Māui dolphins were once a common sight at the Whanganui River mouth and researcher Gemma McGrath wants to talk to people who remember them.
"The first of the species collected way back were from Whanganui," she said.
She's giving a talk about the dolphins at Whanganui's Alexander Library from 1-2pm tomorrow.She's really hoping people will come with their own photos and stories.
She'll describe the dolphins, and said once people know what they are they see them more often.
Māui and Hector's dolphins may be just one species. They were once common right around New Zealand, especially its western coast, and they often interacted with people.
"We once had a very special relationship with them. It's been largely forgotten."
Since the 1970s set netting and trawling have all but wiped these little native dolphins out. They don't usually move far, and their small populations are getting more and more separated.
McGrath spent 10 years working for Whalewatch in Kaikoura, and noticed numbers dwindling.
Working toward a Masters degree, she's studying the dolphins. She's especially interested in talking to kaumātua to gain mātauranga Māori (Māori knowledge) and in finding out how the first Europeans interacted with dolphins.
She's also worked for conservation organisations such as WWF, and lobbied politicians.
And she runs the free Hector's Dolphin Sightings app.
On it people can log sightings of any marine mammal around New Zealand. They can upload photographs, and record the behaviour and numbers seen.
They can also look at other peoples' sightings. The app makes everything as easy as possible. It is scientifically robust, and has a Facebook page. McGrath is excited about what it's recording.
"It's getting more Māui dolphin sightings. We got one off Napier."
She lives in Colac Bay, near Riverton in Southland, and will be visiting Whanganui Regional Museum today,before her talk, to get information.
She can be contacted by emailing aotearoa.dolphin@gmail.com or calling 027 694 3533.