Table 6. — Blemish infestation in skinned fillets 



Table 7. — Percentage incidence of blemishes in Pacific ocean perch 

 according to fishing ground 



Table 8. — Average number of blemishes in designated area of blemished Pacific ocean 



fillet, according to fishing grounds 



harmless and edible. Their presence 

 in fillets nevertheless has caused diffi- 

 culty for more than one producer in 

 the Northwest area. Fortunately, nearly 

 half the blemishes apparently occur in 

 the tail portion of the fillet and there- 

 fore can probably be eliminated without 

 much economic loss if this portion is 

 cut off and discarded. 



CONCLUSIONS 



In general, the findings of this year 

 confirm those of 1958. 



1. The level of infestation of para- 

 sites in Sebastodes alutus was highest 

 in the northern area of catch (Hecate 

 Strait to Cape Cook) and lowest in the 

 southern area (Columbia River to Cape 

 Blanco), but higher levels of infestation 

 were observed in all areas this year 

 than last (45 percent, 44 percent, and 

 27 percent, respectively, for the north- 

 ern, nniddle, and southern areas in 

 1959 as compared with 39 percent, 

 21 percent, and 15 percent for the 

 corresponding areas in 1958). 



2. Prosorhynchus was the most 

 commonly observed parasite, infesting 



