93 



STEELHEAD 



Terminal Area Run Sixe and Escapement Goal* 



Steelhead are managed separately as winter and summer run*. (Bill Freymond, WDW 

 pere. coram.). WDW defines winter run fieh as thoee caught in -.he Chehalis 

 Basin between November 1 and April 30. Summer steelhead are caught between 

 May 1 and October 31 (WDW 1991a). Harvest management plana assume negligible 

 marine interception in the coastal salmon fisheries (QFiD and WDW 1991). 



Winter Run 



Winter steelhead are managed for both 

 hatchery and wild harvest except on 

 certain upper Chehalis tributaries 

 where sport fishing is regulated 

 primarily to provide sufficient wild 

 escapement (Freymond 1989). The dual 

 goal of providing hatchery harvest 

 opportunity while allowing wild 

 escapement is supported, more so in 

 the Humptulipa system, by high early 

 season harvest and lower late season 

 harvest (QFiD and WDW 1991). This is 

 possible because hatchery fish tend 

 to return to the rivers earlier than 

 wild fish, due to historical 

 selection for early-returning fish 

 (Royal 1972). Chehalis Basin 

 hatchery fish follow this pattern to 

 the degree that they were derived 

 from Chambers Creek stock, and not 

 from later-returning local brood 

 stock (QFiD and WDW 1991). The 

 greater timing separation and lower 

 overall hatchery influence on the 

 Humptulips coincides with consistent 

 achievement of the wild escapement 

 goal in that system compared to the 

 Chehalis system (Figure 13). 



CHEHALIS STHllTHH»n RON SIZE 



Fifure 13. Cbehtlu ud Hump<uiip» acclheid run ait* (QFiD and 

 WDW 1990). 



Chehalis River System . Chehalis system runs have averaged about 11.000 

 hatchery fish over the last 3-year hatchery life cycle, and 13,000 wild fish 

 over the last 4-year wild life cycle (Table 5). Wild escapement goals were 

 met In five of the last eight years but only two of the last four (Table 5, 

 Figure 13). Increased harvest of wild fish in the last several years 

 coincides with decreased wild escapement. Hatchery programs expanded until 

 1985, and then remained roughly the same (Figure 13). An increase in winter 

 steelhead releases into the Chehalis Basin is likely since the Aberdeen 

 Hatchery will no longer be allowed to release fish outside the Chehalis Basin, 

 due to disease considerations (Bob Paulsen, WDW,« pers. coram. ) . 



36 



