Analysis of recent commercial catch, research survey and larval data for mackerel icefish (Champsocephalus gunnari) recorded from CCAMLR Subarea 48.3 coupled with historical information indicates that they spawn inshore close to the bays and over the shelf to the northeast. There is also evidence that spawning is protracted and occurs from January through to July. The majority of commercial fishing activities for this species take place to the northwest of South Georgia over 12 nautical miles from the coast and do not overlap with important spawning areas. Therefore the current conservation measure restricting the total allowable catch during the assumed spawning period from March-May is unlikely to protect spawning aggregations of C. gunnari but could, inadvertently, increase the risk of brooding seabirds being caught as by-catch.