Toxic metals in cyanobacterial mat of Big Lachman Lake, James Ross Island, Antarctica

The northern part of James Ross Island is the largest deglaciated area in the Antarctic Peninsula region with a unique ecosystem created during the Late Glacial. This research aims to evaluate the degree of contamination of the locality with toxic metals (As, Hg, Cd, and Pb) through bioindicators in the aquatic environment-colonies of cyanobacteria and algae. For this purpose, bottom lake sediments of Big Lachman Lake were studied for contents of Fe, As, Hg, Cd, Pb, Cr, Co, Ni, Cu, and Zn, as well as samples of cyanobacterial mat, in which Fe, As, Hg, Cd, and Pb were determined. Metal contents were determined by means of inductively coupled plasma optical emission spectrometry and atomic absorption spectrometry. The contents of metals in sediments did not differ from the usual values in the area of the Antarctic Peninsula. The bioaccumulation of metals in cyanobacterial mat was evaluated by calculating enrichment factors (the calculation to Fe as a reference element). According to this method, moderate pollution of Big Lachman Lake was confirmed for Hg and Cd.

Correction to: Model of Mercury Flux Associated with Volcanic Activity

The original version of this article contained a mistake in Fig. 2. The country names have been missed in the figure legend along with the X-axis. The corrected figure is given below.

Model of Mercury Flux Associated with Volcanic Activity

Volcanic activity is one of the primary sources of mercury in the earth's ecosystem. In this work, volcanic rocks from four geotectonically distinct localities (the Czech Republic - intraplate, rift-related alkaline basaltic rocks; Iceland - hotspot/rift-related tholeiitic basaltic rocks; Japan - island arc calc-alkaline andesites; and Alaska - continental arc calc-alkaline dacites) were studied. Ultra-trace Hg contents in all samples ranged from 0.3 up to 6 µg/kg. The highest Hg content was determined for volcanic ash from Mount Redoubt (Alaska, USA). In the case of basaltic volcanic rocks, the obtained results are about two orders of magnitude smaller than values formerly assumed for primary mercury contents in basaltic lavas. They are close to predicted Hg contents in the mantle source, i.e. below 0.5 µg/kg. Hg degassing is probably a key process for the resulting Hg contents in material ejected during volcanic eruption, which is previously enriched by Hg in the shallow-crust.