Thick mangrove trees growing along the Watercare Coastal Walkway
in Māngere have been cleared by landscape students, to assist visiting wading birds.
Ever since the old oxidation ponds were removed as part of the coastal redevelopment more than 15 years ago, mangroves have started growing along the foreshore, which runs from Ambury Farm to the Otuataua Stonefields.
The migratory wading birds that use the bird roosts along the coast like a clear landing, so with the help of 13 Manukau Technical Institute (MIT) students, around 1.5 kilometres of mangroves have been cleared. It’s thought that some migratory birds, such as godwits and dotterels, fear that predators may be hiding in dense undergrowth, like mangroves, so keeping the area clear from vegetation will encourage them to keep visiting.
Watercare environmental scientist Liam Templeton says two arborists removed 2km of mangroves the week before: “We had 2 guys take out 300-400 mangrove trees in the first week. Many of the trunks were as thick as your thigh. They said that cutting them down with chainsaws or horticultural saws and lugging them across slippery mud and over the rocky foreshore was the hardest work they had ever done- and they’re very experienced contractors.
"We were so grateful when we heard that MIT landscape students needed some practical experience as part of their level 4 studies. They were incredibly cheerful and did a wonderful job.”
The bird roosts and the birds that use them are internationally recognised for their significance, which allowed for the clearance work under the Auckland Unitary Plan.
The leaves and branches were put through a chipping machine and the thick mulch was spread at the base of native trees that grow along the coast.
The students learnt about health and safety practices, as well as how to use the equipment.
Special strap-on plastic shoes, called ’mudders’ helped the students stay on the surface, preventing that ‘sinking feeling’.
Around about 40 per cent of the world’s population of bar-tailed godwits visit the area. Other species that rely on the roosts include eastern bar-tailed godwits, pied stilts, red knots, South Island pied oystercatchers, variable oystercatchers and wrybills.
A quarter of the national wading bird population can be found in the Manukau Harbour at any given time and more than half will pass through the harbour at some stage in their life.