A tissue sample from a Hector’s dolphin, spotted off the coast of Thames-Coromandel, has helped scientists understand more about the species and confirmed where the dolphins originated. In October 2023, the Department of Conservation (DOC) was notified about the sighting of an adult female Hector’s dolphin and a juvenile in the Firth of Thames near Te Kouma.
This sighting was unusual and rare for the west coast of Coromandel, leading the DOC to encourage the public to report similar sightings. Initially, DOC marine scientists believed that the dolphins could be from the Hector’s population on the South Island’s east coast, which was later confirmed by the tissue sample analysis.
Kristina Hillock, DOC Marine Technical Advisor, explained that obtaining a tissue sample from a dolphin involves getting close to the animal using a special dart gun. The dart gun collects a small piece of flesh, about the size of a fingernail, which is then sent for DNA analysis.
This was the first time a sample was obtained from a Hector’s dolphin in this area, which is crucial for understanding the species. Confirming that these dolphins originated from the South Island population helps scientists understand more about the species’ distribution.
Hillock added that there are usually a couple of sightings of Hector’s dolphins around the east coast of the Coromandel Peninsula each year. The DOC continues to encourage the public to report sightings of Hector’s dolphins. People can report sightings using a special online form on the DOC website or by calling a hotline. When reporting, people should provide as much information as possible, including the date, time, location, number of dolphins, and their estimated size. Photos and videos are also very helpful.
Reports of dead Hector’s or Māui dolphins are also useful. If the animals can be retrieved shortly after their death, it can help the DOC and other marine scientists learn more about the species.
