"Huge Pressure" on Sharks

I've been here for two weeks and only once to the beach. Here's why:
1. On Sunday, a woman swimming in waist-deep water was attached by three sharks. According to rescuers, her arms were missing by the time they reached her. Yes, a rescuer went to grab her arms to pull her to safety but found she had no arms to grab. This happened on a NSW beach that had been protected for the last 40-some years by shark nets. She was pronounced dead before they could get her to the hospital.
2. Also on Sunday, a girl was attacked by a jellyfish at another NSW beach. As she got out of the water, she collapsed and died from shock.
3. Yesterday afternooon, all swimmers at Tamarama and Bronte Beaches (here in Sydney) were called out of the water due to shark sightings.

Until Sunday, there had not been a fatal shark attack on a New South Wales beach in 44 years. And then I arrive and there are sharks (and a jellyfish) everywhere. Of course, there is now a lot of debate about what to do with this perceived increase in shark activity. But this morning's Sydney Morning Herald quoted a local marine biologist saying that "There's huge pressure on sharks these days. If anything you would expect that sightings would be decreasing."

Mmm, OK. So what kind of pressure, exactly, would that be? Regardless, I'll be swimming tomorrow at Andrew Boy Charleton Pool in downtown Sydney.