FISHERY BULLETIN: VOL. 72. NO. 1 



for coho (Lyles, 1968, 1969; National Marine 

 Fisheries Service. 1971; Riley, 1970, 1971; 

 Wheeland, 1972). In addition, the net economic 

 value of marine and freshwater sport fishing for 

 salmon in the U.S. in 1970 was estimated at 

 $77.7 million. This fishery was made up of 64% 

 coho and 32% chinook.^ 



In 1950 five salmon hatcheries, representing 

 the entire Columbia River production of hatch- 

 ery coho salmon, released about 1 millicjn juve- 

 niles typified by a short rearing period, poor nu- 

 trition, and low survival. In contrast, the num- 

 ber of hatcheries rearing coho increased to 20 by 

 1966-67, and annual releases averaged 20 mil- 

 lion smolts. These salmon benefited from ad- 

 vances in fish culture, especially nutrition, 

 applied during the early 1960's and were char- 

 acteristically large and healthy with a high sur- 

 vival potential (Cleaver, 1969a). 



In 1962 the Columbia Fisheries Program 

 Office started a marking study to estimate the 

 contribution of Columbia River hatchery-reared 

 fall Chinook salrnon to the Pacific coast fisheries. 

 In 1965 this study was exj^anded to include coho 

 salmon. Accordingly, representative (10% ) sam- 

 ples from all Columbia River hatcheries rearing 

 1965- and 1966-brood coho salmon were marked. 

 Sampling for these marked coho took place from 

 1967 through 1969 in the sport and commercial 

 fisheries from Alaska to California. A contribu- 

 tion study of this magnitude had never before 

 been undertaken. The information to be gained 

 from this study was critically needed to deter- 

 mine if increa.sed Federal funding for Columbia 

 River hatcheries was economically justified. 



The objectives of this report are to (1) 

 describe the design and operations of marking 

 and release procedures, (2) estimate the contri- 

 bution (catch) to Pacific salmon fisheries during 

 1967, 1968, and 1969 for the 1965-66 brood coho 

 salmon hatchery releases, and (3) develop bene- 

 fit/cost ratios for these two broods. 



BIOLOGICAL EVALUATION 



Experimental Design 



Procedures were basically the same as 



3 George K. Tanonaka. 1972. A general comparison of 

 the commercial and sport salmon fisheries of the United 

 States, 1940-70. Natl. Mar. Fish. Serv., Northwest Fish. 

 Center, Seattle, Wash. (Unpubl. manuscr.) 15 p., 7 tables, 

 4 fig., App. A-B. 



described by Worlund, Wahle, and Zimmer 

 (1969) for the fall chinook salmon study but 

 will be summarized here. The Columbia River 

 was divided into four sections. These sections 

 will be defined later. Releases of marked fish 

 were intended to identify and estimate the 

 catches from each section. Execution of the plan 

 dejiended. as for the evaluation of fall chinook 

 salmon hatcheries, on the cooperation of many 

 l)eople in the following agencies: 



Alaska Department of Fish and Game 

 Fisheries Research Board of Canada 

 Washington Department of Fisheries 

 Fish Commission of Oregon 

 Oregon State Game Commission 

 California Department of Fish and Game 

 National Marine Fisheries Service 

 Bureau of Sjwrt Fisheries and Wildlife 

 The basic plan was to mark the same propor- 

 tion of juvenile coho salmon released at each 

 hatchery and to sample for marks in commercial 

 and sport fisheries. Total catches of fish from 

 all hatcheries then could be estimated from (1) 

 fractions of marked fish in each release, (2) 

 numbers of each type of mark actually recovered, 

 (3) fractions of the total catches sampled for 

 marks by time and area in each fishery, and (4) 

 information on any bias associated with appli- 

 cation or detection of marks. 



Allocation of Marks 



The 20 hatcheries involved in this study are 

 distributed over much of the mainstem Columbia 

 River accessible to anadromous fish (Figure 1). 

 Klaskanine River Salmon Hatchery, the lower- 

 most station, and Leavenworth National Fish 

 Hatchery, the uppermost, are on tributaries 

 about 25 km and 800 km (15 and 500 miles), 

 respectively, above the Columbia River mouth. 

 Some hatcheries (Bonneville, Cascade, OxBow, 

 and Little White Salmon) are adjacent to the 

 main Columbia River and release their fish al- 

 most directly into it. In contrast, fish released 

 at the Toutle River station must travel 65 km 

 (40 miles) to reach the Columbia River. 



Four different marks were available (from the 

 Pacific Marine Fisheries Commission) for the 

 1965 brood of coho salmon. The Columbia River 

 was therefore divided into four sections — Lower 

 River, Middle River, Upper River, and Upper- 

 most River — and one mark was assigned to 

 each (Table 1). The adipose-right maxillary 



140 



