Uptake of technetium by marine algae. Autoradiographic localization

The uptake of technetium (^95mTc) by marine algae was localized by autoradiography. In the brown (Ascophyllum nodosum, Fucus spiralis and F. vesiculosus) as well as in the red (Porphyra umbilicalis) species, the distribution of technetium was heterogeneous, this radioelement being mostly accumulated in the parts of the plant which bear reproductive cells or which contain young tissues. A close relation was suggested between active cellular metabolism and technetium accumulation. Since brown algae have high concentration factors (CFs), they could constitute an important link in the transfer of technetium through the food chain. On the contrary, the edible alga Porphyra umbilicalis shows a very low incorporation of technetium (CFs ≤5).