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S F O S. School of Fisheries and Ocean Sciences. Insights into the foraging behavior of Steller sea lions using an animal-borne video and data recorder. Paul Olivier – Texas A&M University Russ Andrews – Univ. of Alaska Fairbanks and the Alaska Sealife Center
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S F O S School of Fisheries and Ocean Sciences Insights into the foraging behavior of Steller sea lions using an animal-borne video and data recorder Paul Olivier – Texas A&M UniversityRuss Andrews – Univ. of Alaska Fairbanks and the Alaska Sealife Center Don Calkins – North Pacific Wildlife Consulting, LLC Vladimir Burkanov – National Marine Mammal Laboratory, NMFS, NOAA Randall Davis – Texas A&M University at Galveston
Project Description • Objective • Describe the foraging strategies of lactating SSL • Location • Kuril Islands, Russia • SSL/NFS Rookery onLovushki Island • June 20-23, 2008 • Test Subject Selection • Lactating Female • Healthy, Large Pup
InstrumentationVideo Data Recorder (VDR) • Equipment in deployed VDRs • Head Mount • B&W CCD camera with near-infrared LEDs • GPS • Backpack • Digital video recorder and Flash memory for data • Pressure sensor (depth) • Other sensors • Thermistor • Conductivity sensor • Illuminance sensor • Water (swim) speed • 3-axis accelerometer (pitch, roll, yaw) • 3-axis magnetometer
Dive Durations(Combined data for three animals) Mean = 200 seconds (3.3 min)
Atka MackerelPleurogrammus monopterygius • Display diurnal vertical migration1 • Active vertical movement away from “settling depth” (near 100 m) during daylight hours • Returned to “settling depth” in late afternoon • Vertical migration may increase susceptibility to SSL predation during daylight hours1 1Nichol and Somerton, 2002; Mar Ecol Prog Ser 239: 193–207
Estimated Foraging Success(from approximately 7.5 hours of video data) Consumption rate for SSL 2 • Combination of darkness, speed and camera placement made it difficult to identify which of the fish “encountered” were consumed and which escaped out the bottom of the video frame.
Conclusion: • SSL exploit Atka mackerel behavior • Prey detection appears primarily by vision • Vibrissae may be used with vision in low light conditions
Acknowledgements Bill Hagey, Sarah Norberg,Petr Permyakov Oksana Savenko, John Skinner, Tatiana Shulezhko Boris Solovyev, Andrey Tretiyakov, Jason Waite The captain and crew of the R/V Georg Steller Funding NOAA grant to the Alaska Sealife Center Pinniped Program Texas A&M University National Science Foundation National Marine Fisheries Service National Undersea Research Program