Gisborne Council spartina removal project works a treat on Taruheru River

These before (right) and after (left) photographs illustrate how successful the first phase of the council project to kill off the invasive Spartina grass in the Taruheru River has been.

The first phase of a council project to begin the removal of spartina grass from the Taruheru River, that started with a spraying operation in January, has been deemed a success.

In the sites sprayed, the grass has broken down and been removed through normal tidal flows.

Gisborne District Council liveable communities director Michelle Frey said testing of the sites had backed up the visual results to show a mass reduction in the spartina, an increase in mud crabs and no residue left from the herbicide used.

“It has been a successful start to the project,” she said.

“The second stage of the Spartina Replacement Project will take place by the end of the year when regrowth happens again - with more spraying being carried out this summer.”

The project has been led by freshwater improvement group Haumanu Tū Ora, funded by the Ministry for the Environment and Gisborne District Council.

Frey said the aim was to eradicate the invasive weed spartina to increase biodiversity along the Taruheru River.

“This means encouraging the return of shellfish and wading birds back to the river.

“Testing one month after the first January spray picked up no residue from the herbicide haloxyfop that was used,” she said.

“We look forward to seeing birds and shellfish return to the banks of the Taruheru River over the next few years.”

Spartina was introduced to the Taruheru River in the 1960s.

Since then, it has encroached into the waterway and disrupted the river’s natural biodiversity.

The spraying was carried out by the council’s biosecurity team, with support from Haumanu Tū Ora, in compliance with the EPA regulations.