FISH-CULTURAL PRACTICES IN THE BUREAU OF FISHERIES. 



713 



The construction of the racks under the many varying conditions which are 

 wont to prevail requires good judgment and extreme care. Such barriers must 

 be made in anticipation of and providing for floods and must be fish-tight. One 

 small hole large enough for the entrance of one fish may result in the escape of 

 the entire lot. 



The eying stations adjacent to these collecting stations are small inexpensive 

 structures, a shanty 12 by 16 feet being adequate to eye a million eggs. 



To compensate for the eggs taken from these waters, about 25 per cent of 

 the fish produced therefrom are returned to them, this being an ample propor- 

 tion to keep them well stocked. The parent fish are always returned to the 

 waters from which they were captured. 



Eggs of the landlocked salmon {Sabno schago) are collected by methods 

 quite similar to those pursued in the brook trout work. Although the range of 

 this species has been extended, the field of egg-collecting operations is almost 

 exclusively the native habitat in Maine. 



Perhaps the most extensive trout-culture operations in the world are con- 

 ducted from the station at Leadville, Colo., in connection with which are field 

 stations for the collection of eggs of wild trout of three species. The output of 

 the Leadville station for 1908 was as follows: 



SPAWNTAKING IN COLORADO. 



To see the methods of work in Colorado it may be well to follow the spawn- 

 takers as they leave their camp on one of the Grand Mesa Lakes for a day's 

 work with the native trout of the Rocky Mountains (Salmo clarki) at Big Island 

 Lake, 10,000 feet above the sea level. 



Each spawntaker is provided with a neck yoke and two lo-quart buckets 

 in which to bring in the results of the day's operations. The fish have assembled 

 in great numbers around the outlet of the lake, where as many as can be con- 

 veniently handled are caught at each haul of the seine and the ripe ones imme- 

 diately stripped. Work at this point may continue all day or it may be advisable 

 after a time to seek other spawning grounds, perhaps at the mouths of small 

 inlets where the water from melting snow is flowing into the lake. 



A most interesting phenomenon in connection with this work is the run of 

 trout around the island from which the lake derives its name. Every two or 



B. B. F. 1908— Pt 2—3 



