FISHERY BULLETIN: VOL. 73, NO. 1 



Cadmium 



Concentrations of cadmium in various anchovy 

 and sardine tissues ranged from less than 0.1 to 

 1.4 ^g g^i v^^et weight (Table 8). No significant 

 difference was observed between the two species, 

 except for the anchovy liver which had con- 

 sistently higher levels than all other tissues. 

 Higher concentrations occurred in the skin of 

 both species. 



Lead 



Lead concentrations in sardine tissues paral- 

 leled those in the anchovy (Table 9). High con- 

 centrations occurred in the gills and skin of 

 both species, and a tendency for higher levels 

 in anchovy liver late in the year was observed. 

 The lowest values tended to occur in muscle 

 tissue, with seasonal means ranging from not 

 detected to 1.2 Mg g"^ wet weight. 



DISCUSSION 



The six heavy metals considered during this 

 study fall into two groups with regard to distribu- 

 tion in tissues and differences in concentrations 

 between the two species: nickel, silver, cadmium, 

 and lead, with no major interspecific differences 

 and the highest concentrations occurring in 

 the skin and gills, and mercury and copper, 

 with marked interspecific differences and the 

 highest concentrations occurring in internal 

 tissues. 



The highest concentrations of nickel, silver, 

 cadmium, and lead were observed in the skin 

 and gills, perhaps associated with adsorption. 

 A significant interspecific difference was observed 

 with nickel and lead, with these elements being 

 nondetectable in the sardine liver but frequently 

 being detected in anchovy liver, suggesting a 

 difference in feeding habits and/or migration 

 routes of the two species. 



A tendency for increasing lead concentrations 

 in the skin during wanter was evident, related 

 perhaps to wind-induced roiling of sediments into 

 the water column during this period. The northern 

 Adriatic is known to have relatively high con- 

 centrations of metal pollutants in the bottom 

 sediments (Selli et al. 1972; Stirn pers. commun. 

 1973). A comparison of the concentrations of these 

 metals in various tissues of the Adriatic and 



Table 8. — Concentrations of cadmium (Mg g-i wet weight) 

 in tissues of sardine and anchovy from the Adriatic Sea. 



Table 9. — Concentrations of lead (ngg^' wet weight) in 

 tissues of sardine and anchovy from the Adriatic Sea. 



northern anchovies (Table 10) indicated that both 

 nickel and cadmium occurred at approximately 

 the same level. The relatively high nickel con- 

 centrations reported for the skin of the Adriatic 

 anchovy could be an artifact introduced by 

 analytical techniques (Table 2). 



Copper and mercury showed a very different 

 distribution pattern, with concentrations highest 

 in the digestive tract and liver of the two clu- 

 peids, and seasonal means 2 to 3x greater than 

 in the skin and gills, suggesting that ingestion 

 may be the primary entry route into the organism. 

 Concentrations in anchovy muscle tissue were 

 markedly higher than in the sardine, contrasting 

 with Establier's (1972) report that there were 

 no differences in mercury concentration between 

 these species off northwest Africa. 



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