2026/04/27 by Ίριδα Μάινα, Archontia Chatzispyrou, Nikolaos Fotiadis +5 · 1 voice
Environmental Science · #Ichthyology and Marine Biology #Marine and fisheries research #Fish Ecology and Management Studies
paper · doi:10.1016/j.ecss.2026.109937
This study explores the impact of spatial management measures on bull ray ( Aetomylaeus bovinus) bycatch in the eastern Ionian Sea (Central Mediterranean). Bottom trawlers and small-scale fisheries (SSF) interact with the critically endangered bull rays due to habitat/fishing ground overlap and gear susceptibility. Unlike bottom trawling, which is monitored through Vessel Monitoring Systems (VMS) in the study area, assessing bycatch risks in SSF is hindered by data limitations, including the lack of vessel positioning systems and limited records of bull ray bycatch. To address this, we employed an extended Multi-Criteria Decision Analysis method, alongside VMS analysis and species distribution models, to spatially estimate SSF and trawling effort and map bull ray habitats. The estimated fishing effort and other bio-economic parameters were used as input in a dynamic spatially explicit bio-economic model (DISPLACE) which was applied to simulate fishing effort re-distribution under the scenario of trawling ban in Marine Protected Areas and Natura (2000) sites, based on a national commitment linked with the EU Marine Action Plan provisions. Predicted fishing effort (current and re-distributed) and bull ray spatial distribution were then used as input in the Productivity-Susceptibility Analysis to estimate bycatch risk spatially. The predicted outcomes of the alternative scenario were compared with the baseline situation. Results revealed that the species is more abundant in the northern part of the study area where the highest bycatch risk is exhibited. The trawling ban in protected areas and effort displacement increased bycatch risk by +9% on average, mainly affecting the northern study area, while the central and southern areas remained unchanged. The approach followed aims to support the implementation of ecosystem-based fisheries management by informing on bycatch risks and highlights the need for developing a planning framework integrating multi-objective optimization in each social-ecological system.