Niche Dynamics of Antarctic Krill Predators
|Clock wise from top left: Chinstrap penguin, Antarctic fur seal, Gentoo penguin, Adélie penguin (Mike Polito)|
Steve Emslie (UNCW) Bill Patterson (Univ. Saskatchewan) Wayne Trivelpiece (NOAA) Mike Goebel (NOAA) Simon Thorrold (WHOI) Stephanie Jenouvrier (WHOI)
Recent climate warming and declines in Antarctic krill are believed to have led to divergent responses in krill predators such as penguin and seals. While these species all consume krill, it is possible that the high degree of variation in their population-level response may be due to difference in the breadth and flexibility of their dietary niches. However, tradition methods of studying krill predator foraging ecology are time intensive, invasive, limited in spatial and temporal scale, and biased towards dietary items that are not readily digestible. For this project we are using of naturally occurring stable isotopes as an alternative approach to studying krill predator foraging ecology as isotope ratios in animal tissues are largely determined by isotopic abundances in the animal’s food. This has provided baseline information about these species over a period of time when they are away from their breeding sites and provided managers the information and tools needed to oversee the expanding krill fishery and implement policies to mitigate the effects of recent climate change.