TOTAL MERCURY CONTENT IN YELLOWFIN AND BIGEYE TUNA

Prompted by reports of human health and ecological effects of mercury poisonings, considerable attention has been directed toward quantifying and toxicological interpretation of mercury present in fish. Most, if not all, of these early contamination reports were traced to industrial and agricultural sources. However, in the early 1970's, open-ocean, pelagic species such as tuna, shark, swordfish, and marlin were often found that exceeded the current provisional maximum permissible level of 1. 0 mg Hg/kg established by the U. S. Food and Drug Administration. In the absence of obvious industrial sources, naturally-occurring sources of mercury are under scrutiny, as is the ability and extent of certain bacteria to transform and methylate inorganic mercury. The paper reports and interprets the analytical findings relating to total mercury levels in samples of bigeye (Thunnus obesus) and yellowfin (T. albacares) tuna.