Leveraging earth observation data to monitor boat-based recreational fishing

Recreational fishing is widespread in coastal zones and exerts significant ecological, fisheries-related, and socio-economic pressures. Unlike commercial fishing, small-scale recreational fleets are challenging to monitor because they lack enforced use of vessel tracking systems such as the Automatic Identification System (AIS). Recently, remote sensing technologies have emerged as promising alternatives for monitoring marine activities. Here, we assess the potential of high-resolution satellite imagery to monitor daily changes in recreational fishing boats during a temporal fishing ban within a marine protected area. By comparing satellite-derived vessel detections with AIS records, we demonstrate that satellite data can reliably capture daily changes in recreational fishing activity, including a marked increase immediately following the end of the ban. These findings confirm that satellite observations can consistently detect small fishing boats and reveal their fine-scale spatio-temporal patterns. When complemented with local knowledge, this approach enhances our capacity to contribute to the spatial planning and ecosystem-based management of recreational fisheries.