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Ned Potter is the science correspondent for ABC's "World News with Charles Gibson." He has reported on such topics as space exploration, the human genome and climate change.
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The Long Journey of the Leatherback Turtle
April 04, 2008 8:02 PM
There are migratory animals in this world, and then there are leatherback turtles. Scientists have tracked one 13,000 miles -- halfway across the world -- apparently in search of food.
We did a World News piece on the leatherbacks, and the work being done on them by researchers at NOAA’s Southwest Fisheries Science Center.
"They really are a remarkable creature and we don't know a lot about them,” said NOAA’s Peter Dutton.
The turtles are hard to track because they’re remarkably difficult to find in the ocean. Scientists say the turtles are solitary travelers, often diving thousands of feet, then surfacing only briefly for air.
So the scientists set out by boat and chase plane to find turtles where they could. Peter’s brother John Dutton, a filmmaker, chronicled the search for a documentary called "Jurassic Journey." A link to his production company is HERE; excerpts from "Jurassic Journey" are HERE, and they’re worth watching.
"It is a cryptic, seldom-seen species," said Scott Benson, Peter Dutton’s research colleague. "Many people here" -- even on the staff at the Science Center, he said -- "have never seen this animal."
In a report to a recent conference, the scientists said they successfully attached satellite transmitters to nine leatherbacks in the Pacific. They knew the turtles were migratory animals, but there was one that surprised them.
Over a period of 695 days, it swam from Papua, Indonesia...northeast across the Pacific to Hawaii...and on to the coast of Oregon, where it stopped to feast on jellyfish, the staple of the leatherbacks' diet.
Then it headed back toward Hawaii, and it probably went beyond, but by then the transmitter finally failed.
12,774 miles, sometimes at a pace of 35 miles a day.
This is of more than passing curiosity. Leatherbacks are considered threatened on both the Atlantic and Pacific coasts of the U.S. Some scientists think their numbers in the Pacific have declined 95 percent, as people in tropical countries catch them on the beaches where they lay their eggs, and fishing boats snare them as "bycatch" -- accidental victims -- in their nets. More information is at Seaturtle.org
The long migration, may, in fact, help protect them. It spreads them around, so that if conditions are bad in one place, other turtles may survive elsewhere.
How do they live on the long journey, if the only food they really want is the jellyfish in one part of the ocean?
"Oh, they snack," Scott Benson told me. "Think of yourself on a long car trip. You may pull into a McDonald’s on the way, but the real meal is at grandma’s house when you get there."
(World Wildlife Fund, N.J.Tangkepayung/AP Photo)
April 4, 2008 | Permalink | Share | User Comments (6)
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The law of unintended consequences. Strapping that kind of awkward, non-aquadynamic gear onto that turtle accounts for as much as 20% more energy that the pour turtle has to expend to swim. Wouldn't be as bad if it didn't have to traverse such great distances to feed. Come on, guys. Get your design together.
Posted by: Alan Beattie | Apr 4, 2008 11:08:36 PM
Great report on WN this evening, Ned! I'd never have thought that such a journey was feasible for the leatherback!
Posted by: chuck | Apr 4, 2008 11:24:04 PM
Note from Ned--
Hello Chuck. Welcome back.
Hello, too, to Alan. I ought to add a little in the researchers' defense. They have, in fact, modified their tracking devices since the one in the photo; often, the devices are small enough to be attached to a turtle's back with a suction cup. I'm curious to know more about the 20-percent figure.
Posted by: Ned Potter | Apr 4, 2008 11:59:30 PM
Ned,
Glad to hear that that is not the rig they send the turtles out with now. The 20% figure is intentionally provocative and "qualified" in my first post.
My "as much as" estimate is based on what I perceive to be the flow disruption over the turtle's topside (which of course effects the entire swimming effort), given the apparent design disregard for rather simple aquadynamic principles.
In the ABC clip, they showed a turtle being launched to sea with apparatus attached which would function pretty much like the air brakes on a jet plane at landing. If one looks at the Leatherback straight on from the front, it's easy to admire the evolutionary and efficient profile of the turtle. They are incredibly streamlined and efficient. The water flow dynamics, with this gear attached, are severely compromised (see Wikipedia "fluid dynamics").
I really did not mean to trash the great accomplishments of the researchers. I only meant to point out:
The law of unintended consequences.
AWB
Posted by: Alan Beattie | Apr 5, 2008 1:19:57 AM
Hopefully some of the data will be useful from a protection standpoint. Leatherbacks are intriguing creatures.
Posted by: LauraFromBorders | Apr 5, 2008 6:07:11 PM
I know its late, but I missed this one. Great story Ned. Turtles are interesting animals, especially for their longevity in some species, and tortoses as well. I hope the data helps their protection efforts.
On a side note, nice to see you back Chuck. Haven't seen you here in a while.
Posted by: Lawrence | Apr 9, 2008 8:47:05 AM
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