10 REPORT OF THE COMMISSIONER OF FISHERIES. 



open to them are narrowing each year because of the encroachments 

 of commercial fish culturists. In 1910 Wellington Lake and the 

 Grand Mesa Lakes, heretofore the most productive sources of the 

 Colorado station for eggs of the blackspotted, brook, and rainbow 

 trout, had to be given up to private enterprise. 



The Bureau having been requested to undertake the propagation 

 of the blackspotted trout on the Truckee River with the view of re- 

 plenishing the stock, depleted through excessive fishing, a field station 

 was established at Derby Dam, Nevada, in the winter of 1909-10. In 

 a normal season several millions of eggs might have been obtained, 

 but owing to low water in the river and the destruction of large num- 

 bers of eggs by market fishermen the collections amounted to only 

 1,371,900. These were hatched without unusual losses and the fry 

 deposited in the river. It seems advisable to continue operations 

 here next season, as it is apparently a promising field for fish-cultural 

 work. 



Investigation of the streams in Yellowstone Park demonstrates 

 the possibility of greatly extending operations with the black-spotted 

 trout, and it is intended to increase the force of experienced men in 

 this field with the view of making it a source of supply for the Lead- 

 ville, Spearfish, and Bozeman stations. The work in the park during 

 the past season was entirely satisfactory. 



Taken as a whole, the output of the basses, sunfish, and catfish 

 from stations in various parts of the country was good, the improved 

 results being largely due to increased knowledge of the factors 

 governing the successful propagation of these species. The produc- 

 tion of pond stations was supplemented by the collections on the 

 Mississippi and Illinois rivers, where, in addition to securing suffi- 

 cient bass and allied species for restocking many depleted waters, 

 large numbers of other fishes were seined from shallow sloughs 

 formed by the floods and returned to the main streams. If not re- 

 moved, the fish would perish from drought or cold, and their rescue 

 conserves a valuable local food resource. A new station established 

 at Helena, Ark., late in the summer rescued over half a million fish. 



With the view of extending rescue operations over a larger ter- 

 ritory, temporary collecting stations have been located at Caruthers- 

 ville, Mo., and Rosedale, Miss., which will be made permanent auxil- 

 iary stations if experience proves favorable. It is believed that 

 similar inexpensive stations can be advantageously established at 

 various points on the Mississippi River from New Orleans to St. 

 Paul, as the field for this work is extensive and the number of fish 

 that can be economically reclaimed from the drying sloughs and 

 lakes is governed only by the amount of money available for the 

 purpose. 



Although the propagation and general distribution of carp was dis- 

 continued many years ago, the Bureau constantly receives applica- 



