A New Approach for Protecting Areas in Atlantic Beyond National Jurisdiction Based on Seascapes and Trade-Offs with Human Activities

Abstract

International biodiversity agreements set ambitious goals aiming to expand protected areas by up to 30%, including areas beyond national jurisdiction. The extent of the high seas, the shared governance, and the limited availability of biodiversity data challenge the identification of large-scale protected areas. In this context, this study explores seascapes defined from satellite data as proxies for biodiversity in the Atlantic high seas to assist in preliminary designations of protected areas at large scales. Seascapes extent is compared with the distribution of phytoplankton groups, fish species, and endangered species to assess their biodiversity representability in the Atlantic Ocean. Then, the study addresses trade-offs between the goal of protecting 30% of each seascape and current human activities such as shipping and fishing. For all the trophic levels, each species or group dominates at least in one seascape, suggesting that protecting at least 30% of each seascape is a good starting point for protection, which can be redefined later based on the presence of rare species or key habitats. Four protection strategies have been tested: a) minimize overall activities impact including national waters (Overall Strategy), b) minimize only the impact of high seas activities (Highseas Strategy), c) protect 30% of seascapes centroid (SC-Overall Strategy); and d) protect 30% of seascapes centroid at high seas (SC-Highseas Strategy). Obtained results indicate that implementing a combined protection strategy between Highseas and the SC-Highseas might be the best. This combined strategy defines lanes where there is currently more activity and redirects vessel activities in the proposed protected areas to these lanes, prioritizing the protection of the centroid of the seascapes. This protection strategy requires that activity of shipping and fishing vessels should be reduced or shifted to limit the impact on activities and significantly protect marine biodiversity.

Keywords: Other effective conservation measures, marine protected areas in high seas, environmental quality management, optimizing human activity and conservation, socio-economic and conservation trade-offs, natural resources management