Tracking Turtles By Satellite for Better Conservation
WWF uses satellite tag data to study turtle migration patterns in the Colombian Pacific
- Date: April 02, 2013
- Author: Molly Edmonds
Marine turtles spend most of their time in the ocean, only coming to shore to nest. We still know very little about their migration patterns, though. Satellite tracking is one way of filling that knowledge gap, allowing researchers to track marine turtles as they swim from place to place.
WWF places satellite tags on marine turtles in many areas around the world. The information collected from the tags helps us to design better management strategies for their conservation, such as creating marine protected areas for important feeding areas or addressing threats to nesting beaches. Knowledge of marine turtle migration pathways is also important to reduce interaction with fisheries, when turtles too often become victims of bycatch.
Satellite tracking involves attaching a special piece of equipment to a marine turtle's shell. The transmitter, or ‘tag,’ sends a message to a satellite each time the turtle comes to the surface to breathe. We then know the location of the turtle and plot it onto a map.
In March, WWF placed satellite tags on two juvenile hawksbill turtles in a protected area within the Eastern Pacific. The photos below illustrate the different steps of the process, from capture to tagging to release. (Note: the satellite tags and attachment process are harmless to the turtle. Turtles adapt quickly to carrying the tag, which are designed to eventually fall off.)
This is most easily done at night, when turtles are least active. On this trip, WWF caught turtles both during the day and at night. A free diver caught each turtle by hand and brought it to the surface.
A turtle researcher carefully transfers a green turtle into the boat. Turtles were later transferred to the laboratory.
Back in the laboratory, general data is collected and recorded, such as the size of the turtle. One of these turtles already had an identification tag, meaning it was currently being monitored by scientists. Recapturing a turtle like this provides important information on turtle habits as well.
Prepare Shell: Clean
Before researchers can attach the tag, they must prepare the turtle's shell. First all algae and attached organisms are removed.
Prepare Shell: Sand
Once the shell is dry, then the transmitter attachment site is selected and rubbed with sand paper to create a smooth adhesion area. Acetone is wiped over the area to create a clean surface.
Now it is time to glue the transmitter in place. The most common and successful method to attach a transmitter is to glue it to the turtle's shell using marine epoxy (a kind of very strong glue, which does not harm turtle). Epoxy is applied around all sides, like icing on a cake.
Once the epoxy dries, the turtle can be released back into the ocean.
Each turtle is placed gently back into the water and allowed to swim off. These two turtles were released in a different location than where they were captured. WWF is testing to see whether hawksbills have reef fidelity—they always return to the same place and will stay there.
The turtle swims off, uninhibited by the tracking device.
- Follow the movements of the two recently tagged turtles
- Marine turtles
- Hawksbill turtles
- Our work to protect marine turtles