Sea Turtles Thriving Under UCF's Watch
By Susan Loden

ORLANDO, Nov. 2001 -- Leatherbacks, loggerheads and green turtles have captivated UCF biology professor Lew Ehrhart for 28 of his 32 years with the university. His findings and success in nurturing these ancient creatures to a come back from the brink of extinction could fill a book.

In fact, a chapter dubbed "Turtleheads" in newly published "Fire in the Turtle House", by Osha Cray Davidson, Ehrhart says, gives an accurate look behind the scenes of his base, the Archie Carr National Wildlife Refuge. The refuge, in 1990, developed along 28 miles of Florida's Space Coast as a nesting haven and study site of threatened and endangered sea turtles. The refuge is known as one of the most important nesting areas in the Western Hemisphere.

Aided by an ever-changing group of UCF graduate and undergraduate students, Ehrhart studies sea turtles along the shore as the females return to the beach to nest and juvenile green turtles gather in the nearby Indian River Lagoon. His Marine Turtle Research Group, established in 1981, then follows some of the turtles to sea thanks to attached tags and transmitters that track their international travels.

In 2000, Ehrhart's team examined 2,394 endangered green turtle nests and 15,766 threatened loggerhead nests. And, most remarkably, this year, 39 nests of the elusive, endangered leatherback were found, 29 on Carr refuge shores and 10 more just north of there in South Brevard County.

"We seem to be at the northern fringe of leatherback nesting," Ehrhart notes. In 1996 we noticed only 10 nests. But, that was a lot more than the one or none in previous years. It was up to 19 in 1998 and 21 in 1999. By then, we said something's going on here. In 2000, there were 25 leatherback nests and this year 39."

Although Ehrhart's team has for several seasons successfully glued radio and satellite devices to the shells of loggerheads to track them at sea, he says the new and exciting element this year is the successful attachment by harnesses of satellite transmitters to the softer backs of five leatherback turtles. That comes after the 2000-transmitter-tracking of a single leatherback dubbed "China Girl".

China Girl was first encountered by Ehrhart at the seawall in front of his headquarters at the refuge. It was 1994. "She was the first leatherback I had seen on that beach since 1983. She came back in '96, but we didn't see her in '98. When she came back in 2000, we were waiting for her," he recalls.

In the 2000 season, China Girl nested seven times on the refuge beach. Individual sea turtles typically return from the sea to nest more than once in a season. Eventually, China Girl headed north in the Atlantic, toward Nova Scotian foraging grounds. However, she surprised Ehrhart when she reached the Delaware area. She turned and swam straight back to the Carr refuge to nest for an eighth time that season. "She was a real homebody," says Ehrhart. "Now, we know a Florida leatherback may lay at least eight clusters of eggs."

Of the five leatherbacks harnessed this past season, two followed China Girl's path north, with one going all the way to Nova Scotia. The others headed east, southeast, with contact with one lost. The remaining two swam to Africa. Ehrhart points out that leatherbacks, which may weigh up to one ton, spend most of their lives far out at sea. Tracking "allows us to know how these animals disperse before and after nesting migration. And, we know where they may come in contact with fisheries and may be killed in nets or by hooks."

The team's gritty, grueling, daily, dawn to midnight mission from May through August of tracking and gathering data on sea turtles and their eggs is reaping record-breaking rewards. "It's so fulfilling and satisfying," says Ehrhart, who, in season, sees Florida's east coast literally crawling with sea turtles. "We're seeing turtles respond to all of that land that was set aside [for the Carr center, which recently became federal property]. "The green turtle was another alligator in Florida. It was down for the count, then it was given some protection. There were just enough green turtles left of that once great colony in Florida."

Ehrhart has championed hatchlings by determining that artificial lights along the coast distract them from their scamper into the sea and can draw them to almost certain death inland. Scientists estimate that just one in 1,000 hatchlings reach maturity, which occurs when they are about 25 years old. Thanks, in part, to his findings, coastal Florida counties have outlawed lights that shine on the beach during nesting season.

In studying juvenile green turtles in the Atlantic surf and the nearby Indian River Lagoon, researchers tag and measure turtles, determine what they eat and draw blood to analyze their DNA and to identify diseases. This year, they successfully attached a satellite transmitter for the first time to a young green turtle, whose range of travel may be from Florida to Belize or Nicaragua.

Also, graduate student Tomo Hirama recently determined that a horrific, deforming, deadly disease that covers some juvenile sea turtles with huge wart-like tumors, and first appeared on the Space Coast in 1982, in the Florida Keys 80 years ago, and in 1958 in Hawaii, may not be as devastating to the general turtle population as the world's turtle researchers had feared. Ehrhart says that Hirama noticed that otherwise healthy turtles with the disease, when they were recaptured, had recovered without treatment. Hirama found that anemic sea turtles are the ones ravaged by the disease.

"Only 10 - 12 percent progress to the most severe condition. The situation is not quite as desperate as we thought," says Ehrhart, who supplies diseased turtles to other scientists for study.

Another of Ehrhart's graduate students, Dean Bagley, has dispelled the myth that female sea turtles return to their own birthplace to nest. Through their DNA, Bagley has found that some of the green turtles captured on Florida's east coast are from genetic groups know to nest in the Mediterranean and the Southern Hemisphere. That opens the door for further study of how sea turtles select nesting sites.

Even after 28 years of investigation, Ehrhart continues to find sea turtle mysteries to solve. He will retire in a few years, but vows, "I'll die with my flippers on." He hopes to continue his research as a professor emeritus or as an adjunct. He is concerned that rising ocean levels threaten turtles" nesting grounds as developers press to armor the coast with seawalls that cause erosion of nesting areas. He is working to ensure that some "beach nourishment" projects on the Space Coast will not damage nesting areas.

Ironically, a long-standing seawall in front of Ehrhart's headquarters at the refuge recently washed away and the building that housed his students and their equipment will be torn down and not replaced.

"It's going to affect the whole program, at least for awhile," he says. "The dunes will be restored to natural condition." There is a smaller building on the property, which the researchers can use.

One partner in Ehrhart's work, the the Hubbs-SeaWorld Research Institute [HSWRI], plans to build a $13 million facility in South Brevard to support the work of UCF endowed marine biology professor Graham Worthy, an expert on the manatee. "In a couple of years, we will have it. Hopefully, the new facility will fulfill Dr. Ehrhart's needs too. He is an integral player," says Worthy.

DATE
November 15, 2001

CONTACT
Llewellyn Ehrhart
407-823-2970

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LINKS
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