Greater Wellington land management adviser Kolja Schaller, left, showing a keen resident how dung beetles are released. PHOTO/SUPPLIED
Lake Wairarapa will become the new home to around 70,000 dung beetles, thanks to an initiative by Greater Wellington Regional Council.
Four species of non-native dung beetle were offered to farmers around the greater Wellington region in subsidised packages designed to encourage on-farm trials which will lead to cleaner pastures, and environmental and economic benefits.
Farmers responded positively to the packages with strong uptake resulting in around 200 dung beetle colonies now being active, primarily in Wairarapa.
Greater Wellington land management adviser Kolja Schaller said around 35 packages were concentrated on properties along the eastern shore of Lake Wairarapa.
“We wanted to try to capture the attention of farmers in a certain area to get a feeling for what dung beetles could do if they were concentrated in one area,” he said.
“Lake Wairarapa has a high concentration of dairy farms there, and dairy farms have a good amount of dung on them.”
GWRC also wanted to reverse the current condition of the lake.
Lake Wairarapa contains high levels of nitrates and other pollutants, which leach into the water from dung, and this has resulted in poor water quality in the lake and its surrounding wetlands.
Introducing dung beetles to deal with pastoral dung provides an opportunity to help mitigate risks to freshwater quality.
Farmers will also benefit, as pasture contamination from dung reduces the amount of forage available for grazing.
The packages are made up of four colonies, with each colony containing up to 500 dung beetles, depending on the species.
“We’ve given them the minimum amount that’s going to have a successful colony establishment,” Schaller said.
“It’s enough that they find each other, mate and start their life cycle.”
Schaller said it was still early days, but results should become visible for farmers within three years.
By year 10, he hoped there would be enough dung beetles to get through a paddock after a dairy herd has grazed, burying all the dung within 24 to 48 hours.
“We’re pleased that farmers see eye to eye with us on the benefits the release of dung beetles offers, and that they are willing to invest to realise them,” Schaller said.
“Farmers are making a commitment to innovation which we believe will start paying off in around five years as the beetles spread throughout their farms, remove dung and improve farming conditions.”
Schaller said the dung beetles were still being released in the region and GWRC planned to work with the farmers over the next few years to plan a monitoring regime.