Event aims to turn the tide on loss of wetlands

Nina Pivac, a Black mudfish researcher. Photo / Michael Cunningham

The heavily drained and dairy-farmed Hikurangi Swamp and the dune-country Kai Iwi Lakes are completely different ecosystems being acknowledged on World Wetlands Day.

The day, held internationally on February 2 every year, aims to turn the tide on the worldwide loss and degradation of freshwater wetlands.

Wetlands have a multitude of benefits for the environment, including filtering and replenishing water, providing food and mitigating climate change.

Their complex ecologies support many wildlife and plant species. Since 1900, 64 per cent of the world's wetlands have disappeared. In Northland large wetlands systems, such as the Hikurangi Swamp, have been drained and changed for farming and other use.

The Department of Conservation (DoC) and Northland Regional Council (NRC) will share a save-the-wetlands campaign at an open day at Taharoa Domain (Kai Iwi Lakes) on Sunday.

The World Wetlands Day event will include water skiing demonstrations by the Kai iwi Lakes Water Ski Club on Lake Waikare. Activities based at Promenade Point on Lake Taharoa include guided walks, snorkelling and static displays.

There are no rivers or streams flowing in or out of the rain-fed dune lakes that are surrounded by gumland and wetland. The ecosystem supports native freshwater koura (crayfish), crabs, mussels, eel/tuna and introduced rainbow trout.

A 10-year Living Waters Programme is about to enter its second year in the 13,140ha Hikurangi floodplain at the northern catchment of the Northern Wairoa River which drains into the Kaipara Harbour.

The programme is led by DoC and Fonterra in partnership with dairy farmers, Nga Kaitiaki O Nga Wai Maori, the Integrated Kaipara Harbour Management Group, Whangarei District Council and NRC.

The quality and management of the waterways, including stopbanks, has been a contentious issue for decades. Niwa research indicates that 75 per cent of the sediment in the Kaipara Harbour, New Zealand's largest estuarine ecosystems, comes from the Hikurangi swamp.

As part of the Living Waters programme, NorthTec 3rd year applied science student Nina Pivac is researching black mudfish, a rare, small fish that lives in the Hikurangi Swamp.

The aim of Ms Pivac's project is to find out how wetland health impacts on the "indicator" species.

Millan Ruka, from Environment River Patrol Aotearoa, has raised awareness about the catchment's water quality and its downstream effects on tuna/eel and other resources. During routine patrolling of the complex waterways, in July last year he uncovered "a cow graveyard" in the Te Mata Stream above where Titoki residents drew drinking water.