Monitoring Fish Behavior in Challenging Environments: Special Considerations for Tracking Fish with Acoustic Tags

Over the past decade, acoustic tag studies have illustrated fish behavior in lakes and river systems throughout world. All of these studies strive to minimize the adverse effects that may limit the utility of the system such as the avoidance of entrained air, debris and other sources of acoustic interference. These limitations taken at face value, would generally preclude sampling in highly aerated dam tailrace environments. However, in some cases these limitations can be overcome by careful selection of acoustic tag system and signal type.

Additionally, in order to assess the mechanism that causes changes in behavior, researchers often return to the laboratory or to enclosed net pens to monitor responses to environmental changes. Recent studies have demonstrated the utility of an acoustic tagging system in measuring behavioral responses to controlled environmental changes. Environments tested includes monitoring pile driving activities, in the presence of electric barriers, and in the presence of several types of underwater noise generators. This presentation focuses on the methods and considerations for sampling in these challenging environments. In addition we will discuss how this information can be used to evaluate deterrence, guidance and other identified behaviors.