Thursday, October 6, 2011

Fishtracker detects visitors to Redfish Rocks

The Fishtracker Project is my thesis research into the movement behaviors of fish at Redfish Rocks, located on the southern coast of Oregon, near the town of Port Orford. The area will become a no-take marine reserve on January 1, 2012, and one of my goals is to collect baseline data prior to closure.

I am using acoustic telemetry to track the movement behaviors of six valuable species of fish; Black, Canary, China, Copper, and Quillback Rockfish, and the Cabezon. My goal is to quantify the degree of protection provided by the no-take reserve to different s
pecies, based on the proportion of time they spend within the protected area. To accomplish this, I surgically implant acoustic transmitter tags in fish of each species, and maintain an array of acoustic receivers. Coded transmissions from the tags are recorded when a tagged fish swims within range of a receiver. Periodically, I retrieve data from the receivers in the field, and analyze these data to reveal the movement behaviors of the tagged fish. Please visit to learn more.

One unexpected result of my work is that the receiver array has recorded many transmissions from fish that have been tagged by other researchers. At least sixteen green sturgeon tagged in the upper Sacramento and Klamath Rivers have migrated northward through the array, and three white sharks have also been detected in the area.

This video depicts one week of the movement behavior of one of these sharks. This shark was tagged by Dr. Mauric
io Hoyas, who leads the white shark tagging project at Guadalupe Island in Mexico.

You can watch this video in larger format on and watch more video and learn all about the Fishtracker Project, including how you can help support this work by adopting a tagged fish at

Visit this blog and, and "like" fishtracker on facebook, to keep up-to-date about the movement behaviors of tagged fish, and to learn the identities of our other visitors!

Thanks for reading my post!