greater percentage of sockeye uti- 

 lized the left bank ladder than used 

 either the middle or right bank 

 ladders. In 1959 small sockeye 

 under 16 inches in length com- 

 prised 11.6 percent of the count. 



5. Very few coho salmon have ap- 

 peared at Rock Island Dam in the 

 per-od 1933-1959. The greatest 

 count, 229, occurred in 1947. The 

 1959 count was 118. 



6. The steelhead count of 4,138 in 

 1959 exceeded the 26-year mean 

 of 2,900. 



7. Although no quantitative data are 

 available it was the general im- 

 pression of the fishway superin- 

 tendent that more injured fish 

 were observed in 1959 than in any 

 previous year of counting. This was 



especially true of chinook and blue - 

 back. 



8. Mortalities of do>vnstream mi- 

 grants have occurred in the cooling 

 water facilities at Rock Island 

 Dam. In 1958, modifications were 

 made of these facilities, and ob- 

 servations in 1959 indicated that 

 mortalities had decreased. 



9. Fish counting was begun on May 4 

 and terminated Septennber 30. 

 Sample counting was conducted 

 from May 4 through July 15. 



10. In 1959 the nnaximum number of 

 salmonids counted in one day 

 (4,412) was on July 28. 



11. Trapping facilities in the left bank 

 fishway were used on several oc- 

 casions to collect adult fish for 

 experimental purposes. 



14 



MS #1052 



GPO 919982 



GPO 9 1998 2 



