Volcanic related methylmercury poisoning as the possible driver of the end-Devonian Mass Extinction

The end-Devonian global Hangenberg event (359 Ma) is among the most devastating mass extinction events in Earth’s history, albeit not one of the “Big Five”. This extinction is linked to worldwide anoxia caused by global climatic changes. These changes could have been driven by astronomical forcing and volcanic cataclysm, but ultimate causes of the extinction still remain unclear. Here we report anomalously high mercury (Hg) concentration in marine deposits encompassing the Hangenberg event from Italy and Austria (Carnic Alps). The Hangenberg event recorded in the sections investigated can be here interpreted as caused by extensive volcanic activity of large igneous provinces (LIPs), arc volcanism and/or hydrothermal activity. Our results (very large Hg anomalies) imply volcanism as a most possible cause of the Hangenberg event, similar to other first order mass extinctions during the Phanerozoic. For the first time we show that apart from anoxia, proximate kill mechanism of aquatic life during the event could have been methylmercury formed by biomethylation of a volcanically derived, huge concentration of inorganic Hg supplied to the ocean. Methylmercury as a much more toxic Hg form, potentially could have had a devastating impact on end-Devonian biodiversity, causing the extinction of many pelagic species

Exposure status of sea-dumped chemical warfare agents in the Baltic Sea

About 50 000 tons of chemical weapons (CW) were dumped to the Baltic Sea after the Second World War. Munitions are located in the deep areas of the Baltic Sea, and there they act as a point source of contamination to the ecosystem. Corroded munitions release chemical warfare agents (CWAs) to nearby water and sediments. In this study we investigated known dumpsites (Bornholm, Gotland and Gdansk Deep) and dispersed chemical munitions, to evaluate the extent of contamination of nearby sediments, as well as to assess the degradation process of released CWA. It was found that CWA-related phenylarsenic chemicals (Clark I, Clark II and Adamsite) and sulfur mustard are released to the sediments and undergo environmental degradation to chemicals, of which some remain toxic. The extent of pollution of released CWAs and their corresponding degradation products reaches more than 250 m from the CW objects, and seem to follow a power curve decrease of concentration from the source. Bornholm Deep is characterised with the highest concentration of CWAs in sediments, but occasional concentration peaks are also observed in the Gdansk Deep and close to dispersed munitions. Detailed investigation of spreading pattern show that the range of pollution depends on bottom currents and topography.Peer reviewe

Author Correction: Floating macrolitter leaked from Europe into the ocean (Nature Sustainability, (2021), 4, 6, (474-483), 10.1038/s41893-021-00722-6)

During the preparation of the Supplementary Data spreadsheet “S. Data 3_Regression data,” the mean and median confidence intervals (CI) of FML (items yr−1) were misplaced in relation to their corresponding river names. The Supplementary Data file has now been updated in the HTML version of the article. This update does not alter the results or conclusions of this article.Correction to: Nature Sustainability https://doi.org/10.1038/s41893-021-00722-6, published online 10 June 2021. During the preparation of the Supplementary Data spreadsheet “S. Data 3_Regression data,” the mean and median confidence intervals (CI) of FML (items yr−1) were misplaced in relation to their corresponding river names. The Supplementary Data file has now been updated in the HTML version of the article. This update does not alter the results or conclusions of this article.Peer reviewe

Floating macro litter in European rivers - top items

The JRC exploratory project RIMMEL provides information about litter, mainly plastic waste, entering the European Seas through river systems. RIMMEL has collected data on riverine floating macro litter inputs to the sea. Data acquisition was based on the Riverine Litter Observation Network (RiLON) activities, which collected data from rivers in the European marine basins over a period of one year (September 2016 – September 2017). Data was collected by visual observations and documented with the JRC Floating Litter Monitoring Application for mobile devices, allowing a harmonized reporting, compatible with the MSFD Master List of Categories for Litter Items. This report includes the Top Items lists of riverine floating macro litter, based on the total amount of litter items identified during RiLON activities and ranked by abundance. Top Items lists have been elaborated considering the whole database for the European Seas and further detailed for each individual European regional sea: Baltic Sea, Black Sea, Mediterranean Sea and North-East Atlantic. The North-East Atlantic and the Mediterranean Sea regions showed similar litter categories in their Top 20 Items. These two regions provided most of the available data, influencing the general Top Items list. In the Black Sea and Baltic Sea regions, where data availability was limited, the Top Items lists showed more differences among the different regions. Overall, the general Top Items list for the European Seas showed a predominance of plastic item categories (artificial polymer materials). As a whole, plastic items made up to 80.8% of all objects, with plastic and polystyrene fragments comprising 45% of the identified items in the database. Additionally, Single Use Plastics such as bottles, cover/packaging and bags were also ranked among the most frequently found floating litter. The similarities in the Top 10 and Top 20 items for the different regions, and the appearance of Single Use Plastics scoring high in the ranking, support the need for common actions against plastic pollution at EU level.JRC.D.2-Water and Marine Resource

Micropollutants in urban wastewater : large-scale emission estimates and analysis of measured concentrations in the Baltic Sea catchment

Highlights • Comprehensive study of micropollutants measured in effluents in the Baltic Sea region • Concentration data were found for ⁓90,000 observations and >1000 individual substances. • Differences in observed levels between countries were assessed. • Catchment scale total mass loads via WWTPs were calculated for 280 chemical contaminants.Wastewater treatment plants (WWTPs) transmit many chemical contaminants to aquatic environments. Quantitative data on micropollutant emissions via WWTPs are needed for environmental risk assessments and evaluation of mitigation measures. This study compiled published data on substances analysed in effluents from WWTPs in the Baltic Sea region, assessed country related differences in the data sets and estimated micropollutant inputs to the Baltic Sea catchment. Concentration data were found for 1090 substances analysed at 650 WWTPs. Heterogeneity and low number of data points for most substances hindered adequate comparisons of country specific concentrations. Emission estimates were made for the 280 substances analysed in at least five WWTPs in years 2010 to 2019. For selected substances, mass loads were compared to previously published estimations. The study provides data useful for national and Baltic Sea-scale pressure analysis and risk assessments. However, it also highlights the need for broad scope monitoring of micropollutants in wastewater

Sea-dumped ammunition as a possible source of mercury to the Baltic Sea sediments

After World War II, as a move toward Germany demilitarization, up to 385,000 t of munitions were sunk in the Baltic Sea. Munition containing various harmful substances, including chemical warfare agents (CWA) and explosives, that can affect marine biota were dumped on the seafloor. Some of those objects contained mercury, either as elemental mercury or mercury compounds (e.g., mercury fulminate, a common explosive primer), and thus could act as a specific local source of mercury in the dumping areas. Unfortunately, there is a lack of information on how dumped munitions impact the mercury concentrations in the Baltic Sea sediments. This report aims to answer the question how much sedimentary mercury in the dumping areas originates from munitions and to determine to what extent the mercury present in those areas originates from mercury fulminate. Concentrations of total sedimentary mercury- HgTOT in samples collected from conventional (Kolberger Heide) and chemical (Bornholm Deep) munitions dumping sites are characterized by high variability. However, an increase in HgTOT concentrations was observed with a decreasing distance to particular munition objects at both study sites. Moreover, mercury speciation in sediments from Kolberger Heide proves that the mercury there can be traced back directly to mercury fulminate. Results of our study confirm that munitions dumpsites are a local point sources of mercury. Due to the ecosystem constrains, varying transport modes and pathways, and both unknown and varying decomposition rates, these sea-bed mercury concentrations are hard to evaluate quantitatively. Therefore we recommend that further detailed studies should be conducted to assess sedimentary mercury provenience in munitions dumpsites more accurately

Floating macrolitter leaked from Europe into the ocean

International audienceRiverine systems act as converging pathways for discarded litter within drainage basins, becoming key elements in gauging the transfer of mismanaged waste into the ocean. However, riverine litter data are scarce and biased towards microplastics, generally lacking information about larger items. Based on the first ever database of riverine floating macrolitter across Europe, we have estimated that between 307 and 925 million litter items are released annually from Europe into the ocean. The plastic fraction represented 82% of the observed litter, mainly fragments and single-use items (that is, bottles, packaging and bags). Our modelled estimates show that a major portion of the total litter loading is routed through small-sized drainage basins (<100 km2), indicating the relevance of small rivers, streams and coastal run-off. Moreover, the major contribution of high-income countries to the macrolitter inputs suggests that reducing ocean pollution cannot be achieved only by improving waste management, but also requires changing consumption habits and behaviour to curb waste generation at source. The inability of countries with well-developed recovery systems to control the leakage of waste into the environment further supports the need to regulate the production and use of plastic on a global scale