Isotopic investigation of contemporary and historic changes in penguin trophic niches and carrying capacity of the southern Indian ocean.

ABSTRACT: A temperature-defined regime shift occurred in the 1970s in the southern Indian Ocean, with simultaneous severe decreases in many predator populations. We tested a possible biological link between the regime shift and predator declines by measuring historic and contemporary feather isotopic signatures of seven penguin species with contrasted foraging strategies and inhabiting a large latitudinal range. We first showed that contemporary penguin isotopic variations and chlorophyll a concentration were positively correlated, suggesting the usefulness of predator δ¹³C values to track temporal changes in the ecosystem carrying capacity and its associated coupling to consumers. Having controlled for the Suess effect and for increase CO₂ in seawater, δ¹³C values of Antarctic penguins and of king

SUBMITTER: Jaeger A 

PROVIDER: S-EPMC3032774 | biostudies-literature | 2011 Feb

REPOSITORIES: biostudies-literature