As part of my PhD thesis, I am concerned with understanding where, and in what biotic and acoustic environment Antarctic marine predators (including elephant seals, fur seals and penguins) forage. In particular, I am focussing on two questions: 1) are they using acoustic cues as a guide towards prey patches, and 2) how does their prey field look like, in terms of density and targeted prey species?
To investigate these questions, we have developed a set of new tags, by adding new capabilities to the latest version of the existing Dtag (a miniature sound and movement recording tag designed for use on marine animals), such as integrating new sensors (e.g. a 1.5MHz micro sonar and a light sensor), extending battery life or miniaturising it. These tags will potentially record in-situ data that have never been recorded on polar predators before, such as their acoustic environment or a quantification of their in-situ prey field, combined with fine scale movement and location of the animal, as well as data on in-situ bioluminescence.
Using this dataset, I aim to understand what makes these animals successful foragers and breeders in different places of the Southern Ocean, and in particular what features of each species may pose risks or provide resilience against environmental changes.