Summary: | Due to increasing human activities, a growing number of threats are challenging the fate of biodiversity. Among them, environmental contamination is particularly concerning for living organisms. Used and released in industrialized countries, these highly persistent contaminants can reach remote areas such as the Arctic ecosystem and will biomagnify though food webs and bioaccumulate in organisms. Long-lived seabirds are located in the upper levels of the food chains and thus particularly exposed and sensitive to a chronic contaminants exposure. Through endocrine disruption, these contaminants can impact physiological mechanisms and behavioural traits, inducing in fine, long-term fitness consequences on individuals and populations. My thesis focuses on three groups of contaminants: (i) poly- and perfluoroalkyl substances (PFASs), still broadly used in a vast array of industrial processes and increasing in the Arctic; (ii) “legacy” organochlorine contaminants (OCs, pesticides and industrial compounds), banned from use but still well present in the Arctic and (iii) mercury (Hg), a non-essential metal coming of both natural and anthropic origins. Based on a correlative approach conducted in natura, I investigated the physiological and behavioural consequences of exposure to these contaminants during the whole breeding cycle (from pre-laying to chick-rearing period) in an Arctic seabird, the black-legged kittiwake (Rissa tridactyla) from Svalbard, Norwegian Arctic. Specifically, I examined the relationships between several PFASs, OCs, Hg and fertility (sperm morphology and motility), sexual signaling (visual: integument coloration and olfactory: chemical signature), parental care behaviors (incubation temperature and egg-turning), ageing (telomere length) and energy expenditure (basal metabolic rate). In addition, some potential underlying mechanisms were also studied to better understand the way through which contaminants can be detrimental for kittiwakes. Furthermore, since physiological mechanisms and behavioral ...
|