ping and the fillet surface. They are not 

 known to infest man. 



An unidentified parasitic copepod 

 also was encountered in this investiga- 

 tion. The two species nnentioned above, 

 however, present the greatest problem 

 to the industry. 



FISHING AREAS STUDIED 



As a result of generous cooperation 

 by the industry, access was obtained 

 to processing plants in Seattle, Belling- 

 ham, and the Astoria area. Much useful 

 information was obtained. 



At each plant, the fishermen who had 

 landed the fish being examined were 

 asked when and where the fish had been 

 caught. They also were questioned 

 generally about the rockfish industry 

 and the problem of parasites in this 

 group. From the information obtained, 

 it appeared that the Oregon- Washing- 

 ton-British Columbia fishery (figure 1) 

 could be divided into three areas: 

 northern, middle, and southern. Draw- 

 ing dividing lines through regions of 

 little or no fishing activity, one can 

 define these areas as follows: 



C-l'-"nbia r.iv. r 



Zupe 31ar.co 



Figure 1. —Oregon-Washington-British Columbia 

 fishery. 



Northern - Hecate Strait to Cape 

 Cook. 



Middle - Cape Cook to Colunnbia 

 River (includes rich banks of La 

 Perouse, Flattery Spit, and De- 

 struction Island). 



Southern - Colunmbia River to Cape 

 Blanco (includes most of the Oregon 

 fishery). 



Northern Area : Hecate Strait is a 

 highly productive fishing area. An aver- 

 age otter-trawl tow of 1 hour (maxi- 

 mum 2 hours) usually will net 2,000 

 to 5,000 pounds offish. In fact, as much 

 as 20,000 pounds of fish has been caught 

 during a 1-hour tow. In this area, 

 Pacific ocean perch usually are caught 

 in 100 to 140 fathonns, whereas other 

 rockfish usually are caught in 60 to 

 80 fathoms. The species S. ntbrivinctus , 

 S. pinniger, and ,S'. brevispinis often are 

 mixed in, ho'wever, -with catches of 

 ,S. alutus. 



Middle Area : Several rich fishing 

 grounds are in the middle area. Usually, 

 60,000 pounds of rockfish can be ob- 

 tained in 4 or 5 days of fishing. These 

 fish are less abundant than in the 

 northern area. The average length of 

 tow for a 2,000- to 5,000-pound catch 

 is 2 hours. The grounds are popular 

 because they are near the major fishing 

 ports of Washington and Oregon, and 

 the rockfish are reputed to be less 

 heavily parasitized than are those taken 

 farther north. In general, rockfish are 

 abundant all along the inshore waters 

 of Washington. The species S. pinniger 

 is reported to be plentiful off the west 

 coast of Vancouver Island in the spring. 



Southern Area: The population of 

 Pacific ocean perch seems to be rather 

 scattered in this area. The average 

 length of tow is about 4 hours. The 

 yield is about 2,000 pounds of fish per 

 tow. 



EXAMINATION PROCEDURE 



Permission was obtained to work in 

 a plant on a day when rockfish were 

 being filleted. Fillets for examination 

 were selected at random, by the investi- 

 gator, from the end of the filleting line. 



