The fishing sector constitutes an important source within the economy of northern Spain, primarily due to its extensive coastline and the multitude of fishing ports. However, fishing activities entail various direct environmental impacts, as well as indirect and off-site effects. In this context, various research studies have focused on the application of the five-step Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) methodologies in fishing systems. However, all of them have used environmental indicators that focus on individual environmental issues, hindering the goal of achieving integrated resource management. Therefore, in this study, the water–energy–food (WEF) nexus is employed as an integrative perspective that considers the synergies and trade-offs between water demand, energy requirements, and carbon footprint.

The main objective of this study is to evaluate the operational efficiency and environmental impacts of Cantabrian fishing fleets. To this end, the combined use of LCA and DEA, along with the WEF nexus, was applied to the Cantabrian purse seine fleet to understand the eco-efficiency and potential environmental benefits of operating at higher levels of efficiency within this fleet.

The average efficiency of the fleet was above 60%; inefficient units demonstrated a greater potential to reduce their environmental impacts (up to 65%) by operating according to efficiency projections. Furthermore, the results revealed a strong dependence of environmental impacts on one of the operational inputs (i.e., fuel consumption). These findings highlight the significance of embracing holistic approaches that combine technical, economic, and social factors to achieve a sustainable balance in fisheries systems. In this regard, the five-step LCA+DEA method applied in conjunction with the WEF nexus emerges as a suitable tool for measuring operational and environmental objectives.