Satellites employed to detect illegal fishing

Between a third and a fifth of all fish landed are caught illegally which increases the difficulty of preventing overfishing of vulnerable species.  Satellites are now being applied to detecting illegal fishing.  Satellite-AIS (S-AIS) is a satellite-based automatic tracking system used for collision avoidance among over 200,000 ships, especially in international waters.  AIS provides unique identification (signature), position, course, and speed for individual ships.  Satellites have special AIS receivers which are capable of deconflicting a large number of signatures.  The International Maritime Organization requires AIS to be fitted aboard international voyaging ships with 300 or more gross tonnage and all passenger ships regardless of size.  Global Fishing Watch analyzes data from AIS, which is collected by satellites and terrestrial receivers, to identify apparent illegal fishing behavior based on the movement of vessels over time. Currently over 60,000 fishing vessels are tracked.