PROJECT HIGHLIGHT
This project will study how the surgical implantation of acoustic transmitters impacts longfin smelt — providing essential information that will inform further study of an imperiled and essential species. Understanding how these fish move through the San Francisco Estuary could help protect them from extinction and aid their recovery.
PROJECT SUMMARY
The longfin smelt, once among the most abundant fish in the San Francisco Estuary, served a critical role in its food web. Now, though, this tiny fish is nearly extinct, and the distinct local population — the San Francisco Bay-Delta Population Segment — was listed as endangered in 2024. Unfortunately, there are many gaps in the scientific understanding of the species’ ecology, especially its movements throughout this highly urbanized estuary.
Acoustic telemetry is an established tool for tracking fish movement, but until recently transmitters have been too big to be attached to small fish like smelt. This study will provide essential information about how longfin smelt — both wild and captive-reared — fare after the surgical implantation of transmitters. At what rate do they survive post-procedure? Do they retain the transmitters? How does the surgery impact their swimming performance? Answering these questions offers a first step toward further studies that will be essential to helping this species persist and recover.
This project is funded by the Delta Stewardship Council Delta Science Program under Agreement No. DSC23011 and is administered by California Sea Grant.