It really was the stuff of nightmares. A Swiss tourist, who was swimming with dolphins off the NSW coast, was suddenly mauled by a three-metre bull shark. 

The 25-year-old died from her injuries, despite her heroic boyfriend, an exchange student also from Switzerland, fighting off the shark and carrying her to shore.

Today, environment and climate reporter Caitlin Fitzsimmons, on why the number of people killed by sharks in Australia is rising.