New Zealand’s South has a native, apex predator as high as your bench top but with a ridiculously low profile — the bittern (matuku-hūrepo).
Many people have never heard of the bird, let alone heard its atmospheric booming, like the noise when you blow across the top of a bottle.
Starving and struggling to find a safe place to breed, there are only 250 to 1000 left, says Love Bittern, a not-for-profit calling for urgent action to save them.
In Southland, the formerly-common bird historically lived in vast, rich wetlands teeming with plants, eel, frogs and inanga whitebait.
Every pair of breeding bitterns requires at least 20ha of wetland, but the swamps, marshes, fens and bogs — that also capture carbon and filter water naturally — have nearly all gone, mostly drained for farming.
Remnant southern wetlands have continued to be lost to paddocks in recent years — far more than anywhere else in New Zealand — and pollution, significantly from farms, has damaged some remaining wetland under the Department of Conservation’s management.
In February, Southland’s regional council Environment Southland was hauled through the High Court for letting the destruction happen.
The Environmental Law Initiative (ELI) charity had sought a legal review of the council’s wetland inaction and Justice Harland agreed the council was not fulfilling wetland-protection duties.
It was a clear-cut case of an environmental authority turning a blind eye. Now eyes are on the council to fight for wetlands at a confusing political time when the government is moving to disband regional councils and replace resource management powers.
Meanwhile, charities and some farmers are taking matters into their own hands and trying to rebuild wetlands.
Their efforts are flagged as good news stories in Environment Southland publicity but it is a mammoth feat to replicate nature’s biodiveristy and, so far, efforts have achieved little to change the big picture of wetland devastation.
Conservationists, desperate to save many species, say every little helps: a small patch of wetland could, at least, give a bittern a place to rest and forage while it searches for somewhere bigger to breed.
Last month, hope was in the air. Waiau Fisheries and Wildlife Habitat Enhancement Trust (the Waiau Trust) deployed bittern recording devices on two Fiordland farms, both with some wetland and one with a recent, unconfirmed bittern sighting.
Down the road at the Rakatu Wetland, built by the Waiau Trust, bitterns were heard by Wendy Ambury, national co-ordinator of Love Bittern.
She says children she recently educated "came up with the idea that if wetlands are the kidneys of the earth, purifying our water, then the bittern’s booming must be the heartbeat, telling us a wetland is alive".
"We can’t save a species like bittern without saving wetlands."
The massive loss
An international treaty on wetlands called Ramsar says wetland loss, like rainforest destruction, is a global crisis threatening life, including human survival.
In Southland, wetland once covered a huge 272,000ha, just under half the size of Florida’s remaining Everglades swamp (which has itself shrunk by half due to being drained).
A 2011 report for Environment Southland, "Current and Historic Wetlands of Southland", said more than two-thirds of Southland’s wetlands had been swamp, the most significant wetland type.
But by 2011, most southern wetland had gone, swamp declining by 99%.
Marsh fell 96% and remaining wetland was mostly bog.
Stats NZ says more than half wetland lost nationally in the decade to 2023 was lost in Southland.
In September last year, a report by Environment Southland on wetland extent,used aerial and satellite imagery from 2022-23 to assess wetland that was at least 0.5ha in size and not managed by Doc.
It tracked down just 17,356ha.
Including wetland on Doc land, the council estimated 42,569ha.
In 1996, there had been 51,249ha of wetlands recorded, meaning about 9000ha had been lost in the last three decades.
Contamination
Doc says it is tricky to know exactly how much Southern wetland it manages but losses between 1996 and 2023 were overwhelmingly not from its land.
However, this does not mean Doc-managed wetland is safe.
The 20,000ha Awarua Waituna wetlands, southeast of Invercargill and listed as internationally important by Ramsar, makes up a large chunk of Doc wetlands, including Waituna Lagoon.
However, it is struggling with contaminants — nitrogen, phosphorous, sediment and E.coli — from the extensively drained and farmed catchment around it.
In 2023, Doc had warned in a report about Awarua-Waituna wetland health that "catchment action to address nutrient and sediment inputs remains critical" to restore the lagoon.
Last year’s Environment Southland report had said nearly two-thirds of Southland’s wetland losses over the past decade had been in the Awarua area, which lost nearly 1000ha, about a fifth of its wetland not managed by Doc.
A separate report called Waituna Catchment, by Environment Southland, pointed a finger at dairy farming, which has trebled in the area since 1996 and is now nearly half the catchment’s land use.
Destocking including a reduction in dairy, good farm management practices and re-creation of wetland were all flagged in the report as important to tackle the pollution; only a multi-pronged approach would tackle it.
The nutrient-laden pollution has been causing algal blooms in the lagoon, which destroy biodiversity.
To flush out the lagoon, Environment Southland opened it to the sea using emergency powers in September 2024.
The council said it was also doing this because high water levels impacted infrastructure — including paddocks.
The lagoon stayed open through the summer, negatively impacting important, native, submerged plants such as ruppia, that were trying to grow.
A Earth Sciences New Zealand and Doc report from this year, "Vegetation Status", found ruppia plummeted from being in more than half the lagoon in 2023 to only 2%.
In October this year, in a decision that shone a light on the conflict between where nature wants to flourish and industrial-scale agriculture wants to stay, a resource consent determined when the lagoon will be opened.
Criteria included higher water levels that would increase incrementally over time, in an effort to balance the need to give native species a chance to flourish in freshwater versus the need to flush out contaminants and consider flood implications.
Federated Farmers objected, citing, among other things flood risk and "compromised" drainage systems.
Monitoring to protect?
A further dive into Stats NZ data suggests the rate of Southland wetland loss is slowing.
Between 2018 and 2023, 175ha was monitored as lost — around 35ha per year — compared with 928ha lost between 2012 and 2018.
The damning High Court case against Environment Southland raises an obvious question, however; were some losses not monitored?
Justice Harland had ruled that regional councils’ monitoring obligations extended to more than intermittent mapping.
Regardless of financial pressures, councils should monitor in ways that enable enforcement if a wetland is threatened or drained.
Environment Southland has agreed to meet ELI, to share its plans and ELI senior researcher Anna Sintenie demands the council has a "purposeful strategy that includes comprehensive monitoring, transparent reporting and robust enforcement".
Environment Southland’s science general manager Karen Wilson says the council plans to map wetlands every three years, annually monitor ten wetlands and a newly-appointed ecologist will develop a long-term monitoring plan for "terrestrial ecology".
The council was working on "better governance oversight" of wetland work through reporting to its leadership and councillors.
When asked about the council’s wetland enforcement team and any enforcement success stories, Ms Wilson said the council had not increased enforcement staffing and she did not provide examples of enforcement.
Forum frustration
Three years ago, the community-led Murihiku Southland Regional Forum published its final report on freshwater health.
In urgent terms, it demanded Environment Southland employ a "task force" to enable wetland enforcement and achieve targets for work "at scale to accelerate wetland re-establishment".
Phil Morrison, an Environment Southland councillor who was the forum’s deputy chairman, says now: "Even if every farmer was to adopt best practice we would need to do more to return waterways to a minimum state of health — wetland development and preservation was the most promising and strategic investment to support that work on-farm."
Justice Harland’s ruling had been "helpful" but wetland loss and re-creation was still in a "transition period", he said.
"Our understanding probably precedes action needed.
"Despite council’s best aspirations things move slowly in local government."
Hopes that the council’s water and land plan could take on the forum’s recommendations has fallen foul of the government block to changes due to resource management reforms, he says.
Targets for building?
Ngāi Tahu ki Murihiku demanded, in a 2020 report to the regional forum, restoration of the region’s wetlands to 1995 levels by 2035, which would require around 9,000ha more non-Doc wetland if Environment Southland figures are correct.
The council’s report last year said it was aware of only 66ha of wetland created between 2007 and 2023, with nearly all of it — 58ha — around the Waiau River mouth where Waiau Trust has been building wetlands.
The amount is 0.7% of the Ngāi Tahu target and countered by the losses.
Environment Southland’s Ms Wilson says the council "does not have a formal position" on the Ngāi Tahu goal, describing it as commendable but "an iwi-led objective".
The council was involved in wetland research and preparing resources to "help landowners and others with constructing effective wetlands".
However, the High Court hearing had stressed that re-creating a wetland is far more costly and challenging than protecting it.
Environment Southland calls two wetlands it part-funded at Geoff and Dot Stevens’ Five Rivers farm "magnificent’; six hectares of wetland have been built there over six years.
Refuges for bitterns
Love Bittern’s Wendy Ambury has little choice other than to take a positive approach to all efforts to re-create wetland, because bitterns are on the brink.
"Bitterns need places to rest and forage, as well as larger habitats for breeding."
Farmers can save and build wetlands and also plant diverse riparian strips along waterways, including areas with low planting so bittern can see water and hide in plants such as sedges.
"For farmers, the needs of bitterns and value of wetlands can take a while to sink in but it is really worth it. Wetlands punch above their weight."
The Waiau Trust’s operations consultant Roger Hodson, an Environment Southland councillor, is hopeful bittern could avoid extinction by accessing a network of wetlands including some of sufficient scale to enable breeding.
The trust’s wetlands at the Lower Waiau’s southern mouth and further north at Rakatu are trying to re-create flood plain habitats eradicated by the Manapouri hydro-electric power station, which diverted nearly all water flow to Doubtful Sound.
Rakatu wetlands has been rejuvenated with elements of marsh, fen and bog, with sedgelands and rushes.
Dams have been built across formerly drained and dewatered wetlands and abandoned river channels, with passages for fish.
The wetlands, built among farmland, aim to support migratory food sources, such as eels and whitebait, as well as non-migratory species such as Galaxias gollumoides.
The booming bittern heard here may be only lonely males — but there is hope of breeding.
"It may be that bittern are feeding on whitebait near the coast to gain breeding condition before moving inland to breeding habitat ..." Mr Hodson says.
One Fiordland farm worker also remains optimistic.
Craig Horrell, supervisor at dairy firm Fortuna Group, has lived and worked at its Elya farm at The Key for 20 years — and didn’t know bitterns existed until a possible on-farm sighting.
Elya has ten wetlands varying in size. Another Fortuna dairy-support farm nearby, Mount Prospect station, has around 168ha of QEII-covenanted land, including wetlands, already in place when Fortuna bought it earlier this year — the firm says it is looking to protect more.
Sustainability manager Rosie Hunter says Fortuna is "actively identifying and retiring areas that don’t make sense to graze and enhance them by creating wetlands, nutrient sinks or planting".
The bittern recording equipment placed on both farms by the Waiau Trust has not picked up booming so far but Mr Horrell says it would be "absolutely outstanding if they are proven to be here".
"Hard work creating habitat will have paid off."
"If you think you have an area that could be made wetland, just do it. Do the right thing."
