If what the National Geographic and numerous history books state is true, it is this writer’s opinion that ancient mariners either really missed their girlfriends a lot or had the worst eyesight ever to have mistaken the dugong for mermaids.
Classified as Vulnerable to Extinction by the IUCN Red List, Dugongs (Dugong dugon) are herbivores that graze on sea grass. Closely related to the elephant, dugongs actually do grow tusks. However, only the tusks of male dugongs ever break the skin to become visible. Dugongs also closely resemble another species of marine mammal: the manatee. One way to distinguish these two very similar-looking animals is the tail. Dugongs possess fluked tails which look much more like the tails of a whale or dolphin as compared to manatees, which have paddle-shaped tails. Herds of these creatures have been observed, sometimes numbering into the hundreds, although dugongs normally are found in mother-offspring pairs.
Along with dugongs, the Great Barrier Reef is host to a variety of whales and dolphins, including the humpback whale (Megaptera novaeangliae). These awe-inspiring creatures have the perhaps the largest appendages in the animal kingdom, with their flippers reaching up to five metres in length. The unique patterns on their tails can be used to identify individual whales, especially when they engage in the signature behaviour that has earned these whales their name. When diving to feed on plankton or small fish, humpback whales will dive and arch their backs (hence the name), causing their tails to surface high above the water. Returning to the surface, humpbacks may also breach, driving their 20-30 ton bodies clear out of the ocean in a spectacular display.
Another interesting aspect of humpback whale behaviour is the phenomenon of ‘escort whales’, as seen in this video here. Escort whales are male humpbacks that follow and aggressively defend any female that allows them to follow. Thought to be a form of courtship gesture, humpbacks are also known for their hauntingly beautiful whale songs.