title: Diatom-specific highly branched isoprenoids as biomarkers in Antarctic consumers.
abstract: The structure, functioning and dynamics of polar marine ecosystems are strongly influenced by the extent of sea ice. Ice algae and pelagic phytoplankton represent the primary sources of nutrition for higher trophic-level organisms in seasonally ice-covered areas, but their relative contributions to polar marine consumers remain largely unexplored. Here, we investigated the potential of diatom-specific lipid markers and highly branched isoprenoids (HBIs) for estimating the importance of these two carbon pools in an Antarctic pelagic ecosystem. Using GC-MS analysis, we studied HBI biomarkers in key marine species over three years in Adélie Land, Antarctica: euphausiids (ice krill Euphausia crystallorophias and Antarctic krill E. superba), fish (bald notothens Pagothenia borchgrevinki and Antarctic silverfish Pleuragramma antarcticum) and seabirds (Adélie penguins Pygoscelis adeliae, snow petrels Pagodroma nivea and cape petrels Daption capense). This study provides the first evidence of the incorporation of HBI lipids in Antarctic pelagic consumers. Specifically, a di-unsaturated HBI (diene) of sea ice origin was more abundant in ice-associated species than in pelagic species, whereas a tri-unsaturated HBI (triene) of phytoplanktonic origin was more abundant in pelagic species than in ice-associated species. Moreover, the relative abundances of diene and triene in seabird tissues and eggs were higher during a year of good sea ice conditions than in a year of poor ice conditions. In turn, the higher contribution of ice algal derived organic matter to the diet of seabirds was related to earlier breeding and higher breeding success. HBI biomarkers are a promising tool for estimating the contribution of organic matter derived from ice algae in pelagic consumers from Antarctica.
authors: Laboratoire d'océanographie et du climat: expérimentations et approches numériques, UMR 7159 CNRS, Université Pierre et Marie Curie, Paris, France. agoutte@gmail.com
authors: Aurélie
authors: A
authors: Goutte
authors: Yves
authors: Y
authors: Cherel
authors: Marie-Noëlle
authors: MN
authors: Houssais
authors: Vincent
authors: V
authors: Klein
authors: Catherine
authors: C
authors: Ozouf-Costaz
authors: Mireille
authors: M
authors: Raccurt
authors: Camille
authors: C
authors: Robineau
authors: Guillaume
authors: G
authors: Massé
mesh_terms: D000818:Animals; D000864:Antarctic Regions; D015415:Biomarkers / Q000032:analysis*; D001717:Birds / Q000378:metabolism; D017377:Diatoms / Q000737:chemistry*; D017753:Ecosystem; D033201:Euphausiacea / Q000737:chemistry; D005260:Female; D020387:Food Chain; D008401:Gas Chromatography-Mass Spectrometry; D005843:Geography; D046448:Ice Cover; D008297:Male; D008386:Marine Biology; D010473:Perciformes / Q000378:metabolism; D010839:Phytoplankton / Q000737:chemistry; D046429:Spheniscidae / Q000378:metabolism; D013729:Terpenes / Q000032:analysis* / Q000737:chemistry
chemical_list: D015415:Biomarkers; D013729:Terpenes