Selenium and Mercury in Marine Organisms (I)

Abstract

Skipjack (Katsuwonus pelamis) and seerfish (Scomberomorus niphonius), caught in Kishu, 57 and 70cm fork length, respectively, were determined selenium and total mercury contents in different tissues.Selenium contents in the ordinary muscle, dark muscle, liver, spleen and kidney of skipjack were 0.40, 3.2, 9.2, 2.4 and 2.4μg/g, respectively, and in the same tissues of seerfish were 0.33, 0.78, 2.7, 3.8 and 3.7μg/g, respectively. Ventral portion contained more selenium than dorsal portion in the ordinary muscle of the two fishes.Total mercury contents in the ordinary muscle of skipjack and seerfish were 0.32 and 0.06μg/g, which uniformly distributed in each muscle. In skipjack the ordinary muscle showed the highest total mercury contents among the all tissues, but did not in seerfish.Total mercury contents in the ordinary muscle of the two fishes, increased with fork length, but selenium contents either remained constant or decreased. The similar tendency was observed in yellowfin tuna (Neothunnus albacora).Contents of the both elements were compared amongg the three fishes, mentioned above, mackerel (Pneumatophorus japonicus) and red sea bream (Pagrus major) of nearly same age.Total mercury contents in the ordinary muscle of these five species were significantly different, while selenium contents were not. However, contents of the both elements in the liver were remarkably different.