Methodological guidelines for the calculation of a Water-Energy-Food nexus index for seafood products

Indicators from life cycle assessment methodologies (i.e., footprints) have emerged as useful tools for identifying and communicating the environmental impacts of a system thanks to they are accessible and intuitive and easy to understand to non-expert public. However, the focus on a single environmental problem is one of their main drawbacks. From this idea arises the concept of Water-Energy-Food (WEF) nexus, with the aim of raising awareness of the connections between the universal rights to water supply, energy security and food provision. Regarding the latter, the fisheries sector stands out as a fundamental pillar in the fight against malnutrition. In this sense, the European project "blue growth" aims to ensure that the development of the marine sector is not linked to the degradation of its ecosystems. However, although producers and authorities are willing to communicate the sustainability of products, there is still no standard methodology for reporting it. With the purpose of remedying this current situation, this paper aims to provide technical guidance to calculate a single WEF nexus index for ecolabelling seafood products in the European framework (Atlantic area). Therefore, through this, it is expected to create a useful communication channel between producers and consumers through an easy-to-read ecolabel. Nonetheless, certain aspects, such as the footprints selected or the calculation procedures selected have to be reconsidered to refine the methodology proposed, apart from broadening the approach to other food sectors with the aim that the proposed eco-certification can be present in major supply and retail chains.