Ships ‘going dark’ by turning off tracking devices along with patchy enforcement have fuelled concerns that marine protected areas (MPAs) are little more than ‘paper parks’ which lack true protection. However work led by experts at the University of Wisconsin-Madison, US, suggests that the opposite is true. Focusing on MPAs where industrial fishing is outlawed, they spliced tracking data with satellite imagery and used AI to identify which ‘dark’ ships were likely to be fishing vessels. The “striking” results revealed “little to no signs of industrial fishing” in highly-protected MPAs. A further study revealed “substantial” fishing activity where protection is low.