MATinSEN: NL'SIIAGAK SOCKEVE SALMON FISHERY 



measurement to the other by means of the two 

 following equations: 



S : ME-TF = 536.772 + 0.8279 

 [(snout-TF) — 592.340] 



5 : ME-TF =. 527.481 + 0.8946 

 [(snout-TF) — 569.724] 



Commonly, length measurements were collect- 

 ed throughout the fishing season. These mea- 

 surements were grouped by fishing periods or 

 by time periods for which catch records exist. 

 Finally, a seasonal weighted length-frequency 

 distribution was computed by the use of the 

 period catches as weighting factors. 



Expended Fishing Effort 



Batts and Fischler (1967) have summarized 

 the fishing regulations promulgated during the 

 years 1924-1945. A summary of the allowable 

 fishing time is given in Table 5, without consid- 

 eration for the stage of the tide in relation to 

 closed and open periods. Although the largest 

 or smallest tides generally are inferior fishing- 

 periods compared with the medium-sized ones, 



no correction was attempted on the premise that 

 the plus and minus deviations tended to cancel 

 each other over the entii-e season. 



The number of fishing boats that operated each 

 year for the period 1929-1945 is recorded by the 

 management agents in their annual reports and 

 copied in Table 5. The size of the Nushagak 

 fishing fleet in 1925-1928 was estimated from the 

 data collected by the Alaska Salmon Industry. 

 More than 60% of the total Nushagak catches 

 during these 4 years were made by the reporting 

 canneries, which also submitted records on the 

 number of boats employed. By direct propor- 

 tionality an estimate was derived for the total 

 number of fishing boats and set nets that op- 

 erated from 1925 to 1929 (Table 5). 



So that a common unit of eff'ort could be de- 

 rived, the fishing power of set nets was expressed 

 in terms of that for drift nets according to a 

 method by Robson (1961) .' The conversion was 

 made separately for each year by consideration 



* Robson, D. S. 1961 . Estimation of the relative 

 fishing power of individual .ships. Cornell Univ., Bio- 

 metrics Unit, Plant Breeding Dep., BU-133-M. (Un- 

 published manuscript.) 



Table 5. — Registered fishing effort in Nushagak Bay, Bristol Bay, Alaska, 1925-1950. 



Total 

 fishing 



time 

 in days 



Total 



number 



boats 



(drift nets) 



Total 



boot doy 



units 



Total 

 number 

 set nets 



Total 



set net 



day 



Relative 



efficiency 



set nets/boots 



converted 



to boat 



units 



Total 



effort in 

 boat days 



755 



