Award: PLR-1142076

Many oceanographic projects today incorporate new technologies for making observations on different time and space scales than traditional, ship-based investigations. Our project, based in the Ross Sea, Antarctica, is such an example. We used an autonomous vehicle called a glider that oscillated within the water column and collected data continuously as it moved. During 571 dives over 77 days, we measured temperature, salinity, and concentrations of plankton and small fish using optical and acoustic techniques. In parallel, a number of Adelie penguins were monitored by attaching satellite tags that showed us where they were, how often they dove, and how deep they dove. The purpose of both of these was to determine how penguins changed their diets during the transition from spring to summer, and how the dominant food items were related to the areaÆs oceanography and plankton. We found that plankton distributions were largely independent of penguin prey items; furthermore, penguins appeared to shift their diets from krill (shrimp-like organisms) to small fish as the season progressed. Krill moved deeper in the water, likely in response to penguin predation, while fish did not. These new, cost-effective technologies show tremendous potential for unraveling basic ecological questions that have eluded answers for decades. Last Modified: 06/11/2015 Submitted by: Vernon L Asper