Sunday, October 14, 2007

Not hidden anymore

For decades, scientists have wondered where the green sea turtle goes after it slips into the water. They have known where they hatch and where they return to after they have added size but the "lost years" have been a mystery.

New research though published in the online edition of the journal Biology Letters exposes many of the answers they have sought. It seems that the green sea turle, thought to be a vegetarian, lives those years in the deep sea and feasts on jellyfish and other marine creatures. They reappear around age five along the shores to graze on sea grasses.

The scientists had collected samples from the shells of 44 turtles near the Bahamas and analyzed them for heavy and light isotopes of nitrogen and carbon. They tested newer parts of the shell and older parts and the isotopes revealed where they had been living and what they had been eating.

Green sea turtles are named not for the color of their shell but rather for the color of their meat and fat. Like other sea turtles, they migrate long distances between their feeding grounds and the beaches they are hatched from. They can live up to 80 years but it was the first five years that they seemed to vanish after hatching.

While they have been weighed at up to 694 pounds, the average green sea turtle weighs about 441 pounds. They spend most of their time grazing on seagrasses in shallow laggons and shoals.The adult turtles have only large sharks and humans as an enemy while hatchlings are often dinner for mammmels, crabs and shorebirds.

They do face danger from pollution, habitat destruction and an infectious tumor-causing disease known as fibropapillomatosis. They are very vulnerable and listed as anywhere from critically endangered to threatened in the various regions they live.

The new information as to where they go as a juvenile will only serve to help finds ways to preserve and protect the green sea turtles. It as they have stated, it is difficult to protect a species if you don't know where it is.

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