The Issue: While global seafloor exploration progressively reveals the tremendous diversity and fragmentation of deep-sea ecosystems, their sensitivity to climate change remains largely unconstrained. Not only the conservation of biodiversity needs attention, but also the synergistic effects of climate change and increasing exploitation of resources (fishing, extraction of minerals and hydrocarbons) on deep-sea ecological functions and services.
Synergies across marine and climate sciences, geosciences and economics have established new paradigms and confirmed the vulnerability of the deep sea to climate change. Observations provide growing evidence of the influence of climatic forcing on ecosystems of the deep-seabed over many temporal scales (e.g. from storm events to climatic ocean oscillations). Numerous ecological hotspots are affected such as seamounts, ridges and canyons. Significant climate-driven impacts on ocean biogeochemistry (deoxygenation, acidification, changes in organic carbon fluxes) are predicted from empirical models built on climatic scenarios.
Areas where enhanced vertical mixing of ocean waters coincide with direct pressures of human activities (e.g. deep-sea mining, oil and gas extraction, deep-sea fishing), like seamounts, canyons, upwelling or polar regions, are also particularly sensitive to climatic effects. This justifies the need to consider climate change in environmental management and conservation strategies.
The Working Group: The DOSI Climate WG comprises 95 members from 18 countries and aims to provide a platform to centralize information about scenarios and observations to better assess the impact of climate change on deep-sea ecosystems and to address cumulative pressures. The goal is to facilitate integration of this information in environmental impact assessment and management plans and in the design of Marine Protected Areas. We will also aim to identify high-vulnerability areas and foster interdisciplinary approaches to investigate how deep-sea ecosystems interact with climate on a functional basis. Both experimental and theoretical support is required to improve predictive models for this overlooked but largest component of the Earth system. The working group also presents deep-ocean climate science to policy makers in the UNFCCC (at COP and SBSTA), the International Seabed Authority, the FAO and the BBNJ negotiations, through presentations, policy briefs, webinars and publications.