Stokesbury et al,: Spatial distributions of Oupea pallasi and Theragra cha/cogramma 



407 



October 1995 



D age herring 

 Bags 1+ herring 



adult hemng 

 □ pollock 

  random 



1,2 3 



5 6 7, 8 9-11 12-14 15-18 19-23 24-28 29-35 >36 



March 1996 



S" 20 



" -*^ ^-K«8r-^-^-.w~^ ^ 



A 5,6 7-9 11-13 14-17 18-29 >30 



July 1996 



Jzfl^ ^ m^ ^ 



1 2 3 4 5 6,7 8-10 11-15 >16 



Sum of the three nearshore distances (km) 



Figure 6 



Percent frequency distributions of the sum of the three near shore distances (I3NSD) 

 for Pacific herring, Clupea pallasi. age cohorts and walleye pollock, Theragra chalco- 

 gramma. aggregations and values generated from a random distribution, during three 

 acoustic surveys in Prince William Sound, Alaska. Fish schools with sum of the three 

 near shore distances <7 were usually within bays. 



al., 1985; Sinclair, 1988). Future work should focus 

 on determining the physical and biological variables 

 influencing juvenile Pacific herring and walleye pol- 

 lock within these bays to estimate population fluc- 

 tuations that are critical for ecosystem models and 

 effective fisheries management. 



Acknowledgments 



We thank R. Foy, M. McEwen, S. Gay, and L. Tuttle 

 for assistance with field collections. N. Peters and G. 

 B. Steinhart assisted in collecting and processing the 



acoustic data. S. Moreland and M. Vallerino assisted 

 with data analyses. R. Foy, G. B. Steinhart, and S. 

 Moreland provided helpful comments on the manu- 

 script. The comments of three anonymous reviewers 

 further improved this manuscript. We also thank the 

 captains and crews of the FV Temptation, FV Miss 

 Kayley,FV Kyle David, MV Pacific Star, FY Pagan, FY 

 Cape Elrington, RY Panda lus, and the Alaska Depart- 

 ment of Fish and Game, Cordova, for their help. The 

 Exxon Valdez Oil Spill Trustee Council through the 

 Sound Ecosystem Assessment (SEA) project at the 

 University of Alaska, Fairbanks, and the Prince Wil- 

 liam Sound Science Center funded this project. 



