The efforts of “lots of really dedicated people” are paying off for the health of Wairarapa Moana, reports recently released by Greater Wellington Regional Council [GWRC] show.
The Spring 2023 Australasian Bittern [Matuku-hūrepo] and Spotless Crake [Pūweto] Survey shows a record number of 19 booming male matuku-hūrepo recorded at the core wetlands. These include 10 at Boggy Pond, three at Matthew’s Lagoon, and six at the Wairio wetland.
The previous highest count was 11 in 2022.
Pūweto were also recorded in record numbers, totalling 21 – more than double the number recorded in 2022 and a third higher than the previous record number of 14 recorded in 2014 in Boggy Pond.
“This is a big win site,” Sarah-Jane Jensen, GWRC Kaitohutohu Rerenga Rauropi [biodiversity advisor], said.
The return of the booming call of the critically endangered matuku-hūrepo last year was a strong indication GWRC, in partnership with local iwi, environmental groups and citizen scientists, had “been able to get the wetland into a really good place”, Jensen said
Fundamental to this achievement has been “taking the pressure off” the bittern and other native species by eradicating exotic willows that had overtaken areas of the wetland network, maintaining a comprehensive line of 470 traps – started by GWRC’s senior biosecurity officer Steve Playle in 2013 – and intensive native planting.
“What it’s meant is the natural regeneration of raupō, which is the bulrush, and harakeke [flax] and cabbage trees have been able to come back in. That’s prime habitat for bittern,” Jensen said.
“It’s that combination. There’s food there for the bittern, which is the fish, there’s habitat for them so they can start competing with each other, and they’ve got lots of nesting spots.”
Monitoring the outcomes of wetland restoration projects is critical, Jensen said.
“When you do all this effort for nature, it’s so important to monitor how effective it is.
“And in this case, it’s brilliant because we have gone from a population of bittern that was in rapid decline to one that is not just stabilising, but has shot all the way up. Which is so exciting.”
Of slightly more concern is the wetland’s population of kākahi [native freshwater mussel].
Monitoring of a citizen science kākahi count, now in its tenth year, indicates the local population is “ageing – we are not finding the babies”, Jensen said.
“They are an indicator of lake health.
“A strong focus for many of our partners is the health of the lake and the river, especially with the [Ngāti Kahungunu ki Wairarapa] Treaty settlement. So the kākahi is one of those species that’s telling us it’s not super happy, and now it’s about why and what we can do about it.”
For Jensen, who has a background in Western environmental science, partnering with mana whenua has been particularly rewarding.
“It’s got rid of the blinkers,” she said.
“It’s been so incredible to sit back with two different iwi who have two different views on the many ways we could look after these species or plants.
“All of a sudden, you start looking at the whole ecosystem rather than a narrow focus. I’m not about to forget that way of thinking.”
Work continues to restore and maintain the wetland, including a community planting day on April 21 organised by Pae Tū Mōkai o Tauiri, an environmental collective which runs He Kōtare Native Nursery.
“We are planting a species called karaihe sedge. It’s a beautiful endangered species, and particularly suitable as it’s endemic to Wairarapa Moana and doesn’t mind getting its feet wet,” Pae Tū Mōkai o Tauiri’s Narida Hooper said.
“We can plant it quite close to the water’s edge, and it will serve as a habitat for little wee birds and fishes that like to hide in grasses.”
Planters are encouraged to contribute to the cost of the plants, which can be purchased for $20 for five plants or $1.50 each.
“You can come and plant on the day – or we can plant it for you,” Hooper said.
For more details about the event and how to buy plants and take part, visit Pae tū Mōkai o Tauira’s Facebook.