Contamination impacting snapper
It’s the first home for the majority of the North Island’s west coast snapper, and it’s under threat but farmers and developers deny they’re contaminating the Kaipara Harbour.
The Kaipara Harbour is both a nursery and feeding ground for snapper. A Niwa report from 2009 said 98 per cent of all adult snapper caught from Ninety Mile Beach to Mana Island in Wellington were originally from Kaipara Harbour.
Rodney Local Board deputy chairman Phelan Pirrie said cattle urinating and defecating in streams were contributing to nitrogen making its way into the harbour, putting snapper stocks at risk. The board wants to tackle the contamination at its source offering to match every dollar farmers in the north-west spend fencing off waterways.
‘‘We need to keep stock out of the rivers,’’ Pirrie said. ‘‘Every time I drive up to council I see them [cattle in streams]. That’s an issue and we want to do what we can to encourage farmers to do that fencing that is required.’’
The board proposed a $250,000 fund for the next financial year beginning in July 2017 - to address the problem. The fund doubled the board’s environmental budget, and used up its common development budget. Pirrie said Niwa reports indicated nitrogen run-off was part of the harbour’s degradation problem, and nitrogen tended to come from cattle.
But senior policy advisor for Federated Farmers, Richard Gardner, said cattle was not the biggest issue for the Kaipara Harbour - sedimentation from developments was the main contaminator.
‘‘You’ve probably seen how they take off all the topsoil and are left with the bare clay while they prepare to do earthworks and then cover it up ... They do a lot of work on that to prevent the runoff but they can’t do it all,’’ he said. Gardner said fencing requirements only stated that flat farm land needed to be fenced.
General manager of north-west property developer Cabra Developments, Lloyd Barker, said its consents required the company to construct temporary silt ponds with flock treatment and silt fences. These were designed to remove 95 per cent of silt generated and were regularly monitored by Auckland Council, he said. Studies had shown once completed developments’ silt runoff was lower than rural land.