. Coast watch. Marine resources; Oceanography; Coastal zone management; Coastal ecology. A Photo by Norman Martin The sea turtle has been roaming the globe for cen- turies. But for a creature with such an ancient history, it remains an enigma. For the most part, scientists know only about the ter- restrial portion of the turtles' lives—a small fraction of their lifetime. For males, this time is limited to development in the egg, hatching and a short trek across the beach to the ocean. But females return to land more frequently to lay their eggs. When female sea turtles reach reproductive matur
. Coast watch. Marine resources; Oceanography; Coastal zone management; Coastal ecology. A Photo by Norman Martin The sea turtle has been roaming the globe for cen- turies. But for a creature with such an ancient history, it remains an enigma. For the most part, scientists know only about the ter- restrial portion of the turtles' lives—a small fraction of their lifetime. For males, this time is limited to development in the egg, hatching and a short trek across the beach to the ocean. But females return to land more frequently to lay their eggs. When female sea turtles reach reproductive maturity (about 20 to 25 years), they nest onshore three or four times a season. Some theories suggest they always return to their beaches where they were born, using olfaction, sand temperatures or water composition to guide them. They nest only at night and use the moon to direct them inland. When a female finds an appropriate site below the vegetation line or near a dune, she digs a hole, lays about 120 eggs, then swims back to sea. In 90 days, hatchlings crawl from the nest and head By Sarah Friday i Sea Turtles Provide Scientists With IVIore Questions Than Answers HARD SHELL TO CRACK instinctively for the water in which they'll spend the rest of their lives. But the odds are against them. Only 1 percent of the hatchlings from each nest reach maturity. Once the turtles are in the water, the mystery begins. Scientists find it nearly impossible to keep track of the large reptiles. Most efforts to tag turtles have been unsuccessful. Small tags break or fall off. Tagging by satellite is costly. In addition, research is hindered by the turtle's lengthy life span. Most sea turtles live to be 100 years old or older, making it impossible for one researcher to follow a full life cycle. Studying an endangered species creates problems, too. Population numbers are low. Special restrictions for testing exist. And the work is expensive. But scientists persist. They know a better under- stan
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