Work under way to rid Ahuriri Estuary of tubeworms

Shane Gilmer (left), HBRC water quality and ecology resource technician and senior scientist for coastal quality, Anna Madarasz-Smith. Photo / Supplied

Work has begun on removing colonies of an invasive marine tubeworm in the Ahuriri Estuary in a joint effort between Mana Ahuriri Trust and Hawke's Bay Regional Council.

An estimated 8.1 tonnes was collected yesterday and about 24 tonnes is expected to be removed by the end of the week.

Hawke's Bay Regional Council senior scientist for coastal quality, Anna Madarasz-Smith said the tubeworm, also known as Ficopomatus enigmaticus had been in the estuary since the early 1990s, but expanded its foothold in recent years.

"Reefs of the tubeworm now restrict water movement between the lower and upper estuary. The worm forms tubes which grow into coral-like structures."

There are several areas, which they are planning to tackle.

"We managed to cut 18 metres and probably have about 60 metres left in that one spot," Ms Madarasz-Smith said.

She said they were not aiming to completely eradicate the pest, as that would be "unrealistic".

"It is a long-term project and we don't expect to get it all out by the end of the week. It is a maintenance programme."

She said it was important that the removal programme was completed before the dry summer period, so the estuary could benefit from better flushing, and a more natural tidal flow of moving water.

A combination of diggers and manual labor is being used to remove the worm from areas between the Taipo Stream confluence and the Upper Ahuriri Estuary.

A team of four people were used, including a digger, and dump truck, while Ms Madarasz-Smith and water quality and ecology resource technician, Shane Gilmer worked from the water.

They were hoping to have more "people power" in the water in the days to come.

The estuary is home to several species of bird and fish and there are many other initiatives going on which involve the Napier City Council, Department of Conservation and the Hastings District Council.

"It is part of an wider, ongoing project to restore the health and wellbeing of the estuary. A lot of progress has been made and several groups are involved."

Ahuriri Estuary is one of the Council's 6 hot spot environmental clean-up projects funded by ratepayers in this year's HBRC work programme.