Hector's Dolphin - Cephalorhynchus hectori

New Zealand is home to only two endemic mammal species, the short tailed bat, and the Hector's dolphin.

The population of Hector's dolphins, due to water levels rising and ice ages, has divided into two species. The north island group called "Maui's dolphin" and the south island holds the name "Hector's".

The Maui's dolphin is the rarest marine mammal in the world with only 55 animals over one year of age estimated for the whole population. And the Hector's only grows to 1.5 metres in length and is one of the world's smallest marine mammals, but has a larger population, estimated at 7,270.

Maui's dolphins are only found on the west coast of the North Island, and Hector's have been seen regularly on the north west coast of the South Island and amongst Banks Peninsula on the east coast of the South Island.

I have been extremely lucky to have grown up in Lyttelton Harbour, catching the ferry to and from my home town. All my life I've been aware of the Hector's dolphins, as they regularly come right into the harbour and swim around the boats.

Black Cat Cruises takes trips out Akaroa and Lyttelton harbours to swim with and view the dolphins, encouraging the conservation of these animals and teaching tourists and locals about what is around them.

These dolphins are the only dolphins found in New Zealand with a rounded dorsal find which makes them easier to spot.

Males are smaller and lighter than females.

They life for a maximum of 20 years.

Females reproduce from nine years of age, and even then only have one calf every two to three years. Generally a female dolphin will give birth to four calves in their lifetime, keeping population sizes extremely low.

Meals for the Hector's dolphins includes Ahuru, Yellow-Eyed Mullet, Kahawai, Arrow Squid, Herring and Red Cod. These dolphins are also a snack for many shark species and Orca Whales.

Like all other dolphin species, Hectors and Maui dolphins use echolocation, but not constantly. Which is thought to be why they get caught in fishing nets so often.

The biggest threat to Hector's dolphins is set-nets or gill-nets. These nets are made of fine netting which is un-detectable for the dolphins. They get caught in the nets and are stuck underwater and are unable to reach the surface for oxygen, and drown.

It has been estimated that these nets kill 110-150 dolphins each year, and as you read earlier, the small numbers in the populations can no longer afford to lose that many.

There have been two Marine Protected Areas created for the Hector's dolphins, the first in and around Banks Peninsula in 1988, and the second on the West Coast of the north island in 2003. Though the numbers are still expected to drop as these areas don't reach as far offshore as the dolphins do.

While Helen Clark was the prime minister a few more restrictions were made to protect the dolphins and reduce set-nets, but it appears that since then no further changes have made. These changes are desperately needed to reduce chance of extinction for these little dolphins.

Please do your bit!