LANDER and HENRY: 1965-66 BROOD COHO SALMON 



available at the start of the commercial troll 

 fishery (A^^)- The D, represent the number of 

 fish dying naturally. 



The known data for the two brood years are 

 listed in Tables 1 and 2. The catch data shown 

 are estimated numbers based on sampling (see 

 footnote 2). Each escapement value is the sum 

 of the river catch and returns to the hatchery 

 for a given mark. In making our computations 



we have made some additional assumptions: 

 1) the data in Tables 1 and 2 are accurate, 2) 

 adipose only marks (Ad) were not regenerated, 

 3) all recoveries of fish with appropriate marks 

 were hatchery fish, and 4) all pertinent hatchery 

 marks in catch samples and hatchery returns 

 were detected and reported. 



The events in Figure 2 can be depicted by a 

 multinominal model with the No smolts falling 



Table 1. — Estimated total recapture of 1965 brood marked Columbia River 

 hatchery coho salmon, grouped by river section. 



Table 2. — Estimated total recapture of 1966 brood marked Columbia River 

 hatchery coho salmon, grouped by river section. 



• Includes 92,250 D-Ad-LM and 73,01 1 D-Ad-RM, and 9,474 D-Ad. 



681 



