PROGRESS IN BIOLOGICAL INQUIRIES, 1935 407 



regions in 1934 were continued during 1935. In addition, a new and 

 much-needed investigation dealing with the collection and statistical 

 analysis of daily catch records of the various types of fishing gear 

 used in the salmon fisheries of Alaska was carried on in 1935. 



COLUMBIA RIVER 



The investigation of the fisheries of the Columbia Eiver was con- 

 ducted during 1935 by J. A. Craig, assisted by A. J. Suomela. The 

 activities of this investigation can be summarized under several divi- 

 sions, each forming a part of the general program for the acquisition 

 of facts essential to the preser^•ation of these important fisheries. 



One of the phases which is of fundamental importance is the study 

 of the annual and seasonal fluctuations in the abundance of the im- 

 portant species of fish contributing to the Columbia Eiver fisheries. 

 These fluctuations are being ascertained from a statistical study of 

 the catch records of individual pieces of gear employed in the com- 

 mercial fishery. Records have been made available through the coop- 

 eration of the commercial fishing interests on the river, and some of 

 them extend back as far as 1897. All of the original records of the 

 catches of all important commercial species, namely, chinaok, blue- 

 back, chum and silver salmon, steelhead trout, and sturgeon, made 

 with gill nets, traps, and seines, have been copied from 1897 to 1934, 

 inclusive. Since the chinook salmon are by far the most numerous 

 and important species frequenting this river system, indexes of their 

 abundance are being computed first. Practically all of the gross 

 tabulations and summaries of these data have been completed within 

 the year. 



Another major division of this investigation is the stream survey 

 program. The object of these surveys is to obtain data which will 

 be a guide to the improvement and rehabilitation of the spawning 

 areas in the Columbia River system. 



In the course of this work field parties secured information on (1) 

 the total area in each tributary which forms the present and past 

 spawning areas for migratory species of fish; (2) the location of the 

 spawning areas now available to salmon; (3) the location of the 

 areas which have been made unavailable to salmon, and the cause 

 of their destruction; (4) the sources of pollution which may be detri- 

 mental to spawning populations of salmon and to resident finger- 

 lings; (5) the number and location of irrigation canals and their 

 effect on migratory fishes; (6) the location of natural and artificial 

 obstructions, and the extent to which these form barriers to upstream 

 migrants; (7) the general status of the salmon populations in the 

 Columbia River. 



During the present year. 1935, the survey has progressed satisfac- 

 torily, especially so from the advent of summer to the close of the 

 year. The activities have been concentrated principally in eastern 

 Washington on tributary streams below Grand Coulee. The streams 

 on which surveys have been completed are : Methow, Entiat, and the 

 Wenatchee. The Okanogan has been partially surveyed. In the 

 Yakima system the tributaries examined to date are as follows: 

 Naches River with its tributaries, namely, American River, Bump- 

 ing River, Rattlesnake Creek, and Tieton River; and Ahtanum 

 Creek. Satus Creek, Kachess and Cle Elum Rivers, which empty 



