New data released today by the Department of Conservation (DOC) has revealed the number of marine mammal species classified as ‘Threatened or At Risk’ has increased from 10 in 2019 to 14 as of today.
The sperm whale, pygmy blue whale, southern right whale dolphin, goose-beaked whale, and pygmy sperm whale have been added to the Threatened or At Risk list, while leopard seals have moved from ‘at-risk’ to ‘migrant’.
A ‘Threatened’ species status is given to animals in serious trouble, the Department said. New Zealand has the highest proportion of threatened indigenous species in the world – more than 4,000 native species are currently threatened or at risk of extinction.
Panel lead and DOC Senior Science Advisor, Dr Dave Lundquist says several species have shifted to a more threatened conservation status. This includes sperm whales, which were moved from ‘Data Deficient’ to ‘At Risk – Declining’.
“Research published by the University of Otago in 2022 shows a long-term decline in the number of sperm whales seen off Kaikōura during summer,” says Dr Lundquist.
“We don’t yet know if this reflects a broader drop in sperm whale numbers across New Zealand, but the panel has taken a precautionary approach and assumed it could be.”
Thanks to improved population data, eight other marine mammal species previously considered Data Deficient now have updated conservation statuses, said Dr Lundquist. This includes pygmy blue whales, now listed as ‘Threatened – Nationally Vulnerable’.
The New Zealand sea lion has also been moved to a higher risk category – from ‘Nationally Vulnerable’ to ‘Threatened – Nationally Endangered’. DOC says this is due to a smaller estimated number of breeding adults and a faster rate of population decline than previously thought.
“Estimates suggest sea lion numbers could decline by 30–70% over the next 30 years, which is about three generations. Multiple human-caused threats are likely to be contributing to this decline,” says Dr Lundquist.
Bottlenose dolphins are the only species whose status has improved – from ‘Threatened – Nationally Endangered’ to ‘Threatened – Nationally Vulnerable’. However, Dr Lundquist says this change is due to better information, not an actual increase in numbers.
“We previously estimated fewer than 1000 coastal bottlenose dolphins in New Zealand, plus an unknown number of oceanic ones. We now know there are over 1,000 oceanic dolphins, which improved the overall status. But coastal populations are still at risk and depend on local conservation efforts to survive.”
Dr Lundquist says the positive takeaway is that when people act to reduce threats and protect nature, it makes a real difference.
“This information is valuable for everyone involved in marine mammal conservation – including iwi, community groups, businesses, fishers, councils and government,” he said.
“When we understand the conservation status of marine mammals, we’re all better equipped to make informed decisions to help protect them and their habitats.”
The conservation status of 57 marine mammal types found in New Zealand waters was reviewed by an independent panel of national and international experts. They used the New Zealand Threat Classification System (NZTCS) – a tool that assesses the extinction risk of native species.
NZTCS assessments are reviewed roughly every five years and are based on factors such as population size, trends, and distribution. DOC uses these results to prioritise conservation work, guide resource allocation, and shape policy decisions. The assessments also support collaboration with iwi, researchers, community groups, and others working to protect native species.
Visit the New Zealand Threat Classification System’s website for the latest marine mammal conservation status data and background notes: https://nztcs.org.nz/reports/1165.
