海産橈脚類Acartia clausiによる水銀の蓄積

抄録

Acartia clausi were maintained at various densities (30-1, 100 individuals per liter) in filtered sea water containing mercuric chloride or methylmercury chloride of several concentrations (0.05, 0.1, 0.3 and 0.5ppb). After 24 hours, the uptake of inorganic mercury by the copepods was nearly constant (biconcentration factor=approx. 7, 500 on a ddry weight basis), regardless of both mrcury concentration and the desity of copepods. In contrast, bioconcentration of methylmercury fluctuated markedly; it showed a high negative correlatio (r=-0.9310) with the density of copepods, though there was no relation to the mercury concentration in the sea water. Such results srggest that methylmercury in the sea watre is accumulated rapidly by Acartia clausi, and that the concentration of methylmercury in copepods and sea watre reached equilibrium within the experimental period (24 hours).