BIOSTATISTICAL ANALYSIS 25 



in the totals given above. In recent years, the sockeye run into 

 convention waters has varied from about one-half to about four 

 times the standard run. The pink run in the last three cycles has 

 been less than the standard run, however, for the period of 1947 

 to 1955, the catch alone has been near, or exceeded nine million. 

 Although the total silver and chum run sizes are not accurately 

 known, the run sizes and migration pattern used in this program 

 produced catches which agree well with those observed in recent 

 years. The chum catches indicated by the computer are certainly 

 lower than the average during the past decade. However, the chum 

 catches have shown a consistent downward trend, and the figures 

 used are based on an expected continuation of the present low levels 

 of chum salmon populations. 



Gear 



The three principal types of net gear which participate in the 

 United States Strait-Puget Sound fishery are purse seines, gill nets, 

 and reef nets. For some of the species, other types of gear are also 

 extremely important. Large numbers of silver salmon are taken 

 by trolling and in the sport fishery, and with other miscellaneous types 

 of gear. In the simulation model used to represent the fishery, 

 detailed economic and catch data were summarized for the three 

 major types of net gear. Other types of gear were combined in a 

 category called "miscellaneous gear.'' No economic data were accu- 

 mulated for these other types of gear. However, their effect on the 

 net fishery was represented by including them in the model and 

 allowing the miscellaneous gear to remove fish that would be other- 

 wise available to the net fishery. 



The detailed catch and effort statistics for all of the United States 

 fishing areas in the Strait of Juan de Fuca, adjacent coastal areas, 

 and in Puget Sound were obtained from the Washington Department 

 of Fisheries and summarized for the years 1956, 1957, 1958, 1959, 

 1960, and 1961. These summary tables give the numbers, total 

 weight, and average weight of each species taken each day by each 

 type of gear in each of 58 statistical subareas. The numbers of 

 landings were also summarized and tabulated for each type of gear. 

 In addition to the daily summaries, monthly landings and catch data 

 were prepared for each of the subareas and for the larger districts. 



