|Abstract Title:||Mercury in the Antarctic Food Web|
|Presenter Name:||Agnieszka Jędruch|
|Company/Institution:||Institute of Oceanography of the University of Gdansk; Institute of Oceanology of the Polish Academy of Sciences|
|Session:||Mercury in Polar Ecosystems|
|Co-Authors:||Agnieszka Jędruch,Dominika Saniewska,Aleksandra Cichecka,Małgorzata Jarzynowska,Ewa Korejwo,Patrycja Płońska,Adriana Wojdasiewicz,Piotr Bałazy,Magdalena Bełdowska,Jacek Bełdowski,Anna Panasiuk,Michał Saniewski|
Abstract Information :
Recent studies have found that the Antarctic is a sink for mercury (Hg). However, the Hg cycle in this region is poorly understood. The research aimed to identify Hg sources in Antarctica and determine their potential for accumulation in the marine trophic web. Sampling was conducted in the South Shetland Islands and near the Antarctic Peninsula in 2018. As part of the research, selected terrestrial (rock, soil, flora) and marine samples (water, SPM, plankton, zoobenthos) were collected. Total mercury and its fraction were determined. The correlation between the concentration of Hg in volcanic rocks and the soil was observed. However, the main factor causing the increase of Hg concentration both in soil and in vascular plants was the presence of animals. Melting glaciers were an important source of particulate Hg in the sea. However, this form of Hg was deposited in the sediment close to the glacier. Therefore, this process was important for benthic organisms in the vicinity of melting glaciers. Hg concentration in phytoplankton (50 ?m) was ten times lower than in SPM and was mainly controlled by the occurrence of dissolved Hg in seawater. Similar Hg concentration as in phytoplankton was measured in krill (Euphausia superba), while in salp (Salpa thompsoni) values were 50% higher. The main route of exposure of these zooplankton species to mercury was through food, however, these organisms grew faster than bioaccumulation occurred. Among benthic organisms, accumulation and biomagnification of Hg were observed. The highest concentration of Hg was measured in starfish (Odontaster validus) and it was four times higher than in plankton. In the case of starfish, an increase in Hg concentration was observed with the size of the organism. This study has been performed within the framework of a National Science Center projects No. 2019/33/B/ST10/00290 and No. 2017/27/N/ST10/02230.