Even though large vessel operators are required by law to constantly report their whereabouts via their Automatic Identification System (AIS), some try to avoid detection by turning off their transponders as they engage in illegal activities on the world’s oceans.

But now, the birds might find them.

French researchers outfitted 169 albatrosses with tiny solar-powered, GPS-enabled radar detectors. As the large seabirds roamed over the Southern Indian Ocean, they were able to pinpoint commercial vessels that had turned off their AIS systems.

Albatrosses can travel huge distances for long periods of time and are attracted to fishing vessels, which researchers realized made them perfect for detecting illegal fishing activity.

The bird patrol detected 353 vessels over a six-month period, and the researchers were shocked to learn that 100 of the vessels did not have their AIS systems turned on. The numbers were even worse in international waters.

Read further about the fascinating albatross patrols in this New York Times article.