Identifying fishing behavior groups from vessel movement data: Application to the German brown shrimp fleet

Abstract

The German brown shrimp (Crangon crangon) fleet in the North Sea is declining due to rising fuel costs and unpredictable shrimp prices. Furthermore, this fishery is adapting their area use to new EU Natura 2000 regulations. We analyze thirteen years of Vessel Monitoring System (VMS) data spatially and temporally to investigate fisher behavior for this specific métier. A total of 1938408 VMS pings from 211 vessels are clustered into four behavioral groups differing in vessel length, engine power, total brown shrimp catch, and landing per unit effort (LPUE). We evaluated the potential effect of recently implemented and future marine protected area (MPA) closures linked to the EU Action Plan 2023. The former have negligible overlap with areas exploited by shrimp fishers, but the latter cover grounds from which 70 % of brown shrimp landings originated during 2009–2021. The most affected behavioral group includes 119 vessels, characterized by smaller sizes (vessel length ∼ 16 m), with potential landings decreasing by up to 80 % without effort relocation or behavioral adaptation. Our results show that vessels targeting the same species differ in fishing behavior and spatial footprints. More generally, our approach assesses diversity in fishing behavior and highlights varying adaptability to changing economic and management conditions.