Open access notables Multiple studies indicate changes in the properties of Antarctic bottom water (AABW) over the past half century. These changes involve density and hence will affect both local and distant circulation of the oceans, not least overturning effects that are vital for marine biology but also climate and weather far distant from Antarctica and the Southern Ocean. While we can see what's happening, our understanding of what's driving change is incomplete. By synthesizing multiple observational channels in a uniquely suitable region, Kathryn Gunn et al. produce an important increment in our understanding of what's perturbing this system in Recent reduced abyssal overturning and ventilation in the Australian Antarctic Basin, just published in Nature Climate Change. It looks as though glacial meltwater is an growingly important factor. The paper confirms and extends prior indication that substantial change is occurring in Antarctic bottom waters. This article is also rewarding for a general readership thanks to its excellent introduction and synopsis of the problems the authors attack.