Good progress on Te Waihora biodiversity projects

Environment Canterbury today reported that good progress had been made on fencing projects and willow and weed control around Te Waihora/Lake Ellesmere, one of New Zealand’s most important wetland systems.

Te Waihora, located just south of Banks Peninsula, is a shallow coastal lake formed by the long shore drift of gravel that created Kaitorete Spit. It is internationally significant for its wildlife.

Frances Schmechel, Environment Canterbury Principal Biodiversity Officer, says that over the years the water quality of the lake has declined markedly. “Many of the native plant and fish species are facing increasing pressures, so it is very important that the lake’s ecosystem health is restored,” she said.

Te Waihora is one of three Canterbury Water Management Strategy Regional Committee Immediate Steps Flagship projects. The aim is to have funds allocated to ecosystem health projects around the lake over the next five years.

“This funding will be spent on fencing and weed control to protect the high value wetlands on the lake margin, and restoration projects at several sites around the lake,” Ms Schmechel said. “These projects will be completed in conjunction with landowners, Ngāi Tahu, Selwyn District Council and the Department of Conservation.”

Over the last year the Selwyn-Waihora Zone Committee has also funded projects on the lake shore with Immediate Steps funding. Many of these projects have now been completed, providing protection for native wetland vegetation.

The spread of willows, especially grey willow, and other weeds is a serious threat to the Te Waihora lakeshore. A willow and weed control strategy has been jointly developed by Environment Canterbury, the Department of Conservation and Ngāi Tahu to make sure all funding directed towards weed control is used effectively.

“The area dominated by grey willows has doubled in the last 25 years and this rate is continuing,” Ms Schmechel said. “Willow control is very cost effective for enhancing native vegetation and habitat, and allows native regeneration in the areas where willow has been controlled.”

At the Timber Yard Point site, fencing has been erected to protect lake margin wetland. The fence line provides an effective buffer zone between the lake edge and adjacent farmland. Willow removal was then undertaken as part of the Fonterra Catchment Care Programme with Conservation Volunteers New Zealand and the Selwyn District Council.

Willow control was also undertaken at Ward and Williams reserves as part of the ongoing willow control programme at this site and around the lake shore.

Fencing is now protecting wetland in the Boggy Creek area on the Te Waihora margin. This is also a partnership between landowners and Selwyn District Council. This project links with work that other adjoining landowners have been doing to protect and plant along Boggy Creek.

Background

The Te Waihora lake shore and margins support the most extensive contiguous wetland area in lowland Canterbury, of approximately 4,000 hectares.

The majority is saltmarsh or brackish wetland habitat, supporting a range of predominantly native shrub, rush and herbfield vegetation types. The native wetland vegetation within the freshwater areas is relatively little and in decline due largely to the spread of introduced plant species, particularly grey willows.

Despite this, the remaining native freshwater wetland communities are still an important part of the lakeshore ecosystem. They include significant examples of regionally rare and distinctive vegetation types such as baumea rushland, and are critical habitat for a number of rare or threatened plant and bird species such as orchids, swamp nettle and Australasian bittern/matuku.

Te Waihora shoreline wetlands are ecologically linked to other areas of high biodiversity value - the lake itself, native dry shrubland and dune vegetation on Kaitorete Spit, native forest remnants in Kaituna and Prices Valley on Banks Peninsula, and plains spring-fed tributary streams.

Immediate Steps projects complement the work being carried out in Whakaora Te Waihora, a cultural and ecological restoration programme led by Ngāi Tahu and Environment Canterbury.

In August 2011 a long-term relationship agreement and shared commitment was signed between Te Waihora Management Board (for Te Rūnanga o Ngāi Tahu) and Environment Canterbury. The Ministry for the Environment allocated $6 million to Whakaora Te Waihora.

Whakaora Te Waihora is a two-generation / 35-year restoration plan and the $6 million will support the first two to five years of the work programme.

Whakaora Te Waihora will significantly progress more than 10 years of restoration work already undertaken by Papatipu Rūnanga, landowners, agencies and others around the lake.

At the same time, the relationship agreement was signed for another $5.6 million combined funding from Ngāi Tahu, Environment Canterbury and industry in support of additional clean-up initiatives.