In this paper, we highlight how environmental variability has led to reduced penguin breeding performance, and increased penguin mortality following starvation, such that localised harvesting by the krill fishery at specific times or in particular areas might not be considered to be rational management. However, we also note that the current network of ecosystem monitoring sites currently makes it difficult to obtain the necessary management information at the resolution needed to facilitate precautionary reductions in catch at relevant time and space scales in all areas. Moreover, an experimental framework (such as open and closed areas to test contrasting harvesting protocols) to determine whether the fishery might have an impact upon different ecosystem components (and by how much), has never been implemented; this means that localised impacts from the fishery remain untested. Changing patterns in the operation of the krill fishery mean that either improved management information, or a precautionary spatial management approach is appropriate. Until such time that adequate information is available, and a Feed Back Management approach is implemented, the UK recommends that a precautionary approach constitutes rational spatial management. Tools that would help satisfy this requirement include seasonal coastal buffers closed to fishing. We note that application the precautionary principle using these tools would increase CCAMLR’s leadership in ecosystem based fisheries management and enhance its public image.