Stirling Peverell, Shark Researcher

11. How does your research affect the sharks- positive and negative aspects?
I believe there aren’t any negative aspects regarding sharks. The shark fear factor as displayed through the media is misleading and good for selling newspapers. Our lack of knowledge has lead to one shark species, the grey nurse, to be fished to near extinction given the belief they were man-eaters. Fortunately the sharks I research aren’t man eaters.

12. What is the greatest distance any of your sharks travelled? I have had one freshwater sawfish travel from the freshwater of one river system along the coastal foreshore and up another river to be caught in the freshwater again. The distance traveled was approximately 200km in 2.5 months. What is interesting is that this species is only meant to like freshwater not marine. 13. What is the fastest shark you have tracked? The sawfish I have tracked have only been slow swimmers in comparison to some of our pelagic shark species such as the tiger shark.

Tiger shark Image © Wet Paper Publications

14. Do sharks ever stop moving?
Sawfish are interesting in that they will lie along the current line propping themselves up on their fins to receive oxygenated water. Therefore they don’t have to continually move.

15. Do sharks really smell blood in the water? How do they find their food?
Sawfish are not attracted to blood. They are attracted to the smell of fish and bait seeing they are a scavenger of food as well as an active hunter. Sensory pores on the rostrum help them locate food items whether it is live or dead prey.

16. What temperature ranges do your sharks live in?
Sawfish can live in water temperatures ranging from 18 degrees to 36 degrees Celsius.

17. Why do they cross into different temperature zones?
Sawfish do not like cold water and will seek out the warmest water within their home range. This would require them to swim through different habitats until they find the one best suiting them.

18. Do they migrate like whales?
Not enough information is known about the migratory patterns of sawfish, if indeed they have one.

19. Do sharks sleep?
Sharks shut down many of their senses when relaxing. This is a form of sleep however they sleep different to humans and animals.

20. What can we learn from studying sharks?
There is so much we don’t know about sharks given that there are approximately 296 species of sharks in Australian waters and only a handful have ever been studied fully. The most important issue regarding shark research is; what impact are humans having on global, national, regional and local shark populations. Sharks are generally an apex predator that is they are on the top of the food chain. They are therefore regarded as good indicator species when assessing the health of biodiversity. A healthy biodiversity would support healthy populations of sharks and other marine species.