REPORT OF THE COMMISSIONER OF FISHERIES. 



43 



The cost of production during the year was $0.0689 per thousand, 

 practically double that of the previous year. The increased cost 

 was due to the greater cost oi labor, equipment, and materials. 

 Overhead charges and an allowance for depreciation amounting to 

 SO. 0236 per thousand are included in this computed cost. In con- 

 nection with this work, 51,600 adult and 653,600 fingerling fishes 

 were reclaimed from landlocked waters in the overflowed lands and 

 liberated in public waters. Of the fishes rescued, 150,949, or approxi- 

 mately 21 per cent, were infected with larval mussels before release. 



Experimental plants of adult mussels from the Mississippi River 

 and from Lake Pepin were made in the Roanoke and Shenandoah 

 Rivers in Virginia. 



The following table shows the details of the work of artificial 

 propagation: 



Mussel Propagation 1919, Showing Number ok Each Species Planted and 



Points op Deposit. 



Species. 



Yellow sand-shell . . . 



Mucket 



Lake Pepin mucket. 

 Pockethook 



Total. 



Lake 

 Poke- 

 Rama, 

 Minn. 



21,632,100 



21,632,100 



Mississippi 



River 



at Lake 



Pepin, 



Minn. 



and Wis. 



34,46.3,300 

 959,825 



35, 423, 125 



Mississippi 



River at 



Fairport, 



Iowa. 



15,634,000 



15,634,000 



Mississippi 



River, 



at New 



Boston, 



111. 



193,000 

 10,200,540 



10,393,540 



ALASKA FISHERIES SERVICE. 



GENERAL CHARACTER OF THE SERVICE. 



The duties devolving on the Bureau in connection with the gen- 

 eral fisheries of Alaska include the enforcement of law and regula- 

 tions with regard to the salmon fisheries, the collection of statistics 

 and the dissemination of statistical and other information, the 

 inspection of private salmon hatcheries, the investigation of the 

 ariuatio resources, the improvement of the physical condition of 

 salmon streams, the holding of public hearings on proposed regula- 

 tions for the protection of the salmon supply, and the submittal 

 to the Secretary of Commerce of rccommenaations embodying modi- 

 fications of existing regulations. 



