Using Hydroacoustic Telemetry to Understand Movement and Ecology of Critical Species

Migratory behavior of fish has long fascinated scientists.  Traditional methods of studying behavior had considerable disadvantages in that they only allowed inferences at the population level (e.g., using mass marking techniques) or required the fish to be physically handled (or sacrificed) in order to obtain data.  The ability to tag and remotely track fish using acoustic telemetry has made it possible to expand our understanding of species residence times, origins, migration pathways in different habitats, predator/prey interactions, habitat use, and behavior.  Recent advances in technology (e.g., longer battery life and smaller tag sizes) and detection ability, such as the placement of receivers over increasingly larger spatial scales, has continuously provided new insights into fish behavior and ecology.  For example, studies of Chinook salmon have revealed that populations display complex continuums in migration patterns at multiple scales.  An additional insight provided by this acoustic telemetry is the identification of key habitats that are needed by species throughout their complex life cycles.  In this symposium we explore individual fish movements at a range of spatial (e.g. circum ocean, between basins, speed of movement, etc.) and temporal scales (e.g. seasonal, diel, tidal patterns of horizontal movement etc.).  We contrast the behaviors within and between species for selected species of salmonids, lampreys, sharks, groundfish, and other fish species.  Additionally, we explore how selected environmental and biological factors relate to observed patterns of movement and consider some of the strengths and weaknesses of this rapidly changing technology. Our focus is on work occurring in the North Pacific Ocean coastal environment.  This symposium demonstrates the multiple ways that results obtained from telemetry studies can assist managers in conservation and management efforts.