New Zealand's disappearing wetlands continue to be destroyed

Friday, 1 February 2019

They are wet and dirty and hard to love. And they're disappearing quickly.

New data shows New Zealand is losing significant areas of its remaining wetlands, even though they were prioritised for protection more than a decade ago.

An estimated 30,000 hectares of wetlands have been either fully or partly destroyed since 2001, according to data released by Forest & Bird to mark world wetlands day.

It amounts to about 13 per cent of the nationwide wetlands area that existed in 2001, which was already severely depleted. 

Wetlands come in many forms: Marshes, swamps, bogs, tarns, and fens, to name a few. The common denominator is that they are saturated with water, resulting in a particular type of ecosystem, usually featuring aquatic plants and a wide range of birds, such as waterfowl and waders.

Long before human settlement, wetlands likely covered large parts of the country.

An analysis in 2008 estimated wetlands once covered nearly 2.5 million hectares, or about 10 per cent of New Zealand's land mass.

Wetlands extent has since been reduced by more than 90 per cent, to less than 250,000ha. They now exist in small, scattered pockets, much of which is on private land.

The consequence is that wetlands have become 'probably New Zealand's most depleted ecosystem' and 'remain the most vulnerable,' according to an analysis by Landcare Research in 2017.

The ongoing destruction of wetlands coincides with a rethink about their importance to the environment.

They have long been maligned, often unfairly: In a particularly notable example, then justice minister Judith Collins said in 2014 'I don't like wetlands – they're swamps … Go and find someone who actually cares about this, because I don't,' in response to questions about her husband's link to a company that exported processed swamp kauri.

You should know: Not all wetlands are swamps, but all swamps are wetlands.

In recent years, however, wetlands have undergone a renaissance. 

They can help solve several environmental problems: Wetlands act as purifiers for polluted water, absorb carbon from the atmosphere, and provide a home to threatened birds.

It is why they are sometimes described as 'nature's kidneys' - perhaps unpleasant to look at, but quietly performing a vital, if uncelebrated, function.

For that reason, the likes of Fonterra and DairyNZ have joined with !function(e,t,s,i){var n='InfogramEmbeds',o=e.getElementsByTagName('script')[0],d=/^http:/.test(e.location)?'http:':'https:';if(/^\/{2}/.test(i)&&(i=d+i),window[n]&&window[n].initialized)window[n].process&&window[n].process();else if(!e.getElementById(s)){var r=e.createElement('script');r.async=1,r.id=s,r.src=i,o.parentNode.insertBefore(r,o)}}(document,0,'infogram-async','https://e.infogram.com/js/dist/embed-loader-min.js');'>environmental groups to preserve wetlands to better protect what's left.

Despite growing awareness that wetlands serve multiple important roles, they are continuing to disappear through legal means.

Forest & Bird's data showed that nearly all regions have either damaged or entirely lost wetlands in the past two decades, albeit to varying degrees.

The West Coast and Canterbury have been the biggest culprits, damaging or losing 10,700ha and 5800ha of wetlands respectively. Wellington has lost or damaged the most proportionally (37 per cent).

Some regions, such as Nelson, lost very little, because their wetlands were already gone. Just 3ha of wetland remain in Nelson.

In recent times, Southland has become a focal point for the issue of wetland loss: It has the second largest area of wetlands of all regions, behind the West Coast, which are quickly disappearing, largely because a quarter of those wetlands are on private land.

The extent of this loss was documented through imagery collected on behalf of the Southland Regional Council, which show significant areas of wetlands being destroyed on farmland in the last decade.

The resulting report, released in 2016, noted that wetlands were 'still undergoing rapid decline in lowland areas of Southland, mainly due to land development for agriculture.'

A separate report, published late last year, determined that Southland had lost around one quarter of its wetlands between 1990 and 2012, and said a 'review of policy mechanisms and enforcement efforts intended to protect wetlands at regional and national levels is urgently called for'. 

It noted that protecting wetlands on private land had been given priority by the government in 2007, but the rate of wetland loss appeared to have increased, 'indicating there has been no obvious behaviour change, or regulatory change to indicate a slowing down on land use change over the past two decades.'

Late last year, conservation minister Eugenie Sage said wetlands needed better protection 'urgently' due to the rate at which they were disappearing. 

'Great restoration work is being carried out by DOC, councils, community organisations and some private landowners, but we're still seeing substantial and ongoing loss of wetlands,' she said.

'The trend must be reversed so we don't lose wetlands altogether.'

The theme of this year's World Wetlands Day is climate change, which intends to highlight the role of wetlands in fighting both the causes and the effects of global warming.

'Healthy wetlands will help protect people and wildlife from the impacts of climate change,' said Forest & Bird's freshwater advocate Annabeth Cohen.

'We need every single wetland we've got – and more – if our native bird and fish species are going to stand a chance in the face of climate change.'