PROGRESS IN BIOLOGICAL INQUIRIES, 1923. 11 



bluebacks, and resembled the parent fish of Yes Bay. This resem- 

 blance is not only external but involves also the quality of the flesh, 

 that of the Yes Bay fish being inferior to that of the Columbia 

 River blueback. This confirms the earlier conclusion that heredity 

 is more important than environment in determining the general ap- 

 pearance and quality of the flesh of salmon. 



An investigation of the spawning grounds of the blueback salmon 

 of the Columbia River was made by Harlan B. Holmes during the 

 fall of 1922. 



Up to the present there have been no accurate data as to where 

 this species of salmon noAv spawns in the Columbia Basin. All of 

 the well-known areas formerly used have been rendered inaccessible 

 by the construction of dams and irrigation ditches. Rotable among 

 these old spawning grounds are the large lakes of the Yakima Basin 

 of Washington, the Payette Lakes of Idaho, and Wallowa Lake of 

 Oregon, all of which are now closed to salmon. The especially large 

 run of bluebacks in the Columbia River during the season of 1922 

 made this year a very favorable one for the study of the present 

 spawning grounds. The results of the investigation show^ that a 

 run of these fish passes up the Salmon River in Idaho at least as far 

 as Sunbeam Dam, about 12 miles east of Stanley. The series of lakes 

 known as the Red Fish Lakes are above this point and were visited 

 for evidence of spawning fish. Xo direct evidence that the fish got 

 above this dam was obtained, but it is not at all impossible that 

 many of the fish were on their way to the spawning streams 

 visited but at the time w^ere in the lakes or at points in the river that 

 were not visited. The evidence that there is still a run of bluebacks 

 in the Red Fish Lakes seems sufficient to justify providing a certain 

 passageway over the dam for the returning fish in future years. The 

 present fishway over Sunbeam Dam is considered inefficient. 



INVESTIGATIONS OF SHELLFISH AND TERRAPIN. 



OYSTERS. 



Investigations relating to oyster culture were conducted during 

 the fiscal year by J. S. Gutsell and H. F. Prytherch, scientific assist- 

 ants, aided during the summer months by J. G. Scott. Dr. P. S. 

 Galtsoff also carried on some special oyster investigations. As in 

 recent years, the " setting " problems of Long Island Sound and 

 Great South Bay. Long Island, received chief attention. 



In the summer of 1921 there had been an oyster " set " of exceeding 

 abundance in Great South Bay. Before the suimner was over it was 

 nearly all dead. The work of that summer and fall and of the fol- 

 lowing spring showed that where the spat had attached well above 

 the bottom, as on " pound " stakes and boat bottoms, good growth 

 and ncj excessive mortality had occurred. The discovery that HgS 

 was being generated by decomposing organic material over a large 

 part of the bottom seemed to account for the loss of bottom set and 

 the survival of that which was elevated. It was hoped that in 1922 

 definite evidence might be obtained for or against this hypothesis and 

 especially that the degree of elevation required for the survival of 

 the set might be determined and a way opened for improvement in 

 commercial practice to meet the special needs of this area. Unfor- 



