Assessing spatio-temporal changes in marine communities along the Portuguese continental shelf and upper slope based on 25 years of bottom trawl surveys. (September 2020)

• Record Type: Journal Article
• Authors: Moura, Teresa; Chaves, Corina; Figueiredo, Ivone; Mendes, Hugo; Moreno, Ana; Silva, Cristina; Vasconcelos, Rita P.; Azevedo, Manuela
• Is Part Of: Marine environmental research. Volume 160(2020)
• Publication Date: 2020-09
• Subjects: Biodiversity -- Climate change -- Demersal species -- Fishery impact -- Oceanographic conditions; Marine pollution -- Environmental aspects -- Periodicals; Marine ecology -- Periodicals; Mer -- Pollution -- Aspect de l'environnement -- Périodiques; Écologie marine -- Périodiques; Electronic journals; 577.705
• DOI: 10.1016/j.marenvres.2020.105044
• Languages: English
• ISSNs: 0141-1136

Abstract

Abstract: The Portuguese continental coast is influenced by several oceanographic processes and is located near the confluence of three biogeographic realms (from the North Atlantic, South Atlantic and Mediterranean). Given these features, the topography of the Portuguese coast, possible variations in fishing effort and reported increasing sea surface temperature in the last decades, we hypothesized that changes in marine communities in space and time occurred since 1990. In this study, research survey data collected yearly along the Portuguese continental slope (20–500 m deep) from 1990 to 2016 were analysed with the objective of identifying spatio-temporal changes. Latitude and depth were found to play a major role in communities' spatial differentiation, probably associated to temperature, and three ecological areas were defined (north, southwest and south). In the studied period, Macroramphosus spp. abundance showed a marked decrease in all areas whereas Sparids increased in abundance in the south. Despite these major changes and fluctuations in species abundance over time no major trends in communities were observed. Fishing activity, environmental conditions (including climate change) and biotic factors are all drivers possibly responsible for those changes. Highlights: Long-term dataset was used to infer spatio-temporal changes in marine communities. Latitude and depth play a role in communities' spatial differentiation. Most changes in communities reflect fluctuations in species abundance over time. Trends in species abundance were detected for some species in the 2000′s. Fishing, environment, climate change and biotic factors may be responsible for those changes.