Monitoring inanga habitats

ARTIFICIAL HOME: TEC manager Rena Kohere stands beside an artificial inanga habitat made from coconut matting, hay, and harakeke, which is held in place on the stream bank with bamboo poles. Picture supplied

Environment kaitiaki (guardians) are out monitoring inanga (whitebait) spawning sites around Tairāwhiti as the streams come alive with fish laying their eggs.

Whitebait in New Zealand are described as the juvenile forms of five species of the Galaxiidae fish family — inanga, koaro, banded kokopu, giant kokopu and shortjaw kokopu.

The check is part of the inanga spawning project that started in 2014. The council received funding from the Ministry for the Environment to carry out a community-based pilot project within the lower Waipaoa and Te Arai catchment areas to identify, protect and enhance inanga spawning sites.

Gisborne District Council environmental scientist and inanga habitat restoration project manager Olivia Steven says the council usually increases its monitoring of streams around autumn as it is the best time to check on inanga and their spawning success rate.

Rongowhakaata Iwi Trust and Tairāwhiti Environment Centre’s Katie Foxley were contracted to carry out the monitoring for council.

“It’s a task that must be done on king tides after the full moon as this is the only time during the month when inanga spawn,” Ms Steven says.

The eggs can be found in long grass along the stream banks where the saltwater meets the freshwater, an area known as the “saltwater wedge”.

“Artificial habitats are also used to assist monitoring on stream banks that don’t have suitable habitats for spawning.

These are created using coconut matting, meadow hay and flax to make a long roll that gets staked to the side of the stream,” Ms Steven says.

Fish swim up and lay their eggs in these artificial habitats and they are then checked to see if eggs have been laid and re-visited after a month to make sure the eggs are still present, as rats, floods and sediment are their biggest risks.

Since its inception, the spawning project has an established group to guide the project. Members include representatives from the council, Department of Conservation, Rongowhakaata, Ngai Tamanuhiri and Tairāwhiti Environment Centre (TEC).

The project has also helped identify priority sites on the lower Waipaoa and Te Arai rivers based on mapping the salt water wedge.

TEC has been contracted to coordinate community participation in the site surveying.

Contact the council at https://www.gdc.govt.nz/council/contact-us to register your interest, and to be contacted about seminars, wananga and site surveys taking place.