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Per- og polyfluorerte alkylstoffer (PFAS) har blitt funnet i blodprøver fra sørjo (Catharacta maccormicki) tatt i løpet av hekkesesongen i kolonien i Svarthamaren (Dronning Mauds land, Antarktis). For å undersøke om disse konsentrasjonene i sørjo stammer fra dietten i hekkesesongen, sammenligner denne oppgaven biomagnifisering i to næringskjeder. Ved innenlands kolonien Svarthamaren spiser sørjoene nesten utelukkende egg og unger fra antarktisk petrell (Thalassoica antarctica), og petrellene spiser fisk og krepsdyr. I den kystnære kolonien ved Dumont D’Urville (DDU, Adélie Land), spiser sørjoene hovedsakelig egg og unger fra Adélie pingviner (Pygoscelis adeliae). Væskekromatografi-massespektrometri (LC/MS) ble brukt for å måle PFAS i mageinnhold og egg fra antarktisk petrell, og i blodprøver fra sørjo, Adélie pingvin-unger, og antarktisk petrellunger og -voksne. Stabile isotoper (δ13C and δ15N) ble også analysert som diettdeskriptorer. Resultatene ble slått sammen med resultater fra tidligere studier fra begge koloniene for å oppnå et datasett for sørjo og dens diett ved både Svarthamaren og DDU. Datasettet ble brukt for å beregne biomagnifiseringsfaktor (BMF) og trofisk magnifisering faktor (TMF) for de detekterte PFASene i de to næringskjedene. Ved Svarthamaren var PFUnA over deteksjonsgrensen i alle matriksene, men var ikke tilstede i enkelte prøver. Andre detekterte PFASer var Perfluoroktyl sulfonat (PFOS), Perfluorononanoate (PFNA), Perfluorodecanoate (PFDcA), Perfluoroundecanoate (PFUnA), Perfluorododecanoate (PFDoA), Perfluorotridecanoate (PFTriA) and Perfluorotetradecanoate (PFTeA). PFAS konsentrasjonene økte oppover i næringskjeden, hvorav nivåene for alle detekterte PFASer var høyest hos sørjo. Ved DDU var PFAS konsentrasjonene lavere, men mønsteret var sammenlignbart med det i Svarthamaren. Forgrenet PFOS ble kvantifisert i sørjo fra DDU, men var ikke over deteksjonsgrense i andre matrikser. Byttedyrene hadde flere PFASer over deteksjonsgrensen i Svarthamaren sammenliknet med DDU. Vi beregnet BMF og TMF for alle detekterte PFASer i Svarthamaren, men kun for PFOS, PFNA, PFDcA og PFUnA i DDU fordi bare disse ble funnet i både sørjo og pingvinene. BMF for PFOS var høyere enn forventet i vanlige predator-bytte forhold i begge koloniene, noe som peker på en ukjent kilde. Biomagnifikasjonsverdiene for andre PFASer var varierende, men sammenliknbare mellom koloniene. PFAS-konsentrasjonene i sørjo fra begge kolonier og i antarktisk petrell reflekterer sannsynligvis eksponering utenfor Antarktis i løpet av vinteren. De detekterte konsentrasjoner i Adélie pingviner er ikke høye nok for å forklare de høye PFAS-nivåene i sørjoene i DDU. Derfor, i DDU, disse PFAS-nivåer kommer fra andre byttedyr enten innenfor regioner eller mest sannsynligvis fra utenfor Antarktis.

The Rosenthal Islands lie along the western edge of the Antarctic Peninsula. They are largely inaccessible and the few research projects in the area have focused on seabird colonies, so nothing has been known about the arthropod fauna on these islands. We conducted a preliminary survey of the arthropods associated with large penguin colonies. We identified two species of Collembola (Cryptopygus antarcticus and Friesea grisea), four species of mites (Alaskozetes antarcticus, Hydrogamasellus racovitzai, Tectopenthalodes villosus and Rhagidia sp.) and one insect (Belgica antarctica). The mite A. antarcticus and the collembolan C. antarcticus were common in large aggregations at our collecting sites and were occasionally observed on the surface of penguin guano without vegetative cover. The insect, a chironomid midge, was less common and found only in vegetated areas.

There is increasing interest in using higher-trophic level predators as ecosystem indicators because their performance is presumed to be linked to the overall function of the ecosystem that supports them. In the southwest Atlantic sector of the Southern Ocean, Antarctic krill (Euphausia superba) supports huge predator populations as well as a growing commercial fishery. To utilize information from the ecosystem in an adaptive framework for sustainably managing krill catch levels, performance indices of krill predators have been proposed as a proxy for krill abundance. However, there are several potentially confounding sources of variability that might impact predator performance such as the effects of environmental variability and fishing pressure on krill availability at scales relevant to predators. In this context, our study capitalises on the occurrence of an unexpected El Niño event to characterise how environmental variability can drive changes in predator foraging behaviour. We demonstrate a clear link between coastal downwelling and changes in the at-sea habitat usage of chinstrap penguins (Pygoscelis antarctica) foraging in a local krill fishing area. Penguins tracked from their breeding colonies on Powell Island, Antarctic Peninsula, undertook fewer, longer foraging trips during the downwelling-affected season compared with the season where no such downwelling was detected, suggesting that changes in climate-driven oceanography may have reduced krill availability along the northern shelf of the island. Our study demonstrates that penguin foraging behaviour is modified by scale-dependent processes, which if not accounted for may result in erroneous conclusions being drawn when using penguins as bioindicators of krill abundance.

Penguins are a monophyletic group in which many species are found breeding sympatrically, raising questions regarding how these species coexist successfully. Here, the isotopic niche of three sympatric pygoscelid penguin species was investigated at Powell Island, South Orkney Islands, during two breeding seasons (austral summers 2013–2014 and 2015–2016). Measurements of carbon (δ13C) and nitrogen (δ15N) stable isotope ratios were obtained from blood (adults) or feather (chicks) samples collected from Adélie Pygoscelis adeliae, chinstrap P. antarctica, and gentoo P. papua penguins. Isotopic niche regions (a proxy for the realized trophic niches) were computed to provide estimates of the trophic niche width of the studied species during the breeding season. The isotopic niche regions of adults of all three species were similar, but gentoo chicks had noticeably wider isotopic niches than the chicks of the other two species. Moderate to strong overlap in isotopic niche among species was found during each breeding season and for both age groups, suggesting that the potential for competition for shared food sources was similar during the two study years, although the actual level of competition could not be determined owing to the lack of data on resource abundance. Clear interannual shifts in isotopic niche were seen in all three species, though of lower amplitude for adult chinstrap penguins. These shifts were due to variation in carbon, but not nitrogen, isotopic ratios, which could indicate either a change in isotopic signature of their prey or a switch to an alternative food web. The main conclusions of this study are that (1) there is a partial overlap in the isotopic niches of these three congeneric species and that (2) they responded similarly to changes that likely occurred at the base of their food chain between the 2 years of the study.

Babesia spp. are tick-borne parasites, and 16 avian-infecting species have been described to date, including one species ( Babesia peircei ) that infects penguins. Considering the results of a recent study reporting Babesia sp. in penguins on Deception Island, South Shetland Islands, we re-examined the samples obtained in a previous investigation on the occurrence of blood parasites in adult Adélie ( Pygoscelis adeliae ), chinstrap ( Pygoscelis antarcticus ) and gentoo penguins ( Pygoscelis papua ) on King George and Elephant islands, South Shetland Islands. Notwithstanding a comprehensive re-examination of the blood smears, Babesia sp. was not detected. When we employed two nested PCR tests targeting the 18S rRNA gene of Babesia , a considerable proportion of the samples produced positive results; however, gene sequencing revealed these were due to cross-amplification of non-target organisms. We therefore did not detect Babesia sp. infection in penguins on King George and Elephant islands. Additional studies will be valuable to clarify the distribution and epidemiology of tick-borne pathogens in sub-Antarctic and Antarctic seabirds.

Using GC Orbitrap mass spectrometry to address analytical challenges with trace level detection of persistent organic pollutants in Antarctica.