CHILDS and GAFFKE: MERCURY CONTENT OF GROUNDFISH 



sented for samples of spiny dogfish, sablefish, 

 and lingcod in Figure 2. The graphs of spiny 

 dogfish and lingcod show a random spread. 

 Since this study was concerned with commer- 

 cially important fish, no attempt was made to 

 acquire extremely small or large individuals. 

 Naturally, the lack of linear correlation ob- 

 served cannot be extended beyond the noted 

 size ranges. It was thought there might be 

 correlations within specific catch areas which 

 were obliterated when the data were pooled; 

 however, regression analysis of each catch 

 area also showed no highly discernible linear 

 correlation between length or weight and mer- 

 cury content. 



Fish taken at different times of the year did 

 not contain greatly different amounts of mer- 

 cury, with the exception of sablefish. In this 

 species, 20% of the samples taken in August 

 1971 had a mercury content greater than 0.50 

 ppm, while samples obtained later in the study 

 contained no fish with greater than 0.20 ppm 

 mercury. 



When these data were compared with those 

 for the Bay of Fundy and Nova Scotia Banks 

 (Zitko et al., 1971), Oregon groundfish were 

 found to contain, on the average, slightly more 

 mercury. However, the mean mercury content 

 of Oregon groundfish was less than that re- 

 ported for a number of Swedish coastal areas 

 (Ackefors, 1971). In summary, Oregon ground- 

 fish contain small amounts of mercury, and 

 the 99% confidence intervals suggest there is 

 little probability of normal commercial catch 

 samples exceeding the 0.50 ppm guideline 

 established by the U.S. Food and Drug Ad- 

 ministration. 



ACKNOWLEDGMENTS 



This study was financed in part by the 

 National Oceanic and Atmospheric Adminis- 



tration (maintained by the U.S. Department 

 of Commerce) Institutional Sea Grant No. 

 04-3-158-4. We thank D. L. Crawford, program 

 director of the Seafoods Laboratory, for his 

 administrative direction; V. L. Parsons for 

 superior technical assistance; and Paul Heikkila, 

 Ken Hilderbrand, Dean Murray, Joe Fenander, 

 Fred Anderson, and the Otter Trawl Commis- 

 sion of Oregon for aid in collecting samples. 



LITERATURE CITED 



Ackefors, H. 



1971. III. Effects of particular pollutants. Mercury 

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Bligh, E. G. 



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Hatch, W. R., and W. L. Ott. 



1968. Determination of sub-microgram quantities 

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WiLLFORD, W. A. 



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1971. Methylmercury in freshwater and marine 

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