²¹⁰Po accumulation by components of the Black Sea ecosystem

¹ Department of Radiation and Chemical Biology, the A.O. Kovalevsky Institute of Biology of the Southern Seas, NAS of Ukraine, 99011 Sevastopol, Ukraine
² Marine Environment Laboratory of IAEA, MC 98000 Monte-Carlo, Monaco

Abstract

The naturally occurring radionuclide ²¹⁰Po was determined in different components of the Black Sea ecosystem. The specific activity of ²¹⁰Po in water in the open part of the sea was about 1Bq ⋅ m^-3. The range of ²¹⁰Po specific activity in bottom sediments was 4.5–500 Bq ⋅ kg^-1 dry weight depending on their type, area and depth of collection. The highest values were found in the NW part of the Black Sea. Sediment distribution coefficients (Kd) of ²¹⁰Po for bottom sediments, calculated on a dry weight basis, varied from 0.5 × 10⁴ to 5 × 10⁵. The levels of ²¹⁰Po specific activity in molluscs and pelagic fishes anchovy and sprat were the highest among the investigated species of the Black Sea biota. Concentration factors (CF) of ²¹⁰Po, estimated on a wet weight basis, reached 1.5 × 10³ for macrophytes, 4 × 10³ for total zooplankton, 10³–10⁴ for the entire fishes depending on their ecological groups affiliation and (0.7–6.0) × 10⁴ for molluscs. So, the ability of the Black Sea biota to accumulate the natural radionuclide ²¹⁰Po is comparable with that of similar species from others marine and oceanic areas.