|Abstract Title:||Mercury in the Ecosystem of the Southern Baltic Sea: Effects of Decreased Atmospheric Deposition and Changing Environment|
|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 Marine Ecosystems|
|Co-Authors:||Agnieszka Jędruch,Lucyna Falkowska,Dominika Saniewska,Agnieszka Grajewska,Włodzimierz Meissner,Elżbieta Kalisińska,Magdalena Bełdowska,Józef M. Pacyna|
Abstract Information :
The southern Baltic Sea has improved with respect to Hg contamination over the last three decades, which resulted from a significant reduction in Hg emissions and a decrease in atmospheric deposition. Despite the gaps in the time series on Hg concentrations in organisms, a downward trend accompanying the reduction in emissions was evident. However, observed and projected climate-driven changes are expected to affect Hg uptake and trophic transfer of Hg in the marine ecosystem. After a larger decline in Hg emissions in the 1990s and early 2000s, the reduction slowed and remained relatively stable for more than a decade. This means that future changes in Hg concentrations in the southern Baltic Sea will probably be influenced by emission-independent factors, such as further changes in sweater temperature and food web structure. An early stage of these changes, resulting in a reversal of previous declines, was already observed in fish. Given that the Baltic Sea is one of the fastest warming marginal seas in the world, there is no indication that the changes in its ecosystem will slow down. Although the anthropogenic load of Hg has been reduced, the pool of Hg in the southern Baltic Sea may increase due to the climate change-induced remobilization of legacy Hg deposits located both terrestrial and marine. Furthermore, increased temperature is one of the most important factors that influence changes in the structure of the trophic web and promoting Hg methylation and bioaccumulation. Consequently, the joint impact of climate evolution on the Hg pool and its bioavailability, together with changes in the food chain, is likely to exacerbate wildlife and human exposure to Hg, which means the need for strong actions to reduce Hg emissions more effectively and to pursue a climate change mitigation strategy. This study was funded by the National Science Center (2018/31/N/ST10/00214).