Credit: Ryan Kempster
Credit: Ryan Kempster
For some, sharks invoke an image of a ruthless predator that terrifies beachgoers with their distinctive fin, courtesy of 1970s film Jaws.
But kids these days are probably more likely to have seen Finding Nemo and perceive sharks to be more like 'Bruce' - they're big and scary but they're good fish at heart who live by the pledge, "I am a good shark. I am not a mindless eating machine. If I want to change this image, I must first change myself - fish are friends, not food".
Sharks, whether animated or mechanical, seem to be designed to be big, scary and out to get you, but that is not the view of Ryan Kempster, marine biologist and PhD candidate from the University of Western Australia, who believes that real sharks are being misrepresented and in danger of becoming extinct as a result of human activity.
"My ultimate goal is to educate people about sharks, debunk a lot of the myths surrounding them and show that sharks aren't just mindless killing machines but instead an essential part of any healthy marine ecosystem," he says. "The media portrayal of sharks is often unjustified and I'm working to change that."
Kempster has set up 'Support Our Sharks', a shark conservation website designed to educate the public about the current plight of sharks and show how the real danger is for them not us.
He recently won the '3 Minute Thesis' competition for the university division with his presentation "Survival of the Stillest: Predator Avoidance Strategies of Shark Embryos" and will represent The University of Western Australia in the national division, pitting him against some of the best and brightest minds in Australia.
His presentation was based on research that adult sharks use electroreceptors to detect prey. As part of his PhD work, Kempster asked to what extent do young sharks, still in their eggs, use this electrosensory system to detect the presence of a predator? By stimulating the shark embryos with a weak electric field similar to those generated by larger predatory fish, Kempster found that the embryos reacted by 'playing dead' - that is, stopping their breathing and staying completely still. Which can weaken the embryos' own bioelectric field, making it a lot harder for the potential predator to locate the embryo. He also found that the strength of the electric field determines how long the embryo played dead for - the stronger the electric field, the longer they played dead.
Kempster has recently returned from a field study off the coast of Western Australia in which he mapped and analysed the electrosensory systems of a number of different shark species in a further attempt to gain more insight to how sharks behave. "My research can be used in many ways, but I think the most practical application is for the development of better electric field devices surfers and divers wear to ward off sharks," he says. In light of recent events in Western Australia, where a surfer died after receiving horrific injuries from a shark attack, the potential for his research is a worthy investment.
Kempster's lifelong dream was originally to become a veterinarian but after narrowly missing out on the course requirements that path was closed. After looking around, he became interested in marine biology and "absolutely fell in love with it," he says. And to all the budding marine biologists out there, he advises, "your best bet is to keep your options open. Don't be too specific because that will only end up limiting your future choices".