Sea Change for Sea Turtles
Sea turtles nesting in the southeastern United States are recovering, but the ancient reptiles still face formidable threats
Doreen Cubie
BEFORE AN AUDIENCE OF MORE THAN 300 PEOPLE, a half-grown loggerhead turtle named Portsmouth scooted down a beach in Sandbridge, Virginia, near the mouth of the Chesapeake Bay. The platter-sized, brown-and-white-speckled animal had been nursed back to health at Baltimore’s National Aquarium after swallowing two fishhooks and was wasting no time hustling back to freedom. Not long after Portsmouth slipped into the sea, researchers began tracking the young turtle’s movements with the aid of a satellite transmitter they had attached to its shell. “We’re trying to learn more about where loggerheads forage in the Chesapeake,” says Gwen Lockhart, a Virginia Aquarium and Marine Science Center geographic information system specialist who is following Portsmouth and a number of other loggerheads. “We also hope to better understand turtle migration patterns in and out of the bay.”
One thing scientists already know is that the Chesapeake Bay is one of the most significant North American nurseries for juvenile sea turtles. “It is very important developmental habitat for both loggerhead and Kemp’s ridley turtles,” says Kate Mansfield, who did her doctoral research in the Chesapeake and is now an assistant professor with the University of Central Florida’s Marine Turtle Research Group. The exact number of sea turtles in the bay is not known, but the Virginia Aquarium’s preliminary estimates show that between 7,000 and 10,000 individual turtles spend the summer months there feeding on whelk, blue crabs, hermit crabs and other prey.
Although green, leatherback and hawksbill turtles also have been documented in the Chesapeake, the vast majority are juvenile loggerheads like Portsmouth. One of the world’s seven sea turtle species, the loggerhead can weigh up to 450 pounds and grow a 44-inch-long shell. Named for their big heads, these reptiles’ powerful jaws evolved to crunch and consume hard-shelled prey such as mollusks and horseshoe crabs. The species ranges throughout the Atlantic, Indian and Pacific Oceans as well as the Mediterranean Sea. But the world’s largest concentration of nesting loggerheads is found on beaches of the southeastern United States, where more and more females are coming ashore each summer to lay their eggs.
“It’s pretty thrilling,” says Mark Dodd, a biologist for the Georgia Department of Natural Resources and the state’s sea turtle program coordinator who has seen nesting loggerheads in his state hit new highs for four years straight. “We think we’re seeing the beginning of a real trend.” ...
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