Deep Sea News

Lost years for sea turtles revealed

i-62347be87e93cbc5a07e97e681e014ed-Chelonia_mydas_sm.jpgResearchers used stable isotopes of carbon and nitrogen on old and new parts of the shells of 44 Bahaman green turtles (Chelonia mydas) to examine changes in sea turtle diets between their juvenile and elder stages.

The results indicate green sea turtles spent their “lost years’ in the deep ocean as carnivores feeding on jellyfish, before moving closer to shore and switching to a vegetarian diet of seagrasses. The new research was published in the online journal Biology Letters. Karen Bjorndal led the study. She is a zoologist and director of the University of Florida’s Archie Carr Center for Sea Turtle Research.

The study is interesting for three reasons. First, it demonstrates that green turtles are not life long vegetarians. Second, it helps to explain where the animals disappear to after they leave the beach as hatchlings. Finally, all seven species of sea turtles are listed as threatened or endangered. The findings have implications for conservation of the green turtles, because as Bjorndal explained, “you can’t protect a species if you don’t know where it is.”

MSNBC carries the story here.
Image courtesy of Teresa Zubi from her website.

Comments

  1. #1 Homie Bear
    September 24, 2007

    Does feeding on jellyfish really count as carnivorous behaviour? Technically I suppose it does but it’s not quite the same as feeding on fish or even shrimp. Although probably more dangerous. Anyways, good article.

  2. #2 Peter Etnoyer
    September 24, 2007

    well, a jellyfish is not a plant, so I guess it’s … the other white meat?

    it would be interesting to know how C/N ratios differ for pelagic suspension feeders (medusoid) jellies and benthic suspension feeders (polypoid) sea pens and anemones.

  3. #3 Hank Roberts
    September 25, 2007

    > carnivores feeding on jellyfish

    Now that’s hopeful, since a great increase in jellyfish seems to be a consequence of human overfishing.

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