Deciphering the Role of Water Column Redoxclines on Methyl mercury Cycling Using Speciation Modeling and Observations From the Baltic Sea

A.L. Soerensen; A.T. Schartup; A. Skrobonja; S. Bouchet; D. Amouroux; V. Liem-Nguyen; E. Björn
2018 | Global Biogeochem Cycles | 32

Oxygen-depleted areas are spreading in coastal and offshore waters worldwide, but the implication for production and bioaccumulation of neurotoxic methylmercury (MeHg) is uncertain. We combined observations from six cruises in the Baltic Sea with speciation modeling and incubation experiments to gain insights into mercury (Hg) dynamics in oxygen depleted systems. We then developed a conceptual model describing the main drivers of Hg speciation, fluxes, and transformations in water columns with steep redox gradients. MeHg concentrations were 2–6 and 30–55 times higher in hypoxic and anoxic than in normoxic water, respectively, while only 1–3 and 1–2 times higher for total Hg (THg). We systematically detected divalent inorganic Hg (HgII) methylation in anoxic water but rarely in other waters. In anoxic water, high concentrations of dissolved sulfide cause formation of dissolved species of HgII: HgS2H-(aq) and Hg (SH)20(aq) . This prolongs the lifetime and increases the reservoir of HgII readily available for
methylation, driving the high MeHg concentrations in anoxic zones. In the hypoxic zone and at the hypoxic-anoxic interface, Hg concentrations, partitioning, and speciation are all highly dynamic due to processes linked to the iron and sulfur cycles. This causes a large variability in bioavailability of Hg, and thereby MeHg concentrations, in these zones. We find that zooplankton in the summertime are exposed to 2–6 times higher MeHg concentrations in hypoxic than in normoxic water. The current spread of hypoxic zones in coastal systems worldwide could thus cause an increase in the MeHg exposure of food webs.

Environmental filtering and community delineation in the streambed ecotone

Ignacio Peralta-Maraver; Jason Galloway; Malte Posselt; Shai Arnon; Julia Reiss; Jörg Lewandowski; Anne L Robertson
2018 | Sci Rep

Determination of polar organic micropollutants in surface and pore water by high-resolution sampling-direct injection-ultra high performance liquid chromatography-tandem mass spectrometry

Malte Posselt; Anna Jaeger; Jonas L Schaper; Michael Radke; Jonathan P. Benskin
2018 | Environ. Sci.-Process Impacts | 20 (1716-1727)

Reviews and syntheses: Carbon use efficiency from organisms to ecosystems – definitions, theories, and empirical evidence

Manzoni, S.; Capek, P., Porada, P.; Thurner, M.; Winterdahl, M.; Beer, C.; Brüchert, V.; Frouz, J.; Hermann, A.M.; Lindahl, B.D.; Lyon, S.W.; Santruckova, H.; Vico, G.; Way, D.
2018 | Biogeosciences | 15 (5929-5949)

The cycling of carbon (C) between the Earth surface and the atmosphere is controlled by biological and abiotic processes that regulate C storage in biogeochemical compartments and release to the atmosphere. This partitioning is quantified using various forms of C-use efficiency (CUE) – the ratio of C remaining in a system to C entering that system. Biological CUE is the fraction of C taken up allocated to biosynthesis. In soils and sediments, C storage depends also on abiotic processes, so the term C-storage efficiency (CSE) can be used. Here we first review and reconcile CUE and CSE definitions proposed for autotrophic and heterotrophic organisms and communities, food webs, whole ecosystems and watersheds, and soils and sediments using a common mathematical framework. Second, we identify general CUE patterns; for example, the actual CUE increases with improving growth conditions, and apparent CUE decreases with increasing turnover. We then synthesize >5000CUE estimates showing that CUE decreases with increasing biological and ecological organization – from unicellular to multicellular organisms and from individuals to ecosystems. We conclude that CUE is an emergent property of coupled biological–abiotic systems, and it should be regarded as a flexible and scale-dependent index of the capacity of a given system to effectively retain C.

Longitudinal trends of per- and polyfluoroalkyl substances in children’s serum

Koponen, K.; Winkens, K.; Airaksinen, R.; Berger, U.; Vestergren, R.; Cousins, I.T.; Karvonen, A.; Pekkanen, J.; Kiviranta, H.
2018 | Environ Int | 121 (591-599)

Hyporheic exchange controls fate of trace organic compounds in an urban stream

Jonas L Schaper; Malte Posselt; James L McCallum; Eddie W Banks; Anja Hoehne; Karin Meinikmann; Margaret A Shanafield; Okke Batelaan; Joerg Lewandowski
2018 | Environ. Sci. Technol. | 52 (21) (12285-12294)

A plant-microbe interaction framework explaining nutrient effects on primary production

Čapek P.; Manzoni S.; Kaštovská E.; Wild B.; Diáková K.; Bárta J.; Schnecker J.; Biasi C.; Martikainen P.J.; Alves R.J.E.; Guggenberger G.; Gentsch N.; Hugelius G.; Palmtag J.; Mikutta R.; Shibistova O.; Urich T.; Schleper C.; Richter A.; Šantrůčková H.
2018 | Nat. Ecol. Evol | 2 (1588-1596)

Emerging investigator series: effect-based characterization of mixtures of environmental pollutants in diverse sediments

Jahnke, A.; Sobek, A.; Bergmann, M.; Bräunig, J.; Landmann, M.; Schäfer, S.; Escher, B.I.
2018 | Environ. Sci.-Process Impacts

Isothermal Evaporation of α-Pinene Ozonolysis SOA: Volatility, Phase State, and Oligomeric Composition

Emma L. D’Ambro; Siegfried Schobesberger; Rahul A. Zaveri∥; John E. Shilling; Ben Hwan Lee; Felipe D. Lopez-Hilfiker; Claudia Mohr; Joel A. Thornton
2018 | ACS, USA | 2 (10) (1058-1067)

Evaluating the current situation of PFAS in Lake Mälaren, Stockholm – distribution of PFAS in water column, surface sediment and sediment cores

Filipovic, M.; Kärrman, A.; Benskin, J.; Cousins, I.T.; Edvinsson, J.; Karlsson, E.; Neuschütz, C.; Holmström, S.; Holmström, K.; Temnerud, J.; Iverfelt, U.
2018 | SU

Nordrocs 2018: 7th joint Nordic meeting on remediation of contaminated sites | September 4, 2018 | Helsingör, Denmark

Resistance of soil protein depolymerization rates to eight years of elevated CO2, warming, and summer drought in a temperate heathland

Wild B.; Ambus P.; Reinsch S.; Richter A.
2018 | Biogeochemistry | 140 (255-267)

Zürich Statement on Future Actions on Per-and Polyfluoroalkyl Substances (PFASs)

Ritscher, A.; Wang, Z.; Scheringer, M.; Boucher, J.M.; Ahrens, L.; Berger, U.; Bintein, S.; Bopp, S.K.; Borg, D.; Buser, A.M.; Cousins, I.T.; DeWitt, J.; Fletcher, T.; Green, C.; Herzke, D.; Higgins, C.; Huang, J.; Hung, H.; Knepper, T.; Lau, C.S.; Leinala, E.; Lindstrom, A.B.; Liu, J.; Miller, M.; Ohno, K.; Perkola, N.; Shi, Y.; Haug, L.S., Trier, X.; Valsecchi, S.; van der Jagt, K.; Vierke, L.
2018 | Environ. Health Perspect. | 126 (8) (084502-1-084502-5)

Contact information

Visiting addresses:

Geovetenskapens Hus,
Svante Arrhenius väg 8, Stockholm

Arrheniuslaboratoriet, Svante Arrhenius väg 16, Stockholm (Unit for Analytical and Toxicological Chemistry)

Mailing address:
Department of Environmental Science and Analytical Chemistry (ACES)
Stockholm University
106 91 Stockholm

Press enquiries should be directed to:

Stella Papadopoulou
Science Communicator
Phone +46 (0)8 674 70 11
stella.papadopoulou@aces.su.se