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Dave Owenspeered into the eyepiece of a tiny camera hooked to a plastic tube to see the loggerhead's epididymides -- a duct that revealed its reproductive prowess.
"This guy's very active," Owens said of the 300-pound, upside-down turtle, which periodically exhaled and twitched.


The brief surgery took place Thursday aboard the Georgia Bulldog, an aging, 73-foot shrimp trawler turnedresearch vessel docked at Port Canaveral.
Owens, a biologist from the College of Charleston, and about a dozen other researchers spent the past two weeks netting male loggerheads off Cape Canaveral, examining them, then using epoxy to affix satellite tracking devices to their backs.
Now's the best time. Rules that limit lighting and construction on the beach kick in Tuesday and run through the end of October. As loggers migrate into the area to play their part in nesting season, the scientists seek clues to one of the big mysteries in sea turtle science: What makes male loggerheads tick?
"These turtles are going to be as individual as people are," said Mike Arendt, a biologist with South Carolina Department of Natural Resources.

Male call
Females nest on the beach, where scientists can study them. Biologists know much less about males, including their reproductive cycles, favorite places, favorite food and beaches of origin. The scientists say their study could help to improve protection of the threatened species by better understanding where they go and why.
They hoped by Sunday to fit a few more loggerheads with satellite transmitters. They plan to track a total of 20 male loggers and post the turtles' locations online.
The $500,000, two-year project, funded by the National Marine Fisheries Service, brings together about a dozen government and university scientists, including some from the University of Florida and Florida Fish and Wildlife Conservation Commission.


They've tracked juvenile loggers of both genders for about eight years, but this is the first study that specifically targets the adult males for tracking. They'll track them as long as possible to find their feeding and breeding "hot spots."
"The more everybody knows about these particular animals and how the ecosystem is linked to them, the better stewards we all are of the marine environment," said Al Segars, a veterinarian with the South Carolina Department of Natural Resources. "If the ocean's not healthy, the animals are not going to be healthy."

Picking up signals
Satellites pick up signals from the turtles every time the reptiles surface for at least several minutes. The signal is downloaded at a laboratory in France, which then distributes the information to researchers to post online. They tagged their first 10 male loggers last year at Canaveral. So far, the shipping channel off the cape seems to be one of those "hot spots." "This may be one of the most important mating grounds for the loggerhead in the world," Owens said.Loggers linger off Brevard this time of year to mate, then some migrate north during the summer, possibly following key food sources such as horseshoe crabs, Segars said. The group tracked loggers last year from Florida all the way to New Jersey. Many loggers keep local, however, although biologists don't know why some stay and others go.


This day, they catch two roughly 300-pound male loggers. They bring them back to port for examinations and test the turtles' blood for mercury, testosterone, glucose, protein levels and red blood cells. One turtle swims in circles in a blue pool at the back of the ship as the researchers make two quarter-inch incisions in the other turtle's tough, yellow underbelly, near its tail. They install the camera tube and an instrument for taking a testicular biopsy. "Looks real good. Gut looks real good," said Owens, looking through the scope.Gaelle Blanvillain, a marine biologist from the College of Charleston, monitors the surgery from a laptop. They take snapshots and video of the turtle's internal reproductive organs. The biologists cross-reference those images with ones they get using ultrasound. They want to know whether the ultrasound can be as reliable for gathering images of the turtle's reproductive organs as the camera. After the procedure, they glue on the tracking devices and return the turtles to the ocean in a smaller boat.

Tough odds
Loggerheads, like other sea turtles, face steep odds from the moment they hatch each summer and swim out in a flurry to feed off seaweed in the Gulf Stream. About 1 in 1,000 hatchlings reaches sexual maturity. They must dodge sharks, disease, fishing nets and other threats to reach adulthood. Although loggers are Florida's most plentiful species of sea turtle -- the federal government lists them as "threatened" -- they may be in decline. Nests at 28 often-studied Florida beaches dropped by 42 percent in seven years, state researchers said last November. Loggers had 60,000 nests in 1998 on those "index" beaches, but about 35,000 in 2005. Early figures show 48,775 logger nests statewide. Florida began monitoring those beaches in 1989. Conservationists say the decline is cause for alarm and should inspire more restrictions on commercial fishing gear that kills turtles by the thousands each year in waters near Florida. Other scientists plan to wait for more data before concluding the decline is anything other than natural variation.
"I'm not saying loggerheads are not in decline, I'm saying it's too soon to say," said Llew Ehrhart, a marine turtle researcher for Hubbs-SeaWorld Research Institute who is based in Melbourne Beach.


He said tracking studies such as the one going on at Canaveral are important, because scientists lack understanding of the gender ratios of loggerhead turtles. They also don't know from which beaches most males hatch. Generally, the warmer the sand the more females that hatch. About nine in every 10 loggers hatched in Brevard is a female, Ehrhart said. The researchers hope their tracking study sheds more light on the gender ratio question as well as other loggerhead puzzles. "You don't get the chance to do this kind of thing very often," Owens said. "When you get this type of opportunity, you try to make the best use of it."


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