So when the island floods, groundwater flows through the porous rock, causing caves ... during the Ice Age. Many species couldn’t survive one deadly predator: humans. Many of the blue hole's ...

But during the last ice age when sea levels were much lower, the caves were the high-and-dry habitat for a completely different group of animals. On one dive into a blue hole on Great Abaco Island ...

Follow a fearless team of scientists as they venture into blue holes—underwater caves that formed during the last ice age, when sea level was nearly 400 feet below what it is today. These caves ...