A hikoi organised by the Green Party highlighting sewage spills at a Northland harbour saw about 70 placard-wielding protesters march on Waitangi.
The group went from the site's lower marae to the upper marae on Wednesday, marching for Hokianga Harbour to "keep kaka out of our kaimoana", as one placard read.
Green Party co-leaders Marama Davidson and James Shaw were in the throngs, along with MPs Chloe Swarbrick and Golriz Ghahraman, and a number of bare-footed children.
Davidson said she wanted "to see action" in 2019 from the Government over what she called out-dated sewage treatment plants in the lower socio-economic area.
Hokianga resident Janine McVeagh (right) has been protesting the harbour's water quality since 1982.
"People in the Hokianga are struggling. It shouldn't fall on small communities to fix this – that's why we need funds from the central Government."
She said she grew up swimming in and eating seafood from the harbour, which had made her take its health to heart.
A hikoi arranged by the Green Party protested sewage flowing into the Hokianga Harbour.
Northland Regional Council documents released in December, showed waste from nearby treatment plants was flowing into the harbour, which is considered a place of spiritual importance by Maori.
Hokianga resident Janine McVeagh said she had been "working to fix this issue" for almost 40 years.
"I'm an environmentalist, I live in the Hokianga, and I find it flagrantly insulting to Māori to put human waste into this water," she said.
Protesters cross Waitangi's one-way bridge between the lower and upper marae.
"Clever people have figured out that you don't have to do this. We've moved on as a people and technologically, surely."
As the rally crossed Waitangi's one-way bridge, waka were paddled underneath. The group marched up the hill through the Treaty Grounds and circumnavigated the flagpole. As they passed, their chant of "Hokianga no paru [filth]" was briefly drowned out by the navy brass band.
Veteran activist and former politician Catherine Delahunty said the hikoi was an appropriate event for Waitangi Day as "it's a Treaty breach to have s... in the water like this - it's s....... on Maori culture".
She said the Treaty "was supposed to give Maori the authority to decide how to rule their resources".
"But in this case they don't have the power to make the decision to not pollute the water of the Hokianga Harbour."
The government has been approached for comment.