Updated environmental indicators show indigenous marine and land species are struggling against extinction, and wetland area continues to be lost, Stats NZ says.
These latest figures come as New Zealand records one of the hottest Novembers on record, expected to have a serious impact on marine species but also, just as two new species of gecko have been discovered in the South Island.
Stats NZ's indicators "extinction threat to indigenous marine species" and "extinction threat to indigenous land species" show the population trends of particular indigenous marine and land species, and how close Aotearoa might be to losing them altogether.
"Environmental indicators are essential for building the bigger picture of what's happening in our environment," Stats NZ environmental reporting manager Angela Seaton says. "They help us track changes and support decision-making."
According to the indicators, 90 per cent of seabird species, 82 per cent of shorebird species, and 94 per cent of reptile species are either threatened with extinction or at risk of becoming threatened. In addition, the populations of many indigenous species are expected to decline.
Taonga species
The extinction threat to indigenous marine species also highlights marine taonga species – those of cultural significance to Māori – that are threatened with extinction. The partial list of marine taonga species was developed through research and consultation and complements data previously published on freshwater taonga species.
The extinction threat to indigenous freshwater species was released in June 2021.
Many of New Zealand's indigenous marine species are found nowhere else in the world. This makes New Zealand a marine biodiversity hotspot. For example, New Zealand has the highest number of endemic seabirds in the world.
New Zealand's marine species and their ecosystems also provide food species (enabling fisheries and aquaculture) and support cultural opportunities (for example, tourism and fishing).
The report notes that indigenous marine taonga species hold considerable meaning to Māori identity through whakapapa, which obligates and guides kaitiakitanga priorities.
They perform an important role for Māori in understanding the mauri of an ecosystem. The presence, or lack, of indigenous marine species provides insight into biodiversity and the state of mahinga kai.
29 marine taonga threatened
For shorebird species, population trends show 29 per cent are predicted to decrease (five of 17); 18% are expected to increase (three of 17); and 53 per cent are not expected to change (nine of 17).
Stats NZ has identified 29 marine taonga species threatened with extinction, of which 18 have populations that are predicted to decrease; one has a population predicted to increase; and10 have populations that are not predicted to change.
The taonga species are toroa (five species), and one species each for hoiho, ihu koropuku, Kaikōura tītī, kawau, kōtuku, kūtai, maki, mangō taniwha, matuku moana, popoto, rāpoka, tāiko, tara, tara iti, taranui, tarapirohe, tarapuka, tawaki, terehu, tohorā, tutumairekurai, tūturiwhatu, Eastern rockhopper penguin and Pacific white tern.
Among the threats to marine species such as birds are rising water temperatures.
Last month New Zealand's coastal waters again warmed to reach "marine heatwave" conditions – raising the chances of another major ocean event and scorching days this summer.
Niwa meteorologists Ben Noll told Stuff water temperatures had ranged from 1.1C to 1.4C above average for November, with daily sea surface temperatures more than 3C above average around the western and northern North Island and eastern South Island over the last week.
Graph / Stats NZ
2017 heatwave
Marine heatwave conditions, classified when the sea temperature is above the 90th percentile for at least five days, have been observed in waters offshore of all regions of New Zealand.
That was comparable to the conditions observed in November 2017, which marked the beginning of a freakish and unprecedented marine heatwave around the country and in the Tasman Sea – and helped precipitate New Zealand's hottest ever summer.
Over that period, air temperatures over the country reached between 1.7C and 2.1C above average, while sea surfaces heated up to between 1.2C and 1.9C above average.
Marine heatwaves are becoming increasingly frequent in a warmer climate, with 963 marine heatwave days observed in the New Zealand region between 2010 and 2019 compared with 366 between 2000 and 2009.
Scientists also warn that marine heatwaves will grow longer and more intense under climate change and have severe impacts on ocean ecosystems and industries that rely on them.
In the 2017-18 event, glaciers melted as some pockets of ocean off the South Island's west coast warmed to 6C above average, while elsewhere, mussel beds suffered cascading losses.
More lizards
Meanwhile, a skink discovered in Southland's Mataura Range and a gecko from the Nelson Lakes are the newest additions to New Zealand's lizard line-up, Stuff has reported.
Genetic tests confirmed the two new lizard species from discoveries made during Department of Conservation surveys in South Island alpine areas last summer.
DoC lizard survey project leader Dr Jo Monks says the intensive surveys had resulted in discoveries in some of the country's least explored places.
"We're still in the 'age of discovery' for our lizards, and we're likely to find more as we continue our survey work this summer."
In the past 30 years, the number of known lizard species has increased nearly four-fold with new discoveries.
New Zealand now has 126 gecko and skink species found nowhere else in the world. They are unique and give birth to live young, unlike many lizards elsewhere that lay eggs.
The recently updated Conservation Status of New Zealand Reptiles 2021, shows about 90 per cent of the skink and gecko species are threatened or at risk of extinction and more lizard populations are in decline.
Lizards are vulnerable to a wide range of introduced predators, including mice, hedgehogs, weasels, and feral cats, in addition to rats, stoats and possums, which cause the most damage to native birds.
Stats NZ's indicators have also found a continuing pattern of net loss. New Zealand's (including the Chatham Islands) freshwater wetland area decreased by almost 1500 hectares between 2012 and 2018.
These indicators are part of a larger tranche which will inform the Ministry for the Environment and Stats NZ report Environment Aotearoa to be released in April 2022.
