering into the road.

So Aresco has proposed a permanent solution. He wants to see a series of underground culverts and concrete walls built that would help wildlife cross the highway safely. The design would be based on a similar series of passages along U.S. Highway 441 that crosses the Paynes Prairie State Preserve outside Gainesville.

County Commission Chairman Dan Winchester, who supports the plan, estimated the cost at several hundred thousand dollars. He hopes fellow commissioners will vote Tuesday to help find money for the project.

For Winchester, a key figure in Lake Jackson restoration efforts, the ecopassages are needed for reasons beyond saving wildlife. He said the underground passages are necessary to prevent traffic crashes on the highway.

More than 36,000 cars drive along the road each day, according to state estimates. And during migration periods, hundreds of turtles would be crossing the road if not for Aresco's barriers.

"What this really boils down to is a wildlife and a traffic safety issue," Winchester said. "Lake Jackson was one large body of water, and they built a road through it. It's time to do the right thing and correct a wrong that was done decades ago."

The turtles also are a vital part of the Lake Jackson ecosystem. The omnivores eat massive amounts of algae, feed on invasive plants such as hydrilla and scavenge on dead and dying fish.

"So they actually keep the lake clean," Aresco said.

Aresco, who spends at least a few hours at the lakes every day, wants to see a solution to the problem before he finishes work on his doctorate, which could lead him to job opportunities away from Tallahassee.

"These temporary fences worked fine while I was up here and maintaining them almost daily," he said. "I would really hate to leave with the future of Lake Jackson's turtles in the air."