Grass volunteers protect Mangawhai spit

Volunteers have been hard at work planting thousands of native coastal grasses on Mangawhai’s Distal Spit in recent weeks, in an ongoing mission to safeguard the natural landmark.

Led by Mangawhai Harbour Restoration Society (MHRS), volunteers planted 3000 spinifex and 300 pingao. The work follows the erection of 200 metres of sand trap fencing by volunteers earlier in the month.

Both the planting and fencing are done annually and are essential in retaining the spit, which shields the mainland from the wild coastal elements, MHRS chair Peter Wethey says.

“The planting helps stabilise the sand on the spit, which would otherwise be at risk of coastal inundation,” he says. “This work would not be possible without volunteers from the Mangawhai community. We had a couple of magnificent mornings – everyone gets a kick from working on the Spit.”

Thanks to some local Kiwi ingenuity, the last two years of planting have been a bit easier on volunteers, with holes dug by a three-pronged device fitted on the back of the tractor.

Since the Department of Conservation (DoC) first approved the planting programme in 1991, more than 200,000 sand-hardy grasses have taken root on the spit.

Spinifex and pingao aid sand stabilisation and help stop dune erosion. Pingao grows vertically, catching flying sand to form dunes and dies off once the dune becomes stable. If erosion starts to occur, the plant sends out shoots and grows again.

Spinifex grows horizontally, along the base of dunes or sandbanks, forming dense masses to hold the sand and continues to grow even when covered.

“We always believed the combination of the two grasses was better to stabilise the sand, but up until now, we’ve been restricted in what we can plant,” Wethey says. “This year, DoC allowed us to do a trial of pingao and, with a bit of luck and if it goes well, we’ll be able to include it in our planting next year.”

Anyone interested in volunteering with Mangawhai Harbour Restoration Society, can find out more at www.mangawhaiharbourrestorationsociety.com