Contaminants in Antarctic and Arctic avian wildlife: Climatic and ecological drivers, comparative polar perspective, and effects

The Polar Regions have developed from pristine, undiscovered nature into important areas that notifies changes in the environment. This is where pollution ends up and effects of climate change are occurring first and with highest amplitude. Hazardous substances are found in all parts of the polar ecosystem, with the highest levels in the Arctic in animals positioned high in the food web. Compared to the Arctic, we have less knowledge about pollutants in Antarctica, in particular regarding temporal trends, occurrence of emerging contaminants, and the effects of environmental contaminants on the local wildlife. Seabirds are often used as indicators of the ecosystem health, and can provide important understanding on how contaminants are transported with atmospheric and oceanic currents, and how they are accumulated and transferred in the food web. Diet is often the most important factor explaining differences in pollutant load among seabird species. In addition, other factors such as physiology and ecological strategies play important roles toward the seabirds exposure to contaminants and sensitivity to effects. Most seabird species typically migrate from the Polar Regions to warmer, more polluted areas outside the breeding season. We have compared current concentrations, profiles and effects of legacy persistent organic pollutants (POPs), Mercury (Hg) and emerging contaminants (perfluorinated and new brominated compounds, and chlorinated paraffins) between resident (black guillemot, King penguin and Adelie penguin) and migrating (great skua and south polar skua) seabirds from the Arctic and Antarctica. We found low levels of emerging contaminants in all the species, especially in Antarctica. This resulted in challenging chemical analyses as the blood sample volume is addition was low. The levels of chlorinate paraffins and new brominated flame retardants were below the detection limit in all species. In addition, the PFAS level were low in all species, with many substances below the detection limit. In particular, the levels were low in resident Antarctic species (the penguins), while they were higher in migrating species (south polar skua) and in the Arctic species (both black guillemot and great skua). In migrating species, all contaminants levels were lower in the Antarctica than in the Arctic, when colonies of similar dietary ecology were compared. The exception was Mirex and HCB, that were higher in Antarctic breeding south polar skua than in Arctic breeding great skua. Method development to measure DNA damage in birds showed that the method Comet assay functions satisfactory on white blood cells. The background level of DNA damage was not related to contaminant level. We found no relationship between contaminant exposure and oxidative stress or telomer length. In the Antarctic region, there is good knowledge of population dynamics in certain seabird species over time, showing that some penguin populations are negatively affected by food shortages and climate change. It was unknown if contaminants have contributed further to the negative development, with multiple stressors affecting the populations simultaneously. We analyzed temporal trends in contaminant occurrence in Antarctic King penguin, and the connection to changes in climate, diet and population development by analyzing persistent organic persistent pollutants (POPs) in 510 blood samples of King penguin chicks (11 months old). The contaminant levels are in general low, and it has been analytically challenging to develop methods that provide satisfactory results. Pesticides (HCB and ppDDE) dominated the contaminant pattern in the King Penguins throughout the time period, with concentrations two orders of magnitude higher than PCBs. There was generally no time trend in the contaminant levels in the King penguins, with the exception of Mirex, that showed decreasing levels over time. Total contaminant levels in the chicks were higher in cold years when the distance to the Antarctic polar front was reduced, and the parents fed the chicks with feed from the Antarctic water masses (rather than sub-Antarctic). The distance from the breeding colony at Crozet Island to the polar front is determined by large scale climatic conditions, and was estimated from sea surface temperature. There was not relationship between contaminant levels in chicks and their return rate as older, which is a common measure of survival. Contaminant levels in King Penguin increase by an order of magnitude from 11-month-old chicks to adults. Breeding adult king penguins show somewhat fluctuating contaminant levels that probably reflect both variation in exposure from food, and variable physiological status and remobilization of stored contaminant from their storage fat. The contaminant pattern differed between life stages, with higher relative occurrence of low chlorinated PCBs in chicks, and increasing occurrence of high-chlorinated PCBs in adults.

Resultatene har vekket stor interesse fra det internasjonale vitenskapelige miljøet, selv før publisering. Det foreligger fremdeles få systematiske miljøgiftstudier fra Antarktis, og om sammenlikningen med Arktis, så resultatene har betydning for miljømyndighetene både nasjonalt, og internasjonalt inn mot Stockholmskonvensjonen for Persistente Organiske Miljøgifter. Resultatene er dermed med og styrker og synliggjør behovet for en Antarktisk variant av Arctic Monitoring and Assessment Programme AMAP. Dokumentasjonen av miljøgifter på ulike livsstadier er sjeldent hos fugl generelt, og dette er første studie av voksne kongepingviner, og viser en størrelsesorden økning i miljøgiftbelastning fra ungestadiet. Studiet viser også viktigheten av å forstå miljøgifter i dyr opp mot andre endringer i miljøet, slik som storskala klimaindekser, og lokale værforhold, og at dette kan maskere eventuelle tidstrender som respons på internasjonale restriksjoner på produksjon og bruk av miljøgifter.

The Arctic and Antarctica have proven to be final sinks for contaminants. Seabirds are common-used bioindicators for contaminants, but seabirds differ in both physiology and ecology, which in turn, may influence concentrations and potential effects of contaminants among species. As the Polar Regions are experiencing increased input of new contaminants, avian wildlife are experiencing increased environmental stress. In addition, climate change may also influence their exposure to contaminants (i.e. change in diet and released stored contaminants from melting sea ice) and susceptibility to individual and population level effects. The Polar Regions differ in contaminant levels and avian wildlife, moreover, the knowledge base differ; being large in the Arctic, but scarce in the Antarctica. In this study we will analyse temporal trends of persistent organic pollutants (POPs) and Mercury (Hg) in the Antarctic King penguin (Aptenodytes patagonicus), and quantify the effect of direct and indirect climatic factors (temperature, long range transport of POPs and Hg, dietary changes) as well as species-specific ecological and physiological factors, such as diet and life history traits (age, sex) on the contaminant levels. We will compare current levels of legacy contaminants between resident and migratory Antarctic and Arctic seabirds (i.e. King penguin, Adèlie penguin (Pygoscelis adelia), South polar skua (Stercorarius maccormicki), Black guillemot (Cepphus grylle) and Great Skua (Stercorarius skua)). We will also investigate potential population level effects of legacy POPs and Mercury, and coupling effects between contaminants and climatic changes in a King Penguin population.