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Marine Ecology Progress Series

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MEPS 338:211-224 (2007)  -  doi:10.3354/meps338211

Movements, behavior and habitat preferences of juvenile white sharks Carcharodon carcharias in the eastern Pacific

Kevin C. Weng1,*, John B. O’Sullivan2, Christopher G. Lowe3, Chuck E. Winkler4, Heidi Dewar1, Barbara A. Block1

1Tuna Research and Conservation Center, Hopkins Marine Station of Stanford University, 120 Ocean View Boulevard, Pacific Grove, California 93950-3024, USA
2Monterey Bay Aquarium, 886 Cannery Row, Monterey, California 93940-1023, USA
3California State University, Long Beach, Department of Biological Sciences, 1250 North Bellflower Boulevard, Long Beach, California 90840-0004, USA
4Southern California Marine Institute, 820 South Seaside Avenue, Terminal Island, California 90731-7330, USA

ABSTRACT: Understanding of juvenile life stages of large pelagic predators such as the white shark Carcharodon carcharias remains limited. We tracked 6 juvenile white sharks (147 to 250 cm total length) in the eastern Pacific using pop-up satellite archival tags for a total of 534 d, demonstrating that the nursery region of white sharks includes waters of southern California, USA, and Baja California, Mexico. Young-of-the-year sharks remained south of Point Conception whereas one 3 yr old shark moved north to Point Reyes. All juvenile white sharks displayed a diel change in behavior, with deeper mean positions during dawn, day and dusk (26 ± 15 m) than during night (6 ± 3 m). Sharks occasionally displayed deeper nocturnal movements during full moon nights. On average, vertical excursions were deeper and cooler for 3 yr olds (226 ± 81 m; 9.2 ± 0.9°C) than young-of-the-year animals (100 ± 59 m; 11.2 ± 1.4°C). Juvenile white sharks are captured as bycatch in both US and Mexican waters, suggesting that management of fishing mortality should be of increased concern.

KEY WORDS: Juvenile white shark · Carcharodon carcharias · Habitat · Diel behavior · Satellite tag · Bycatch

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