A year of hand-clearing done in a day

Murray Pocock and his mudtrack mulcher can chew three hectares of mangroves into fine chips in a day. Photo / Alan Gibson

The back-breaking task of removing mangroves by hand has been eased by ground-breaking technology which does a year's manual work in a day.

In a New Zealand first, Environment Bay of Plenty has begun mechanically cutting down mangroves in the Tauranga harbour, sparing community groups hundreds of hours of toiling in the mud.

A hydraulically-operated mulcher attached to a digger can chew three hectares of mangroves into fine chips in a day, while its wide tracks exert less pressure than a human footprint.

Omokoroa Estuaries Restoration Group chair Marny Bradley has watched mangroves swallow up beaches and creep across the harbour.

"The volunteers who do this clearing work are not young people generally. There's a limit to what you can do.

"Everyone looked on with delight when the machine started ... there's been eight days of work which would've probably taken us eight years."

The build-up of mangroves chokes up the harbour with silt, and restricts the nesting area for godwits, she said.

The restoration group used to gather fortnightly for two hours to clear the plants with brush-cutters, before waiting for them to dry and burning them off.

A crowd of 100 turned out last week to see the mulcher begin work at the Matua Estuary, with several councillors from out of town showing interest in adopting the technology.

The regional council has consent to remove 92 hectares of mangroves at Matua Estuary, Omokoroa and Athenree.