Warming ocean temperatures mean sharks are spending more time in high-population areas, yet shark net data shows no significant changes in numbersFollow our Australia news live blog for latest updatesGet our breaking news email, free app or daily news podcastRob Harcourt is heading back from a “beautiful surf” at Bondi on a warm and sunny winter’s morning in Sydney.But for him and many of his surfing mates, the compelling pull of the city’s world famous surf breaks has been neutered by tragedy,