Dugongs are closely related to manatees, and both are distantly related to elephants – surprising but true! They can grow up to three metres long and weigh as much as 400 kilograms. Despite their size they are extremely gentle, spending most of their time slowly drifting across seagrass beds, munching away. They can live for 70 years or more.
A dugong eats up to 40 kilograms of seagrass every day. Seagrass meadows are underwater fields of grass-like plants that grow in shallow sunlit water. These meadows are nurseries for fish, hiding places for sea horses, and important feeding grounds for turtles as well as dugongs. When dugongs eat, they sometimes pull up the whole plant including the roots, which actually helps new seagrass grow by aerating the sediment.
Sailors from long ago sometimes called dugongs 'mermaids' when they glimpsed them at the surface in low light. A dugong's rounded shape, flippers and the way it holds its body upright to look around may have sparked those legends. It is a charming thought that the famous mermaid stories might have started with a dugong taking a breath of air.
Dugongs are vulnerable to boat traffic because they swim slowly and spend time near the surface. In Eritrea, protected marine areas help keep boats away from the best seagrass zones, giving dugongs space to feed and raise their young, which are called calves.