Dolphin Days

#Dolphins

Around 30 species of whales and dolphins are found on the Great Barrier Reef. And there’s nothing fishy about that because both dolphins and whales are warm blooded, air breathing marine mammals, not fish.

The Bottlenose dolphin is one of the most commonly seen species on the Reef. These social creatures tend frequently accompany tour boats, surfacing and playing in the wake of the ship and sometimes spectacularly leaping out of the water. They live in pods that can range from 10 - 1000 dolphins and hunt in groups, using geo-location to locate their food. Like all other mammals, they breathe oxygen to survive. They must surface every few minutes, especially when in a high speed chase. 

Other dolphins often spotted on the Reef include the Spinner dolphin, aptly named for its tendency to leap and spin out of the water, the Indo-Pacific humpback dolphin, Australian humpback dolphin, Australian snubfin dolphin, and pan-tropical spotted dolphin.

#Dolphin data

  • Making a meal of it

With a diet that includes small fish, squid, crab, and prawns, dolphins are renowned for their teamwork in rounding up prey much like herding farm animals.

  • Smart sounds

In order to locate their food, dolphins use a form of “natural sonar” based on echoes, called echo-location. Using this, dolphins can determine both the location and distance of their potential dinner. 

  • Sleeping / not sleeping

Dolphins literally sleep with one eye open! Scientists have found that dolphins only allow one half of their brains to sleep at a time. That's because, unlike humans, they need to be conscious to breathe. When the right half of their brain is sleeping, their left eye closes, and vice versa.

  • Protected species

While all species of dolphin are protected in the Great Barrier Reef Marine Park, two species are considered high priority for management. 

Numbers of the Australian snubfin dolphin and the Indo-Pacific humpback dolphin throughout the inshore waters of northern Australia may be in decline. Because these dolphins live in areas where there are high levels of human activity, they may be vulnerable to impacts from activities such as boating, netting and poor water quality.