Influence of temperature on the accumulation and retention of 11 radionuclides by the marine alga Fucus vesiculosus (L.)

Accumulation of the radionuclides 241Am, 110mAg, 133Ba, 109Cd, 57Co-cobalamine, 60Co, 134Cs, 152Eu, 54Mn, 106Ru and 65Zn in the brown macroalga Fucus vesiculosus (L.) Phaeophyceae, was compared at 2°C and 12°C in a series of laboratory radiotracer experiments. Concentration factors in the thallus were temperature-dependent and significantly decreased at 2°C for 110mAg, 109Cd, 60Co, 54Mn and 65Zn (CF = 439, 51, 101, 92 and 162, respectively) but not for 241Am, 133Ba, 134Cs, 152Eu and organic 57Co (CF = 329, 210, 3.3, 470 and 214, respectively); hence, for these last isotopes concentration factors in this species derived from temperate latitude (12°C) studies can probably be applied to radiological assessments made under Arctic conditions. Between 2 and 14 days of depuration, the radionuclides, except 133Ba and 134Cs, remained tightly bound to the alga. Our results suggest that: 1. temperature must be considered when modelling the radiological impact of radioactive waste dumping in the Arctic Seas; and 2. Fucus spp. would be excellent bioindicators of radionuclide contamination and dispersion in the Barents and Kara Seas.