Anne L. Soerensen Baltic Sea water column mercury profiles 2014–2016 Bolin Centre for Climate Research, Stockholm University 2018 Datafile Marine Marine chemistry Mercury Methylmercury Baltic Sea Sub-Arctic Earth science > Oceans > Ocean chemistry Anne Soerensen 2018-10-02T11:07:05+00:00 English 1.0 None The dataset is included in one xlsx file having the following data columns: Cruise, Year, Station, Depth [m], Latitude [Degrees], Longitude [Degrees], THg [pM], Hgᴵᴵ [pM], Hg⁰ [pM], MeHg [fM], MeHgdissolved [fM], MeHg/THg [%], Hg⁰/THg [%], km [/d], kd [/d], kdphoto [/d], kdphoto [m²/E], Turbidity, Temperature [℃], Salinity, Oxygen [mL/L], Oxygen [% saturation], H₂S [µM], pH, PO₄ [µM], Total P [µM], NO₂ [µM], NO₃ [µM], NH₄ [µM], Total N [µM], SiO₃ [µM], Chlorophyl A [µg/L]. For ancillary data numbers in italic are averages of measurements at depths above and below the given depth. When mercury observations are below level of detection (LOD), LOD x 0.5 is given. The data represent water profiles taken from the ship during the cruises. THg: total Hg (Hgᴵᴵ+Hg⁰+MeHg), Hgᴵᴵ: inorganic divalent Hg, Hg⁰: elemental gaseous Hg, MeHg: methyl-Hg. Dimethyl-Hg was measured in July 2016 but was always below detection limit (2 fM). Methylmercury (MeHg) is a neurotoxin and the only mercury (Hg) species that biomagnifies in aquatic biota. Hg is classified as a contaminant of major health concern by WHO and is a leading toxin in the Baltic Sea food web. In the Baltic Sea monitoring efforts have focused on measuring total Hg concentrations. However, there is no direct relationship between total Hg load to the system and MeHg levels in biota. This disconnect suggests that other important processes control the variability of MeHg formation, bioaccumulation and biomagnification in the Baltic Sea. In this project we have used a combination of field work and laboratory and modelling studies to improve our understanding of the impact of eutrophication and climate change on mercury concentrations in the Baltic Sea water column and food web. Ancillary data (all physical and chemical parameters other than mercury) are compiled from data available online at the <a href="">Swedish Meteorological and Hydrological Institute</a>.