NOTE Adams and McMichael: Mercury level in four species of sfiarks from tfie Atlantic coast 



375 



females (.v=624 mm PCL) were significantly larger 

 than males (.v =541.9 mm PCL) (^test, P<0.05), to- 

 tal mercury levels of males (.V =0.92 ppm) and females 

 (3c =1.15 ppm) were not significantly different (Mann- 

 Whitney rank sum test, P>0.1). A total of 72.8% of 

 all juvenile and adult Atlantic sharpnose sharks 

 tested had mercury levels that were greater than or 

 equal to the 0.5-ppm threshold level. 



Total mercury levels for the six embryos (74-85 

 mm PCL) examined ranged from 0.17 to 0.29 ppm 

 (x=0.22 ppm; median=0.19 ppm). Mercury levels for 

 embryos within each litter were very similar (Table 

 2) and equaled 8.3-15.3'^ of levels observed in their 

 respective mothers. Overall mercury levels among 

 litters were also similar (±0.02 SD). All confirmed 

 pregnant females had levels greater than 1.0 ppm. 



There was a significant positive correlation be- 

 tween total mercury level and Atlantic sharpnose shark 

 length (both sexes combined)(P<0.0001; Fig. 3). Total 

 mercury level in this species increased as individu- 

 als grew larger. Total mercury levels for larger At- 



100 200 300 400 500 600 700 800 900 

 Precaudal length (mm) 



Figure 3 



Relation between In total mercury- level (ppm) and 

 precaudal length (mm) for juvenile and adult Atlantic 

 sharpnose sharks, i?/!izopr;onorfon terraenovae, from 

 the Atlantic coast of Florida. 



