to this hatchery. Releases have been made 

 annually since 1964. High water in 1967 pre- 

 vented hatchery personnel from trapping and 

 counting all the fish, but about 50 adults and 

 385 jacks were captured out of the many that 

 returned to the stream below the hatchery dam. 

 In 1968, 2,200 fish were trapped at the hatchery 

 and about 150 remained in Icicle Creek imme- 

 diately downstream from the hatchery and 

 several hundred more used the rest of Icicle 

 Creek to spawn. These fish are larger than 

 usual in the Columbia River and weighed from 

 5.5 to 6.8 kg. Thus, it appears that the stocks 

 introduced have adapted to the conditions; the 

 prospects of reestablishing a run of coho 

 salmon to Icicle Creek is excellent. 



The fishery agencies of Washington and 

 Oregon have recently made annual estimates 

 of the "minimum" run of coho salmon (table 

 7). The estimates are derived by combining 

 the gill net catches below Bonneville Dam, the 

 sport catch in the lower Columbia River, and 

 counts at fishways and hatcheries. Coho salm- 

 on that spawn in many small streams below 

 Bonneville Dam are not included nor are the 

 ocean catches by sport and commercial fish- 

 ermen. 



Recent ocean catches along the coasts of 

 southern British Columbia, Washington, Ore- 

 gon, and California have been large, but the 

 percentage of the catch that is of Columbia 

 River origin is unknown. The recapture along 

 the coast of many marked coho salmon from 

 the Columbia River, however, indicates that 

 the percentage may be large. 



On the basis of rought estimates of catches 

 and escapements in 1957, it is possible to ar- 

 rive at an approximation of the total (rather 

 than minimum) coho salmon run in the Co- 

 lumbia River in that year: 



1. Ocean troll catch 184,428 



2. Lower Columbia River 



sport catch 38,163 



3. Offshore sport catch 59,666 



4. Commercial fishery below 



Bonneville Dam 55,812 



5. Count at Bonneville Dam . . 4,675 



6. Spawning escapement below 



Bonneville Dam 70,000 



Total 412,844 



Data for the first three figures were from the 

 Bureau of Commercial Fisheries (1960) and 

 for items 4 and 5 from the Fish Commission 

 of Oregon and the Washington Department 

 of Fisheries (1968); data for item 6 appear 

 in tab'e 6. The percentage composition of the 

 1957 run was as follows: ocean catch, 59.1; 

 Columbia River catch, 22.8; and escapement, 

 18.1. If this same percentage of ocean caught 

 coho salmon is estimated for more recent years, 

 it would give the following total runs for 1961- 

 67: 475,880, 644,000, 593,000, 1,669,700, 

 2,029,500, 2,077,500, and 2,651,000. 



Since 1963 the runs have increased, and the 

 proportion of ocean catch to the other segments 

 of the run may vary greatly from that in 1957. 

 These estimates are given to show the possible 

 magnitude of the coho salmon runs; their ac- 

 curacy cannot be verified. 



Future of Coho Salmon Runs 



The future of coho salmon runs in the Co- 

 lumbia River appears good in view of the in- 

 crease in 1960-67. Artificial propogation is 

 believed to be mainly responsible because of 

 the good returns of adult fish to streams where 

 releases were made. Runs to Columbia River 

 hatcheries were in excess of rearing capacities, 

 and surplus fish and eggs were transported to 



Table 7.— Estimated minimum run of coho salmon in the Columbia River, 1961-67 

 [Dashes indicate that no data are available] 



22 



