Abstract:

Textural composition, chlorophyll a and nutrients (phosphate, nitrate and silicate) of newly formed sea ice of the Weddell Sea, Antarctica, were analyzed during the period of austral autumn in 1992. Frazil ice, congelation ice and mixture of frazil/congelation ice were main textural composition types, which were formed in related conditions at the sea. The mean concentrations of chlorophyll a and nutrients in the sea ice varied considerably with ice texture. The higher concentration of chlorophyll a occurred mostly in ice floe consisting predominantly or mainly of frazil ice. The concentration of nutrients showed an inverse relationship with frazil ice, being significantly lower than that in the congelation ice. This is due to subsequent microalgae growth using the available nutrients in the sea ice. The data by analysis of the one year old sea ice with higher chlorophyll a correlated to lower nutrients supports the extrapolation as above.