We use a bit of data manipulation, science, and technology.
It is not easy to follow a sea turtle as it roams the oceans, but each year the technology gets better and better.
Platform Transmitter Terminals (PTTs) are small, battery powered devices that are most often attached to the carapace of a sea turtle. These can be attached with epoxy to hard shelled turtles like loggerheads and green sea turtles or via a simple direct attachement for leatherback sea turtles. The PTT collects data and then sends regular updates to the Argos equipped satellites each time the turtle surfaces for air. After a period of time the batteries are exhausted and the transmitter stops working and falls off the turtle, or is removed by researchers when the turtle is encountered again.
The Argos system is a satellite-based location estimation and data collection system. Researchers place small devices onto sea turtles that collect and transmit data to an Argos-equipped constellation of satellites; devices that transmit to Argos are called PTTs (Platform Transmitter Terminals). The Argos system receives data from a PTT and then uses a special algorithm to estimate its location at the time of transmission based on the Doppler shift of the signal frequency received during the passing of one of the polar-orbiting satellites. More information about Argos can be found here
While the technology is amazing and getting better each year, a lot can go wrong with satellite tagging. Often when we no longer receive data from a turtle is is because of biofouling or a depleted battery. Since these transmitters are in the marine environment they are subject to growth of algae and barnacles. Researchers will apply certain anti-fouling compounds to the PTTs but the protection does not last forever. With proper programming, batteries can last several years, but their capacity is not infinite and they will eventually die. Sometimes a PTT will fall of a turtle prematurely. This can happen during mating season when male turtles are competing for females. It can also occur when turtles rest under coral reefs or other underwater structures.
Tracking sea turtles is often a very expensive endeavor for researchers.
Please consider supporting this work by making a small donation or adopting one of the tracked sea turtles. Even a few dollars helps. If you are a researcher actively tracking an animal and would like your turtle to appear on this site, let us know!
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