Results 



A summary of mercury and selenium concentra- 

 tions in the marlin is given in Table 1. Average 

 total mercury and selenium values were greatest 

 in kidney (26.33 mg/kg Hg, 23.42 mg/kg Se) and 

 least in blood (0.18 mg/kg Hg, 1.29 mg/kg Se) and 

 gill (0.32 mg/kg Hg, 1.29 mg/kg Se). Average 

 methyl mercury was highest in muscle (0.40) 

 mg/kg) and lowest in blood (0.04 mg/kg) and gill 

 (0.06 mg/kg). The percentage of organic to total 

 mercury ranged from 19f in kidney to 279f in 

 gonad. The molar ratio of mercury to selenium 

 ranged from 0.06 in blood to 0.62 in muscle. (Molar 

 ratio is computed here using sample average 

 statistics of combined male and female data.) 



An analysis of variance revealed significant dif- 

 ferences (P<0.05) in total mercury between males 

 and females for all tissues except gill and blood. A 

 similar pattern was found for selenium. The or- 

 ganic mercury levels were not statistically differ- 

 ent (P>0.05) between the sexes. In earlier studies 

 on marlin caught from the same area during 

 fishing tournaments in 1971, 1972, and 1973, mer- 

 cury concentrations in both sexes were found to be 

 similar. 



Table 2 presents correlation coefficients for body 

 weight and tissues. In most cases, the relation- 

 ships are positive and highly significant. Figures 

 1-6 illustrate the dependence of mercury and 

 selenium on weight and on each other. 



Discussion 



The data clearly demonstrate that methyl mer- 

 cury concentrations are low relative to total mer- 

 cury in blue marlin. Westoo (pers. commun.) and 

 Nishigaki (pers. commun.) confirmed this low 

 percentage in our samples based on subsamples 

 sent to them. Nishigaki has also confirmed our 

 selenium results. 



In a study of 37 Pacific blue marlin (50-238 kg, 

 average 109 kg) from Japanese waters, Nishigaki 

 (pers. commun.) found total mercury levels rang- 

 ing from 0.02 to 13.0 mg/kg (average 2.83 mg/kg) 

 and methyl mercury ranging from 0.02 to 1.28 

 mg/kg (average 0.57 mg/kg). Selenium values for 

 11 marlin ranged from 0.52 to 1.99 mg/kg, averag- 

 ing 0.97 mg/kg. These values are similar to our 

 findings for mercury and selenium in marlin from 

 Hawaiian waters. 



Muscle 



Liver 



Kidney 



Spleen 



Stomach 



F>ylonc 



caecum 

 Gill 



Gonad 

 Blood 



3.12 



11.58 



26 33 



693 



1.27 



1 83 

 0.32 

 0.40 

 0.18 



2.83 



12.53 



2625 



6.34 



1 33 



1.74 

 0.26 

 030 

 0.18 



3 76 



9.46 



26.53 



821 



1,16 



2.03 

 0.44 

 0.68 

 0.18 



0.09-10 00 

 0.13-39 20 

 0.18-77.00 

 08-17 60 

 0.06-3.00 



0.17-4.50 

 008-096 

 0.03-2.15 

 0.02-0.53 



040 

 026 

 22 

 18 

 0.12 



030 

 006 

 0.11 

 0.04 



032 

 21 

 16 

 12 

 0.08 



022 

 003 

 006 

 004 



0.58 

 038 

 0.35 

 030 

 021 



0.49 

 0.11 

 025 

 0.05 



0.02-1.02 

 009-0.76 

 004-086 

 002-0.66 

 003-0.47 



008-0.98 



0.01-0.34 



0.03-0.65 



;0.01-0.11 



13 

 2 

 1 

 3 

 9 



16 

 19 

 27 

 22 



198 1.88 2.21 0.63-5.32 



17 47 20 36 1106 2 50-61 12 



23.42 2533 1906 2 63-56 25 



9.31 912 973 63-24 25 



291 316 239 135-4 03 



4 92 

 1.29 

 2.14 

 1.29 



5.10 

 1.31 

 1.97 

 1.33 



4 52 

 1.26 

 2.60 

 1.19 



2.28-10.10 

 0.71-2.21 

 1 .24-3.80 

 0.72-2.30 



0.62 



026 

 0.44 

 0.29 

 0.17 



0.15 

 0.10 

 0.07 

 0.06 



'Weights of 32 males ranged from 58 to 112 kg (average 80); 14 females weighed 39. 75, and 115-342 kg (average 166) Average for all samples was 106 kg. 



Table 2. — Correlation coefficient of mercury, selenium, and weight in 46 blue marlin from the 



Hawaiian Islands by sex. 



Total Hg/wt 



Organic 

 Hg/wt 



Organic 

 total Hg 



Sewt 



Total 

 Hg/Se 



Organic 



Hg/Se 



873 



