Dissolved carbohydrates in Antarctic sea ice

Concentrations of dissolved monocarbohydrates (MCHO) and polycarbohydrates (PCHO) were analysed in a variety of ice habitats from summer Weddell Sea s ea ice (surface ponds, ice cores, gap layers and platelet ice). The dissolv ed organic carbon (DOC) pool in these habitats was also measured and the co ntribution of carbohydrate to this pool was assessed. The DOC concentration s within all sea ice habitats were high compared to surface seawater concen trations with values up to 958 mu MC being measured. Total carbohydrates (T CHO) were highest in the ice cores and platelet ice samples, up to 31% of t he DOC pool, a reflection of the high algal biomass in these two habitat cl asses. TCHO in the other habitats ranged between 10% and 29% of DOC. The ra tios of MCHO to PCHO varied considerably between the ice habitats: in surfa ce ponds and ice cores MCHO was 70% of the TCHO pool, whereas in gap layers and platelet ice there were lower PCHO concentrations resulting in MCHO be ing 88% of TCHO.