Acoustic Telemetry Studies: Considerations for Field Deployment

Advances in underwater acoustics have enabled researchers to collect three-dimensional behavior data and conduct large-scale survival studies on migrating juvenile salmon. We have designed and deployed acoustic hydrophone arrays to gather three-dimensional behavioral data and survival data on over 20,000 juvenile salmon during their seaward migration in the Columbia River Basin and in the Sacramento and San Joaquin rivers. While we clearly showed that this relatively new technology produces otherwise unattainable data, we also determined the requirements for optimizing data collection and data downloading. The goal of this presentation is to discuss considerations for the deployment and data downloading using the experience we gained conducting field studies from 2000 to 2011. Some of the areas we focus on include: 1) hydrophone deployment and potential sources noise influencing data quality; 2) hydrophone geometry for 3D positioning hydrophone arrays and the resulting effect on position estimates; 3) discussion of data downloading options and the benefits of an automated download system.