Overall winner and underwater worlds winner: Bubble-jetting emperors by Paul Nicklen (Canada) This was the image Paul had been so hoping to get: a sunlit mass of emperor penguins charging upwards, leaving in their wake a crisscross of bubble trails. The location was near the emperor colony at the edge of the frozen area of the Ross Sea, Antarctica. It was into the only likely exit hole that he lowered himself. He then had to wait for the return of the penguins, crops full of icefish for their chicks. Paul locked his legs under the lip of the ice so he could remain motionless, breathing through a snorkel so as not to spook the penguins when they arrived. Then it came: a blast of birds from the depths. They were so fast that, with frozen fingers, framing and focus had to be instinctivePhotograph: Paul Nicklen (Canada)/2012 Veolia Environnement Wildlife Photographer of the Year