47 



Permanent damage has resulted from the taking of spawning 

 ponds for water supplies and diverting or screening the original 

 outflow. The forme{ prosperity and number of the alewife 

 streams can never be regained, since the extent of the artifi- 

 cially created spawning grounds can in no measure compensate 

 for the great loss of natural territory taken for water supplies. 

 The constant use of the water either so reduces the level that it 

 will not flow out through its former outlet in sufficient quantity 

 to allow alewives to enter the pond, — e.g., Wenham Lake and 

 Cape Pond, — or reduces it to such an extent that during the 

 period of low water in the fall the young alewives are unable to 

 leave the pond, as at Great Quitticas Pond. To avoid the 

 serious nuisance of dying fish clogging the water mains it has 

 been customary to screen the outlets in the spring to prevent 

 the entrance of fish. 



Geographically the greatest damage has occurred north of 

 Plymouth, as can be seen by the accompanying list of streams 

 wholly or partly ruined by the use of the spawning grounds 

 for water supplies. 



Naturally, the question of a good water supply is far more 

 important than the existence of an alewife fishery. It is inevi- 

 table that other ponds, such as Chebacco Lake, Essex, may 

 later be taken for this purpose. In most of these cases it is 

 utterly impossible to restore the alewife fishery, although in 



