Annual Fish Passage Report - Rock Island Dam 

 Columbia River, Washington, 1963 



By 

 PAUL D. ZIMMER AND JOHN H. BROUGHTON 



ABSTRACT 



Fish utilizing the three fishways at Rock Island Dam in 1963 were counted from 

 May 1 to October 30. The 106,554 salmon and steelhead trout counted exceeded the 



1962 count by about 34,800 fish. 



The count of 34,688 chinook salmon recorded in 1963 was well above the mean 

 of 16,777 for the 30-year period 1933-62 and exceeded the 1962 count by only 534 

 fish. The count of 64,768 sockeye salmon exceeded the 30-year mean of 51,164 and 

 was about 35,500 more than recorded in 1962. The coho salmon count of 20 in 1963 

 was about 25 percent of the 30-year mean of 83 and 3 percent of the record count of 

 737 in 1962. The steelhead trout count of 7,078 in 1963 was more than twice the 

 30-year mean of 3,336 and about 500 less than the number recorded in 1962. Fish 

 other than salmon and steelhead trout passing through the fishways at Rock Island 

 Dam in 1963 numbered 137,367, as compared to 164,574 in 1962, and exceeded the 



1963 count of salmon and steelhead trout by about 30,800 fish. 



Of the 106,554 salmon and steelhead trout passing Rock Island Dam in 1963, 

 about 2 percent had evidence of injury about the head or body. 



INTRODUCTION 



Rock Island Dam, located on the Columbia 

 River about 12 miles downstream from We- 

 natchee, Wash., has been in operation since 

 1933. The dam is owned and operated by Chelan 

 County Public Utility District No. 1. 



This report on passage of fish at Rock Island 

 Dam during 1963 provides information on 

 operation of fishways and numbers of fish 

 using them. 



Rock Island Dam has three fishways: one 

 located on the right bank, another on the left 

 bank, and the third approximately inthe center 

 of the dam. The bank fish ladders began 

 operating in 1933, and the middle ladder in 

 1936. All three ladders have been modified 

 since then. 



Fish ascending Rock Island Dam ladders 

 have been counted annually since 1933, the 

 longest continuous record of Columbia River 

 fish counts. 



Included in this report are comments cov- 

 ering various fishery investigations at Rock 

 Island Dam during 1963. 



COUNTING PROCEDURES 



Fish counting in 1963 began on May 1 and 

 ended October 30. From May 1 through August 

 31, fish were counted 16 hours each day, 



Note. — Paul D. Zimmer, Fishery Biologist (Manage- 

 ment), and John H. Broughton, Fishery Technician, Bureau 

 of Commercial Fisheries Program Office, Portland, Oreg. 



starting at 5 a.m. and ending at 9 p.m. From 

 September 1 through October 30, counting was 

 reduced to 14 hours each day, starting at 6 a.m. 

 and ending at 8 p.m., to conform with the avail- 

 able daylight. 



Fish counters were allowed a 15-minute rest 

 period at the end of each hour; during all peri- 

 ods of noncounting, ladders were closed to fish. 



A covering of one-half inch thick plexiglass 

 is mounted on floats over each counting board. 

 This eliminates sunglare and water surface 

 disturbances and permits clear observation 

 of each fish. 



ENUMERATION OF FISH 



All species of fish using the fishways at 

 Rock Island Dam are identified and recorded 

 Salmon and steelhead recorded are discussed 

 separately, and all other species are included 

 in the category "Miscellaneous Fish." 



Chinook Salmon, Oncorhynchus tshawytscha 



The chinook salmon count in 1963 of 34,688 

 (jacks included) was well above the mean of 

 16,777 for the 30-year period 1933-62. It was 

 about 2 percent greater than the 1962 count, 

 but only 68 percent of the record count of 

 50,713 in 1957 (table 1). Monthly totals of 

 chinook salmon given in table 2 show a peak 

 movement of these fish in August. Maximum 

 day's count of chinook salmon (jacks excluded) 

 was 430 on August 5 (table 3), as compared 

 to 570 fish on August 10, 1962. Tables 4 and 



