Rare Hector's or Māui Dolphin Sighting in Northland Prompts DNA Collection Effort

Marine science personnel confirmed the presence of a solitary Hector's or Māui dolphin in New Zealand's Bay of Islands during the final weeks of December 2025. Dolphin researcher Jochen Zaeschmar of the Far Out Ocean Research Collective first documented the animal, prompting the Department of Conservation (DOC) to swiftly authorize the collection of a DNA sample for definitive subspecies classification. This event is significant as it marks only the second verified sighting of a Hector's dolphin recorded in the Northland region over the past century.

Both the Hector's dolphin and its Māui subspecies are endemic to New Zealand's coastal waters, sharing physical characteristics such as a small stature and a distinctive, rounded dorsal fin. The Māui dolphin, a distinct subspecies, is currently listed as Critically Endangered on the IUCN Red List and Nationally Critical under the New Zealand Threat Classification System. Genetic monitoring conducted in 2020 and 2021 estimated the adult Māui dolphin population within the survey area to be approximately 54 individuals, a figure some analyses suggest may be lower following subsequent mortalities.

Geographically, the two types maintain separate distributions. Hector's dolphins are primarily concentrated in various sub-populations around the South Island and are classified as nationally vulnerable, though they are only occasionally observed further north. Conversely, the Māui dolphin population is almost exclusively restricted to the west coast of the North Island, specifically the area between Taranaki and the Kaipara Harbour entrance. The rarity of this Northland observation is emphasized by historical data, as previous confirmed sightings of Hector's dolphins on the Northland east coast were separated by a hundred years.

The Department of Conservation has directed the public to immediately report any sightings of these rare cetaceans via the emergency hotline, 0800 DOC HOT (0800 362 468), or by using the SeaSpotter application. DOC Marine Species Senior Advisor Kristina Hillock stressed the importance of observers maintaining a respectful distance to mitigate the risk of dangerous interactions, as both species are highly susceptible to fatal collisions with watercraft. The DNA analysis from the collected sample is anticipated to provide crucial genetic data, enhancing scientific understanding of the species' contemporary geographical spread and movement patterns.

This ongoing monitoring, which includes genetic mark-recapture methods conducted every five years, is vital for informing the Threat Management Plan (TMP) jointly managed by DOC and Fisheries New Zealand. The TMP addresses human-induced threats, including bycatch from commercial fisheries, and the data gathered from public sightings and targeted surveys directly influences the implementation of critical protection measures for these endemic New Zealand marine mammals.