Retrospective monitoring of mercury in fish from selected European freshwater and estuary sites

Abstract

Levels and trends of total mercury (THg) and methylmercury (MeHg) compounds in bream (Abramis brama) from different European sites were compared. Bream were collected between 2007 and 2013 in the estuaries of the rivers Scheldt (Netherlands), Rhône (France), Göta älv (Sweden), Tees (United Kingdom), and Mersey (UK), and in Lake Belau (Germany). A direct mercury analyzer was used to determine THg concentrations while MeHg was measured by gas chromatography/inductively coupled plasma-mass spectrometry applying stable isotope dilution. THg and MeHg in annual pool samples of bream ranged between 15.9 and 251 μg kg(-1) wet weight (ww) with lowest concentrations found at the reference site Lake Belau and highest in samples from the river Rhône. The EU environmental quality standard (EQS) of 20 μg kg(-1) ww was exceeded at all sites and in all years except at Lake Belau in 2012. Significantly decreasing trends over time were observed only in bream from the Rhône, while THg increased in bream from the Western Scheldt. The MeHg fractions of THg were always >80% and a significant difference between sites was detected only in one case (Rhône vs. Lake Belau).

Detection of tetrabromobisphenol A and its mono- and dimethyl derivatives in fish, sediment and suspended particulate matter from European freshwaters and estuaries

“…All fish results were subsequently transformed to the concentration by lipid weight; the lipid contents were taken from Nguetseng et al as all details on the fish samples were described there as well [26]. …”

“…Samples were stored at temperatures <−150 °C. Based on stable isotope data for nitrogen, bream had a trophic level (TL) of about 2.5–3.9 at the investigated sites [26]. The generic TL according to FishBase based on diet studies is 3.1 ± 0.1 [27].…”

Seasonal variability in metal and metalloid burdens of mussels: using data from the German Environmental Specimen Bank to evaluate implications for long-term mussel monitoring programs

“…Measurement of total mercury (here designated as Hg) was performed with dedicated atomic absorption spectrometry (AAS) methods applying a Direct Mercury Analyzer (DMA) instrument (DMA-80 for solid; MLS GmbH, Leutkirch, Germany). For details of sample treatment and measurement method, see [36].…”

Mercury Biomagnification between Two Trophic Levels of a Grazing Food Chain (Plankton and Planktivorous Fish) in a Fresh Water Ecosystem

“…Methylmercury is extremely poisonous, non-biodegradable, accumulates in living organism's tissues, biomagnifies in food chains with long biological half-life and is able to be transmitted over natural food webs [1,9,10].…”

“…Planktons [8,11], aquatic plants, fish tissues and organisms in higher trophic levels of a natural food chain [10,12] can absorb methylmercury at the higher levels easily. Hence, the highest concentrations of methylmercury would be accumulated in the upper predatory fishes such as sharks and tuna [2].…”