DBPapers
DOI: 10.5593/SGEM2014/B51/S20.012

ASSESSMENT OF MERCURY IN FISH IN THE MOUTH OF THE NORTHERN DVINA RIVER AND THE DVINA BAY OF THE WHITE SEA

A. Ovsepyan , Y. Fedorov , V. Savitskiy
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-17-9 / ISSN 1314-2704, June 19-25, 2014, Book 5, Vol. 1, 81-88 pp

ABSTRACT
A substantial portion of Northern Russia is waterlogged. Consequently, the high
content of humic substances and hydrogen ions contribute to the formation of
bioavailable forms of mercury. In such circumstances, even low levels of mercury
concentration in water can pose a serious threat to aquatic life. The consumption of fish in Northern Russia is on average 2.6 times higher than in the rests of the country. It is therefore important to investigate characteristics of accumulation and distribution of mercury in the fish tissues. Samples were collected during 3 years in different seasons and water regimes of the Northern Dvina River, and in the Dvina Bay of the White Sea. A total of 50 samples of aquatic organisms were selected: whitefish, bream, flounder, Siberian roach, rainbow smelt and perch. Samples of fish tissues were preserved in a solution made of K2Cr2O7 4% and pure nitric acid. They were analyzed at the Laboratory of the Southern Federal University (Rostov-on-Don) using cold-vapor atomic-absorption spectroscopy. The detection limit ranged 0.004-0.005 μg g-1. The accuracy fall in the range of a 30-laboratory AMOSproficiency intercomparison in which the Laboratory of the Southern Federal University (Rostov-on-Don). Replicates were also analyzed at the Regional Laboratory Center of the Yuzhgeologiya Federal State Unitary Geological Enterprise and gave reproducible results. Concentrations of mercury varied from 0.009 to 0.57 μg g-1 in muscle, from 0.038 to 0.765 μg g-1 in liver, from 0.013 to 0.15 μg g-1 in gills.

Keywords: mercury in fish, Northern Dvina River, White Sea, assessment