Patterns of Seafloor Biodiversity and Ecosystem Function in the Clarion Clipperton Zone: Are No-Mining Areas Representative of Regional Patterns?

The Clarion Clipperton Zone (CCZ) in the equatorial Pacific, a vast (1000 x 4000 km) region of abyssal plains punctuated by seamounts, is targeted for seabed mining of polymetallic nodules. To safeguard biodiversity and ecosystem functions across the region in the face of mining, the International Seabed Authority (ISA) in 2012 provisionally designated nine 400x400 km no-mining areas, called Areas of Particular Environmental Interest (APEIs). The APEIs were designed, based on environmental correlates of biodiversity and ecosystem function, to be representative of the full range of habitats and seafloor communities potentially impacted by nodule-mining activities, including those within the 16 licensed mining exploration areas spanning the CCZ. Since 2012, a number of research expeditions have collected biodiversity and ecosystem function data within the CCZ providing a new opportunity to assess regional patterns. We recently convened ~45 scientific experts at the Deep CCZ Biodiversity Synthesis Workshop (Oct 1-4, 2019 at Friday Harbor, WA, USA) to (1) collect and review available biodiversity and ecosystem function data from the CCZ, and (2) synthesize patterns of seafloor and benthic-boundary-layer biodiversity, community structure, species ranges, genetic connectivity, ecosystem function, and habitat heterogeneity along and across the CCZ. A major goal of this workshop was to evaluate the representivity of the APEIs relative to the licensed mining exploration areas. We will report the general results and conclusions of this workshop. Workshop output will inform the Legal and Technical Commission of the ISA during its review of its current CCZ Environmental Management Plan, which includes assessing the potential effectiveness of the APEI network for conserving regional biodiversity and ecosystem functions across the CCZ.