Large ships are supposed, by international agreement, to be fitted with what is known as the Automatic Identification System (AIS), and to keep it on all the time. Arrangements for small ones vary from country to country, but most require some sort of beacon to be fitted to craft sailing in their waters.
The beacons’ main purpose is to avoid collisions. But monitoring them can also give away who is fishing nefariously, if you develop the software to sift through masses of location data looking for patterns. Beacon-watching has also helped identify hot spots for the transfer of catches at sea from IUU fishing boats to refrigerated cargo vessels, a practice which conceals the origin of a catch. Transshipment hotspots have been identified in this way off west Africa and Russia, and in the tropical Pacific. But beacons can be (and are) switched off.
Global Fishing Watch—a collaboration between Oceana, a conservation group, Google, a division of Alphabet, and Sky Truth, a charity that uses remote sensing to monitor environmental problems—has turned to America’s National Oceanic and Atmospheric Administration for help. NOAA has long collected satellite data on clouds. These are available to outsiders at no cost. The agency’s Visible Infrared Imaging Radiometer Suite consists of two sensors, each mounted on a different satellite. Between them, these sensors photograph the entire planet every 24 hours. Though their target is cloud cover, they can also see small, bright sources of light. Some of these give away the activities of fishermen. Many marine species are attracted to light, so it is common practice to shine floodlights into the water.
To find those illegals who do not so conveniently illuminate their activities Global Fishing Watch turns to satellite radar data. These are gathered mainly by private companies for sale to customers who want to do things like monitor the logging of forests. Global Fishing Watch, too, has to pay for them. Radar data have proved themselves useful, though. In 2016, for example, radar turned up a fleet of ships off the coast of Chile that had their AIS turned off…. The European Union’s Sentinel satellites now provide radar data free of charge. Global Fishing Watch is working on an automated vessel-detection system that uses these data.
Better detection would certainly help limit IUU fishing. The Port State Measures Agreement, introduced in 2016 and now ratified by 55 countries, is supposed to stop vessels engaged in such fishing from landing their catches. But ports can act against a vessel only if they know what it has been up to. The technology being developed by Global Fishing Watch makes it possible to report offenders quickly, thus giving port authorities time to act.
The future, moreover, looks brighter still—or dimmer, if you are an illicit fisherman. CubeSats, satellites the size of a loaf of bread, are lowering the cost of Earth observation. making it feasible to track all boats continuously.
Excerpts from Netting the Crooks: Curbing Illegal Fishing, Economist, Sept. 8, 2018