Here's the four shark species you should be most concerned about
Wednesday, August 13, 2014, 5:10 PM - While we've dispelled the myths about sharks being mindless killing machines that are only out to devour all humans, there are still somewhere between around 60 to 80 attacks every year. So, while you're swimming, there are a few shark species that you really need to beware of.
Before we get to the 'usual suspects' line-up, it's worth it to talk about the types of attacks that happen - specifically the unprovoked attacks, where the shark initiates contact. The first and most common is the 'hit and run' attack. This is the case of 'mistaken identity' that is responsible for most shark attacks, where the shark delivers a quick bite, usually somewhere along the person's lower leg or foot, realizes the person is not actually food, and quickly retreats, leaving a minor wound behind. Second is the 'bump & bite' attack, which is a more directed and concentrated assault, starting with circling and bumping and then escalating into one or more attacks that involve several powerful and sustained bites. Third is the 'sneak' attack, where the shark really comes out of nowhere (from the perspective of the victim) to deliver a vicious attack. While far less common than the 'mistaken identity' attacks, these other two are definitely the ones that inspired many scenes in the Jaws movie franchise, and they are responsible for most of the fatalities.
DID YOU KNOW?: The study of sharks (and rays) is known as elasmobranchology, which is a branch of ichthyology - the study of fish.
Now for the suspects:
Great White Sharks
This one really goes without saying, but it's going to be said anyway. Whether it's actually true, or simply the result of this being the most well-known species (thanks to Jaws), Great Whites are the #1 shark implicated in both sneak attacks and bump & bite attacks. Although the whale shark and the basking shark can grow to be much larger than the white shark, both of those species are 'filter feeders' - eating large quantities of plankton as they swim about. Averaging at 4-5 metres long and weighing in at over a ton (but with specimens up to 6.4 metres long and over 3 tons), white sharks are the largest species that is a threat to humans.
Slightly less well-known, but still common enough, tiger sharks have similar colour pattern to white sharks, but with a distinctive spotting or striping pattern along their back. They average around 3-4 metres long, and up to over 600 kilograms, and are known for having the widest range of diet of predatory sharks, and is even a bit of a 'garbage eater' - with things like tires and license plates showing up in their stomach.
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Although not quite a fierce-looking as the white shark or even the tiger shark, bull sharks average around 2.0-2.5 metres long, and mainly swim in shallow waters, where they're most likely to come into contact with humans.
A shallow water species, shown here with its almost ubiquitous school of pilot fish, this one looks to have a bit more of a 'classic shark profile' except its dorsal fin tends to be more rounded at the tip. They're relatively small, averaging at a little under 2 metres long, but they're known to be quite aggressive.
Although some tips for avoiding shark attacks are fairly obvious, such as don't go into the water if you're bleeding, avoid waters where sharks are swimming, etc, there are a few others that should be mentioned:
- Don't swim alone, as sharks are more likely to attack lone targets than ones in groups
- Swim during the day, since most sharks are nocturnal, and most attacks happen at dusk, at night or dawn
- Don't wear shiny jewelry in the water, as it may look like sun glinting off fish scales
- Don't splash around in the water and don't let pets in the water, as erratic movements attract sharks
CELEBRATE SHARKS!: Come back every day this week for more stories about the awesome nature of sharks. If you have your own questions about these incredible creatures, leave them in the comments section below and we'll answer them later in the week!
(H/T to George Burgess from the Florida Museum of Natural History, for his great info on sharks and shark species.