The use of remote sensing to detect illegal, unreported, and unregulated (IUU) tuna fishing activities in the Peruvian Exclusive Economic Zone

Illegal, unreported, and unregulated (IUU) fishing activities have historically been difficult to detect due to a lack of adequate monitoring and surveillance technologies. In recent years, advances in computational capacity and the growing availability of fleet tracking datasets have enabled the development of algorithm-based tools for monitoring fishing activity. Additionally, satellite geolocation systems, such as Automatic Identification Systems (AIS) and Vessel Monitoring Systems (VMS), have been implemented across multiple fishing fleets worldwide, further enhancing surveillance capabilities. The current study proposes the combined use of AIS and VMS data with satellite imagery to detect and characterize IUU activities of foreign fishing vessels targeting the tuna fishery in the Peruvian Exclusive Economic Zone (EEZ) in the year 2022. Fishing effort was quantitatively characterized according to permit compliance considering three categories of IUU activities: fishing beyond the permit timeframe, inside a marine protected area (MPA), or without a valid permit. Out of a total sample of 61 vessels evaluated, 56 were detected fishing within the Peruvian EEZ, of which 47 operated within allowed permit lengths, 6 exceeded their authorized days within the EEZ, and 3 had no permit at all. However, of the 47 vessels complying with their permit timeframes, 16 engaged in IUU fishing within the Dorsal de Nasca MPA. These results revealed distinct behavioral patterns of fishing effort not only within the Peruvian EEZ, but also within the broader Eastern Pacific Ocean. • The use of AIS and VMS signals with satellite-based imagery allowed identifying IUU fishing. • A group of 61 foreign tuna-targeting purse seining vessels potentially operating in the Peruvian EEZ was selected. • About 5.5% of fishing effort hours were either performed beyond temporal permits or in marine protected areas. • Offenders appear to have been subject to sanctions in the past, but these have not been dissuasive from further IUU fishing.