Development of an Injectable Micro-Acoustic Transmitter for Fish Passage Evaluation: Applications for Non-North American Systems

Acoustic telemetry has been identified as a technology for examining behavior and assessment of survival for juvenile Chinook salmon on their seaward migrations . Although its size meets current tag burden guidelines for most yearling Chinook salmon, size reduction would reduce the possibility of adverse effects of implantation and would likely provide additional biological benefits for tagged fish. The current transmitter is too large for smaller juvenile Chinook salmon. At the request of the U.S. Army Corps of Engineers, we started the development of a downsized transmitter that could meet weight and volume targets for implantation by injection by designing an application-specific integrated circuit and alternatives to current battery and PZT ceramics transducers. The downsized transmitter will broaden the range of applications so it could be used to study more fish species that are too small for the current transmitter, and provide information for the development of fish-friendly hydro systems internationally.  We report the progress of the design process and testing results of the first generation prototype injectable transmitters. This small tag would allow research to be conducted where large numbers of small fish species or life stages could be compromised if hydro development is conducted without fish friendly guidelines.