HALL ET AL.: MERCURY IN PACIFIC HALIBUT 



Table 6.-Summary of mercury concentration in Pacific halibut. 



£ 



Q. 



a. 



> 



O 



cn 



LJ 



1.50 



1.00- 



25 



0.50- 



50 100 150 200 250 



WEIGHT (pounds) 



Figure 2. -Relationship between heads-off eviscerated weight 

 and mercury concentration in the edible muscle tissue of Pacific 

 halibut from the Bering Sea. 



E 



Q. 

 Ql 



> 



O 



cc 



1.50 



1.00- 



0.50 



100 



100 150 



WEIGHT(pounds) 



250 



Figure 4. -Relationship between heads-off eviscerated weight 

 and mercury concentration in the edible muscle tissue of Pacific 

 halibut from southeast Alaska. 



50 too 150 200 250 



WEIGHT (pounds) 



Figure 3.-Relationship between heads-off eviscerated weight 

 and mercurj' concentration in the edible muscle tissue of Pacific 

 halibut from the Gulf of Alaska. 



mercury concentrations in the edible tissue for 

 each area are shown in Figures 2 through 6. 

 Correlation coefficients (r values) are shown on 



each plot and are significant at the 0.1% level. 

 Correlation coefficients between length and mer- 

 cury were also significant at the 0.1% level within 

 each area and were essentially identical to the 

 correlation coefficients between weight and mer- 

 cury. This would be expected from the weight- 

 length relationship. Correlation between age and 

 mercury was higher than between weight or 

 length and mercury for fish from the Bering Sea, 

 the Gulf of Alaska, and southeast Alaska; the same 

 for fish from British Columbia; and lower for fish 

 from Washington-Oregon. These correlation 

 coefficients between age and mercury were also 

 significant at the 0.1% level in all areas. 



In evaluating the data, areas were used that are 

 either the same as the fishery management areas 

 defined by the International Pacific Halibut Com- 

 mission (1974) or subdivisions of a management 

 area. This was both logical and practical for the 

 purpose of providing useful information to the 

 halibut industry. The plots of mercury concentra- 

 tion in the edible muscle against weight of fish 

 taken from both the Bering Sea and the Gulf of 



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