Table 1 . — Comparison of mercury levels in striped marlin 

 tissues analyzed by two laboratories. 



Laboratory 

 no. 1 



Laboratory 



Mean HG 

 Standard 



deviation 

 >0.5 ppm 

 <0.5 ppm 

 High value 

 Low value 



0.77 ppm 



0.35 



15 fish 



2 fish 



1.0 



0.4 



0.84 ppm 



0.50 



12 fish 



5 fish 



2.1 



0.1 



Some of this variability may be due to analytical 

 technique for it should be remembered that differ- 

 ent laboratories provided the analytical data. While 

 analytical methods were being developed there ap- 

 peared to be considerable variability between 

 laboratories, although the reproducibility within a 

 given laboratory was very high. Our data from the 

 17 samples that were run by two of the laboratories 

 tend to bear out this feature. Extreme values were 

 repeatable within both laboratories, but there were 

 differences between the laboratories. These differ- 

 ences are illustrated best in tabular form (Table 1). 



Looking at individual samples, one laboratory 

 was not consistently high or low and no two values 

 for a particular fish were identical. In several in- 

 stances one laboratory reported mercury values 

 over the FDA guideline while the other was below. 

 Again, neither laboratory was consistent in this re- 

 spect. 



The livers from four Hawaiian fish also were 

 analyzed for total mercury. Mercury levels of the 

 three small fish (81, 83, and 96 pounds— 36.7, 37.6, 

 and 43.5 kg, respectively) were all less than 0.2 

 ppm, but the single large fish of 139 pounds (63.0 

 kg) had a value of 1.54 ppm. 



Blue Marlin 



The mercury data for all 

 from fish taken in Hawaiian 

 levels of white muscle tissue 

 from 0.7 ppm to 7.86 ppm in 

 96 and 906 pounds (43.5 and 

 are presented in Figure 2. 

 striped marlin, the mercury 

 were much higher. Only 7 



the blue marlin were 

 waters. Total mercury 



in this species ranged 

 fish weighing between 



410.9 kg). The results 

 When compared to 



levels in blue marlin 

 of the 37 blue marlin 



tested had levels less than 1 .0 ppm, while for striped 

 marlin 45 of the 56 fish tested were below that level. 

 The highest value recorded for blue marlin was 7.86 

 ppm which, surprisingly, was not from the largest 

 specimen, but from a fish weighing 21 1 pounds (95.7 



kg). 



As with striped marlin, the range in mercury level 

 for blue marlin is large. However, there appeared to 

 be an indication of a positive relationship between 

 mercury level and fish size when a regression was 

 fitted to the data (Fig. 2). Again, this relationship 

 shows a wide variation around the regression. We 

 would find it difficult to use these data for predict- 

 ing mercury content in a given specimen. 



For comparative purposes we have plotted the 

 linear regression presented by Rivers, Pearson, and 

 Schultz (1972) for blue marlin samples from 

 Hawaiian waters. Since many of the same fish 

 tested by Rivers et al. (1972) were included in our 

 study, we can only conclude that the marked differ- 

 ence in regressions is due to differences in analyti- 

 cal technique. There is agreement, however, that 

 the levels of mercury in blue marlin are consider- 

 ably higher than the FDA guideline. 



The livers of 26 blue marlin also were analyzed 

 for total mercury. The values ranged from 0. 13 ppm 



400 500 600 



700 



800 



900 P0UOG 



200 250 



300 



3SO 



400 kg 



FISH SIZE 









Figure 2. — Relationship between total mercury (ppm) in 

 white muscle tissue and size of fish of blue marlin from 

 Hawaiian waters, (o denotes Rivers et al. (1972) samples, 

 x denotes our samples.) 



162 



