Award: PLR-1142044

This project involved a collaboration between multiple US universities. Stanford University was in charge of collecting and interpreting data on the physical and biological characteristics of seawater in the Ross Sea, Antarctica. Our data, which is all publicly available for easy download, and interpretations show that very high rates of primary production can occur in the Southern Ocean, even at very low temperatures (-2 to 0 degrees C) and with decreasing amount of light. In turn this work helps answer fundamental questions regarding how and when food is produced in the ocean – food that ultimately supports a large food chain leading all the way up to fish, seals, seabirds, and whales. We also determined the state of carbonate mineral saturation during a previously unsampled time of year. Carbonate mineral saturation state is a property that determines the health and viability of a number of key Southern Ocean organisms such as pelagic snails. By working with our project collaborators we have observed and explained a number of previously unknown or poorly understood features of the annual cycle of primary production and microbial decay in the Ross Sea. Importantly, we observed and measured unusual blooms of golden algae (diatoms) in newly formed sea ice patches, wherein the concentration of plant cells was directly connected to the circulation of the upper ocean under strong wind conditions. We also used an isotopic technique to demonstrate that continuing freshening of the Ross Sea is associated with continental ice melt moreso than with increased snowfall over the ocean. Last Modified: 11/16/2016 Submitted by: Robert B Dunbar