Social-ecological systems as a new approach to enhance marine conservation

• ¹ Spanish National Research Council, Natural Products and Agrobiology Institute, Spain
• ² Leuphana University of Lüneburg, Faculty of Sustainability, Institute of Ethics and Transdisciplinary Sustainability Research, Germany

Humans exert a strong influence in the environment and marine ecosystems are not free of anthropogenic impacts. Fishing, pollution, habitat destruction, and other global and local impacts such as temperature rise or acidification have increased exponentially in the last century. Effects are particularly noticeable in coastal environments, where humans concentrate their activities. These marine coastal ecosystems provide multiple essential services for society but unsustainable uses of the marine resources may jeopardize our welfare and eventually lead to socio-ecological collapse. As the first modifying driver of the environment, it is about time to include humans in ecological approaches. Current management tools such as marine protected areas (MPAs) have applied a social view, but most researches do not include social data in the ecological system. Social-ecological systems (SES) approach accounts for the human-nature relationships and it has the capacity to enhance marine management by providing new environmental guidelines that improve sustainability and resilience. In this study, we aim to integrate social (population density, type and area of crops, number of fishing vessels…) and ecological variables (richness, Shannon biodiversity, SSTmax…) to characterize the SES of the Andalusian marine coast. To achieve this goal, we obtained social data from public databases (INE and SIMA) and environmental data from the satellite database BioOracle. We then quantified a number of marine biological data using underwater visual census as described by the citizen science program Reef Life Survey. To identify the Andalusian SES we used principal component analysis (PCA) to reduce dimensionality of the input social database, followed by a hierarchical cluster analysis (HCA) to group similar sampling sites into homogeneous categories. Finally, Kruskall-Wallis tests were used to identify the social traits in each group and test for differences in environmental and ecological traits. We obtained four social groups characterized by one or more social, biological, and environmental variables. The first group with an elderly population has the highest value of fish biomass; in contrast, the second group with more marine pollution, agriculture and unexpectedly, the most protection percentage, has the lowest values of fish biomass. The third group had the highest values of phosphate and it is characterized by a strong human pressure (tourism, building). Finally, the fourth group characterized by high percentage of illiteracy population and strong use of land, shows the highest values of nitrates concentration. Our data suggest the possibility to maximize marine biodiversity through new management rules. Anthropogenic impacts are the main cause of loss of marine resilience in the globe. Maybe, these impacts are difficult to remove, but easier to mitigate through management actions. Complexity to define relationship between biological, oceanographic, social, and economic variables is an obstacle in the efficient management of marine resources. However, scientists have to do an effort to include human pressure in their studies, as it is an important driver of ecosystem change, and to convey this information to all audiences. With the approach followed in our study, we apply new social-ecological analyses to marine systems, an area that will benefit tremendously from empirical evidence, providing solid bases to assess the historical influence of human activities in marine ecosystems and to develop efficient management tools.