Figure 12. — Downstream migration of pink salmon 

 fiy at Fish Bay in 1957 and 1958. 



PIGOT 

 BAY 



Figure 13. --Comparative magnitude of outmigration 

 of pink salmon fry in six Prince William 

 Sound streams. 



W21S considerable variation in production 

 between streams. The size of the outmigra- 

 tions by streams in 1958 varied between 1 

 and 109 percent of that in 1957 (figure 13). 

 Chum fry production in these six streams 

 was estimated at 2.5 million in 1957 and 

 0.5 million in 1958. 



More data are needed before a fore- 

 cast can be made of adult returns; based 

 on the magnitude of the fry migration. 

 Present evidence indicates the run in 1959 

 will be much poorer than it was in 1958. 



In the second method studied the 

 relationship between the numbers of adult 

 spawners per key stream and the return two 



MOST PROBABLE 

 RETURN 1959 ^ 



« 5 6 7 8 9 10 II 12 13 

 ESCAPEMENT PER STREAM IN THOUSANDS OF FISH 

 -1957 ESCAPEMENT 



Figure 14. — Relationship of escapement to return, 

 70 key pink salmon streams, Prince 

 William Sound. 



years later was used to forecast the 1957 

 and 1958 returns. On the basis of this 

 correlation, a poor run of pink salmon Wcis 

 predicted for 1957; the return was smaller 

 than expected. For 1958 the expected 

 return was 6 million; the actual return was 

 about 7.2 million. Even though there were 

 some differences between the expected and 

 the actual return, the general magnitudes 

 of the forecasts were substantially correct. 



The 1957 escapement was the lowest on 

 record, only 1,325 pink salmon per key 

 stream. At this low level of abiuidance the 

 trend line is somewhat uncertain because 

 there are few data available. However, the 

 most probable return in 1959 is about 

 500,000 pink salmon (figure 14). The odds 

 are 2 to 1 that the return will be between 

 and 2.1 million fish. There is about 1 

 chance in 20 that the run will be greater 

 than 3.7 million. This is the most reli- 

 able forecast for 1957 now available. 



The Fisheries Research Institute, 

 under contract to the Bureau of Commercial 

 Fisheries, continued its studies of migra- 

 tory routes and timing of salmon runs in 

 Prince William Sound. Of 3,341 pink salmon 

 tagged in Prince William Sound in 1957, 1,135 

 were recovered, 23.8 percent coming from the 

 commercial fishery and 10.2 percent from the 

 spawning grounds — a total recovery of 34 

 percent. In addition, of 576 chum salmon 

 tagged, 135 were recovered. In all of the 

 experiments, regardless of the location of 

 tagging, the wide scattering of recoveries 

 gave evidence of considerable wandering of 

 individual fish in a "to-and-fro" manner. 



12 



