Sockeye Egg-to-Fry Mortality in the Fulton River Spawning Channels

Possible causes of low egg-to-fry survival of sockeye salmon (Oncorhynchus nerka) in the Babine Lake artificial spawning channels were studied from November, 1971 to March, 1972. Concurrent studies were conducted on the Fulton River and Pinkut Creek spawning areas. Intragravel and surface water levels of dissolved oxygen and free carbon dioxide were conducive to satisfactory embryonic growth, development and survival in the spawning channels, but not in all sections of Fulton River and Pinkut Creek. Significant mortalities occurred in areas of the two rivers characterized by high silt loads and low dissolved oxygen concentrations. Other ionic constituents of river and channel water were present in normal amounts in all spawning areas except in Channel No.2 where abnormal nitrate concentrations prevailed.