Characterisation of Megabenthic Community Structure at the Fåvne Hydrothermal Vent Field, with Implications for Environmental Management of Seabed Mining

Abstract

There is an increased interest for deep-sea mining in Norwegian waters due to the potential use of minerals in the green shift. However, concerns have been raised regarding the sustainability of such activities. This study contributes to the characterisation of benthic community structure at the Fåvne hydrothermal vent field located on the Arctic Mid-Ocean Ridge as a contributor to inform management and conservation policies. The research involved collecting data using remotely operated vehicles (ROVs) at a depth of approximately 3000 metres, annotating images, making a morphospecies catalogue, and performing quantitative data analysis. The results showed that the basalt had the highest species diversity and richness, whereas the inactive sulphide had the lowest. The non-metric multidimensional scaling (nMDS) plot revealed significant differences between active vents and background habitats, with individual images displaying considerable variations. There was a clear difference in species contributing to dissimilarities between habitats, particularly the amphipods sp. indet and gastropoda sp. Indet. The findings suggest that there are significant knowledge gaps that need to be addressed before any deep-sea activities can commence. A moratorium may be necessary to allow for further research on potential destructive ecological effects, as technological advances and recycling may reduce the need for minerals. Overall, this study highlights the potential impact of deep-sea mining and the need for caution and further research in this area.