Sydney2009. The beaches were hit by a spate of shark attacks. Maneaters explores the reasons for this escalation in this documentary. Shark attacks are still very rare, but the number is rising and scientists are asking why? Is it that swimmer numbers have increased massively or perhaps shark numbers; or are changes in the climate changing shark behaviour? Shark expert Ralph Collier describes how shark attacks have also changed on North American coasts – leading him to believe that shark behaviour is altering.