Blacktip Reef Sharks
Although Koh Tao is famous for it's scuba diving, the local blacktip reef sharks are easiest to spot while snorkeling as they don't like the bubbles scuba divers produce. This makes visiting them both cheap and easy, with a short swim off shore at Shark Bay or Sai Daeng beach!
Every year in March the pregnant females swim close to shore to give live birth to their offspring. Generally this occurs around Thian Og Bay, Sai Daeng or Ao Leuk beach. The juvenile blacktip sharks are tiny, no bigger then your shoe and seeks out the shallow waters of the beach for protection against predators. On Koh Tao they have few threats, although Giant Groupers are known to feed on juvenile sharks. However they are far more likely to be fished out by humans or getting tangled up in trash.
As the sharks grow older they gradually leave the safety of the shallows so they may hunt. Although they mostly hunt small fish at this age, they gradually start seeking bigger and more varied pray, such as squid, octopus & shrimps.
Blacktip Reef Sharks are not aggressive and doesn't attack people. Humans are too big to be considered food and the sharks show caution towards snorkelers and divers. If you do want to have a close experience with them however, snorkel the areas where they frequent and try to stay motionless. Their inquisitive nature will often have them circling you to check you out!