Lake Ngāroto an environmental disaster: Fish and Game NZ

Dead birds being removed from Lake Ngaroto. Photo / Supplied

Auckland/Waikato Fish & Game Council game bird manager David Klee is challenging Waipā District Council and Waikato Regional Council to step up their game on the care of Lake Ngāroto, describing the current condition as akin to an effluent pond.

He has written an open letter to councils and councillors inviting them to join him, and his volunteers, as they deal with the death of animals the toxic lake levels have caused and to discuss ways it can be avoided in the future.

This is David's letter:

I have just returned from another trip to Lake Ngāroto, showing Waipā District Council's new contractor how to try and mitigate the region's latest environmental disaster.

As he was retrieving another week-old maggot-infested shag carcass with a stomach full of decaying fish, I could see the gag reflex starting to kick in, and I thought whatever he's getting paid, it's not enough.

In amongst the dead and dying mallard ducks, we found dead grey teals, black shags, little black shags, a heron, and we even flushed an Australasian bittern, a critically endangered species.

Polluted state of Lake Ngaroto. Photo / Supplied

It made it to the other side of the lake. Hopefully, it will move on to cleaner water elsewhere.

Otherwise, it will likely end up a casualty in the coming weeks.

We managed to retrieve a few sick birds, but unfortunately, they were so far gone, and the odds of recovery so slim, the most humane option was to euthanise them there and then.

I have been getting feedback that apparently some local body officials hold the belief that "Hey, it's a dry year and shallow lake, these things happen in these environments, it's part of a natural cycle."

So, if you read this and hold that belief, this letter is addressed to you.

Here are some basic facts.

First, these lakes do not naturally have nutrient levels off the charts and get cyanobacterial blooms with cell counts high enough to kill a dog if they took a drink.

Second, these lakes do not naturally go anoxic (without oxygen) for days, causing even the hardiest fish species such as koi carp, goldfish and eels to die on mass.

Third, these lakes do not naturally get botulism outbreaks that will likely kill the birds that inhabit them.

These are symptoms of highly degraded ecosystems, the result being similar to an effluent pond.

These issues also don't just happen overnight; they are due to the systemic failure of our institutions to set and implement appropriate policy and rule frameworks to safeguard our freshwater ecosystems.

Instead, the ratepayer, the council's staff/contractors and those hardy volunteers assisting in the clean-up are paying the burden for these inactions, not to mention the wildlife dying needlessly.

So, if you are one of those local government officials that believe that this is all just natural, then I challenge you to contact me and turn up at the lake next week like our volunteers are doing.

Dead birds and polluted water of Lake Ngaroto. Photo / Supplied

We will provide all the required PPE so that you won't get sick, providing you don't touch the water.

Spend a morning picking up maggot-infested carcasses and doing a bit of dry retching as the acrid smell of decay hits your nostrils, and then maybe we can have a chat about how we can start addressing some of these issues.

Waipā Mayor Jim Mylchreest said Waipā District Council have been involved in trying to clean up Ngāroto for more than 25 years.

"Council has invested considerable money and effort towards restoring the lake margin, the quality of water and to prevent the run off into the lake," says Jim.

He says to date they have fenced the reserve, diverted most of the contaminated water, installed multiple silt traps, purchased low lying adjoining land to enhance the peat lake catchment, diversion of Ngā Rotoiti inflow to improve water quality and invested in planting and education programs.

The education programmes include a walkway with educational interpretation signage for the public.

To restore the lake margins council has planted around 18,000 native plants from 2014 – 2021.

With involvement from Fish & Game and other parties, council has also invested significant money in a resource consent process to set water levels and build a weir.

"We understand this is a long standing intergenerational issue and it needs a whole catchment approach which includes the involvement of a lot of private farmland," says Jim.

"Council are about to commence a Reserve Management Plan for Ngāroto to determine work with iwi and community to address the causal factors that led to current condition."