Figure 3. — Distribution of herring catches in Prince William Sound (including Resurrection Bay and Day 



Harbor), 1937-58. 



COLLECTION AND INTERPRETATION 

 OF THE BIOLOGICAL DATA 



The methods used in the Bureau program 

 of collecting data from the reduction fishery 

 changed little between 1929 and 1966. Some 

 minor technical improvements were made in 

 the sampling equipment such as the use of 

 microprojectors instead of microscopes in the 

 analysis of scales and improvements in the de- 

 vices to measure the lengths of herring. Other 

 aspects remained much the same, however, as 

 they were in 1929 under the program described 

 by Rounsefell (1930). 



Although the method remained the same, the 

 scope of the sampling increased. Before 1952, 

 sampling during the fishing season was not con- 

 tinuous at any station nor was it concurrent 

 within or between districts. Individual sam- 

 ples often ranged anywhere from 25 to 50 fish. 

 The sampling procedure was standardized be- 



tween 1952 and 1956; a 30-fish sample was 

 taken from every vessel unloaded at one op- 

 erating reduction plant in each district. Be- 

 ginning in 1957, a biologist, who sampled every 

 delivery, was stationed at each plant for the 

 duration of the fishing season. He examined 

 every fish in each sample for age, weight, 

 length, and sex. 



Migrations of tagged herring (Dahlgren, 

 1936; Skud, 1963) and statistical studies of 

 vertebral counts (Rounsefell and Dahlgren, 

 1935) suggest that fished herring populations 

 in the southeastern district are not entirely 

 homogeneous." I suspect that the same may be 

 true for stocks within the Kodiak and Prince 

 William Sound districts. Since vessels ranged 

 wider during years of low herring availability, 



' Tagging experiments have indicated that major 

 fishing locations such as Cape Ommaney contain her- 

 ring from more than one stock. A stock is defined 

 here as fish from a common spawning location. 



