Highly and fully protected marine areas successfully exclude industrial fishing

Code repository to accompany Raynor et al. (In Review). Marine protected areas (MPAs) restore marine life within their boundaries, which can incentivize poaching, but monitoring them is costly. This has led to widespread perception that illegal fishing is rampant in MPAs. We use artificial intelligence and satellite-based earth observation to estimate industrial fishing activity inside fully and highly protected MPAs, where all industrial fishing is illegal. We find insignificant to no apparent illegal fishing activity within these MPAs–about one-quarter (24%) of MPAs never had a fishing vessel present at the satellite flyover time, and the average MPA only had 1 fishing vessel per 16,000 km2. Only a handful of MPAs, primarily located in the Republic of Korea and China, exhibited high industrial fishing vessel presence. Overall, our findings show that highly protected MPAs prevent industrial fishing more successfully than previously thought.