THE INFLUENCE OF SEASON ON MERCURY METABOLISM IN BREAM (ABRAMIS-BRAMAL.)

Considering the fact that in fish, as opposed to terrestrial animals a nd man, the main tissues cumulating mercury are skeletal muscles. Thus it is most probable that the element will be differently distributed and that the proportions between that element concentrations in partic ular organs at the time following intensive preying (autumn) and after winter limited food intake (spring) will vary. The present investigat ion aimed at confirming the above hypothesis. The investigations were performed on 20 breams fished in October and May of the following year . The contents of mercury in the muscles, hepato-pancreas, kidney, gil ls and intestine was determined by the ASA method. It has been demonst rated that seasons did not significantly affect the concentration of m ercury in the tissues and organs of bream. In the autumn season, follo wing intensive preying the Hg metabolism is more dynamic than in sprin g. On the basis of the obtained results one can assume that the main r oute of mercury entering the muscles is the gill absorption.