Broad-scale predictability of carbohydrates and exopolymers in Antarctic and Arctic sea ice

<jats:title>Significance</jats:title> <jats:p>Many marine microalgae and bacteria secrete polysaccharide gels (exopolymers) in response to environmental stresses, such as the freezing temperatures and salt concentrations that organisms experience when in sea ice. This study of sea ice cores from both the Antarctic and Arctic identified compelling relationships between ice thickness and salinity, algal biomass, and the concentration of polysaccharides in the ice. Knowing the first three parameters, we were able to predict the polysaccharide concentrations of the ice. This predictability is the first step in estimating the importance of such secretions to the organic carbon content of the millions of square kilometers of the ice-covered Arctic and Southern Oceans.</jats:p>