Spatio-temporal patterns in Antarctic minke whale (Balaenoptera bonaerensis) vocal behaviour in the Weddell Sea. Antarctic minke whales (Baleanoptera bonaerensis) occur in open as well as ice-covered waters throughout the Southern Ocean. Their low visual detectability and ice-associated habitat makes the species difficult to study using traditional visual methods. The recent identification of Antarctic minke whale vocalizations now allows the use of passive acoustic monitoring to investigate year-round spatio-temporal patterns in occurrence in ice-covered areas. Here we present preliminary results on Antarctic minke whale occurrence patterns based on a multi-year passive acoustic data set from 6 locations throughout the Atlantic sector of the Southern Ocean. Analyses were based on daily presence of the bio-duck call, which is characterized by its repetitive nature, consisting of regular down-sweeped pulses with most energy located in the 50-300 Hz band. Antarctic minke whales were present at all six Antarctic recording locations from June to December, with highest presence occurring between August and November (>80% of days with bioduck calls present). At the southernmost recording locations, the bioduck call was present up to ten months of the year. Substantial inter-annual variation in the seasonal on- and offset period of vocal activity was observed at the different recording positions, possibly corresponding to variation in local ice conditions.