Persistent organic pollutants and flame retardants in birds of prey: an exposure assessment using non-invasive biomonitoring
19 September 2016
UAntwerpen, Campus Drie Eiken, S1 - Universiteitsplein 1 - 2610 Antwerpen-Wilrijk (route: UAntwerpen, Campus Drie Eiken
Organization / co-organization:
Department of Biology
Marcel Eens, Veerle Jaspers
PhD defence Igor Eulaers - Faculty of Science, Department of Biology
Non-legacy flame retardants (FRs) and several legacy persistent organic pollutants (POPs) are of concern due to their environmental persistence and ongoing leaching. Current biomonitoring of such compounds using birds of prey requires, however, further development of non-destructive strategies. This thesis firstly aimed at further developing the use of feathers and preen oil to biomonitor POPs and FRs. Body feathers were found to be most promising among different types of feather due to minimal confounding of their concentrations by moulting and external contamination. Moreover, the sampling and analysis of body feathers allowed to reconstruct time trends of POP and FR exposure. This thesis also showed the potential of body feathers and preen oil to predict nestling plasma POP concentrations.
Plasma POP concentrations were strongly associated to stable carbon and nitrogen isotope values, established proxies for dietary habits, showing bird of prey nestlings’ sentinel capacity for their immediate environment. A trade-off exists, though, between the ease and minimal invasiveness of sampling body feathers and preen oil versus their methodological reliability, favouring body feathers that integrate exposure over the larger part of the nestling stage. Moreover, the integrated analysis for POPs and stable isotopes was found to be most robust using body feathers. This methodology was therefore used for the second aim of this thesis, i.e. assess POP and FR exposure in ecologically distinct species, with a special focus on nestlings. The intensity of POP exposure was the result of species-specific bioaccumulation and habitat-specific foraging. In contrast, the non-legacy FRs did not show strong bioaccumulation. The analysis of moulted feathers was found most promising to retrospectively reconstruct temporal trends of bird of prey POP and FR exposure. This strategy showed that the exposure intensity of several non-legacy FRs has already peaked. Furthermore, both variability in climate and dietary habits explained inter-annual variation in exposure in a highly compound-specific manner.