Sherrie Chambers is a fish biologist, shark wrangler, Ph.D. candidate, and lover of anything with fins. She studies the behavior and cognition of Port Jackson sharks at Macquarie University in Sydney. Check out their website for more information.
If the thought of encountering a shark in the wild conjures up images of sinister shadows lurking beneath the surface of the ocean, sharp teeth tearing through human flesh, and mindless killing machines patrolling the waves in search of their next victim, you’re not alone.
Since Jaws hit our screens in 1975, sharks have become the fish that everyone loves to hate, and are usually portrayed in the media as fearsome creatures that swim around the ocean with a taste for blood, hell-bent on attacking humans.
Unfortunately, Discovery Channel’s Shark Week programming does little to dispel this myth. Whilst there are some great documentaries on the biology and ecology of various shark species (a few featuring my friends and colleagues!), much of the language used by the media when talking about sharks is sensationalist, making them seem scary or exciting, and is designed to increase viewership and gain ratings. Sadly, this does little to help the reputation of these misunderstood animals.
That’s not to say you shouldn’t enjoy watching Shark Week (I certainly will), but what if I told you that sharks can be social creatures, with individual behaviours and personalities, and that they are capable of complex thought processes including the ability to adapt and learn? Would it change your perception of them?
Shark researchers around the world have accepted the challenge of uncovering this secret life of sharks, and are working to gain a better understanding of what makes them tick.
Anyone who has spent some time with sharks knows that there are behavioural differences between species, for example oceanic whitetips are known for their confidence, juvenile whale sharks are often playful and inquisitive, whilst blacktip reef sharks can be quite timid.
However, just like humans, not all sharks within the same species act in the same way. Each individual animal will respond differently to a given situation, and when their reaction to a stimulus is consistent over time, we can say this is a measure of their personality. The study of animal personality is relatively new, although animals from over 60 different species, from dogs to birds and even octopuses, have now been shown to have personalities – and sharks are on the list.
A recent study on wild lemon sharks in The Bahamas has shown that when placed in a novel environment, some individuals exhibit bold, exploratory behaviour such as fast-paced swimming around the enclosure, whilst others are shyer and more tentative when investigating their new setting. Similarly, in an Australian study on captive Port Jackson sharks, individuals took different amounts of time to emerge from a known area of shelter into an unknown arena, suggesting that some individuals are braver than others.
Whilst some sharks are lone rangers and like to swim around the ocean solo, others prefer to hang out in groups and can have complex social networks made up of interactions between many individuals. Social network analysis of blacktip reef sharks and Port Jackson sharks has shown that there are usually a few ‘popular’ individuals (the social butterflies) that interact frequently with each other, and other sharks that are more peripheral to the group. Meanwhile, small-spotted catsharks exhibit different social personalities, where some individuals seem to always enjoy hanging out with their mates and others prefer to just keep to themselves.
Understanding personality and sociality in sharks is really important because these animals are capable of shaping our ocean ecosystems. As top predators, where a shark chooses to live and what it chooses to eat can greatly affect the abundance of other sea life in the area. If sharks disappear, the oceans would become overrun with mid-level predatory fish, which would consume all the herbivorous fish, and with nobody around to mow the lawn, reefs would become overwhelmed with algae growth, limiting coral survival. This could result in total ecosystem collapse!
So look carefully as you’re watching the programs this Shark Week – there’s more than meets the eye when it comes to our fast, finned friends. Can you spot the shy sharks, or the social ones?
For some intelligent and witty sharky commentary on all things Shark Week, check out this list of shark scientists to follow on Twitter, and for more information about these magnificent animals, head on over to The Fins United Initiative.