The Antarctic and the surrounding Southern Ocean are one of the most important, yet least observed of marine habitats. Connecting all the world’s oceans, the physical structure of the Southern Ocean profoundly influences world climate and ecology, and plays a key role in global climate.
The merging of oceanography and marine mammal ecology advances our understanding of the world’s oceans and its top predators, and allow us to predict how these species will be affected by future climate changes. Furthermore, recent technological advancements permits the collection of important data on ocean properties throughout the Antarctic winter – data previously unavailable but crucially important to oceanographic and climate studies.
Seals are top predators that are sensitive to changes in climatic variation and the distribution and abundance of their prey. The responses of seals often manifest in changes in their foraging location, foraging success and reproductive output. Therefore monitoring the distribution of these predators at sea, achieved via contemporary bio-logging tags, can provide information on the spatial and temporal variability of their prey and their environment. As seals forage successfully, they increase their stores of blubber, become more positively buoyant and change how they sink or float in the water. Change in the daily rate at which they sink or float, known as drift rate, can then provide a measure of biological productivity. The power of such an approach is that combining at-sea movements of multiple individuals enables identification of important persistent and ephemeral hotspots of biodiversity in the Southern Ocean. This program is also highly complementary with ongoing monitoring of lower trophic level abundance in the Southern Ocean.