West of the Islands of Four Mountains , k?^ miles from the Bristol Bay- 

 rivers 5 the catches dropped to virtually nothing though one or more fish 

 one or mors fish were taken at every locality fished. After fishing 

 abeam of Semisopochnoi Island (Petrel Bank) - 870 miles from the Bristol 

 Bay rivers - it was decided to retiorn to more productive waters. Fishing 

 operations were carried on during the return trip at four localities, the 

 results of these operations being in agreement with those obtained on the 

 trip westv;ard„ The data are presented in tables Ik and 1$. 



Table lUo Gill net catches along the section line from Unimak Pass to 



to Petrel Bank, during I9UI 



Number of salmon caught 



Ivliles 



Date Station from 



number Bristol Reds Chums Pinks Cohos Total 



Bay rivers 



300 



U95 

 650 

 755 

 870 

 625 

 565 

 515 

 k^$ 



6 

 2 



lUi 



39 



53 



3 



3 

 5 

 1 

 8 

 U 

 l;05 



Average catch per set made by gill nets between Unimak Pass 

 and Petrel Bank, during I9UI 



liiles from No. of 

 Bristol Bay sets 

 rivers 



Reds 



Average catch per set 



Chums Pinks Cohos Total 



2.0 



222.0 



21.7 



2.3 



5.0 



These data indicate that the concentration of salmon in the offshore 

 waters drops off markedly to the westward of the Islands of Four Mountains 

 but that salmon are present in small numbers in the entire area in which 

 operations were carried on (see figures 7 and 8). 



There is no reliable index of the ultimate destination of the fish in 

 this vicinity as tagging experiments have rtbt, been carried on. It is known 

 that snail populations of all species of salmon spawn in certain rivers of 



23 



