TABLE 7. FISH-SPECIES IN THE GREAT LAKES THAT HAVE 



EXPERIENCED SEVERE DECLINES, LAKE AFFECTED, 

 AND SUSPECTED CAUSE OF DECLINE 



Species 



Principal 

 lakes affected 



Primary cause(s) 

 of decline 



Atlantic salmon Ontario 



Sturgeon 



Lake trout 

 Northern pike 



Lake herring 



Burbot 



Cisco (chubs) 



Sauger 

 Lake trout 



Walleye 



Blue pike 

 Whitefish 



All lakes 



Erie 



Erie, Ontario 

 Huron 



All lakes 



All lakes 

 All lakes 



Huron, Erie 



All lakes 

 (except Erie) 



All lakes 



Erie and Ontario 

 All lakes 



Yellow perch 



Fourhorn sculpin Ontario, Erie 



Erie, Huron, 

 Michigan 



Emerald shiner 



Michigan 



Deterioration and blockage of 

 streams, exploitation 



Exploitation, destruction of spawning 

 streams 



Exploitation 



Destruction of spawning areas, ex- 

 ploitation 



Exploitation, environmental changes, 

 competition with introduced species 



Sea lamprey, environmental change 



Exploitation, competition with intro- 

 duced species, sea lamprey 



Environmental change, exploitation 



Sea lamprey, exploitation 



Environmental changes, exploitation, 

 destruction of spawning streams 



Environmental changes, exploitation 



Environmental changes, exploitation, 

 sea lamprey 



Competition with introduced species, 

 exploitation, environmental changes 



Competition with introduced species, 

 environmental change 



Competition with introduced species, 

 environmental change 



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