Proxy records of biogenic sulfur gas obtained from ice cores suggest that variability in marine biogenic sulfur emissions may reflect changes in climate [Saigne and Legrand, 1987; Legrand et al., 1988, Legrand et al., 1991; Anderson and Charlson, 1991>. Increased sea-ice extent has previously been proposed as one cause of relatively high methanesulfonic acid (MSA) in glacial-age ice core samples [Gibson et al., 1990>. We have analyzed MSA, one of the oxidation products of the biogenic sulfur gas dimethylsulfide [Hatakeyama et al., 1985>, from snowpit samples recovered from a coastal site in Southern Victoria Land, Antarctica. Time series of MSA correlate significantly with the longest continuous record available of Southern Ocean sea-ice extent (two decades) [Jacka, 1990>. ¿ American Geophysical Union 1993