Size-dependent Concentrations of Radiocesium and Stable Elements in Muscles of Flathead Flounder Hippoglossoides dubius†

Abstract

Concentrations of stable 133Cs in muscles of flathead flounder Hippoglossoides dubius were determined in separate individuals by means of neutron activation analysis, and were found to decrease with increasing size (age), following the relationship C=470L-1.05 (C, stable Cs concentration in μg/kg wet weight and L, standard length of fish in cm), over the range of 16.0 to 36.0 cm standard length, von Ber-talnffy growth model for the sample fish was fitted as: Lt=37.55(l -e-0.l03(t+1-83)), (Lt, standard length in cm at age t). Since the specific activity or 137Cs: stable Cs ratio was found to be fairly constant (average 1.2 × 104 Bq/g Cs) over this range, radiocesium 137Cs concentrations are expected to vary with fish size according to the relationship given above. In radio-environmental monitoring programs, the size composition of samples may have to be taken into consideration in assessing monitoring data. © 1995, The Japanese Society of Fisheries Science. All rights reserved.