Three decades of increasing fish biodiversity across the north-east Atlantic and the Arctic Ocean

Abstract

Observed range shifts of numerous species support predictions of climate change models that species will shift their distribution northwards into the Arctic and sub-Arctic seas due to ocean warming. However, how this is affecting overall species richness is unclear. Here we analyse scientific research trawl surveys from the North Sea to the Arctic Ocean collected from 1994 to 2020, including 193 fish species. We found that demersal fish species richness at the local scale has doubled in some Arctic regions, including the Barents Sea, and increased at a lower rate at adjacent regions in the last three decades, followed by an increase in species richness and turnover at a regional scale. These changes in biodiversity paralleled an increase in sea bottom temperature. Within the study area, Arctic species probability of occurrence generally declined over time. However, the increase of species from southern latitudes, together with an increase of some Arctic species, ultimately led to an enrichment of the Arctic and sub-Arctic marine fauna due to increasing water temperature consistent with climate change.

Machine learning applied to global scale species distribution models (SDMs)

“…The impact of climate change on marine ecosystems has increasingly been recognized as a global-scale phenomenon, with numerous studies highlighting its effects on a worldwide basis [1][2][3][4] . As environmental conditions continue to change, marine species must adapt and potentially shift their distributions to areas with more suitable conditions for their survival and reproduction 1,[5][6][7][8][9][10][11] . Therefore, understanding the present spatio-temporal distribution of marine species and accurately predicting their future is a critical challenge in the current context of global warming 12,13 .…”