Temporal and organ-specific variability of selenium in marine organisms from the eastern coast of India

Temporal and organ-specific variations of selenium concentration in selecte d coastal organisms (seagrass, bivalves and fish) were investigated in diff erent biotopes of the deltaic Sundarbans, in the eastern coastal region of India. The bivalves and fish were obtained from local fishermen and were de stined for human consumption. The samples were digested with HNO3-H2O2 and selenium was extracted from the aqueous solution with triisooctylamine and stripped with dilute hydrochloric acid. The concentration of selenium was m easured by hydride generation-atomic absorption spectrometry. The results o btained were verified using inductively coupled plasma-mass spectrometric a nd fluorometric methods. The mean selenium concentration found in the vario us species ranged from 0.05 to 3.94 mug g(-1) (dry wt.). It was observed th at bivalves accumulated more selenium compared to fish and seagrass. The se quence of selenium levels found was, bivalves > fish > seagrass. In seagras s, the selenium concentration was higher in the roots (0.21 +/- 0.03 mug g( -1); dry wt.) than the stems (0.17 +/- 0.02 mug g(-1); dry wt.) and the lea ves (0.11 +/- 0.01 mug g(-1); dry wt.). But, in bivalves, the maximum conce ntration of selenium was found in the gill (3.94 +/- 0.11 mug g(-1); dry wt .). The results of the analysis of variance indicated that significant diff erences in Se concentration were evident between seasons and organs in thes e species. The variations in uptake of selenium may be due to different met abolic requirements for selenium among the three species, variations in foo d and differences in interspecies retention and elimination mechanisms. (C) 2001 Elsevier Science Ltd. All rights reserved.