6,000-Year Reconstruction of Modified Circumpolar Deep Water Intrusion and Its Effects on Sea Ice and Penguin in the Ross Sea

The Ross Sea has the world's largest marine protected area. Modified Circumpolar Deep Water (MCDW) has significant effects on physical and biological processes in the Ross Sea. Totally 13 penguin ornithogenic sediment profiles were collected from Inexpressible Island, Ross Sea, and the Cd/P ratios were used as a proxy of MCDW intrusion, enabling to reconstruct the variability of MCDW intrusion into the Ross Sea during the past 6,000 years. During the intervals of similar to 0.7-1.6 and similar to 2.8-6.0 kyr BP, enhanced MCDW intrusion increased the heat supply which warmed the surface water and reduced the coastal sea ice concentration. By contrast, reduced MCDW intrusion during similar to 1.6-2.8 kyr BP caused a decrease in the penguin population via restricting food supply and/or increasing sea ice concentration. Thus, changes in MCDW were responsible for driving millennial changes in sea ice and penguin population in the Ross Sea.

Automated summary

The study found that changes in MCDW in the Ross Sea have impacted the evolution of sea ice and penguin population, leading to changes in marine biological and physical processes.