Trends and drivers of marine fish landings in Portugal since its entrance in the European Union

Marine landings in Portugal have decreased at a higher rate than fishing effort in the last 20 years. Identifying the variables driving the quantity and composition of landings is pivotal to understand the dynamics of the fisheries sector, which entails complex social and environmental aspects. In this study, we investigate the main drivers of marine fish landings in continental Portugal between 1989 and 2014. To identify common trends in time series, and quantify the importance of environmental factors, we applied a dynamic factor analysis considering four regions and three types of gear (trawling, purse-seine, and a multi-gear fishery). Our results show the importance of fishing effort as the most relevant factor driving marine landings in Portugal, both at the long and short terms. In addition, the effect of environmental factors such as the winter river discharge and the spring East Atlantic Teleconnection index should not be neglected, probably through mechanisms affecting coastal productivity. We provide a comprehensive amount of information that permits to improve our understanding of the trends of the most important commercial species in Portugal during the period of study.Fundacao Calouste Gulbenkian Oceanos, within the project "The Economic Valuation and Governance of Marine and Coastal Ecosystem Services" [BPD/UI88/6454/2014]CITABCESAM through FCT Portuguese Foundation for Science and Technology [UID/AGR/04033/2019, UID/AMB/50017/2019]FEDER within the PT2020 Partnership AgreementFCTPortuguese Foundation for Science and TechnologyEuropean Commission [UID/Multi/04326/2019, CCMAR/Multi/04326/2013, DL57/2016/CP1361/CT0035, DL57/2016/CP1361/CT0008]Portugal 2020, n2/SAICT/2017SAICT (Projetos de ICDT)Compete 2020