White Shark Attacks Upon Humans in California and Oregon, 1993-2003

We report on 20 confirmed and five purported but unreliable incidents of unprovoked attacks by white sharks on humans in California and Oregon between 1993 and 2003. All attacks involved white sharks (Carcharodon carcharias). The discussion, map, and tables from McCosker and Lea’s (1996) report are updated. The majority of attacks occurred at or near the surface, near shore, and often in the vicinity of pinniped colonies and/or river mouths and harbors. Attacks have now occurred during all months, and on surfers, breathhold and scuba divers, swimmers, hookah divers, kayakers, and, for the first time, on bodyboarders, a windsurfer, and a scuba diver using an electric propulsion device. Typical attack scenarios suggest that an adult C. carcharias mistakes its victim for a pinniped, its normal prey. Shark attacks were fewer during the extreme 1997–1998 ENSO (El Nino/Southern Oscillation) oceanographic warming event. The defensive activity of humans after being attacked and its effect are discussed. We also comment on recent legislation concerning white shark protection and disallowing the attraction of white sharks by chumming.