Our goal is to examine an Antarctic food web, all the way from the microalgal primary producers at the bottom to the predatory mammals and birds at the top. We seek to understand whether this system is driven from the bottom up – that is, it all depends on how much food is available – or the top down – dependent on how many predators there are. We conduct our research in Antarctica as the only place on the planet where we still have intact populations of top predators. Everywhere else in the world, humans have eliminated or greatly reduced predators, which are either a direct threat or a strong competitor with humans for resources.
We use a micro-remotely operated vehicle, or ROV, to collect data. Our ROV is called SCINI (Submersible Capable of under Ice Navigation and Imagery), and for this project we have expanded her capabilities to include fluorometry and sonar, in a tow package we call FATTI (Fluorometry and Acoustic Transducer Towable Instrument). With these we are mapping chlorophyll as a proxy for phytoplankton, crystal krill (Euphausia crystallorophias), and silver fish (Pleurogramma antarctica) distributions, the bottom three levels of the food web. At the top of the food web, we are tagging and tracking Minke whales (Balaenoptera bonaerensis), type C killer whales (Orcinus orca), and Adelie penguins (Pygoscelis adeliae). With this coordinated data set of all trophic levels we are seeking to understand the control processes in a relatively undisturbed ecosystem. We hope that our results will inform managers and politicians involved in creating a Marine Protected Area in the Ross Sea.