War on weed
Mark Erskine's property used to back on to a white sand beach just 12 years ago.
Wading birds crowded the shallows near his Mangere property on sunny days and sang so loudly he had to shout to be heard, he says.
Today his backyard is bordered by hectares of "mangrove quagmire" stretching far out to sea.
The "marine gorse" has "obliterated not only the beaches but also wading bird habitats and fish species".
"Everything is gone."
Mr Erskine is among residents urging the Auckland Council to overhaul its mangrove management policy.
They have been joined by marine scientists and mangrove removal groups from around the upper half of the North Island.
It is calling on the council to recognise mangroves as a weed and fund the widespread removal of mature plants, restoring the white sand beaches that once bordered the Manukau Harbour.
They are drawing on backing from experts like Warwick Silvester, a professor of biological sciences at Waikato University, who says that "as manuka is the weed of the forests, mangroves are the weed of the estuaries".
Council policy, which now allows residents to remove mangrove seedlings under 60cm tall, is not workable in a practical sense, Mr Erskine says.
"The mangrove forests are actually too dangerous for people to enter because of the suction of the mud," he says.
"You wouldn't want to go in there without a fully charged cellphone."
The policy also does not account for the "trillions" of seeds the mature plants release into the water three times a year.
"Left to float out there, they will re-seed our harbour perimeters all the time," he says.
An overhaul of council policy would bring it in line with the 2010 New Zealand Coastal Policy Statement, which removed mangroves from the list of flora which is "of any benefit whatsoever" to the coastal environment, Mr Erskine says.
But the council is sticking firm to its mangrove management policy, which was updated in 2010 in response to issues arising from the "massive" spread of mangroves in parts of the Auckland region.
A council document on seedling removal reads: "Mangroves play an important role in the ecosystems of our estuaries and provide a habitat for a range of animals and other plants.
"They also help with erosion control and shoreline protection by slowing the flow of water and reducing the impact of waves."
As well as allowing seedling removal, the policy allows mature plants to be taken out outside of areas with a coastal protection rating of 1 where mangroves are "adversely affecting use and value of the coast".
"The current regulatory framework acknowledges both positive and negative aspects of mangroves and strikes an appropriate balance within its policies and rules," council spokesman Glyn Walters says.
"We're going to facilitate consultations with the council and we would like to see big things happen within six months," Mr Erskine says.
"If they don't, then we need to approach our MPs to take it to Parliament because it's not just about Mangere inlet or the Manukau Harbour - this is about the whole upper half of the coastal North Island."
- © Fairfax NZ News
Do you wear a lifejacket when you are on the water - no matter what vessel you are in?