Manawatū's wetlands need protecting

Tuesday, 6 February 2018

The Manawatū Estuary is classed as a wetland of international importance under the Ramsar Convention.

More than 95 per cent of Manawatū's wetlands have diminished and environmentalists fear they will continue to degrade.

On World Wetlands Day last week, Forest and Bird warned that New Zealand's wetlands would keep suffering if more wasn't done to protect them.

Forest and Bird freshwater advocate Annabeth Cohen says not enough is being done to protect what's left of the nation's wetlands.

Forest and Bird's freshwater advocate Annabeth Cohen said 99 per cent of New Zealand's original wetlands had been destroyed by agricultural and urban development.

'We aren't doing a very good job of protecting what's left.'

Ninety-nine per cent of New Zealand's original wetlands, in red, have beed destroyed by agricultural and urban development, a freshwater advocate says.

Manawatū's wetlands, in red, before human settlement.

* Foxton Estuary welcome to returning birds comes with warning

* Wetland responsibility comes at a cost for farmers**

New Zealand has lost 2.2 million hectares of wetland and only 249,776ha remain.

Before human occupation, the Manawatū-Whanganui region had 264,511ha of wetland ecosystem. Now 6983ha remains, less than 3 per cent.

Cohen said wetlands provided a unique habitat for threatened plants, birds and fish, and they also improved water quality.

A fifth of native bird species used wetlands as their primary habitat, relying on a linked series of wetlands for resting and feeding, she said.

'The trouble is, our original wetlands have been drained for agriculture, and the now rare remnants can't cope with the huge amounts of nutrient and sediment-loaded runoff, which degrades the quality of the water, making it very difficult for whitebait, eels, and other native freshwater species to survive there.

'Regional councils must do more to protect wetlands. That means better management of surrounding agriculture, enforcing rules to prevent illegal vegetation clearance and wetland drainage, and working with community, iwi, and [the Department of Conservation] to restore wetlands that have become degraded.'

Horizons Regional Council natural resources and partnerships group manager Dr Jon Roygard said the One Plan put in place protections for wetlands, including rules about drainage and measures for change in land use.

'We actively respond to any issues identified regarding non-complying activities such as draining of wetlands, vegetation clearance, land disturbance and cultivation.'

Horizons manages 60 of the highest priority wetlands in the region in partnership with landowners, Roygard said.

Horizons hoped to protect more in the proposed 2018-28 Long Term Plan, he said.

The Department of Conservation has been working to free the Manawatū Estuary – classed as a wetland of international importance under the Ramsar Convention – from a weed that is taking over mudflats.

Conservation senior ranger Sue Moore said in the late 1980s the weed, spartina, covered about 90ha of the estuary’s mudflats.

'Shorebirds couldn’t feed where the spartina was growing and it just kept spreading. It grows fast and forms dense, knee-high mats that reduce water flow and increase flooding.'

After 20 years of work, only a few pockets of spartina remained, Moore said.

'Eradication is tantalisingly close.'

The estuary was valued as a feeding and roosting site for wading birds, she said.