MONTANA STATE FISH AND GAME COMMISSION 



23 



of the pond with three side floors, equidistant, of the same width running from 

 the center floor to the outer edges of the pond. The portions of the pond, not 

 floored, produces a dense growth of aquatic vegetation, absolutely essential to the 

 successful operation of a pond of this type. 



The water generally used in this pond is deficient in oxygen, being used in 

 the hatchery and smaller fry ponds before reaching the large pond, it also carries 

 a certain amount of waste material which must be taken care of. These two con- 

 ditions are remedied through the presence of aquatic vegetation which absorbs 

 the carbon dioxide thrown off by decay of waste material and respiration of 

 fish, and in turn throws off oxygen which is essential to fish and all aquatic 

 animal life. Thus gases thrown off as a waste product by the plants are 

 essential for the well being of the fish and the waste product thrown off by 

 the respiration of the fish and other animals are taken up by the growing plants, 

 plants. 



Fish reared in this type pond are far superior to the fish reared in ponds 

 constituting entire artificial conditions, for the reason there is more natural 

 fo'^d, natural conditions with more room provided for the range of the fish. 

 Ponds of this type have been constructed at Big Timber, Lewistown, Emigrant, 

 Anaconda, Hamilton and Libby. 



A shortage of fish food is facing us at this time on account of the 

 slaughter of the surplus cattle which became necessary on account of the extreme 

 droup^ht. Plans are under way to secure pasture land upon which range horses 

 will be raised for fish food. 



WHERE THE LOCH LEVEN RUN 



Approximately 5.000,000 Loch Leven, and 5,000,000 Rainbow eggs are stripped 

 from these traps each year. They are on the Madison River at 



Hebgen Lake. 



