Turtles' epic long-distance journeys eyed

U.S. scientists say they've been studying how baby loggerhead sea turtles embark alone on a migration that takes them around the entire North Atlantic basin. After emerging from their underground nests on the beaches of eastern Florida, the turtles begin an epic migration that eventually returns then to North American coastal waters. Researchers looking at precisely how young loggerheads navigate their transoceanic migration say the 2-inch-long hatchlings likely advance along their open-sea routes through a combination of strategic swimming interspersed with passive drifting on favorable ocean currents that allow the young turtles to migrate long distances on limited energy stores. "Young turtles probably rely on a strategy of 'smart swimming' to optimize their energy use during migrations," University of North Carolina marine biologist Kenneth J. Lohmann said. "The new results tell us that a surprisingly small amount of directional swimming in just the right places has a profound effect on the migratory paths that turtles follow and on whether they reach habitats favorable for survival." Once in the open ocean, rafts of plants often provide young loggerheads with food, resting places and camouflage from large fish and birds, the scientists said. "Most researchers have assumed that, because ocean currents in some places move faster than young turtles can swim, the turtles cannot control their migratory paths," Lohmann said. "This study shows otherwise."