Deciphering the Attacks

Recent statistics show rise in shark attacks on West Coast

| posted on January 28, 2013

Great white sharks have either been confirmed or strongly suspected in 90 percent of shark attacks on the U.S. West Coast since 1900.

Last week, the Shark Research Committee released their annual report detailing the statistics behind the attacks that occurred along the U.S. West Coast in 2012. According to the report, shark attacks have been on a steady rise over the past decade, with a total of eight attacks occurring on the West Coast last year. The number of attacks in 2012 is six times the average from the 20th century. While this trend in attacks may seem alarming, it should be noted that there were also substantially less people frequenting the ocean along the American West Coast for a large portion of the 20th century.

Dating back nearly 50 years, the Shark Research Committee was founded with the Office of Naval Research, with help from the Smithsonian Institute. According to Ralph Collier, who heads the committee, while the 2012 statistics are indeed indicative of a rise in attacks, they should always be viewed in context.

“If you look at the number of attacks in the American West Coast we’ve recorded over the 20th century, you’ll see that we only noted one attack from 1900 to ’49. From 1950 to 2000, we were averaging about two attacks per year, and from 2000 to 2012, we were averaging about three a year,” says Collier. “When you increase the number of people in the water, even with a smaller shark population, you’re going to see an increase in attacks.”

In 2010, there were seven confirmed attacks, and in 2011 there were eight. The victims in the vast majority of recorded attacks have been surfers; since 2000, they’ve made up 67 percent of attacks. Great white sharks have either been confirmed or strongly suspected in nearly 90 percent of attacks since 1900.

Collier cites population dynamics as the fundamental reason for the rise in attacks in recent history. “If you couple the increased amount of people in the water along with the rise of the seal population, that helps explain some of it.” As Collier referenced, in 1972, under the Marine Mammal Protection Act, it became illegal to kill seals in the United States.

Alarmingly, according to the Shark Research Committee, the majority of all attacks seem to occur in a three-month window spanning from August to October. Since 2000, 49 percent of all attacks on the West Coast have occurred in this window. Collier says there a few different theories to account for the attacks that occur during the fall. One is a potential connection with salmon and steelhead making their way downstream when rivermouths burst into the ocean, often times creating good sandbars and feeding grounds. This period also lines up with when many seal pups, who are easy prey, are born. “To be honest,” says Collier, “I’m almost surprised there aren’t actually more attacks.”

  • phil

    Bit of scaremongering here folks, many many marine animals likly gonna cause you a problem (jellyfish, stonefish e.t.c.) than a shark. The biggest risk to our health is the polution that we produce, better to report that! How about a nice article on how cool it is to see a shark and how awesome they are next time please?

  • DanO

    The Global Shark Tracker website released their tracking data online recently and you can go there and see the routes of sharks they have tagged. Currently there is a 16foot, 3500 pound female that has been swimming up and down the eastern seaboard. Its fascinating stuff. They even have a picture of the shark when they tagged it and its monstrous in size.

  • Alan

    DanO, that website is sick! thanks!

  • Jimmy the Saint

    Yeah, that is a great website. thanks for sharing DanO


    If the Great White Shark expends the energy and effort to hunt, it will almost always aim for fatty fishes, cetaceans, seals, or sea lions. And while piercing onyx eyes may haunt humans, a sense of sight serves no significant purpose in seeking prey.

  • oregon111

    we need to hunt/fish the sharks and also cut down on their prey…

    people are more important than sharks..

    what if a person was killing 7 people a year while surfing? Would the liberals say “that is just because there are more people in the water”

    “you have a better chance of drowning in your own bathtub”

    of course not! It is time to take power away from shark worshipers and do the right thing – hunt sharks and save lives

  • stefano

    you have no idea what your talkin about @oregon111:disqus if theres such a worry we need to look more into “shark repelling” technologies like the shark tracker website. killing wont solve anything