A Hikurangi Swamp kaitiaki wants the Whangārei District Council prosecuted over ongoing issues with its $23 million Hikurangi Swamp flood management scheme killing thousands of tuna whakaheke (migrating eels).
Nicki Wakefield, Ngā Kaitiāki o Ngā Wāimāori supporter, said issues with the scheme's pumping stations chopping the up to 100-year-old tuna whakaheke as they begin their autumn journey to the sea were ongoing.
"Northland Regional Council (NRC) should be getting tough on the council and prosecuting it for ongoing breaches of its scheme operating consents," Wakefield said.
Colin Dall, NRC group manager regulatory services, said his council was investigating whether consent conditions had been breached. A decision on what action would be taken was expected by the end of the month.
NRC is the consenting authority for the WDC-run scheme.
Rob Forlong, WDC chief executive, said the council was not breaching its resource consent with pumps killing the tuna whakaheke.
"But our aim is to minimise deaths to eels," Forlong said.
Eight Ngā Kaitiāki o Ngā Wāimāori hapū members on Friday dumped 20 litres of rotting tuna, chopped up by the pumps about 10 days earlier, at the front doors of NRC and WDC in Whangārei.
"We have had enough," Chantez Connor-Kingi, Ngā Kaitiāki o Ngā Wāimāori hapū member, said.
Ngā Kaitiāki o Ngā Wāimāori looks after Hikurangi Swamp tuna and comprises Ngā Kāhu o Torongāre, Ngāti Hau and Ngāti Hine hapū.
The dumped tuna were pieces of some of what the kaitiāki say were among more than 1000 eels chopped up in Hikurangi swamp's pumping stations.
They were chopped up after February 14 autumn rain when pumps automatically switched on to lower raised river water levels to stop surrounding farmland getting flooded - at the same time the rain triggered the start of an age-old 2500 kilometre tuna whakaheke migration from the swamp into the Kaipara Harbour and on to the Pacific Ocean's Tonga-Kermadec trench.
The Hikurangi Swamp's up to 100-year old short and long fin tuna whakaheke swim about 25 kilometres daily to release up to 20 million eggs each into the sea then die.
Resulting larvae drift back to New Zealand on ocean currents to become tiny glass eels, migrating up into the Kaipara Harbour as elvers and onwards into the Hikurangi Swamp.
"It was devastating," Hori Kingi, longtime Ngā Kaitiāki o Ngā Wāimāori member, said of discovering the chopped tuna whakaheke.
Wakefield said WDC had a management agreement with Ngā Kaitiāki o Ngā Wāimāori to protect the tuna whakaheke. This was that the pumps would not be turned on for 12 hours after the first rains, allowing the tuna whakaheke to successfully start their migration.
Forlong has apologised to hapū for what happened.
He said WDC was not letting the interests of Hikurangi Swamp farmers predominate.
"We walk a tightrope every autumn. The problem is the rain and the eel run often come at the same time" he said.
"When the pumps are run they kill eels. If the pumps are not run the water kills the grass," Forlong said.
"After last year when we were criticised (by farmers) for leaving the pumps off and leaving the floodwater on the pasture, we planned changes to our procedures," Forlong said.
"We intended to leave the pumps switched off until after the hapū had confirmed the eels had migrated for the season and then set them to automatic. Unfortunately the protocols for this – which need to be agreed by hapū and farmers – had not yet been drawn up at the time of the recent rain.
"As a result, we turned the pumps to automatic when we were warned of coming rain, in line with the management scheme as it has been operating for some years."
The 5600-hectare Hikurangi Swamp scheme manages flooding in what was once one of the Southern Hemisphere's largest wetlands, after it was drained from 1919 to enable farmers to today milk thousands of cows on what's highly productive farmland and a major economic producer.
Connor-Kingi said a solution that protected tuna as the taonga they were and enabled farmers to conduct business as usual was required.
Initial swamp draining started in 1919, continuing until the 1930s. WDC took over responsibility for the scheme's management in 1953.
The current scheme was constructed between 1969 and 1977, aiming to provide 1:5 year flood protection for farmers. It has about 20 pumps across its seven pumping stations.
Hikurangi Swamp produces more than $31 million of milk annually and is one of Northland's top dairy production areas. Its 15,000 dairy cows produce about 4.5 million kilograms of milk solids each year on roughly 100 farms.