COHO 



CHINOOK 



>iu Sir. of Juan 



' Vancouver Island cJq Fuca Q /^ 



t, 



■1 



k 



WASH. 



V Columbi a Ri ver 



50' 



46* 



44c 



42< 



40* 



38' 



36' 



^:. '^^ ^i5£r. of Jum 

 Vancouver Island ^q Pijca Q r^ 



Flattery'- yA f; 



;{^S Paget 



Sound 



!♦ 



. ^... WASH 



t ^^fci^ Columbia River 



50* 



48* 



46' 



.Coos Bay 



'tape Mendocino 



44< 



42* 



40' 



— 38* 



36^ 



Figure 1. — Migration patterns of tagged echo and chinook salmon released at sea. For fish recovered in the ocean ofF Oregon, 

 Washington, or Vancouver Island, release latitude is indicated by the tail of the arrow and recovery latitude by the head of the arrow. 

 For fish recovered in inland waters or river systems the head of the arrow points to the system in which the fish was recovered. Solid 

 dots indicate fish released and recovered at the same latitude. Numbers offish are approximately proportional to thickness of arrows. 

 Most releases and recoveries were within 50 km of the coast and the positions of arrows do not represent true distances from shore. 



in coastal bays or river systems, including the 

 Columbia River (squares) (4.4, 3.5, and 2.7 km/ 

 day, respectively, Fig. 2B). Similar low net move- 

 ment rates were found for coho salmon in coastal 

 waters by Van Hyning (1951) off Oregon (3.0 km/ 

 day), by Kauffman (1951) off Washington and 

 Vancouver Island (3.9 km/day), and by Milne 

 (1957) also off Vancouver Island (9 km/day). 



In all studies the stresses related to capture and 

 tagging may cause some mortality and weaken 

 some surviving fish, affecting speed of migration. 

 Hartt (1966) suggested that tagging retards mi- 

 gration by at least 1 day. However, movements of 

 fish immediately after release in sonic tagging 

 experiments were often rapid (Madison et al. 

 1972; Stasko et al. 1973). 



822 



