There are new calls to cull sharks in NSW after four surfers were attacked within 48 hours this week. But what is actually most effective at preventing attacks? Shark expert Dr Chris Pepin-Neff says more education and awareness is needed about the most dangerous times to go in the water. #shark #sharkattack #ocean #sydney #nsw | 7NEWS Australia

Shark attacks are rare but four of them this week has New South Wales in shock. It's left many asking how, and why, this happened. 7.30’s Jason Om reports. | 7.30