XL REPORT OF THE COMMISSIONER OF FISHERIES 



Experiments initiated several years ago to determine the relation 

 between the numbers of spawning fish and the numbers of their 

 progeny that returned at maturity are nearing completion. Weirs 

 have been operated for the last four or five years at Chignik and 

 Karluk, Alaska, and at other places where the extent of the escape- 

 ment of salmon into the spawning streams has been determined by 

 actual count. Detailed observations of the young resulting from the 

 first complete life cycle of fish at Karluk were under way during the 

 spring of 1926, and 48,000 of the returning young salmon were 

 tagged and liberated. Knowledge thus obtained makes it possible to 

 determine what regulations are necessary to insure an adequate 

 escapement of spawning fish to maintain and build up future com- 

 mercial runs, and it is confidently expected that the stock of salmon 

 can be so regulated that eventually salmon streams may be restored 

 to their original productivity. 



The investigations of the salmon of the Columbia River, con- 

 ducted in cooperation with the Oregon Fish Commission, have 

 yielded valuable results, not only in affording an understanding of 

 the habits of these salmon but in proving the importance of certain 

 changes in fish-cultural methods, such as the use of rearing ponds 

 to hold the salmon fry until the proper time for liberation. Salmon- 

 marking experiments have been conducted for a number of years. 

 Returns of marked yearling sockeye salmon liberated in February, 

 1924, have been exceptionally numerous ; but from a previous experi- 

 ment, in which the young fish were liberated in the fall of their first 

 year, no returns were received. These results agree with those of 

 former experiments in showing that when it is not possible to liberate 

 sockeyes in a lake in which they can remain until the spring of their 

 second year (which is their natural time of migration) they should 

 be held in rearing ponds until that time. Many other marking ex- 

 periments with chinook salmon in the Columbia River have been 

 followed energetically with excellent results. In addition to these 

 studies, the life history of the blueback salmon in the Columbia River 

 has received attention and a complete report is in preparation. 



A biological investigation of the herring of Alaska begun in the 

 spring of 1925 was continued in 1926. A preliminary survey was 

 made of the commercial fishing establishments throughout the 

 region, and research into the composition of the fish stock, natural 

 fluctuations in abundance, and overfishing was initiated. As a neces- 

 sary preliminary to other work, a study was begun to determine 

 whether local races exist and the degree of variation between them. 

 From measurements of physical proportions and counts significant 

 differences have been discovered, which indicate that the races of 

 herring in southeastern Alaska are different from those to the west- 

 ward, and these again are distinct from the races that occur farther 

 south in the States. The herring fishery of the Northwest is capable 

 of great expansion, and it is hoped that these biological investiga- 

 tions will develop means for preventing depletion. 



FISHERIES OF INTERIOR WATERS 



During the past year a comprehensive report on the commercial 

 fisheries of the Great Lakes was published, a report on detailed 

 studies on the life history of the lake herring in Lake Huron has 



