Movements of tagged adult 

 yellowtail rockfish, Sebastes 

 flavidus, off the west coast 

 of North America 



Richard D. Stanley 

 Bruce M. Leaman 



Pacific Biological Station 



Department of Fisheries and Oceans, Canada 



Nanaimo, British Columbia, V9R 5K6 



Lewis Haldorson 



Juneau Center, School of Fisheries and Ocean Sciences, 

 University of Alaska, Fairbanks 

 11120 Glacier Highway 

 Juneau, Alaska 99801-8677 



Victoria M. O'Connell 



Alaska Department of Fish and Game 

 304 Lake Street, Room 103, 

 Sitka, Alaska 99835 



The Department of Fisheries and 

 Oceans, Canada, and the Univer- 

 sity of Alaska conducted indepen- 

 dent tagging studies on yellowtail 

 rockfish, Sebastes flavidus, in the 

 early 1980's. The Canadian study 

 was designed to validate ageing 

 methodology for rockfishes (Lea- 

 man and Nagtegaal, 1987). The 

 Alaskan study was part of a larger 

 survey of nearshore bottomfish re- 

 sources in southeastern Alaska. 1 ' 2 

 While neither study was designed 

 to quantify the extent of this spe- 

 cies' movement, the recoveries pro- 

 vided new insight into rockfish be- 

 havior and new implications for the 

 management of this species. 



Tagging studies of shallow dem- 

 ersal (<100 m) species of rockfish, 

 Sebastes spp., have typically indi- 

 cated very limited movement (Table 

 1), with the exception of a report of 

 a brown rockfish, S. auriculatus, 

 that travelled over 50 km from San 

 Francisco Bay 3 Authors have also 



suggested limited movement for the 

 deeper demersal or "slope" rockfish 

 species, such as Pacific ocean perch, 

 S. alutus, that are found along the 

 continental slope at depths greater 

 than 200 m (Fadeev, 1968; Gunder- 

 son, 1971; Wishard et al., 1980; 

 Leaman and Kabata, 1987). While 

 they appear to make seasonal 

 bathymetric migrations, the avail- 

 able evidence from commercial fish- 

 ing patterns, parasite occurrence, 

 and age/size compositions have led 

 investigators to hypothesize that 

 these species make very limited 

 latitudinal movements along the 

 continental shelf. However, because 

 of decompression and other injuries 

 associated with surfacing from 

 depths of over 200 m, no tagging 

 studies have been performed to test 

 this hypothesis. 



It is the semi-pelagic species that 

 inhabit the continental shelf ( 100- 

 200 m ) which appear to exhibit sig- 

 nificant movement. Studies of black 



rockfish, S. melanops, and imma- 

 ture yellowtail rockfish indicate 

 that at least some individuals move 

 long distances. In northern Puget 

 Sound (Fig. 1), Mathews and 

 Barker ( 1983) tagged 123 black and 

 153 yellowtail rockfish. Three of 

 eight black rockfish and eight of 10 

 confirmed yellowtail rockfish recov- 

 eries came from the west coast of 

 Washington at distances up to 400 

 km from the release site. Because 

 the yellowtail rockfish were all im- 

 mature, the authors proposed an 

 ontogenetic movement offshore in 

 conjunction with reproductive 

 maturation. Similarly, Barss 4 re- 

 ported that 12 of 23 recovered im- 

 mature canary rockfish, S. pin- 

 niger, travelled more than 100 km 

 along the Oregon coast. Culver 

 (1987) provided the first evidence 

 of long distance movement of adult 

 or reproductively mature rockfish. 

 He recovered 484 tags from 14,795 

 black rockfish tagged off Washing- 

 ton and northern Oregon. One fish, 

 which had been tagged off Oregon, 

 was recovered off northern Califor- 

 nia, 555 km south of its release site. 

 More than 12% of the recovered 

 black rockfish moved farther than 

 80 km. 



Contrary to those reports, which 

 documented long distance move- 



1 Rosenthal, R. J„ L. J. Field, and D. Meyer. 

 1981. Survey of nearshore bottomfish in 

 the outside waters of southeastern Alaska. 

 Alaska Coastal Research, P. O. Box 368, 

 Langley WA, 98260. Final report to State 

 of Alaska, Dep. Fish Game, Comm. Fish. 

 Div. Juneau, 84 p. 



2 Rosenthal. R. J., L. Haldorson, L. J. Field, 

 and V. M. O'Connell. 1982. Inshore and 

 shallow offshore bottomfish resources in 

 the southeastern Gulf of Alaska. Alaska 

 Coastal Research, P. O. Box 368, Langley 

 WA, 98260. Final report to State of Alaska, 

 Dep. Fish Game, Comm. Fish Div. Ju- 

 neau, 166 p. 



3 Lenarz, W. Tiburon Laboratory, Nat. Mar. 

 Fish. Serv., CA 94920. Personal commun., 

 March 1993. 



1 Barss, B. Marine Science Center, Oregon 

 Dept. Fish, Wildl., Newport, OR 97.365. 

 Personal commun., December 1985. 



Manuscript accepted 29 November 1993. 

 Fishery Bulletin 92:655-663 (1994). 



655 



