Science activity

Observations of individual and population dispersal of delta smelt are essential for improving models that can inform management strategies potentially improving movement into favorable areas or reducing movement into areas of poor habitat quality and risk of pumping loss. However, delta smelt movement patterns are largely unknown. Pacific Northwest National Labs has developed a much smaller Juvenile Salmon Acoustic Telemetry System (JSATS) tag, called the "Shad tag." Recent experiments suggest these tags can be successfully implanted in delta smelt without having significant, negative effects on individual condition and swimming behavior. The next step to determine if the newest technology may provide a tool for acoustic observation of fish dispersal over small spatial scales. Filling this data gap is important because changes in delta smelt spatial distribution (i.e., movement or dispersal) play a significant role in the management and recovery of the species.

This project includes two years of field-based experiments necessary to move this technology into the field. The existing San Francisco Estuary's JSATS array was designed to detect larger, more powerful tags and may not be as effective at detecting the smaller, less powerful tags. Therefore, first, we will test the detectability of the Shad tag by the existing JSATS array and explore detectability at potential locations for new receivers at delta smelt-relevant locations. Secondly, we will design and deploy a 3D
positioning array to test performance of such an array in upper San Francisco Estuary habitats. Finally, we will conduct several small releases of delta smelt implanted with the new Shad tag to assess the capacity of the JSATS receiver arrays to detect and position live fish. This feasibility study will lay the groundwork for the development of a receiver array and post detection
signal processing algorithm to detect delta smelt tagged with Shad tags in later phases of the project.