Table 4. — Estimated numbers and mark ratios of fall chinook salmon released from study hatcheries for 1961-64 hrood years 



Origin of mark 



Marki'd Marked and Marked/ Marked/ 



release uunrarked Marketl and unmarked 



release unmarked 



1961- - Ad-RM 



1962 Ad-LM 



1963 - Ad-RM 



1964. Ad-LM 



1961 -.- Ad-LV-RM 



Ad-RV-RM 

 LV-RM 

 RV-RM 



1962 Ad-LV-LM 



Ad-RV-LM 

 LV-LM 

 RV-LM 



1963 Ad-LV-RM 



Ad-RV-RM 

 LV-RM 

 RV-RM 



1964 Ad-LV-LM 



Ad- RV-LM 

 LV-LM 

 RV-LM 



All hatcheries. 



do 



do 



do 



Suhtotal. 



Spring Creek 



Kalama 



Elokomin 



Oxbow..- 



Spring Creek.. 



Kalama 



Grays 



Cascade 



Spring Creek 



Kalama 



Klickitat 



Big Creek.. 



Spring Creek 



Kalama.- 



l^onneviUe 



Little White Salmon. 



Subtotal. 



9,610,973 , 



Total 30,931,192 



amount of subjectivity is inlierent in .such a scor- 

 ing system, these \iilues indicate tliat a liigh 

 quality was attained. 



During tlie marking, o\er >'>0 million fingerlings 

 were examined for naturally missing adipose and 

 ventral fins. A total of 156 missing adipose and -201 

 missing \entral fins were observed. Although in- 

 significant in relation to the fish examined, these 

 numbers represent the frequency of naturally 

 missing fins for these hatchery-reared fish only. 

 A more direct measure of this source of error (i.e., 

 occurrence of natural marks) in the hatchery 

 contribution study will be possible during the years 

 when fish of the 1965 brood ai'e in the fishei'y. The 

 marks used in the study were not applied to the 

 1965 brood. 



Marked fingerlings obtained at time of release 

 from the hatcheries were held in salt-water rear- 

 ing ponds at Bowman Bay, Wash., for as long as 

 .'54 months. Periodic examinations were made to 

 determine the extent of regeneration of the fin and 

 maxillarj- marks, and the re.sults are summarized 

 in table 5. 



Regeneration of the adipose mark was not ap- 

 parent. Similarly, com])lete regeneration of the 

 ventral mark did not occur. Some regeneration 

 of the ventral mark, however, was apparent for 

 a substantial portion of the fish in each group 

 (up to 47 percent). In most cases, the ventral fin 

 regenerated to less than 25 percent of its original 

 size (as judged by the size of the paired ventral 



T.\BLE .5. — Regeneration of adipose j\n, maxillary hone and 

 ventral fin in lest lots of fish, 1961-64 lirood years, held 

 at Bowman Bay, Wash. 



Adipose fin 



Brood year 



Age 



Fish 

 examined 



Regeneration 



Months 



19IU.. 20 



1962 12 



23 

 29 



1963 12 



17 

 26 

 34 



1964. 14 



27 



Maxillary bone 



Brood year 



Age 



Fish Complete regeneration 

 examined 



Number Number Percent 



19(J1 - 

 196-2, 



1963. 

 1964. 



Ventral fin 



Brood year 



Regeneration 



1961. 

 1962. 



1963. 

 1964. 



I Complete regeneration did not occur in any of the groups. 

 - Degree of regeneration was not deterniined. 



CONTRIBUTION OF COLUMBIA RIVER HATCHERIES TO FALL CHINOOK SALMON HARVEST 



373 



