Native plantings to help lagoon

The arrival of thousands of native plants near a Southland lagoon has been heralded as a success, despite some falling victim to pests.

Whakamana te Waituna Charitable Trust led an initiative last month which resulted in 8625 plants going in the ground at Webster Block — a 48ha piece of land it acquired from Environment Southland for $1.

Trust project manager Sarah Yarrow said 18 months’ preparation had gone into the job, which included weed control, fencing and sourcing the plants.

‘‘The planting is part of the wider efforts of the trust to repurpose retired farmland to support the ecological functioning of Waituna Lagoon, increase biodiversity and support improved water quality,’’ Ms Yarrow said.

Situated next to Toetoes Bay on the southern tip of the South Island, the 1350ha lagoon is an area of cultural and ecological significance which forms part of the much larger Awarua-Waituna Wetlands.

But it also sits next to farmland, and has faced challenges in recent years including algal blooms and debate over when it should be opened to the sea.

The trust has warned the lagoon’s health ‘‘will continue to decline unless changes are made within the catchment’’, and is on a mission to restore 2000ha — or 10% — of the wider area.

All of the plants for the May 8 initiative were sourced from nearby areas and planted by 13 people from one company, Ms Yarrow said.

A half-and-half split of ‘‘hardy’’ native plants and nurse crop mānuka was used along with 2000 protectors, she said.

‘‘Unfortunately, hares, rabbits, possum and deer all like to browse on young plants, so it is expected there will be some loss to browsing.

‘‘The trust has established an animal pest management programme, which includes night shooting and a network of bait stations.’’

Ms Yarrow said the number of hares had been cut to low levels through consecutive control efforts, but about 5%-10% of the plants were expected to be lost.

The trust was established in 2018 and includes representatives from Environment Southland, the Southland District Council, Te Rūnanga o Awarua, Fonterra and the Department of Conservation, as well as an independent person.

The lagoon was last open to the sea from September 2024 to April last year.

In October last year, a new 20-year consent for opening the lagoon was granted to Environment Southland, Te Rūnanga o Awarua and Doc, although it has been appealed by Federated Farmers.

• LDR is local body journalism co-funded by RNZ and NZ On Air.