Solazzi, 1984

Solazzi, M. F. 1984. Relationship between visual counts of coho, chinook and chum salmon from spawning fish surveys and the actual number of fish present. Oregon Department of Fish and Wildlife, Information Reports (Fish) 84-7, Portland, Oregon.

We developed relationships between the number of adult and jack coho, adulat and jack chinook, and adult chum slamon observed per mile on spawning fish surveys and the estimated number of salmon present per mile. On the average surveyors observed 75.5% of the adult coho, 49.1% of the jack coho, 76.1% of the adult chinook, 63.6% of the jack chinook and 85.0% of the adult chum present in the survey sections. In addition, surveyors observed an average 62.8% of the coho carcasses, 75.6% of the chinook carcasses and 100% of the chum carcasses present in the survey sections. The percentage of live salmon observed did not vary with spawner density. The effects of several habitat features and environmental variables on the percentage of salmon observed were not statistically significant (P>0.05). There was no significant difference between the percentages of coho salmon observed before and after the date of peak spawning. Results for coho salmon suggest that about 243, 000 more wild coho produced at maximum sustained yield (MSY) and 66, 000 more spawners are requiered to achieve MSY than previously estimated.

http://nrimp.dfw.state.or.us/crl/Reports/Info/84-7.pdf