Research priorities and roadmap for deep-sea ecology in the Bay of Biscay (Northeast Atlantic)

The Bay of Biscay is a structurally complex region, exhibiting high biodiversity and productivity and hosting a wide variety of benthic habitats. Unfortunately, current scientific knowledge of deep-sea ecosystems is limited. Our investigation provides an updated vision of the existing knowledge on key aspects of the deep-sea ecosystem and identifies research priorities for the definition of a research roadmap in support of sustainable management, including the protection and conservation of deep-sea ecosystem of the Bay of Biscay. To achieve this, firstly a revision of projects, surveys and studies conducted in the region, was carried out resulting in the identification of 62 publicly available scientific documents. Secondly, an online survey was carried out, receiving 51 responses from 24 research institutions in 9 countries. Finally, a workshop was attended by 39 scientists to identify and discuss ways forward on deep-sea research in the Bay of Biscay. Results indicate that knowledge of benthic habitats, and vulnerable and sensitive habitats/species is good or very good for 45% of the respondents, while limited knowledge was reported for deep pelagic habitats. Almost 75% of the scientists agreed that deep-sea processes affect shallower areas. Funding (71%) and research vessel availability (57%) were considered the most constraining aspects limiting deep-sea research. More than 50% of the scientists perceived a short- or medium-term threat from human activities and pressures, while over than 40% of the respondents considered that there are no, or limited, data available to assess the environmental status. Regarding climate change, 55% of scientists partially or fully agreed with the existence of evidence of climate change effects, but 47% of them totally or partially considered that climate change monitoring is insufficient to assess eventual changes and effects. Most respondents (63%) considered that deep-sea ecosystems are not properly represented in the current Marine Protected Areas network. In terms of future needs, the development of monitoring strategies to reduce costs and guarantee an optimal design, data sharing and an increase in transnational collaboration are most cited. Finally, a proposal for a roadmap to fill in knowledge gaps for a better understating of the ecosystem processes of the deep sea of the Bay of Biscay is delivered.