<p>Sea-ice in the Southern Ocean plays a crucial role in transporting and redistributing freshwater/salt and heat via freezing, melting, and transport. Changes in northward freshwater transport by sea-ice and its melt are suggested to change the salinity of intermediate water and stratification, which could affect the global carbon budget. However, very few observational studies have estimated the ice-melt amount because of the complexity of the melting processes. Here, we estimate the ice-melt amount from the salinity deficit caused by the ice-melt, using ~25,000 spring hydrographic data. The spatial distribution of ice-melt reflects the northward advection of coastal thick-ice and its melting via the three cyclonic gyres. Combined with the estimation of sea-ice production, we further estimated the net freshwater flux by sea-ice in the Southern Ocean on an observational basis. It shows large latitudinal variations: a change from negative to positive at 62°S, suggesting its dominant role in the budget.</p>