Figure 4. — Locations of study streams (Harris River and Indian and Twelvemile Creeks) in the Kasaan Bay 



region of Prince of Wales Island, Southeastern Alaska. 



Field studies began in 1956 when FRI personnel 

 selected six spawning riflles ranging in area from 

 260 to 650 m. L ' for sampling. Spawning riffles 

 were sampled in 1956, 1957, and 1958 to measure 

 mortality of eggs and larvae and the quality of 

 intragravel water (table 1). 



The study areas were enlarged in 1958, when 

 FRI personnel selected five spawning areas 



ranging in size from 3,400 to 1^,400 m. 2 The 

 areas included major spawning grounds of pink 

 and chum salmon in Harris River and Indian 

 and Twelvemile Creeks and incorporated the six 

 spawning riffles previously sampled. The sam- 

 pling areas were selected to represent both inter- 

 tidal and upstream areas of the study streams 

 (table 1). Factors measured included density 



:m 



U.S. FISH AND WILDLIFE SERVICE 



