1972-1973. InD.F. Soule andM. Ogxiri (editors), Marine 

 studies of San Pedro Bay, California, Part IV, p. 1-42. 

 Univ. South. Calif Sea Grant Publ. USC-SG-2-74. 



Taylor, F. H. C. 



1957. Variations and populations of four species of Pacific 

 coast flatfish. Ph.D. Thesis, Univ. California, Los Ang., 

 351 p. 



Karl F. ehrlich 



Department of Biology, Occidental College 



Present address: Lockheed Center for Marine Research 



6350 Yarrow Drive, Suite A, 



Carlsbad, CA 92008 



JOHN S. STEPHENS 



Department of Biology 

 Occidental College 

 Los Angeles, CA 90041 



Gerald Muszynski 



Department of Biology, Occidental College 



Present address: Lockheed Center for Marine Research 



6350 Yarrow Drive, Suite A 



Carlsbad, CA 92008 



J. Myron Hood 



Department of Mathematics, Occidental College 

 Present address: Department of Mathematics 

 California Polytechnic University 

 San Luis Obispo, CA 93407 



MERCURY AND SELENIUM IN 



BLUE MARLIN, MAKAIRA NIGRICANS, 



FROM THE HAWAIIAN ISLANDS 



In a previous study, nine species of pelagic and 

 inshore fish caught in Hawaiian waters were 

 analyzed for total and organic mercury (Rivers et 

 al. 1972). In all but one species the organic mer- 

 cury was >80% of the total, a finding consistent 

 with other mercury values reported (Kamps et al. 

 1972; Westoo 1973). In muscle and liver tissues of 

 blue marlin, Makaira nigricans Lacepede, how- 

 ever, only a small portion of the total mercury was 

 found to be organic mercury. Additional studies on 

 marlin landed during fishing tournaments in 1972 

 (Schultz et al. 1976) and 1973 (Schultz and Crear 

 1976) revealed low levels of organic mercury in six 

 other tissues. These studies also showed that the 

 difference between total and organic mercury was 

 indeed inorganic mercury. G. Westoo (National 

 Swedish Food Administration, Stockholm. Pers. 

 commun., 1972) had previously identified the or- 

 ganic fraction as methyl mercury. 



An assessment of mercury is complicated by the 

 presence of selenium. Selenium has been shown to 

 reduce the toxicity of mercuric chloride and 

 methyl mercury in laboratory animals when given 

 as selenite, selenomethionine, or as selenium pre- 

 sent in tuna (Pah'zek et al. 1971; Ganther and 

 Sunde 1974). The presence of selenium in tuna, a 

 principal food item of marlin (NaughtonM, indi- 

 cates that it should also be present in marlin. 



For this report, nine tissues from blue marlin 

 were analyzed for selenium, total mercury, and 

 organic mercury. 



Materials and Methods 



Samples of muscle, liver, kidney, spleen, pyloric 

 caecum, stomach, gill, gonad, and blood were col- 

 lected from 46 marlin landed during a fishing 

 tournament in Kailua-Kona, Hawaii, during Au- 

 gust 1974. The tissues were ground with Dry Ice^ 

 in a blender and stored in acid-washed plastic 

 vials. 



The organic extraction was carried out as de- 

 scribed by Rivers et al. (1972), i.e., a benzene ex- 

 traction of the methyl mercury was reextracted 

 with cysteine, oxidized with permanganate, and 

 reduced to elemental mercury with stannous ion 

 prior to being volatilized into the flameless atomic 

 absorption apparatus. Total mercury digestions 

 were performed (Rivers et al. 1972) but with 10 ml 

 of concentrated nitric acid instead of 30 ml. All 

 analyses were made with a Perkin-Elmer 303 

 atomic absorption spectrophotometer equipped 

 with a vapor chamber (Manning 1970). 



Selenium was determined by a fluorometric 

 technique (Watkinson 1966), as modified by S. 

 Nishigake (Tokyo Metropolitan Research Labo- 

 ratory of Public Health, Tokyo, Japan. Pers. com- 

 mun., 1975), i.e., following sample digestion with 

 nitric and perchloric acids, the selenium was com- 

 plexed with 2,3-diaminonaphthalene and this 

 fluorescent compound then extracted into cyclo- 

 hexane. All analyses were made using a Turner 

 Model 110 fluorometer equipped with a primary 

 filter at 369 nm and a secondary filter at 522 nm. 



'Naughton, J. J. 1973. To all billfishermen. (Summary report 

 of 15th Hawaiian International Billfish Tournament, 27-31 Au- 

 gust 1973), 9 p. Southwest Fisheries Center Honolulu Laborato- 

 ry, National Marine Fisheries Service, NOAA, Honolulu, HI 

 96812. 



^Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



872 



FISHERY BULLETIN: VOL. 76, NO. 4, 1979. 



