Evidence for the impact of climate change on deep-sea biodiversity

Deep-sea ecosystems (at depths of >1000 m) comprise more than 60% of the Earth surface, and are the main reservoirs of global biodiversity.

Climate changes are expected to induce significant modifications in biodiversity on the global scale, yet little is known on the impact of recent climate changes on the deep-sea biodiversity. In the forthcoming issue of Ecology Letters, Danovaro, Dell’Anno and Pusceddu demonstrate that an extensive climate anomaly, which occurred in the Eastern Mediterranean, caused a significant deep-sea biodiversity change.

These results indicate that temperature shifts of 0.05-0.1 °C in the deep sea are sufficient to induce significant changes in species richness and functional diversity. They conclude that deep-sea fauna is highly vulnerable to environmental alteration, and that very minor temperature shifts in deep-water masses can rapidly and significantly alter both structural and functional deep-sea biodiversity. This study provides new elements towards a better understanding of the potential large-scale consequences of climate change.