Bottlenose dolphins tend to hang out in large pods, but usually in groups of 50 or 60. Now, researchers studying Indo-Pacific bottlenose dolphins off the coast of South Africa have found that populations there have skyrocketed. In 2008 there was an average of 18 dolphins per group but by 2016 there were around 76 dolphins in a group. The growth of the pods remains a mystery. Researchers speculate that the dolphins may be gathering in the shallows in large groups for protection against sharks. White sharks are known to attack dolphins and there are many in the area.