Wednesday, December 14, 2016

Wildlife Wednesday - Sharks

Just a timid black-tip reef shark
Over the last few years, particularly in WA and the north coast of NSW, there have been a higher than usual number of shark attacks. It's caused quite a lot of rather hostile discussions and a lot of media coverage.

Only a few of the victims of these attacks have died, which to me indicates curious sharks rather than vicious man-eaters, especially with Great White Sharks, those responsible for many of the attacks.

When I was a kid, a friend of my father's was killed by a Great White. We heard about it on the radio in our kitchen one morning when having breakfast. This chap had a very unusual name, so there was no mistaking the victim. We were stunned, mostly because he'd visited not long before and given us health products and not chocolates, and we'd complained - which now made us all feel guilty. The vivid images in my mind when I heard about his attack, were nothing compared to an eyewitness account that I overhead later. When a Great White is after a feed, you don't get away - or at least Dad's colleague didn't. All they recovered was some wetsuit material.

Random attacks have always occurred - we're prey in the predator's ocean after all. But these higher number of curiosity attacks have me puzzling. I hope that there are people doing some big picture thinking on this issue.

For shark behaviour to change, or to have seemingly changed, something must have changed to cause it. So I've been puzzling over a few things that may have lead to these changed patterns:
  • Are there more surfers in the water, thus more opportunity for attacks?
  • Are the surfers/swimmers moving into areas that haven't typically been used, so young/juvenile sharks aren't used to these targets on the surface?
  • Has something happened to the young/juvenile shark's usual territory to make them move out?
  • Have fish stocks depleted so sharks are looking in different areas for food?
  • Has water temperatures/currents changed, thus changing shark movements?
  • Have shark numbers risen?
  • Have sharks lost their usual habitat, or has the area shrunk? 
  • Have board shapes/colours changed mush recently? Are they more attractive to sharks?
  • Has fish behaviour changed, affecting shark behaviour?

I know on social media, there's been a huge increase in drone photography and footage, and many people are shocked at the number of sharks sighted, the numbers of bait balls, the proximity of sharks to the shore. I'm not sure that these are indicative of any oceanic changes. I think a lot of this is just that people have never seen these phenomena for themselves before, and so they're startled to see it. They share it, causing a heap of people who may never have seen this all to panic. Bail balls, sharks close to shore, dolphins herding fish, are all things that you can see from shore, if you know what to look for and spend any time looking. I know people who do plane shark spotting and they don't think numbers on the south coast are much different - but I think people's access to seeing this has hugely increased.

But photos and social media aren't what I'm thinking about for WA and northern NSW. I'm thinking more of a scientific approach where a whole heap of aspects are looked at and a big picture is created to see if we can work out why these changes are occuring - or possible reasons for the changes.

I don't think there will be one answer. I think it'll be a multi-faceted answer. But if we had some idea of what had changed, we might be able to find some way of minimising risk, without using bandaid solutions like drum lines and shark nets.

Just my two bob's worth!


  1. I would like to see you photograph the timid black-tip reef shark with a Christmas beetle. Then I will pay attention!

    1. So many demands :) At least you didn't want a shark having sex with a Christmas beetle, I should be grateful!!

      Cate xo