AGENCY : 



SCALE ENVELOPE NO. 



MARK RECOVERY FORM 



COMMENTS : 



FiiiURE f). — Form for recording type of mark observed. 



smu'ct's of variation must await (•oniijletioii of tlie 

 study. 



Table 4 shows for eacli mark type and l)rood 

 year the estiinatcd niimbei-s of chinook salmon 

 released and the proportions of fish that were 

 marked, and ratios of marked-to-unmarked fish. 

 Detailed data for each hatchery are ^iven in 

 appendix tables 1, 2, 3, and 4. 



During the 4 years of markino- (i.e., I'.)(;i-fi4 

 broods), 213 million fall chinook salmon were 

 released from the hatcherit's under study. In- 

 cluded were 21.3 million Hsli with the adipose- 

 maxillary mark. This mark, common to Jill of the 

 12 hatcheries, was 9.0 to 10.1 i)ercent of the 



relea.ses. In addition, the release included 0.6 mil- 

 lion fish with special marks unique to individual 

 hatcheries. These special marks were 9.1 to 30.5 

 l)ercent of the yeai-ly releases from the hatcheries 

 where used. 



Samples of over 100,000 marked fish were ex- 

 amined each year and graded according to quality 

 of mark. A score of 5 was assigned for a good 

 mark, 3 for an acceptable mark, and for an un- 

 acceptable mark. Average scores were 4.9, 4.9, 4.9, 

 and 4.S for lOC.l, 1962, 1963, and 1964 broods, re- 

 spectively. The lowest average score for any hatch- 

 ery-mark type combination was 4.1 ; all remaining 

 scores were i;reater tiian 4.5. Althouah a certain 



372 



r.S. PISH AXD WILDLIFE SERVICE 



