Hume et al. 1996

Hume, J. M. B., K. S. Shortreed, and K. F. Morton. 1996. Juvenile sockeye rearing capacity of three lakes in the Fraser River system. Canadian Journal of Fisheries and Aquatic Science 53:719-733.

We used three methods to estimate sockeye salmon (Oncorhynchus nerka) escapements that maximize production (SMAX) in Fraser River lakes: (i) effective female spawners and adult returns using Ricker stock-recruit analysis (SR models), (ii) effective female spawners and fall fry or smolts (fry models), and (iii) photosynthetic rates (PR model), a modification of an Alaskan sockeye production model (EV model). Adult SR models were not useful in predicting SMAX because of high variability in Shuswap and Chilko lakes (r2 < 11%) and because of linearity in Quesnel Lake. Fry models using Ricker stock-recruit analysis provided SMAX escapements of 0.90, 1.38, and 1.06 million for Quesnel, Shuswap, and Chilko lakes but were still highly variable (r2 < 51%). Fry data indicated that fry numbers did not increase above escapements of 0.85, 1.5, and 0.51 million to Quesnel, Shuswap, and Chilko lakes. PR model predictions of SMAX escapements to Quesnel, Shuswap, and Chilko lakes of 1.06, 1.85, and 0.62 million were similar to escapements that first produced maximum observed fry numbers. While fry models provide a direct estimate of rearing capacity, many years of data are required to generate a relationship for any lake. The PR model appears to be a useful predictor of rearing capacity and predictions can be made after 1–2 years.