New thermal technology could help protect and save the critically endangered Māui and Hector's dolphins.
A new study shows the dorsal fin on both species shows up distinctly on thermal imaging. The Māui and Hector's dolphins are the only dolphins in New Zealand with a rounded black dorsal fin.
Christine Rose of the Dolphin Defenders says it could be a crucial aid to protecting the animals.
"If it's at night or there are sea conditions that mean that it's hard to spot the dolphins, this technology will enable the distinctive pattern to be determined," she said.
She says the thermal imaging cameras could be deployed on board all commercial ships in order to reduce by-catch deaths.
The waters occupied by Māui dolphin are shared with recreational and commercial fishers - they like harbours and tend to stay within 30km of the shoreline. They are often seen at the mouths of the Manukau and Kaipara harbours, and others along the west coast of the North Island.
The study was led by Martin Stanley of Ocean Life Survey. His previous work with thermal imaging showed the technology could be used to detect whales from a distance, allowing ships to avoid collision with the whales.
About the Māui dolphin
- The dolphin is known as popoto in Māori. The name 'Māui' comes from Te-Ika-a-Māui - the name for the North Island, which is the habitat of the Māui dolphin.
- The Māui dolphin are a sub-species of the Hector's dolphin.
- It's the smallest known dolphin in the world.
- It's one of the rarest dolphins, with estimates there may be less than 100 in existence now.
- The Māui dolphin is found living in and around the coastline near the shore of North Island, in water less than 20m deep.
- It's identified by its small black rounded dorsal fin.
- Estimates say they have a lifespan of around 20 years.