Workshop to develop methods in determining effort metrics for bottom-contacting static gears (WKSTGEM)

The main gear types considered were benthic traps/pots, bottom longlines (including semi-pelagic variants such as 'piedra-bola' and 'umbrella-and-stones' gears), and bottom-set gillnets and trammel nets. An idealised uniform methodology for estimating bottom contact area was reviewed, accounting for mainline geometry, anchor dimensions, lateral movement, hauling dynamics, and gear-type-specific parameters. Key findings confirmed that static gears do no remain stationary during deployment, and lateral movement during soaking and gear drag during hauling both contribute significantly to the effective seabed footprint, with depth and environmental conditions being major modulating factors.</p><p dir="ltr">Under ToR (b), the workshop examined VMS, AIS, GPS, logbook, and fleet register data as sources for mapping static gear activity.

A fundamental mismatch was identified between the data infrastructure designed primarily for mobile gears and the requirements for characterising static gear deployment, soak time, and retrieval. Hauling time and soak time derived from tracking data were identified as practical proxies for effort intensity, applicable at multiple spatial scales. Spatial resolution was found to be critical: ping rates of at least one per minute are required to accurately capture gear deployment and retrieval, whereas current mandatory VMS reporting rates (30-minute intervals under EU Control Regulation 2023/2842) remain insufficient.

Small-scale fisheries vessels (generally below 12 m) are the most significant data gap.</p><p dir="ltr">Under ToR (c), the workshop reviewed case studies and novel approaches that demonstrate practical application of effort estimation methods. These included sensor-based direct gear monitoring, a pot movement and swept area ratio study in a whelk pot fishery in North Wales, and a hidden Markov model approach to classify fishing behaviour phases from AIS data for the Portuguese polyvalent passive gear fleet.

The workshop concluded that a pan-European single methodology is not feasible; regional and fleet-specific approaches are required given the marked heterogeneity of static gear types, vessel characteristics, and data availability across EU ecoregions.</p><p dir="ltr">The workshop produced a set of conclusions and recommendations spanning methodological development, data collection improvements, and regulatory and institutional actions.

Priority recommendations include: developing agreed terminology for static gear effort and footprint metrics (distinct from mobile gear SAR); advocating for increased ping frequency requirements (minimum one-minute intervals) for vessels deploying static gears; differentiating longline sub-types in ICES data calls and EU logbook regulations; promoting the integration of sensor-based gear monitoring data into regulatory frameworks; and supporting regional case studies to parameterise and validate effort estimation models.</p>