Talk about a beach goer!
Ever thought of how newborn turtles seem to know how to get to the water? Well, they actually use the bright, low horizon of the ocean to navigate and get there just right after 24 hours of hatching.
However, they now have a possible major problem: light pollution. You see, this may disorient these tiny night crawlers, consequently leaving them to thrive longer on land. That means while they only need just about a few minutes to get to the sea, these disoriented turtles sometimes have to wander on land for hours.
So, to know if these hatchlings could be strong enough to survive all this land crawling and still manage to swim, biologists Karen Pankaew and Sarah Milton of the Florida Atlantic University collected 150 hatchlings from wild loggerhead and green sea turtle nests in Palm Beach County, Florida. (Note: All of which were then released back to the open waters after the study.)
They were then placed in a special treadmill created specifically for them, with an artificial light source at the front so that the turtles would go in that direction. Attracted by the glow, the hatchlings actually had a slow and sure walk for 656 feet in one experiment and 1,640 feet in another, occasionally pausing to rest--distances similar to how far they'd have to walk on the actual beach.
Then, with special swimming harnesses on, they were then lowered them into a water-filled tank on which they paddled. For the next two hours, they were just observed. And to measure the exhaustion they've gone through with this, the oxygen levels in the air, their breathing rates, blood glucose levels, and plasma lactate production—indicators of energy exertion were calculated. Even their stroked rates were recorded.
"We wanted to see how much oxygen they were using because that was a measure of, essentially, their endurance," says Milton, whose studyappeared in November in the Journal of Experimental Biology.
And guess what? Surprisingly, even with long periods of crawling, the hatchlings could still paddle in the water for the two-hour swimming period! "These animals are resilient," says David Godfrey, executive director of the Sea Turtle Conservancy, who was not involved in the study. "They still had the ability to swim."
However, they needed to take their time and have long rest periods. This may be a threat in the wild as the more time they spend on the beach, the more susceptible they are to predators, dehydration, and other threats.
"Even if the sea turtle hatchlings are not as exhausted," she says, "that increased time on the beach is still detrimental."
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