Coastal management challenges in declining clam fisheries: insights from local ecological knowledge in Spain

Spanish clam fisheries have experienced declining landings and repeated closures, raising questions about how ecological pressures and governance constraints are understood by those involved in their management. We conducted 94 semi-structured interviews with fishers, guild leaders of fishers and regional managers across the Mediterranean and southern Atlantic coasts of Spain between April 2024 and August 2025. Focusing on (Donax trunculus), (Chamelea gallina) and (Callista chione), we used thematic analysis to examine perceived pressures, institutional constraints and contextual variation among study areas. Interviewees identified multiple pressures, including environmental variability, habitat alteration, pollution, episodic mortality and fishing-related factors. Assessments of management and governance were predominantly negative, with recurring concerns about coordination, participation, uneven implementation of rules, monitoring and enforcement. Accounts also highlighted conflicts with other coastal users and differences in the fishing contexts represented across study areas. These findings are consistent with a context-dependent understanding of decline in which perceived ecological pressures and institutional constraints are closely connected. However, the purposive sample does not support population-level estimates, causal attribution, or independent validation of management effectiveness. Policy options arising from the analysis include more coordinated rules across modalities, participatory monitoring, traceability and enforcement adapted to nearshore conditions, and stronger integration of fisheries into coastal decision-making. The study identifies priorities for more coherent governance while distinguishing stakeholder accounts from demonstrated ecological mechanisms and management outcomes.