24 



U. S. BUREAU OF FISHERIES. 



cially made iron rake shown in Figure 32 has also proved a very 

 effective implement. The main bar, 3 inches in diameter and 8 

 feet long, is set with 15 teeth 15 inches long and forms the 

 diagonal of a square frame, at the two remaining corners of which 

 is fixed an iron ring. With a strong rope through each ring, the rake 

 is drawn from one side of the pond to the other, making an 8- foot 

 swath. Two men are usually required on each side of the pond to 

 manipulate the rake. 



At the Cold Springs (Ga.) station there is but one pond in which 

 vegetation (Myriophyllum) is sufficiently dense to necessitate its 

 removal prior to seining for the young fish. In this pond it grows 



Fig. 32. — Iron rake in use at San Marcos (Tex.) station. (For description see text.) 



exuberantly from bottom to surface and is removed by the use of a 

 wire, about the size of a telegraph wire, loaded with weights and 

 pulled through the pond much as a seine is hauled, except that it is 

 jerked vigorously from side to side. In this way the tender growth 

 of the Myriophyllum is easily severed. It is then dragged ashore 

 with a long rake similar to the one in use at San Marcos. 



Owing to the necessity for periodically removing the aquatic foli- 

 age at pond-culture stations and the expense involved in the present 

 methods of performing this task, it is obvious that here also is a field 

 for experimentation, but that in this, as in other efforts of the fish- 

 culturist to effect economies, each station has its own problems. 



o 



