Four years ago, we posted about an attempt to use “big data” to crack down on illegal fishing. Google partnered with SkyTruth and Oceana to produce a new tool, Global Fishing Watch, to track global fishing activity. The problem is that to avoid detection, boats fishing illegally often turn off their AIS (Automatic Identification System) to avoid detection. The Google project uses satellite data to provide detailed vessel tracking and aims to harness the power of citizen engagement to tackle overfishing.

A recent study led by Henri Weimerskirch, a marine ornithologist at the French National Center for Scientific Research, takes a more hands-on, or perhaps, wings-on approach. Weimerskirch and his colleagues have outfitted nearly 200 albatrosses with tiny 65-gram GPS trackers that detect marine radar signals. While illegal fishing boats may choose to turn off their AIS transponders, it seems likely that they will keep their radars on for navigation.

As reported by Sciencemag.org, albatrosses make good spies. The birds, which prey on fish, can spot a fishing vessel from as far away as 30 kilometers. Some species fly hundreds or thousands of kilometers while foraging.

In an initial 2017 study with the data loggers, Weimerskirch and colleagues showed that albatrosses from the Crozet Islands (about 2300 kilometers south of Madagascar) flew across 10 million square kilometers of the western Indian Ocean. Almost 80% of them encountered ships.

In a subsequent study between December 2018 and June 2019, the birds encountered 353 ships. Those locations were transmitted to the lab typically in less than 2 hours. If they did not match the locations of vessels with an active AIS beacon, the team knew the ships had switched it off. The result: Twenty-six percent of the vessels had illegally turned off their AIS within the exclusive economic zones (EEZ) of the three islands, the team reports this week in the Proceedings of the National Academy of Sciences. In international waters, 37% of detected vessels had their AIS switched off.

Thanks to Irwin Bryan for contributing to this post.