Medicine for the Outdoors
Dr. Paul Auerbach is the world's leading outdoor health expert. His blog offers tips on outdoor safety and advice on how to handle wilderness emergencies.See all posts »
Great White Shark Attack
A great white shark attack was reported this past Sunday from Dillon Beach, California, which is northwest of San Francisco. A surfer had his board struck, and fortunately suffered only a couple of skin nicks. It certainly could have been far worse, so this surfer was very lucky.
White shark attacks are most common in the waters of southern Australia, the south coast of South Africa, the middle Atlantic coast of North America, and the American Pacific coast north of Point Conception, California. Attacks by great white sharks, which reach a length of nearly 20 ft (6 m) (making it the largest predatory shark), off the coast of northern California have led to the designation of a “red (or bloody) triangle” bordered on the north by Point Reyes and Tomales Bay, through the Farallon Islands to the west, and down south to Año Nuevo and Point Sur facing the Monterey Bay.
It is difficult to generalize about shark attacks on humans. Most attacks likely occur as cases of mistaken identity in which the shark misinterprets the splashing of humans at or near the water surface as the activity of normal prey items. Less commonly, attacks may be direct feeding events where large sharks simply perceive the human as appropriate sized and demonstrating appropriate behavior patterns.
The great white shark attains maturity at a length of approximately 2.5 m (8.2 ft). It is a man-attacker, but not always a man-eater. This statement reflects the observation that this highly feared animal usually releases its victim following a single “inquisitory” bite, a behavior it also employs on floating pieces of Styrofoam, surfboards, and marine mammals it does not consume, such as sea otters. Humans may survive and avoid consumption by having the ability to retreat to boats or surfboards prior to return of the shark, a luxury unavailable to the white shark’s normal prey. The great white shark has only recently been closely observed in the wild and is thus the subject of much speculation about predation strategies. The feared trait of the great white sharks is that they initiate contact with humans. Their unpredictable nature ranges from a seemingly docile approach to a research boat to a powerful attack on a surface sea lion. Breath-hold diver behavior and the similarity of the silhouette of a contemporary surfboard to that of a surface seal may be responsible for attacks on humans. Most attacks on humans occur at the water’s surface.
It has been noted that some great white sharks remain in one vicinity for a few days, so after an attack, it is probably best to stay out of the water in that location for at least a week, unless there is some compelling reason to risk encountering the same predator.
Tags: great white shark, shark attack , shark, wilderness medicine, outdoor medicine, healthline
photo by Carl Roessler
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