266 



Tabic VI Fish Lengths Corresponding to various Consumption Advisory Levels (MDH, 1991)* for Sites 

 along the St. Louis River 



water body 



site # 



species 



fish length (inches) where indicated advisory is equaled 

 160 ppb - 660 ppb 1000 ppb 2810 ppb 



Chambers Grove 



Fond du Lac Reservoir 



Thomson Reservoir 



Scanlon Dam 



1590 walleye 



1610 



1654 



channel catfish 

 sm. bass 

 walleye 



nonhem pike 

 sm. bass 

 walleye 



< 12.2** 



12.9* 

 8.2 

 9.4* 



13.7 



7.8 



11.0 



1710 channel catfish < 10.2* 



StLR above town of Cloquet 1760 



mouth of White Pine River 



channel catfish 11.4* 



northern pike < 15.8** 

 sm. bass 9.8* 



walleye < 12.1*' 



1762 channel catfish 14.0* 



StLR above White Pine River 1763 channel catfish < 15.2** 



mouth of Cloquet River 



1777 



channel catfish 

 nonhem pike 

 white sucker 

 rock bass 

 sm. bass 

 walleye 



10.3* 



13.8* 



13.8 



7.0* 



9.4* 



< 10.0** 



StLR above ctyrd.31 



1782 channel catfish 11.3* 



15.7 



24. 6 1 

 16.2t 

 15.01 



> 24.5tt 

 17.6t 

 16.5i 



14.6 



26.6t 



> 25.3tt 

 14.2t 

 21.5t 



22.5 



> 28.6tt 



20.2 



19.7 



t I 



Ti 

 tt 



tt 



rt 



18.5t 

 19.2 



tt 

 tt 



15.9t 

 tt 



25.9t 



tt 



24.0t 



1 1 

 tt 



tt 

 tt 

 tt 



> 25.5tt 



tt 

 tt 

 tt 

 tt 



tt 



tt 



"advisory categories: 



(1) less than 160 ppb 



(2) 160-660 ppb 



(3) 660-2810 ppb 

 greater than 1000 ppb 



FDA restriction for commercial use 

 ♦extrapolated below actual range of fish sizes collected (up lo 20% below smallest fish) 

 **bclow 20% extrapolation range; entries with "<" indicate length of smallest fish sampled 

 textrapolated beyond actual range of fish sizes collected (up to 20% above largest fish) 

 ttbeyond 20% extrapolation range; entries with ">" indicate length of largest fish sampled 



tt 



Mercury in Plankton. In some cases (e.g. sites 1590 and 1654) mercury in plankton data are 

 extremely variable and depend highly on the plankton density in the water column (low 

 densities yield high mercury concentrations). The highest consistent concentrations were 

 found at site 1710 (Scanlon Dam) and coincide with the highest concentrations observed for 

 mercury in fish. 



15 



