An integrative toolkit for quantifying ecological regime shifts in pelagic ecosystems: a proof-of-concept study in the Southern Ocean

One of the great challenges of the Anthropocene (mid 20th-century to present) is protecting intact ecosystems and restoring degraded ones. Paramount to restoration is a comprehensive understanding of the pre-disturbance state of an ecosystem and the development of analytical tool kits to quantitatively guide restoration. Ecosystem restoration has occurred in terrestrial, limnic, and neritic systems; however, ecosystem restoration on the open ocean has not yet been attempted. The proposed work will combine biogeochemical, eDNA, and microscopic analyses of Southern Ocean sediment cores to quantify ecological regime shifts of the 20th century, with a focus on the impact of Antarctic whaling – one of the swiftest removals of animal biomass ever. Our approach will quantify the pre-disturbance state of one of the most biologically productive ecosystems in the world and provide a framework for restoration targets in pelagic ecosystems worldwide.