42 U. S. BUREAU OF FISHERIES 



Dr. Frederick A. Davidson continued an important series of 

 investigations dealing particularly with the application of the parent 

 stream theory to pink salmon. During the spring of 1931 he success- 

 fully marked a large series of the young pink salmon at Olive Cove, 

 southeastern Alaska, on their seawa^rd migration. 



A more detailed account of these investigations will be found in a 

 separate document. - 



OBSERVATIONS ON THE ESCAPEMENT OF SALMON 



Careful observations of the extent of the salmon runs during the 

 season and examination of the spawning grounds at the close of fishing 

 operations were made by bureau employees in 1931, as heretofore, 

 with a view to securing the required escapement of not less than 50 

 per cent of the runs. These surveys are the means of determining 

 what modifications in the regulations are necessary to build up the 

 runs in certain localities and to maintain the salmon resources at a 

 high level of productivity. Reports indicate that although a number 

 of salmon streams had an insufficient escapement in 1931, the spawn- 

 ing areas in general were adequately seeded. 



Southeastern Alaska. — Contrasting strongly with conditions in 

 the previous year, the pink salmon run in the southern district was 

 normal, both as to time of arrival and volume of run. While the fish 

 were not as numerous as in 1930, the size was nearly twice as great 

 and the quality vastly superior. Excellent runs occurred in all por- 

 tions of the district with the exception of Portland Canal and the 

 Cape Fox shore, where for a long time the odd-year run has been 

 comparatively light. Even in these sections, however, the streams 

 were better seeded than in other similar years. There was a marked 

 increase of red salmon, and chums were much more abundant than 

 last year. The coho run alone decreased sharply. Until late in 

 the season the flow of water in most of the streams was low, but 

 there was little or no loss of fish from this cause, as the rains came in 

 time to save them. An exceedingly heavy run of chums and pinks 

 reached the east shore of Prince of Wales Island toward the close of 

 the fishing season, all streams in this area being seeded to capacity. 

 Karta River had one of the largest runs of chums on record, and reds 

 were also more numerous in this stream than in recent years. 



The escapement of pink salmon into the streams along the west 

 shore of Prince of Wales Island was unevenly distributed. Good 

 escapements of pinks and chums were recorded in C alder Bay and 

 El Capitan Passage, but in Tuxecan Passage and Staney Creek the 

 runs of all species were disappointing. The red salmon run at Dew- 

 eyville, which had been good for the past four years, was a failure in 

 1931, although the stream contained fair numbers of pinks, chums, and 

 cohos. From Klawak Inlet southward to Cape Chacon pink salmon 

 were much more abundant than in the region from Klawak to Point 

 Baker. Red salmon were more plentiful in Hunter Bay and Klakas 

 and Hetta Inlets than in any other recent year. The run of pink 

 salmon throughout Sumner Strait, Ernest Sound, Bradfield Canal, 

 and Wrangell Narrows showed a marked increase over 1930, and the 

 escapement into the streams was more uniformly distributed than in 

 that year, when some streams were heavily seeded, while others had 

 inadequate escapements. 



' Progress in Biological Inquiries, 1931. Report of Commissioner of Fisheries for the fiscal year 1932. 



