Data from: The value of satellite tracking across multiple years to identify key areas for conservation

While satellite tracking is widely used to identify areas of particular
conservation importance, whether there is a need to continue tag
deployments across many years is unclear. We show that the destinations of
migrating animals from the same breeding population may differ
significantly across years, and hence we highlight the value of multi-year
tracking studies. Between 2012 and 2024, we used Fastloc-GPS Argos and
Iridium tags to track 58 green turtles (Chelonia mydas) from their nesting
sites in the Chagos Archipelago. If tracking had taken place in a single
year, the number of countries used as foraging destinations could have
been hugely underestimated (n = 1 country in 2024 versus 7 countries used
across years). Overall, 47 % of tracked individuals foraged in the
Seychelles, which likely hosts hundreds of thousands of foraging turtles
across age-classes. Further, the importance of foraging in areas beyond
national jurisdiction (ABNJs) was only revealed by tracking across years.
Across years 9 % of tracked individuals foraged on the Saya de Malha Bank,
a remote ABNJ, equating to likely > 1000 adult females and >
10,000 green turtles using this foraging area. This added information from
tracking across multiple years likely extends across sea turtle
populations as well as other taxa.