Characterizing Migration Behaviour of Adult Fraser River Sockeye Salmon (Oncorhynchus nerka) During Costal and Estuarian Passage Using Acceleration Transmitters

Abstract

Though behaviour during the reproductive migration of Pacific salmon (Oncorhynchus spp.) has been studied during upriver migrations, equivalent information for coastal marine migrations has been difficult to obtain. Newly developed acoustic acceleration transmitters provided a possible tool for the study of swim speed and depth of salmon in both marine and freshwater. In Chapter 2, I used swim tunnel respirometry and demonstrated that these transmitters could be used to predict swim speed and energy use from acceleration output. In Chapter 3, I tagged ocean migrating sockeye salmon (O. nerka) with these transmitters and tracked swim speed and depth as they crossed several acoustic receiver lines in coastal waters and the lower Fraser River. Using statistical models developed in Chapter 2, I examined how environmental factors influenced swim speed, and depth. These are the highest temporal and spatial resolution data collected on coastal migration behaviour of adult sockeye salmon, to date.