By Andrea Vance from
Photo: Supplied/ Waikato Times – Christel Yardley
A strange silence took hold of Whangamarino. It’s dead silence.
The bodies of thousands of dead birds piled up around the vast mosaic of swamps, marshes, bogs and open water between Waikato’s Meremere and Te Kauwhata.
Wetlands are generally an oasis for rare wildlife. It is home to the largest population of matuku (or Australasian Bittern) in the world, and their resounding calls echo through the water.
But large populations of Whangamarino birds fell ill with avian botulism, dying horrific deaths after losing the ability to walk and use their wings.
Fish & Game staff are horrified by the number of dead birds killed in an outbreak of avian botulism in the Whangamarino Wetlands.
Photo: Provided/ Fish & Game
The paralysis eventually robs them of the ability to hold their heads up and they drown in the waters that were once a refuge.
Appalled by the outbreak, Fish & Game New Zealand has launched a scathing attack on Waikato Regional Council, accusing the local authority of allowing dairy intensification and failing in its legal duty to protect freshwater environments .
Fish & Game chief executive Corina Jordan said the disease outbreak, in its third month, was “appalling” and a call for “urgent action”.
Devastated Fish & Game staff and community volunteers have collected nearly 2,000 birds, including matuku, over the past month.
Waikato Regional Council said a “black water event” caused the outbreak. This is when organic matter – like nutrients – reduces oxygen in the water, after heavy rains and warm temperatures.
Photo: Supplied/ Waikato Times – Christel Yardley
Although listed as internationally important, the wetland has long faced environmental challenges, overloaded with sediment and nutrients from agricultural and industrial runoff and stormwater.
Poor water quality and changes in the way water flows have contributed to low oxygen levels in the marsh.
Lake Waikare, one of the most polluted lakes in the world, has been diverted to the wetland as part of a flood control program.
Locals call it Fanta Lake, because of its bright orange color.
As the ponds become stagnant, this creates perfect breeding conditions for bacteria that produce botulinum toxin that is deadly to birds but harmless to humans.
Cyanobacteria – or blue-green algae – which can produce dangerous toxins, thrive in Lake Waikare. Polluted water flows into Whangamarino.
Photo: Provided / Stuff – Ian McGregor
The toxin is consumed by fish and aquatic invertebrates, which are then eaten by waterfowl.
When Stuff visited the site on Friday, some of the water was orange and there was an overwhelming, rotting smell.
Jordan said even freshwater eels, which are hardy and able to tolerate low oxygen environments for short periods, perished.
The matuku, or Australasian bittern; more endangered than most kiwi species.
Photo:
“We are concerned about the rhetoric we are hearing from authorities calling these incidents natural,” said Jordan, who is a freshwater ecologist.
“Parts of this wetland have been without oxygen for most of the three months, leading to the mass death of even the hardiest freshwater species, such as eels. This is not normal in systems of healthy freshwater wetlands.”
Jordan said the council must now take a close look at how the catchment is managed and limit discharges into waterways. She also wanted to see a long-term plan for dealing with Whangamarino.
Corina Jordan, General Manager of Fish & Game.
Photo: Provided
Ngāti Naho said he wanted “answers, not apologies”.
“We are tired of the hui with consultants who lack follow-up, or empty rhetoric from iwi leaders or mayors that leads nowhere,” said Ngāti Naho Trust chief executive Haydn Solomon.
“Our waterways are being hammered. Our wetlands, lakes, rivers and springs are at breaking point, but nothing substantial and meaningful is being done.”
He was cynical about the consultation exercises. “Sometimes you are lucky if the local or iwi officials show up for the waterways meeting.
“But when it comes to big flash infrastructure projects like Auckland in Hamilton [transport] corridor, high-density housing, solar farms, landfill expansion or the removal of water and sand from our river for Auckland, they are all there to cut the buck.”
Waikato Regional Council scientific director Mike Scarsbrook said the council is seeking to control land use intensification and control nutrient and sediment sources in the Waikato and Waipa rivers through a change in regional plan.
But he had come up against legal proceedings, with more than 20 appeals.
“Unfortunately, this is a protracted process which is currently under appeal in the Environmental Court,” he said.
The wetlands cover more than 7,000 ha and are considered of international importance.
Photo: Supplied/ Waikato Times – Christel Yardley
Sarah Lealand, Waikato Council’s lower area manager, said she was working with landowners in the Waikare and Whangamarino catchments to stabilize hills and stream banks and said infrastructure in flood protection were continuously improved.
“The flood program plays an important role in protecting rural and residential properties and key national infrastructure, such as roads, from flooding,” she said.
The wetland is close to Te Kawhata and Meremere.
Photo: Supplied/ Waikato Times – Christel Yardley
Covering 7,290 hectares (approximately 18,000 acres), Whangamarino is the second largest wetland complex on the North Island.
Attracting duck hunters, it is a resting and feeding place for dabbling ducks, mallards, grays and northern shovelers.
It is also the only remaining location for the extremely rare Tiny Marsh Helmet Orchid and a stronghold of the Black Mudfish.
In 1989 it was classified as a wetland of international importance under the Ramsar Convention, a protection treaty.
Black mudfish are endangered, primarily due to widespread habitat loss, invasion by nuisance fish, and reduced water quality.
Photo: RNZ / Alison Ballance
Wetlands reduce the impacts of flooding, absorbing heavy rains and gradually releasing water.
They are also a natural buffer against floods and tsunamis, and a recognized tool for mitigating climate change. They are our densest natural carbon reservoir.
But New Zealand has less than 10% of its original wetlands. Between 1996 and 2018, 5,761 hectares (14,235 acres) were lost, mostly drained for agriculture.
Agricultural and industrial runoff is the source of the botulism epidemic.
Photo: Supplied/ Waikato Times – Christel Yardley
Last month, Stuff revealed that the government had rolled back wetland protections, introduced in 2020, after pressure from industry groups.
The Department of Conservation (DOC) said it believed at least 1,400 birds were affected, but had no reports of dead or diseased matuku or mudfish, but confirmed eels were dead.
DOC Hauraki, Waikato and Taranaki director of operations Tinaka Mearns said the outbreak was concentrated on the Whangamarino and Maramarua rivers.
The government recently rolled back protection for wetlands, although swamps and bogs are important defenses against flooding.
Photo: Supplied/ Waikato Times – Christel Yardley
“Historically there has been a matrix of management models and organizations that need to work together to manage wetlands like Whangamarino and other waterways across the country,” she said.
“New Zealand as a whole is addressing this legacy and DOC is working constructively with other agencies, tangata whenua, landowners and other stakeholders to address these issues. We are optimistic and motivated to working with others to improve our wetlands.”
* This story originally appeared onThing.