This research examines the feasibility of using Automatic Identification System (AIS) data as a high-resolution alternative to the Vessel Monitoring System (VMS) for mapping fishing effort across the European Union. While VMS has traditionally been the primary tool for spatial fisheries research, its use is often limited by confidentiality restrictions and a low temporal resolution, typically transmitting data only every two hours. In contrast, AIS data is publicly accessible and provides updates every few seconds to minutes, potentially allowing for far more precise mapping of fishing activities.
The sources detail three primary areas of investigation:
- System Adoption: Following EU regulations in May 2014 making AIS compulsory for fishing vessels over 15 metres, the study found a 75% uptake rate within the EU fleet by August 2014.
- Methodology: Using the Swedish fleet as a case study, researchers developed a data-driven approach to distinguish between fishing and "steaming" (transit). This involves using an Expectation Maximization (EM) algorithm to identify bimodal speed profiles, where lower speeds indicate active fishing.
- Validation and Resolution: The method was validated against detailed Swedish logbook data, demonstrating that AIS can produce fishing effort maps with a resolution of 1 nautical mile or less, providing a significantly more detailed view of environmental impacts than standard reporting.
Despite these advantages, the research highlights ongoing challenges, including discontinuous signal coverage in offshore areas and the current inability of AIS to provide direct data on catch volumes or species, which still necessitates integration with traditional logbooks.
