Can stable isotope (δ13C and δ15N) measurements of little auk (Alle alle) adults and chicks be used to track changes in high-Arctic marine foodwebs?

摘要: The little auk (Alle alle), a small and abundant planktivorous seabird that breeds in the high Arctic, has potential to be used as monitor of composition abundance lower trophic-level zooplankton. We investigated age- sex-related sources variation diet stable isotope (δ13C δ15N) values auks breeding Spitsbergen during summer 2002 evaluate this possibility. Stable profiles both adult chick blood changed over season, with δ15N increasing δ13C decreasing. This could represent switch higher prey derived from more pelagic sources. However, while followed those their meals, was not case for values, suggesting additional physiological mechanisms influencing growing chicks. Chicks had consistently than parents, which may indicate they were being fed on items or alternatively reflect complexities through growth period. These results have several important implications use analysis tool detect changes availability high-Arctic marine environments. Until aspects discrimination are well understood, we caution against using chicks any form isotopic monitor.