Figure 10. - -Intertidal spawning of pink sabnon, 

 Prince William Sound. 



ing axea in the Sound. Owing to a low cycle 

 of abundance in red salmon, the Eshamy dis- 

 trict was closed to fishing in 1958. No 

 in^jrovement is expected in this area in 1959. 



Significantly, in contrast to the 

 even-year production, the odd-year pink 

 salmon run in Prince William Sound is at a 

 minimal commercial level. In 1957 a total 

 run of less than a million fish was indi- 

 cated from an estimated escapement of 

 100,000 and a pack of 35,000 cases. In com- 

 parison, the 1958 estimated total run was 

 7.2 million fish. 



A troll fishery developed off 

 Middleton If land for the first time 

 this year. During a 6-week period 

 a fleet of some 30 boats produced 

 210,000 pounds of salmon, about 45 

 percent king and 55 percent coho. 



Research efforts in the Prince 

 William Sound district were directed 

 toward developing two methods of 

 predicting the magnitude of return- 

 ing adult runs of pink and chum 

 salmon. 



The first method, zm enumera- 

 tion of pink and chum salmon fry, 

 saw continuation and expansion of 

 an extensive fry sampling program 

 that was initiated in 1957. Migrant 

 trapping stations were operated on 

 six streams to determine production 

 of stream areas above the intertidal 

 zone. The intertidal areas of 14 

 streams were sampled to determine 

 production in this zone. The impor- 



tance of intertidal spawning to overall 

 production in Prince William Sound is evi- 

 dent from the fact that one-half to three- 

 fourths of all spawning occurs in this zone 

 (figure 10). Intertidal spawners tend to 

 dominate the even year runs. 



Intertidal area sampling was accom- 

 plished by using a technique developed by 

 the Fisheries Research Institute in which 

 an "egg pump" flushed pink and chum larvae 

 out of the gravel with a mixture of air and 

 water under pressure (figure 11). Funda- 

 mentally, the method is that of sampling 

 unit areas and then estimating the total 

 number of living organisms from fractions 

 of the total area sampled. Based on this 

 sampling technique, intertidal production 

 for 131 streams in Prince William Sound was 

 estimated at 9 milion pink and 6 million 

 chum salmon fry. 



Sampling in stream areas above the 

 intertidal zone was conducted in a similar 

 manner as in 1957 by fishing an array of 

 traps at the mean high tide line in each of 

 the six streams. The downstream migration 

 this year was far different in character 

 from that of 1957. It was of less magni- 

 tude, got underway earlier, sind was of 

 shorter duration (figure 12). The 1958 out- 

 migration for the six study streams was 

 estimated at 1.1 million pink salmon fry, 

 compared with 3.5 million for 1957. There 



Figure 11. — Collecting samples of eggs and fry 

 with "egg pump". 



11 



