Citizen scientists called on to help protect endangered dolphins in top of the south

Wednesday, 17 October 2018

Nelson populations of dolphins may be a threatened crucial link, but citizen science can help save it.

Gemma McGrath, a dolphin researcher and independent consultant, said a review of the Threat Management Plan for Hector's and Māui dolphin that was taking place this year was the perfect opportunity to get better protection for Te Tau Ihu (top of the south) dolphin populations.

'The top of the south is the most important area for Hector's and Māui dolphins, because it connects the east and the west coast of the South Island, and the North Island,' she said.

**Read more:

* Help study dolphins with free app

* Māui dolphin found dead in Te Akau

* Fisherman set nets where dolphins play

* Five dolphins die in nets in a month**

'Hector's dolphins, you may hear that there are 10,000 or 15,000, but when you understand how they are as a species you realise that that's not quite the full picture.'

The reality, McGrath said, is that the species tended to live in very small, localised territories, and not travel very far.

'That 10,000 or 15,000 is made up of little inshore communities that have a range of just 50 kilometres,' she said.

McGrath likened these communities or hapū to chain-links in a necklace, as each territory had a small overlap of a few kilometres where dolphins from each hapū could meet.

'For them to be healthy, the whole chain needs to be in place. Each population is important for adjacent genetic exchange. Each is a critical link.'

She said the only place where Hector's dolphins were really abundant was near Akaroa, despite historical records up until the 1970s describing them as a common sight around New Zealand.

Many areas known to be Hector's or Māui dolphin habitats have some form of protections in place to prevent dolphin by-catch in set-net fishing, however the Nelson Bays area was unprotected, which McGrath said was due to a lack of information about dolphins living in the area.

'I don't blame the fishermen; it's not their fault, it's just the way the system has been set up.'

The Threat Management Plan for marine mammals, being reviewed this year, was an opportunity to try to extend protections for the local dolphin populations. McGrath said there was a perfect opportunity for citizen scientists to help her efforts.

'That's why we started  the Hector's Dolphin Sightings app … you just open the app and it's got the date, time, and location automatically listed, you just add your sighting.'

She said data from the app, which has been up and running for about two years, could help DOC and policy-makers identify areas that needed protections.

'The Government is taking this data into the next threat level assessment, so we're encouraging people if they see any dolphin to add it in.'