Impacts of cetaceans on the structure of Southern Ocean food webs

Here we present three scenarios that demonstrate how cetaceans may influence the structure and dynamics of the Southern Ocean food web. These should be considered in addition to several other examples recently identified, and reviewed herein. Marine trophic cascades resulting from top-predator removal are not a novel concept. While we acknowledge the correlative nature of our examples, we nonetheless contend that they indicate fruitful directions for current and future research in the Southern Ocean. Data from the Southern Ocean are most easily attained by remote sensing, which sheds light on why, in part, researchers are preoccupied with physical factors as ecosystem drivers, i.e. climate, that lend themselves to this technology. While much of what we relate cannot be easily resolved using remote sensing, and instead requires direct observation, we hope our perspectives will enable the establishment of a broader scientific basis for management of Antarctic marine resources, which are increasingly coming under the pressure of cumulative impacts from climate change, fishing and other anthropogenic factors.