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Interception 



Interception is the catch of a given salmon stock outside itB terminal area, 

 where a salmon fleet fishes on a mix of stocks bound for different rivers. 

 Interception may occur on the high seas or in coastal waters. The high seas 

 are defined for this report as marine waters outside the 200-mile national 

 fishery management zone. 



Hioh Seas Japanese Salmon Gillnet Fisheries . There is little or no catch of 

 Washington Chinook, coho, or chum salmon or steelhead in this fishery (Harris 

 1988; Walker 1990). 



D.S. and Canadian CoaBtal Salmon Sport and Troll Fisheries . Marine fisheries 

 within 200 miles of the Washington, British Columbia, and Alaskan coast 

 intercept large numbers of Chinook and coho bound for the Chehalis Basin. 

 This remains a major influence on terminal run size, and appears to contribute 

 tc the difficulty in meeting wild escapement goals. Grays Harbor coho have 

 been a limiting stock in U.S. ocean salmon fisheries management and have 

 limited access to other stocks in terminal fisheries (Dick Stone, WDF, pers. 

 coram. ) . Marine fisheries do not intercept enough Chehalis Basin chum salmon 

 or steelhead to affect terminal fishery management. 



Terminal Area Fisheries 



Fishery managers make pre-season, in-season, and post-season run size 

 estimates. The pre-season estimates help to set the fishing regulations and 

 in-season estimates provide an opportunity to adjust regulations based on how 

 the season is progressing. Overfishing in the directed fishery results when 

 fishery managers overestimate the run size before or during the season, and 

 consequently allow too much fishing. Inaccurate pre-season predictions may 

 result from variation in migration route, variations in marine survival, 

 and/or changes in time and intensity of mixed-stock fishing pressure. 

 Differences between pre-season and post-season estimates of Grays Harbor 

 terminal area natural coho run sizes clearly show the magnitude of the problem 

 (Salmon Technical Team 1991). 



Inaccurate in-season run size updates during terminal fisheries, resulting 

 from unusual entry timing into the terminal area, variations in effort, and 

 variations in catchability caused by temperature patterns, flow regimes, and 



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