Facts tangle in mangrove fight

A council leader says mangroves don't deserve their protected status; a conservationist says requests to clear mangroves are "histrionics".

Northland Regional Council chairman Mark Farnsworth and Forest and Bird's Basil Graeme encapsulate the two sides in the mangrove debate.

"Some applications to clear mangroves may be justified; most of them at the moment are just histrionics," Mr Graeme says. Any council considering making it easier to clear the plants is being "totally irresponsible".

Not so, says Mr Farnsworth.

"I'm not trying to demonise mangroves, but putting them on a pedestal is based on shoddy science. They are prematurely ageing estuaries."

There is a good reason for that, says Mr Graeme.

"It's climate change. They need heat and lack of frosts to proliferate, and there have been less frosts because the climate is getting warmer."

There is a natural brake on mangrove spread because they grow only about halfway between the shore and low tide, he says.

Mr Farnsworth says the plants are out of control.

"It's clear from aerial photos and baseline data there has been an absolutely rapid escalation in the growth of mangroves."

He wants protection of mangroves reviewed to determine whether they deserve that status under the country's national coastal policy statement. The policy is implemented by councils through district plans.

Anyone wanting to remove mangroves must apply for resource consent, which is then notified, often leading to long and relatively expensive hearings.

Mr Graeme says no attempt should be made to review the plant's status and Forest and Bird would oppose any such move.

"They should be left to expand. They're fulfilling a useful role."

Coastal engineer Andre Labonte, involved in a trial removal near a subdivision at Mangawhai in Northland, says mangrove protection is based on research by an American university professor, now dead, who studied mangroves in the United States and simply transferred his findings to New Zealand.

National's Coromandel MP, Sandra Goudie, found herself offside with regional council Environment Waikato after she lent support to an illegal chainsaw attack on mangroves at Whangamata last month.

Environment Waikato has called a meeting for next week with residents and those opposed to mangrove removal so agreement can be reached to issue a resource consent to remove some plants.

TAKING SIDES

For
* Important source of food for eels, other marine life and birds.
* Act as carbon "sinks", absorbing the greenhouse gas that contributes to global warming.
* Trap silt, thereby protecting harbours and shellfish.
* Keep deep-water channels clear of mud.

Against
* Taking over parts of the coast at an increasing rate, closing large areas to swimming, boating, waterskiing.
* Turn beaches and estuaries into mud.
* Protected status based on "shoddy" science.
* Spreading into areas where they pose danger to important wildlife such as migratory birds at Miranda, which won't roost near mangroves.