More shark sensationalism from the popular press

Whenever there's a documentary about shark attacks on the Discovery Channel or a popular press article involving the supposed "alarming rise" in shark attacks, the International Shark Attack File (ISAF) is usually mentioned. This project is primarily concerned with data-gathering and statistics, and this focus has led to some amount of criticism from other researchers concerned with shark attacks. The director of this project is George Burgess, who was quoted as saying the following in a LiveScience article likely spurred by the recent death of an Australian tourist who was bitten while diving in water that had been chummed to attract sharks;

"There are more people in the water than there ever have been. ...We can pretty much predict that next year there will be even more attacks. Even if shark populations are declining, which we know they are, even in a local situation if populations have been depleted, there is still a probability of getting an attack."

This seemed like a pretty tenuous and abstract statement to me, so I decided to have a look at an online resource available to the public that keeps track of shark attacks as they occur. The Global Shark Attack File (GSAF) has an excel database of shark attacks from about 1850 to the present, and you can have a look at the data yourself here. (I should probably say that for a few months I worked on this project and think it a better collection of information than the ISAF.)

The GSAF database is set up so that incidents that are only possibly connected to sharks (i.e. a drowning victim with a shark bite that cannot be proven to have been the cause of death, a boat that was bumped by something no one saw, etc.) are included with verified attacks, and the total amount of incidents reported in each of the past few years is as follows;

2007 - 96

2006 - 95

2005 - 94

2004 - 86

2003 - 87

Some of these events are not confirmed shark attacks, however, and provoked attacks (i.e. a diver tugs on a shark's tail) aren't what the public is most concerned with. It is unprovoked attacks, marked in tan in the GSAF database, that are of the greatest interest. Here are the number of unprovoked attacked for each of the years mentioned above;

2007 - 80

2006 - 72

2005 - 71

2004 - 74

2003 - 71

Have the number of unprovoked attacks and number of incidents per year increased? It appears so, but not to an alarming degree. In considering these numbers it's important to remember that these databases are global in scope and incidents are only recorded if reported; some incidents might get little coverage, or an event might get covered twice and look like two separate events. Indeed, reporting and the response of the public to news of shark attacks can influence the data in terms of where attacks are more likely to be reported. In 2007 there were a total of 63 incidents reported from the USA, a large percentage of the incidents but not surprising considering how our media operates (shark bites, when they occur, often make the news).

Will the number of shark attacks rise in coming years? Maybe yes, maybe no. Even if a greater number of incidents are reported, it's easy to deceive by throwing around numbers culled from new reports emanating from all over the globe, and there is always a question of what is not being reported. Overall, though, 86-97 attacks each year is a very small number when you consider the number of car accidents or injuries received putting up Christmas ornaments each year, but being attacked by a shark is a far more terrifying experience than more common dangers. This common fear will result in news broadcasts about "the summer of the shark" or "alarming increases" in the number of shark attacks whenever a string of bites occur close together (typically in the summer when more people are in the water), and I can't see a way around such inevitable hype.