SEABIRDS AS BIOINDICATORS OF SOUTHERN OCEAN ECOSYSTEMS: CONCENTRATIONS OF INORGANIC AND ORGANIC CONTAMINANTS, ECOLOGICAL EXPLANATION AND CRITICAL EVALUATION

Antarctic and subantarctic marine environments are reached by inorganic and organic contaminantsthrough ocean circulation and atmospheric transport. Yet, environmental contamination is poorlyknown in the Southern Ocean, in particular in the Indian sector. Among environmental contaminants,mercury (Hg...

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Bibliographic Details
Main Author: Carravieri, Alice
Other Authors: Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Université de La Rochelle, Paco Bustamante, Yves Cherel
Format: Doctoral or Postdoctoral Thesis
Language:English
Published: HAL CCSD 2014
Subjects:
Online Access:https://theses.hal.science/tel-01104730
https://theses.hal.science/tel-01104730/document
https://theses.hal.science/tel-01104730/file/Carravieri_Alice.pdf
Description
Summary:Antarctic and subantarctic marine environments are reached by inorganic and organic contaminantsthrough ocean circulation and atmospheric transport. Yet, environmental contamination is poorlyknown in the Southern Ocean, in particular in the Indian sector. Among environmental contaminants,mercury (Hg) and persistent organic pollutants (POPs) are primarily of concern, because they aretoxic, highly mobile, and they bioaccumulate in the tissues of living organisms and biomagnify up thefood web. Seabirds, as upper predators, are exposed to large quantities of contaminants via foodintake and have widely served as biomonitors of marine contamination, notably through the nondestructivesampling of their feathers and blood. My doctoral work has focussed on the abundant anddiverse seabird species (more than 40) breeding in the French Southern and Antarctic Lands,southern Indian Ocean, in order to describe and explain contaminant concentrations over a largelatitudinal gradient, from Antarctica to the subtropics, and to identify the best bioindicator speciesfor contaminant biomonitoring. In a first methodological step, seabirds with synchronous moult ofbody feathers (adult penguins and chicks of all species) were recognised as good candidates asbioindicators, because, unlike most adult birds, they present low within-individual variation in feathercontaminant concentrations. In a second explanatory step, the influence of intrinsic (individual traits)and extrinsic factors (feeding ecology inferred from the stable isotope method) driving variation incontaminant concentrations was evaluated in feathers of the large avian community of the KerguelenIslands (27 species) and in blood of wandering albatrosses from the Crozet Islands (180 birds ofknown individual traits). Feeding ecology was the main factor driving variation in contaminantconcentrations of blood and feathers, both at the community, population and individual levels, whereasage, sex, phylogeny and breeding status played a minor role. Age-class was however an ...