Amid discoveries about lost cities and lost treasure come new findings on something else that has been long lost to science: knowledge of sea turtles' "lost years." As Phys.org explains, little has been known about the period of time bookended by turtles hatching and then reappearing in waters near the coastline. In the interim, they head to sea for a minimum of one to two years, and what those young turtles do during that time has previously only been "inferred through genetics studies, opportunistic sightings offshore, or laboratory-based studies," explains the lead marine biologist behind the new study, published in Proceedings of the Royal Society B. For loggerhead turtles, which is what Kate Mansfield and her team studied, the lost period can be as long as seven to 12 years, reports Smithsonian.
They tracked 17 loggerheads using small, solar-powered satellite tags adhered to the animals' backs using, among other things, manicure acrylic and hair-extension glue, and followed the turtles for anywhere from 27 to 220 days. "We were surprised by how quickly ... and how far they traveled," says Mansfield, who estimated one traveled 700 miles from West Palm Beach, Fla., to Cape Hatteras, NC, in 11 days. As suspected, most turtles avoided the continental shelf, where seabirds and sharks are a threat. Where turtles did spend a lot of time was near the surface, and the tags on their shells recorded more heat than expected. This led the team to theorize that the reason the cold-blooded creatures may spend time in giant rafts of seaweed known as Sargassum in the deep ocean is to get a "thermal refuge." And Mansfield says that if the young turtles are warm, "their metabolism kicks in and they start feeding more, and they may grow faster ... so temperature can also help turtles grow and survive." (Read more discoveries stories.)