Loggerhead Crisis Brewing?

Surprising Study Results Show More Females Than Males Hatching in Northern Population p.2

Once the calls started rolling in that the baby turtles were on the move, the research teams hit the road to collect the hatchlings and bring them to their temporary homes at the three research facilities. At Beaufort the turtles were housed in a converted fish shed in several water-filled tanks. Since no one had ever raised this many turtles, the teams were kept busy figuring out how much and what to feed them, Crowder said. In Beaufort, they got a menu of mostly shrimp, laced with extra vitamins and minerals.

The hatchlings grew rapidly, and at about three months, they were big enough for a small surgical procedure to determine their gender. Wyneken conducted the laparoscopies, which involved making a small incision and briefly inserting a tiny scope to examine the babies' gonads.

"These turtles have very small gonads at this age and are difficult to identify," said Wyneken, an expert on sea turtle anatomy and turtle conservation and an FAU assistant professor of biological sciences. "By relying on several different criteria, we were able to get the information."

The babies, as big as your hand at that point, took two weeks to recover, and then were ferried out from shore to begin their lives at sea in the warm waters of the Gulf Stream. The Beaufort turtles hitched a ride on a Coast Guard cutter to make the 25-mile journey.

The charismatic adult loggerhead is a reddish brown reptile with powerful jaws and a head as big as a log. As adults, they weigh between 150 and 400 pounds and sport shells that are as long as a yardstick or bigger. They swim the Atlantic with five other species of sea turtles and enjoy hanging out in fairly shallow coastal waters to eat crabs and mollusks. Shallow water can be a dangerous place for these turtles, which were classified as threatened in 1978 in the United States. In the past, commercial fishermen trawling for shrimp have inadvertently caught and drowned loggerheads.

People and beach development are among the turtle's biggest threats. The 30-year-old female turtles returning to the beaches where they were born to dig a nest and lay hundreds of eggs may find beach renourishment or development have made their beaches unsuitable. Hatchlings, blinded by artificial lighting, may head toward death instead of the water. It's a tough life. Only one in 1,000 of the hatchlings will live long enough to reproduce.

As a result of research by Crowder and other scientists, the National Marine Fisheries Service now requires commercial fishermen to install devices called turtle excluder devices (TEDs) on their nets, which allow the smaller turtles to escape. These seem to have reduced the number of juvenile and young adult loggerhead deaths, Crowder said.

In fact, the TEDs and other conservation measures appear to have helped reverse the decline of the adult female loggerhead population between Jacksonville, Fla., and Miami. This subpopulation is now increasing by 4 percent annually.

While this is good news for the southern turtles, the northern turtles aren't as fortunate. The loggerhead numbers from Jacksonville through North Carolina are still dropping at about 2 percent annually, said Crowder. When you combine this fact with the surprising results of the gender study, it is cause for major concern.

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