Where Are the Fish... Really? Taking the Error Out of Fish Positioning for Jsats

Acoustic telemetry is widely utilized for studying the survival and behavior of fish.  The Juvenile Salmon Acoustic Telemetry System (JSATS) was developed to specifically address the need to estimate fish passage and survival through hydropower facilities and systems.  JSATS provides species- and route-specific passage data, and high resolution 2- and 3-dimensional fish movement.  Data can be acquired using a combination of cabled arrays of hydrophones deployed at the dam face and autonomous node arrays deployed at specific cross-sections throughout the river reach.  2-D and 3-D monitoring of tagged fish approaching and passing at the dams requires knowing the location of hydrophones and understanding the precision of the location estimate.  Thus it is necessary to estimate the error associated with each 2- or 3-D position calculated from the acoustic tag signals detected by multiple hydrophones on the cabled array system.  We developed a series of techniques that includes traditional land surveying, remote controlled in-water surveying and monitoring, signal processing and tracking to provide an error estimate for the entire coverage area of the system and its resultant data.  This technical combination of error analyses improves JSATS performance by accurately determining route-specific passage and survival estimates, and fish movements.