Sea turtles travel hundreds, and sometimes thousands, of miles during their seasonal migrations between foraging and nesting habitats. Using satellite telemetry, scientists have observed their movements as they track warm waters in search of food and places to build their nests. The leatherback turtle holds the record for the longest migration amongst sea turtles – it crosses the entire Pacific Ocean, traveling more than 10,000 miles each year in search of it’s favorite food, jellyfish!
These movements take sea turtles across oceans, using migration corridors and crossing national and international human boundaries. During their migrations, they face many challenges from human disturbance, including habitat destruction, pollution, bycatch fishing mortality, noise, and boat strikes. Because of this, 63% of sea turtle subpopulations are listed as Nearly Threatened or Threatened by the by the International Union for Conservation of Nature (ICUN). And sea turtles are not alone. For other marine species who migrate such great distances, like whales, sharks, and seabirds, how can we protect their habitats and migration corridors when so many different organizations and interests are involved?
When a species migrates, it does so without consideration to countries or jurisdictions. This is especially true for ocean species. Throughout these migrations, they interact with humans in many ways, having implications for their population persistence. They also play important sociocultural roles, providing recreational and tourism experiences, spiritual and religious significance, aesthetic value, and providing other ecosystem services. To determine why the populations of so many marine species are in decline, we need to understand their migration patterns and connectivity between their habitats. Tracking studies need to be integrated into decision making by international policy makers.
A recent paper took a synthesis approach to look at existing migration datasets. They created a prototype system, MiCO, to integrate telemetry data, in the hopes that it could now be more easily used to inform policy and management decisions. At the time of publication, their system included data from 357 animals from 7 species, and categorizes areas used by populations by the activity type (e.g. breeding, migrating, non-breeding, ranging, etc.). Their hope is to serve as a model for how migratory data can be catalogued and synthesized, eventually leading to data from the tens of thousands of publications to be more easily accessed by policy makers and conservationists across the globe.
Dunn D.C. and Harrison A.-L. et al. 2019. The importance of migratory connectivity for global ocean policy. Proc. R. Soc. B 286: 20191472.