Sevengill Shark Research with UC Davis

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Supporting our mission of creating experiences that inspire conservation of San Francisco Bay and its watershed, Aquarium of the Bay is pleased to further its field research of Sevengill Sharks, Notorhychus cepedianus, by working with scientists from the Biotelemetry Lab at the University of California, Davis.

“Almost nothing is known about sharks in the Bay.  Aquarium of the Bay is one of the first groups to fund a study on cowsharks, so now we’re finally learning about shark movements in the Bay,” said A. Peter Klimley, PhD, Director of the Biotelemetry Laboratory at UC Davis.

Sevengill sharks, live and reproduce in San Francisco Bay, but little is known about their behavior and ecology. Working with UC-Davis’ Biotelemetry Lab, Aquarium of the Bay staff are implanting two different types of transmitters into sevengills to track and detect the movements of sevengills in the bay.   Watch "City of the Shark," a short documentary on our efforts, below.

During the 2008 project season, the Aquarium actively tracked four adult sevengills using ultrasonic transmitter tags implanted in the shark’s body. After tagging the shark, it is released back into the bay. Then, the transmitter sends a continuous record of the shark’s swimming direction, depth, and geographic coordinates. On the Aquarium’s research vessel, the Blue Shark, staff follow the tagged shark continuously for one to three days. The data collected will reveal valuable information about sevengill movements and activities in the San Francisco Bay. 

In addition to the ultrasonic transmitters, the Aquarium Team implanted coded signature beacons in twenty sevengills. These beacons have a lifespan of five years, and transmit a signal every 45 to 95 seconds. Monitors positioned throughout the bay detect and record these signals, collecting information that will provide a long-term perspective on the sharks’ life patterns and basic ecology.

Researchers are continuing to analyze Sevengill shark movements and other data gained from this research project.