Earthwatch Expeditioner: Ten Years of Turtle Tracking
- wallacejnichols
- Feb. 1, 2007
Ten years ago today, Adelita, a female loggerhead sea turtle, was about halfway across the Pacific Ocean, a few hundred miles northwest of Hawaii. Adelita was the first sea turtle to wear a radio transmitter bonded to her shell, and head out across the Pacific Ocean.
She was originally captured by a fisherman in 1986, when she weighed about 8 pounds, and was given to a research facility in Bahia de los Angeles. Earthwatch provided Wallace J. Nichols, Jeffrey Seminoff, and Antonio Resendiz with their first research grant for sea turtle research in Bahia de los Angeles, where Adelita was being held in captivity. Earthwatch volunteers and researchers fed and cared for Adelita in captivity, and learned a great deal about sea turtle behavior. Continuing Earthwatch support allowed researchers to set up long-term studies in the area. In August 1996, the researchers set the now 223-pound reptile on the beach at Santa Rosalillita in Baja California, and wished her well.
“Adelita’s journey was truly the start of an ocean revolution,” says Nichols, who has received Earthwatch support for a new research project: Tracking Baja’s Black Sea Turtles. Adelita would eventually make the 6,000-plus mile journey from Baja California to her birthplace of Kyushu Island, Japan, confirming that animals do cross the Pacific Ocean, and, says Nichols, “that what we do on one side of the ocean impacts the other side.” For the first time, researchers had confirmation that sea turtle conservation programs must span the globe in order to be effective.
Whenever Adelita would surface, the one-pound transmitter would beam her location to a satellite. Nichols kept track of Adelita through emails send to him by a private satellite for a year. In August 1997, two weeks went by without receiving signals before a final set was received indicating that Adelita was moving very quickly in a straight line toward the nearest port, Sendai. Researchers believe she was probably caught in some kind of fishing gear, which we now know is major threat to sea turtles the world over. A reconnaissance trip to squid fishing village in Japan led Nichols to believe that she had quite likely met her end this way, though he was unable to find her transmitter. (For more details and photos of this trip, visit the Oxygen group website.)
Ten years later, our knowledge of the ocean has expanded considerably. Researchers and Earthwatch volunteers have tagged numerous sea turtles of all species, birds, sharks, marine mammals, and even pelagic fish like tuna, since Adelita. With the data from all these animal-based transmitters, we have identified important ocean hotspots where ocean wildlife congregates to feed, and know much more about migration patterns of various marine species.
Despite our newfound knowledge, sea turtles throughout the world are struggling for survival. Pacific leatherbacks have completely disappeared from some of their age-old nesting grounds. The Malaysian beaches that used to host one of the biggest leatherback nesting populations in the world did not produce a single hatchling in 2006.
Sea turtles are facing numerous challenges – pollution, entanglement in fishing nets, the stealing of turtle eggs (considered a delicacy), and poaching of adults for meat have all been contributing to their decline for decades. They now face a new threat: global warming. The gender of hatchlings is determined by the temperature of egg incubation, just as with many reptiles. Warmer temperatures lead to more females, which has been the case in Malaysia, say researchers.
Even with so much against them, sea turtle biologists like Nichols aren’t ready to give up. And neither is Earthwatch. Earthwatch continues to support sea turtle conservation efforts by working with local community conservation projects, contributing to global initiatives, and providing support for researchers and volunteers to conduct vital data collection.
