Kendall and Picquelle: Egg and larval distributions of Thersgra chatcogramma 



139 



of the larvae occurred in the Shelikof stratum (Table 

 4). The ne.xt most important stratum for eggs was 

 Chirikof, where 5.2% occurred. The Amatuli stratum 

 contained 2(3% of the larval catch, and the Semidis- 

 Shumagin stratum contained 14%. Larval catches in 

 the Amatuli stratum were based mainly on sampling 

 done in 1985, a year in which larval occurrences in 

 Shelikof Strait were dissimilar to all other years sam- 

 pled (see later). 



Distribution of eggs in Slielil<of Strait 



All ages Throughout the five time intervals, most sec- 

 tors with high abundances of walleye pollock eggs were 

 in Shelikof Strait proper (Fig. 3). The geographic pat- 

 tern of abundance varied little among the time inter- 

 vals. IVIost eggs were found near Cape Kekurnoi during 



the second time interval, although they were somewhat 

 south of there during all other time intervals. Relatively 

 few eggs occurred southwest of a line between Sutwik 

 and Chirikof Islands. 



The centroid for the first time interval was located 

 off the southwest end of Kodiak Island (Fig. 4). In the 

 second time interval, when most (67%) of the eggs were 

 collected, the centroid was midway between Kodiak 

 Island and the Alaska Peninsula, off Cape Kekurnoi. 

 This is the area of maximum spawning as indicated by 

 fishery catches and hydroacoustic surveys of adults 

 (Alton 1987, Nelson and Nunnallee 1987). The centroid 

 position from the first time interval is in an area where 

 adults seem to congregate shortly before their ultimate 

 move to the Cape Kekurnoi area. The size of the ellipses 

 increased somewhat from the second through fifth time 

 intervals, particularly in the along-strait direction, 



