Fishing industry in seas, bays, rivers give the considerable share of protein in ration feed on population of the country. Water always contains definite quantity of natural radionuclides. At the same time, radioecological characteristic of reservoir abrupt deteriorate out of anthropogenic radiocontamination in consequence of development atomic power both military and peaceful aims. The anthropogenic radionuclides in ecosystems of Amursky bay and Razdolnaya River (Peter the Great Bay, Japan East Sea) generally have its origin from nuclear weapon tests pursued formerly. Cs-137 and Sr-90 are the most hazardous in regard to sanitary-hygienic aspect. Artificial redionuclides Cs137 and Sr-90 are analogies to biogenic elements potassium and calcium accordingly and accompany them in nature. Entering hydrobionics by different ways Cs-137 accumulates mainly in muscular tissues and Sr-90 - in bone tissues. The objects of investigation were freshwaters fishes of Razdolnaya River such as Silver carp, Carp, Crusian carp and semipassing by species of fishery (Far Eastern dace, Asiatic smelt, Haarder). Razdolnaya estuary being the largest in Primorye in the same time is the transitive zone between the freshwater and seawater place for semi-passing species of fish and their fatten getting from the river basin. To fix contamination of the radioisotopes in ichthyofaune the radiochemical method was used. Cs-137 was picked out as cesium bismuth iodide and Sr-90 was defined by its daughter´s isotope Y-90 in the form of yuttrium oxalate. During investigation it was ascertained that the lowest concentration of radionuclides have semi-passing fishes Cs-137 (1.9-2.9 Bk/kg) in muscles and Sr-90 (0.8-2.4 Bk/kg) in bone tissue, concentration of Cs-137 and Sr-90 in fresh water living fishes of Razdolnaya River was 3.5-5.6 and 2.7-6.6 Bk/kg respectively. It shows that the way of life of fishes determines its radionuclide concentration level essentially. Semi-passing fishes calling at Razdolnaya River to propagate mainly lives at sea and thus concentration of Cs-137 and Sr-90 in them are lower of fresh water ones. Adduced data shows that the low level of mineralization of Razdolnaya river water increase concentration of radionuclides in fish tissues.
According to existing standards, which prescribes "Hygienic requirements of food´s safety and food´s value" the Cs-137 contents in living fishes and in raw must not be more then 130 Bk/kg and Sr-90 contents - 100 Bk/kg. Obtained of artificial radioactivity of fish in Japan Sea with sanitary norms for food production we can see that these levels considerably lower of permissible and consequently the fish safe in radiationally-hygienic terms.
The work was submitted to international scientific conference «Monitoring of Environment», September, 9-16, 2008, Italy (Rome, Florence), came to the editorial office on 21.07.2008.