A view of Whatipu from the newly opened Omanawanui track in the Waitakere Ranges. Photo / Auckland Council
More tracks are reopening in the Waitākere Ranges this summer, with high hopes
a Covid-like epidemiological approach to kauri dieback disease will unlock more of the forested area.
It's been an unusual year with a few challenges, but some significant work, says Auckland Council's senior park ranger for kauri dieback,
Stu Leighton.
The August 30 storm that left a trail of destruction across Kumeū, Huapai, Rānui, Piha and Henderson Valley caused a massive slip on the Muir track and washed out a bridge on the Winstone track, Leighton said.
Covid has also slowed work, causing delays in getting materials, but two long tracks, Omanawanui and Puriri Ridge, have reopened nevertheless.
"Our track programme is now at a point where we are starting to join the dots – that is opening tracks that link with other open tracks to create much longer and varied options," Leighton said.
"It shouldn't be too long before Gibbons and Muir tracks reopen. People will then be able to walk from Huia all the way to Anawhata again on the track network."
The original plan was to have completed about 80 per cent of planned track reopenings by the end of this summer.
"However, we have had to divert track crews to fix significant storm damage on open tracks to enable them to reopen and this work is ongoing. This combined with the impacts of Covid means this target will most likely be pushed out a bit," Leighton added.
Alongside physical work, staff have also been busy trying to tackle the cause of the closures.
A new epidemiological approach was introduced this year to understand the prevalence, risk factors, cause and impacts of kauri dieback disease.
It also looked at how successful some management interventions had been.
Council biosecurity manager for kauri dieback Lisa Tolich said between February and May, a team randomly visited more than 2100 kauri trees of the 60,000 in the area to collect a representative sample of the population. Past surveys had only visited trees already with the disease.
From the trees visited, a "really large sample size" of 768 soil samples were taken. They are being analysed to look at the prevalence of the disease and risk issues, including aspect, exposure to climate and the soil's water content, Tolich said.
Most people think the Waitākere Ranges is one big area and the whole area is diseased, said Tolich, but different catchments may be affected differently.
The "landmark" work, involving Landcare Research, Department of Conservation, Massey University and mana whenua, is starting to yield information, Tolich said.
Partly funded through the council's natural environment targeted rate - started in 2018 to raise $311 million over 10 years - Tolich hopes the results can be shared with the public and scientific community.
Similar work could be done at the Hunua Ranges, one of the largest kauri areas in Auckland, where there has been no detection of the disease so far, she said.
The results will feed into new criteria to evaluate the next stage of track reopening in the Waitākere Ranges, including the prevalence of the disease within the track network. Other considerations will be recreational and tikanga values.
The next stage is set out in a new regional parks management plan that went out for public consultation late last year.(SUBS: 2020) It includes about 40 temporarily closed tracks and nine permanently closed tracks not part of the current reopening plan.
"We are working at full steam, even though we have been somewhat distracted by Covid and the big storm," Tolich said.
Leighton has some handy advice for people wanting to enjoy the Waitākere Ranges this summer. Research which tracks are open, check road closures, turn up with clean gear, use the cleaning stations and stick to the track.
Another handy hint. Look for tracks that may not be well known, but are close to home.
"We recognise it's important for people's wellbeing to get out, exercise and get time with nature. That is what the regional park network is there for.
"If people are coming out it is important that they follow the rules, because the more people come, the more pressure gets put on a place. Be kind, be respectful of each other and the places you are visiting," he said.
What is kauri dieback?
A soil-borne organism that attaches itself to kauri roots and slowly starves the tree of its ability to gain nutrients and water. Because it is soil-borne it can move on human and animal feet. The fungus-like organism is called Phytophthora agathidicida. There is no cure for the disease, which kills most if not all the kauri it infects. However, some treatments, like phosphite, halt the progression of the disease. It can be spread by a tiny amount of soil, and it is hard to tell by looking whether a tree is infected or not.
The disease has become prominent over the past decade, spreading throughout the Auckland region, the Coromandel, and to the Waipoua Forest in Northland, the home of our most iconic kauri - Tane Mahuta. The disease has not reached Auckland's Hunua Ranges.
How did kauri dieback become a problem in the Waitākere Ranges?
It was identified in the Waitākere Ranges in 2006 on the Maungaroa Ridge Track at Piha.
In 2011 a comprehensive survey was carried out to ascertain the spread of the disease with a follow-up report in 2016, which found it was spreading. That led to mana whenua Te Kawarau ā Maki placing a rāhui over Te Waonui-a-Tiriwa, the forested areas of the Waitākere Ranges, in December 2017.The rāhui prohibits people from entering the area in order to preserve the environment until kauri dieback is under control.
In May 2018, Controlled Area Notices (CAN) were put in place in parts of the Waitākere Ranges and the Hunua Ranges in order to open some tracks. A CAN is part of the Biosecurity Act. Under the CAN, anyone entering the area must not have any visible soil on their footwear or equipment, and must use the hygiene stations at the track entrances and exits.
What are the most popular tracks open to the public?
The classics, like Kitekite Falls in the western part of the Ranges, near Piha Beach. The spectacular 40 metre multi-stepped waterfall into a large lake-like pool at the bottom is reached after a reasonably easy 45-minute walk from the end of Glen Esk Rd. Also, the hour-long 2.7km Mercer Bay Loop walk, an easy walk with some steady hill climbs suitable for people of all ages that offers spectacular clifftop views. Head to Piha, turn left onto Te Ahuahu Rd (1.2km after the Karekare turnoff). Follow the road until it becomes Log Race Rd to a car park at the end. The popular Jubilee Walk at Cornwallis is also due to be reopened this summer.
How popular are the Waitākere Ranges?
About 900,000 people visit the ranges every year. In the past few years there has been a noticeable increase in visitors. This has been spurred by population growth and tourism, but also people wanting to reconnect with the outdoors, go for walks, trail running and swimming near waterfalls.
What measures do people have to take for walking in the Waitākere Ranges?
They must use the hygiene cleaning stations provided at the track entrances and exits to scrub and spray. They must not have any visible soil on their footwear or equipment. They must not enter any closed tracks.
For information on open and closed tracks go to: https://aucklandcouncil.maps.arcgis.com/apps/webappviewer/index.html?id=090a929b13884cfdb17078f7bb41c8a4
Two biosecurity dogs are the latest weapons in the fight against kauri dieback.
Six-year-old German Jagdterrier Mawhai and five-year-old English Springer Terrier Pip began training to sniff out the pathogen at a secure facility in Huia in February(SUBS: 2020).
Jagdterriers, also known as German Hunt Terriers, are intelligent and unrelenting hunters both above and below ground. English Springer Terriers are smart and eager-to-please hunting dogs.
The dogs' training, on the edge of the Waitākere Ranges, took place under strict cleaning procedures due to the risk of spread of the soil-borne organism, which included them wearing boots and having their paws cleaned.
Samples for training were inoculated by Plant & Food Research in Havelock North and couriered to Auckland with the permission of the Ministry for Primary Industries.
In the past year, the dogs and their trainers have undertaken specialist training of up to 10 hours a week to detect kauri dieback disease in a range of materials including kauri tree roots.
The training has not been easy as the phytophthora agathicida pathogen is not visible to the naked eye. Mawhai and Pip have had to rely on their good noses to detect the deadly pathogen and ignore other phythopthoras commonly found in kauri trees.
The next step was sensitivity training to phytophthora agathicida using odour recognition tests and checking of soil samples. This will allow samples from suspected infected trees to be quickly and cost-effectively tested.
It currently takes up to six weeks to test a soil sample, which the dogs can identify immediately.
Mawhai and Pip are being eased into their work, starting with the testing of soil samples from possible infected kauri trees. The next step will be to use them on islands in the Hauraki Gulf, including Waiheke, which are free from kauri dieback.
They will work on high-risk loads being sent to islands in the gulf; checking people's footwear or other items at the waterfront before departure; and searching equipment and materials being used to create walking tracks on islands.
The dogs will also check quarries and nurseries before goods and materials are transported to kauri-forested areas.
Mawhai and Pip have been certified by the Conservation Dog programme itself certified by the Department of Conservation.
Pip has two pups, Marty and Jamie, who are in training to join their mother on the hunt for kauri dieback.
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