Source: NZ Department of Conservation
Date: 24 February 2026
The wetland spans 7,000 hectares of swamps, fens and peat bogs and is one of New Zealand’s seven sites recognised globally for its ecological significance under the international Ramsar Convention on Wetlands.
Under the Convention, Ramsar Sites must be continually monitored. New Zealand is required to notify the Convention if the ecological character of one of our Ramsar wetlands has changed or is likely to.
This is the first time New Zealand has delivered an international report integrating science alongside maatauranga Maaori, underpinned by the principles of the Ramsar Convention, to comprehensively assess changes in ecological character.
DOC Regional Director Tinaka Mearns says the report, released today, concludes the Whangamarino has deteriorated since it was designated a Ramsar site in 1989.
“Whangamarino has faced mounting pressures for decades, but recent events have made things worse. Poor water quality led to fish and bird deaths in 2022-23, triggered by very low oxygen and a botulism outbreak following floods and extensive input of contaminants and organic matter into the wetland. The human-induced fire in October 2024 was another setback.”
The report identifies a concerning decline in water quality, indigenous wetland habitat, the wetlands’ Australasian bittern/matuku population, and cultural values recognised by mana whenua.
These declines are driven by the modified water regime in the wetland, poor water quality, large-scale fire, and invasive species such as koi carp.
For Waikato Tainui, Whangamarino is a taonga, deeply connected to identity and wellbeing, with significant ecological and cultural values.
“This report confirms what our people have been observing over many years. Maatauranga Maaori and lived experience tell us that the pressures on Whangamarino are cumulative and long-standing, and that restoration must address the whole system; water quality, hydrology, invasive species, and land use, not just individual symptoms,” says Marae Tukere, General Manager, Oranga.
“We acknowledge mana whenua and their tireless mahi monitoring, reporting, and working to mitigate impacts. Their kaitiakitanga and commitment are integral to protecting and sustaining our taiao.”
Internationally, there’s growing recognition that incorporating traditional knowledge and cultural perspectives into conservation reporting produces better conservation outcomes.
Tinaka says the report gives a fuller picture of the ecosystem’s decline and a deeper understanding of what this loss means for mana whenua and local communities.
“By thoroughly assessing the state of both ecological and cultural values in the Whangamarino, the report targets restoration efforts and builds the foundation for a strong collaborative response to revive both the ecology and mauri of Whangamarino.”
Waikato Regional Council Environmental Science Manager Dr Mike Scarsbrook said degradation had occurred over many decades, with the causes and solutions complex and interconnected.
Waikato Regional Council is leading the development of an action plan to respond to the decline, supported by DOC, Waikato Tainui, Waikato River Authority, mana whenua representatives, Fish and Game, landowners and other stakeholders.
The action plan will assess and prioritise actions to improve the health of nearby Lake Waikare (one of the adjacent waterbodies that feeds into the wetland) and Whangamarino itself. The action plan will address the full system, including hydrology, land use, water quality, biodiversity, cultural values and community connection.
“It’s taken a long time for Whangamarino and Lake Waikare to degrade, so it will take a long time for it to recover. Success of the action plan depends on sustained collaboration, investment and accountability – no single intervention will solve the problem. Progress relies on multiple coordinated actions,” says Dr Scarbrook.
DOC also has work underway to control pest plant species at the site, to reduce the spread of willow, golden dodder and royal fern.
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