A new study has confirmed a whale research method has negligible impact on the majestic marine mammals - just as an exciting whale sighting off the Otago coast emphasises why this work matters.
DOC has received a report of a group of southern right whales/tohorā around the mouth of Otago Harbour. This is an unusual and exciting sighting, as typically only individuals or mother and calf pairs are seen around mainland Aotearoa New Zealand – not a group of this size.
"Tohorā came close to extinction due to 19th-century whaling," says DOC Senior Science Advisor Dr Dave Lundquist.
"Seeing a group like this is a promising sign their population may be slowly recovering. It's moments like these that reinforce the value of long-term monitoring and science-led conservation."
At this time of year, tohorā are usually found around their breeding grounds in the subantarctic Maungahuka/Auckland and Motu Ihupuku/Campbell Islands. Sightings around mainland New Zealand are still relatively rare, and this week's sighting offers hope these taonga of the sea may be returning more frequently to our coastal waters
The newly published research, led by the University of Auckland with DOC's support, shows collecting small skin samples from tohorā using remote biopsy darts results in only minimal short-term behavioural impact. Of the more than 500 whales studied at Auckland Islands, 90 percent showed either no reaction or only a mild, brief response.
Published in Conservation Science and Practice, the study underpins a long-term monitoring programme essential for understanding how the tohorā population is recovering. The genetic and chemical information gathered has helped confirm New Zealand tohorā are a distinct population, track population growth, map the whales' feeding and migration patterns, and even estimate whale ages — insights that would otherwise be impossible to gather.
"At DOC, we need to focus our efforts where it matters most. We invest our time, money and energy guided by the best science, and with a clear understanding of the trade-offs and opportunities in front of us," says Dave.
"This research is a great example of that approach in action. It gives us confidence that scientists can continue collecting critical information about our recovering marine mammals, without compromising their wellbeing."
DOC is building new tools and systems to help assess the cost of conservation outcomes, identify the most effective actions, and prioritise the investments that will have the biggest impact. Long-term research like this strengthens those tools and supports transparent decisions about what work can be done, where others can help, and where choices must be made.
Senior author Associate Professor Emma Carroll from the University of Auckland says the findings should reassure both scientists and the public.
"We've shown remote biopsy sampling — when carried out carefully — is a low-impact way to get high-impact insights," she says. "It means we can monitor this population over time and respond to change, all without harming the whales."
The research was also supported Live Ocean, and the Royal Society Te Apārangi, and was undertaken in consultation with mana whenua connected to the subantarctic islands.
DOC reminds people to share the coast with whales respectfully. If you see southern right whales or other whales, please give them space and follow the Marine Mammal Protection Regulations. Report sightings using DOC's online form or the SeaSpotter app, including the number of whales, date and time, location (ideally with GPS), and direction of travel. Photos or video are very helpful for DOC — if they can be taken safely.
