ANAS: HEAVY METALS IN SEALS 



Farmington, Mich.^ A sample of paper lid liners 

 from the glass bottles was analyzed by the use 

 of neutron activation by Battelle Pacific North- 

 west Laboratories, Richland, Wash., to deter- 

 mine amounts of mercury, lead, cadmium, and 

 arsenic. 



Age Determinations 



Ages were assigned to fiir seals by counting 

 layers of dentine in sectioned upper canine 

 teeth (Scheffer, 1950; Fiscus, Baines, and 

 Wilke, 1964). Errors in assigning ages to fur 

 seals are small in young seals but increase 

 sharply in animals older than 7 yr (Anas, 

 1970b). Most errors in older animals, however, 

 are only of a magnitude of ± 2 yr. Although 

 canine teeth of harbor seals have layers of den- 

 tine, it is not known if these layers accurately 

 portray age. Ages were not assigned to harbor 

 seals, but body lengths were taken. 



RESULTS 

 Heavy Metals in Fur Seal Tissues 



Amounts of total mercury were higher in 

 liver than in muscle or kidney of fur seals (Table 

 1). Mercury in liver ranged from 0.4 ppm in a 

 fetus taken 3 mo before birth (the liver of the 

 11-yr-old mother had 86 ppm), to 0.1-0.3 ppm 

 in 10 pups, 3-19 ppm in 30 young males, 7-78 



^ Reference to trade names does not imply endorse- 

 ment by the National Marine Fisheries Service, NOAA. 



ppm in two young females, and 19-172 ppm in 

 36 adult females. For muscle, 0.1 ppm was 

 found in five pups, 0.1-0.4 ppm in 29 young 

 males, and 0.2-0.4 ppm in 10 adult females. 

 Mercury in kidney ranged from 0.2 ppm in a 

 fetus (the mother had 1 ppm), to 0.7 ppm in a 

 young male, and 0.6-1.6 ppm in eight females, 1 

 to 20 yr old. 



A wide range of mercury was found only in 

 the liver, so variability due to sampling is more 

 important for liver than for muscle or kidney. 

 The 95% confidence limits of within-sample 

 variability for the 20-mg samples of liver were 

 ± 11% of the mean values. The average variabil- 

 ity between seals within ages was 55 times 

 greater than the variability within the 20-mg 

 samples. Thus, to increase accuracy, larger 

 samples of seals are more important than addi- 

 tional 20-mg samples from each piece of liver. 



Methylmercury was not determined in this 

 study. However, in samples of liver from Cal- 

 ifornia sea lions, about 2% of the total mercury 

 was methylmercury (Buhler, see Footnote 2). 



On the average, amounts of lead and cadmium 

 were higher in kidney than in liver (Table 2). 

 Arsenic was not detected in any of the samples. 

 Lead in liver ranged from 0.8 ppm in a fetus 

 (the mother also had 0.8 ppm), to 0.2 ppm in a 

 young male, and 0.4-0.8 ppm in eight females. 

 Lead in kidney ranged from 0.3 ppm in a fetus 

 (0.8 ppm in the mother), to 1.8 ppm in a young 

 male, and 0.8-1.2 ppm in eight females. Cad- 

 mium in liver ranged from 0.5 ppm in a fetus 

 (4.6 ppm in the mother), to 0.6 ppm in a young 



Table 1. — Parts per million mercury on a wet weight basis in liver, muscle, 

 and kidney of fur seals taken off Washington and on the Pribilof Islands, 

 1970-71. 



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