21 July 2009

Harbour Hector’s identity confirmed

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Photo: Dianne Proctor

A rare dolphin residing in Wellington Harbour has been confirmed as a male Hector’s dolphin.

Sporting the distinctive rounded dorsal fin which is a characteristic of Hector’s dolphins, he was nicknamed ‘Harbour Hector’ by locals, who have been reporting sightings of him to the Department of Conservation since January.

Keen to find out if the dolphin was a member of the even rarer sub-species of Hector’s dolphin, the Maui dolphin, DOC sent its marine mammal expert Nadine Bott out into the harbour, with the biopsy tool she uses to take tissue samples from humpback whales during DOC’s annual Cook Strait Whale Survey.

“This little guy has been elusive but we were able to take a biopsy sample, which has confirmed that he is from the South Island population of Hector’s, of which there are only around 7000 in existence.”

Taking a biopsy sample involves firing a small light-weight dart that hits the dolphin, bounces off and floats, retaining a small bit of tissue sample on the tip.

“It’s important that we take these samples to help us understand these vulnerable species better. It’s a safe technique for identifying marine mammals and doesn’t cause them any harm,” Ms Bott said.

The Hector’s dolphin is one of the smallest, rarest dolphins in the world, and the Maui dolphin is even rarer, with only around 110 living along the North Island’s west coast.

While this is the first live Hector’s dolphin ever recorded in Wellington Harbour, New Zealand has an interesting history of wild solitary dolphin visits. More famous examples include: Pelorus Jack a Risso’s dolphin known for escorting boats in the Cook Strait in the late 1800s; Opo, the Bottlenose dolphin in the Hokianga harbour in the 1950s, and more recently Moko the Bottlenose dolphin that has been visiting the Mahia peninsula since 2007.

While DOC hasn’t received any reports of sightings of ‘Harbour Hector’ since May, if you are lucky enough to spot him or any other marine mammals it is important to follow these simple rules:

On shore
• Do not disturb, harass or make loud noises near marine mammals.
• Do not feed or throw any rubbish near them
• Avoid sudden or repeated changes in speed or direction of any vessel or aircraft near a marine mammal.
• There should be no more than three vessels and/or aircraft within 300 metres of any marine mammal.

At sea
• Ensure that you travel no faster than idle or ‘no wake’ speed within 300 metres of any marine mammal.
• Approach whales and dolphins from behind and to the side.
• Do not circle them, obstruct their path or cut through any group.
• Idle slowly away. Speed may be gradually increased to out-distance dolphins and should not exceed 10 knots within 300 metres of any dolphin.

In the air
• Aircraft should maintain a horizontal distance of greater than 150 metres when flying near any marine mammal.
• Avoid flying or imposing a shadow directly over a marine mammal either at sea or on shore.

Take care with set nets
• Stay with your net at all times.
• Don’t net if dolphins, seals or diving birds are nearby.
• REMEMBER set nets catch more than fish.

A guide for responsible set netting can be obtained from your local Ministry of Fisheries office, or visit www.fish.govt.nz

All seals, dolphins, whales and porpoises are fully protected under the Marine Mammals Protection Act 1978. Offences carry penalties of up to six months imprisonment or fines up to $250,000 and further fines of up to $10,000 for every marine mammal in respect of which the offence is committed.

The rules are outlined in a brochure entitled Sharing our coasts with marine mammals which can be obtained from DOC offices or downloaded from the marine mammals section of the DOC website: www.doc.govt.nz>conservation>native animals>marine mammals

Refer to the Marine Mammals Protection Regulations 1992 for a complete list of conditions prescribing behaviour around marine mammals. Visit: www.legislation.govt.nz.

What to do if you see a Hector’s or Maui’s dolphin in the North Island
Report sightings of Hector’s or Maui’s dolphins to DOC, preferably as soon as possible, by calling the 0800 DOCHOT line (0800 36 24 68). DOC needs to know the date, time and location of the sighting, the number of dolphins, whether there were any calves, and any other observations regarding their behaviour. If possible, take a photograph (from a camera or mobile phone) of the dolphins with a land feature in the background and a record of the GPS position of the sighting.

Further Information:
Hector’s dolphins have distinctive grey, white and black markings and a short snout. They are the only New Zealand dolphins with a rounded black dorsal fin. Dolphins are generally found close to shore travelling alone, or in groups or pods of several dolphins. They’re often seen in water less than 20 metres deep, but may also range further offshore. Females can be up to 1.7 meters long and weigh between 40-60 kilograms. Males are slightly smaller and lighter than females.
For more information about Hector’s dolphins, the threats they face and what you can do to help, visit the DOC website:
http://www.doc.govt.nz/conservation/native-animals/marine-mammals/dolphins/hectors-dolphin/

ENDS

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