Plasma concentrations of organohalogenated pollutants in predatory bird nestlings: Associations to growth rate and dietary tracers

Abstract

The extent to which persistent organic pollutants (POPs) with different physicochemical properties originated from the food (dietary input) was assessed in raptor nestlings. Lipophilic polychlorinated biphenyl (PCB) 153, 1-dichloro-2,2-bis(p-chlorophenyl)ethylene (p,p'-DDE), and hexachlorobenzene (HCB), and protein-bound perfluorooctane sulfonate (PFOS), were measured repeatedly in blood plasma of individual goshawk (Accipiter gentilis) and white-tailed eagle (Haliaeetus albicilla) nestlings, 1 to 3 wk after hatching and near fledging. Maternally derived POPs dilute as nestlings grow (growth dilution), and increasing plasma concentrations would indicate dietary input. First, plasma concentrations given no dietary input were estimated, and concentrations of p,p'-DDE, HCB, and notably PFOS were significantly higher than predicted from a growth-dilution scenario (approximately 1.5-fold to 2.5-fold higher; p < 0.001). In contrast, PCB 153 declined in both species, although concentrations were still higher than predicted in white-tailed eagle nestlings (p < 0.05). Second, the relationships between plasma POP concentrations and trophic position (δ(15) N) and dietary carbon source (δ(13) C) were analyzed, controlling for growth rate. Both δ(15) N and δ(13) C (measured in body feathers) were significantly associated to the accumulation of most POPs, except PFOS. In conclusion, pollutant data acquired in plasma of nestling raptors should be interpreted and further investigated in the light of individual feeding ecology, and the use of raptor nestlings as sentinels for POP monitoring could be optimized by correcting for different factors such as body condition, brood size, and age.

The effect of long-range transport, trophic position and diet specialization on legacy contaminant occurrence in great skuas, Stercorarius skua, breeding across the Northeast Atlantic

“…The study by Elliott et al, (2009) also included some individual eagles breeding in estuaries or further up river and therefore reflect more riverine and freshwater systems. For white-tailed eagles in Norway, there was a negative relationship between δ 13 C levels and POPs (Bustnes et al 2013) similar to this study. δ 13 C measurements from the present study varied only from -19.8 to -17.7‰, which is at the end of scale compared to the study by Elliott et al (2009), which might explain the contrasting findings.…”

“…Although lipophilic recalcitrant HOCs show increasing concentrations with trophic position in the food web (Borgå et al 2001, Fisk et al 2001, Ruus et al 2002, Lavoie et al 2010, such relationships are rarely shown within one species. However, δ 15 N levels were found to be positively related to OC concentrations in both bald eagles (Haliaeetus leucocephalus) (Elliott et al 2009) and white-tailed eagles in Norway (H. albicilla) (Bustnes et al 2013), and to HCB, DDTs and PCBs (from muscle) in Bjørnøya glaucous gulls (Larus hyperboreus) (Sagerup et al 2002. ), and weak positive relationships were found between δ 15 N and HOCs in liver of northern fulmars (Fulmarus glacialis) (Knudsen et al 2007).…”

Plasma concentrations of organohalogenated contaminants in white-tailed eagle nestlings – The role of age and diet

“…The white-tailed eagle (Haliaeetus albicilla) occupies a high trophic level and can accumulate a wide range of OHCs, even at an early age (Bustnes et al, 2013;Eulaers et al, 2014;Løseth et al, 2019;Sletten et al, 2016). Nestlings are exposed to maternally transferred OHCs during development in the egg (Faxneld et al, 2016;Nordl€ of et al, 2010;Nygård and Polder, 2012) and the exposure continues after hatching through their dietary intake (Bourgeon et al, 2013).…”

“…As many OHCs have been shown to interfere with physiological processes linked to development and growth (Cassone et al, 2012;Jenssen et al, 2010;Nøst et al, 2012), there is special concern about levels and effects of these compounds in young developing birds. As nestlings develop and grow, their maternally transferred contaminants are significantly diluted by their growth (Bourgeon et al, 2013;Bustnes et al, 2013). However, nestlings are also exposed to OHCs through their diet and plasma concentrations of compounds with high ability for bioaccumulation may increase as the nestlings reach their adult body size at fledging (Borgå et al, 2004;Bustnes et al, 2013).…”

“…As nestlings develop and grow, their maternally transferred contaminants are significantly diluted by their growth (Bourgeon et al, 2013;Bustnes et al, 2013). However, nestlings are also exposed to OHCs through their diet and plasma concentrations of compounds with high ability for bioaccumulation may increase as the nestlings reach their adult body size at fledging (Borgå et al, 2004;Bustnes et al, 2013). Previously, only few studies have accounted for age and growth when investigating OHCs in nestlings (Bourgeon et al, 2013;Bustnes et al, 2013;Dauwe et al, 2006;Olsson et al, 2000).…”