Our Changing World
Thursday 27 August 2015, with Alison Ballance & Veronika Meduna
On This Programme
- Vanuatu after Cyclone Pam
- Volcanic Hazard at Mt Taranaki
- The Bugs are in the House
- Berry Good News for the Brain
- Neutrinos - a Poem
Vanuatu after Cyclone Pam
by Veronika Meduna
On 13 March 2015, Cyclone Pam tore through Vanuatu. The category five storm caused widespread damage throughout the archipelago, leaving thousands of people homeless and destroying most crops. In Vanuatu’s capital Port Vila, on the main island Efate, most buildings were destroyed.
Four months later, when I had an opportunity to visit Efate, Port Vila was returning to life, with cafes and shops reopened, amid ongoing construction, including a new convention centre. Cruise ships had also returned to the harbour.
Further out from the capital, at the Eratap village, villagers say they began rebuilding the day after the cyclone struck and most homes are inhabitable again. During the night of the cyclone, some sought shelter in the school, which lost its entire roof and is still waiting to be re-roofed.
Richard Shing, an archaeologist at the Vanuatu Cultural Centre, says people are now realising that they have to build better houses to be prepared for disaster. He says traditional building techniques could help increase resilience.
We have documented accounts of traditional houses that withstood hurricanes in the past. There is a style of housing, not practiced a lot today in Vanuatu, where the roof touches the ground and anchors the beams of the roof into the ground. Where I come from down south we use that a lot and what happens during a hurricane is that you leave your house and go and hide in the traditional hut, and you’re safe.
He says people are aware of climate change, and that it is likely to bring more intense cyclones.
Margaretha Wewerinke is a Dutch environmental law lecturer who moved to Vanuatu a day before Cyclone Pam hit. She has joined the law faculty at the University of the South Pacific, where she teaches law with a focus on equitable development. She says climate change is already affecting island nations throughout the Pacific.
Not long after she left the Netherlands, the Dutch people made legal history. In the world’s first climate liability suit, they brought a claim against the Dutch government for failing to meet its obligation to protect its citizens from dangerous climate change. As a result, the court ordered the state to reduce greenhouse gas emissions by 25 per cent within five years.
She says she would prefer if no legal action was needed, but “it may become desirable for people and nations to use legal action to hold people who pollute and those who have the power to regulate polluting activities to account”.
Volcanic Hazard at Mt Taranaki
Mt Taranaki, the second-highest mountain in the North Island, has a classic cone shape, which indicates that it is an active volcano. Detailed studies by scientists at Massey University have worked out the history of Mt Taranaki's volcanic eruptions over the last 130,000 years. The team found that while eruptions have not occurred at regular intervals, on average there has been a moderate-sized eruption every 340 years, with numerous small ones.
Mt Taranaki last erupted around 1854, at the culmination of several eruptions in the preceding few hundred years. The western side of the Taranaki region is a volcanic landscape, constructed from the products of eruptions. On three occasions, twice within a very short period of geological time, former cones have collapsed to the north-east, south-east and the west. In each instance extremely large volumes of material flowed more than 40 kilometres across the landscape, reaching the present Taranaki coastline. They have created the distinctive mounds or hummocks on the lowlands surrounding the volcano.
Geologists think of Mt Taranaki as a "slumbering" volcano - active, in a state of quiescence, but certainly not extinct.
Any future eruptions could bring ground-hugging lava flows and landslides or more volatile explosions of ash and pumice. To find out more, Ruth Beran meets Massey University PhD student Rafael Torres-Orozco at his study site below the Curtis Ridge to talk about Mt Taranaki’s volcanic history, its potential for future eruptions and the damage that it could cause.
The Bugs are in the House
By Alison Ballance
A year ago some little, brightly-coloured buildings appeared around the campus of Lincoln University. With names like the Bug Ale House and the Blue Lagoon Hotel, they are Bug Hotels, also called Insect Hotels. They were built by landscape architecture students, with advice from ecology students, and the idea is to encourage native biodiversity by giving creepy crawlies places to live and raise a family in.
“We call them Insect Hotels,” says Nathan Curtis, an ecology tutor at Lincoln Unviersity. “But we’re obviously looking for any little invertebrates … all sorts of things that might be helping the environment.” He also pointed out that the hotels might provide a safe refuge for lizards.
Twelve months on ‘Bug Bloke’ Rob Cruickshank, one of the masterminds behind the Bug Hotels, is curious to find out what has taken up residence. I joined Rob and Nathan on a demolition job to investigate, which raised an interesting dilemma: how do you judge whether your Bug Hotel is succeeding without destroying it?
The answer is that you can’t, so Rob and Nathan opted to closely investigate just two of the Bug Hotels that had already been condemned because of tree felling in the immediate area, in one case, and building work in the other case.
The first Bug Hotel they autopsied was a small multi-coloured, multi-storey affair that had been in a copse of vegetation by the side of the road. The second one was a letterbox-based design that had been in a shrubbery next to a path. Both hotels used a range of materials to try and attract a variety of invertebrates, including dried grass, sphagnum moss, pine needles, old toilet roll tubes, corrugated cardboard, bits of bamboo, lengths of wood with holes drilled along their length, pine cones and a wide variety of other materials. Rob noted that among the features that make an effective Bug Hotel are the use of mesh across the front and back to prevent all this small material from spilling out.
“Lots of insects are thigmotactic,” says Rob. “They like to crawl into narrow spaces between things and feel their body pushed against the side of the place they’re hiding away in.”
Some hotels are made of untreated timber, and the idea is that these will slowly rot into the surrounding environment, providing home to different kinds of creatures over time, including wood-boring beetles. Other hotels are painted, to keep them weather-tight. Yellow, blue and white colours were chosen as they have been shown to attract different kinds of insects.
We were searching the Bug Hotels in the middle of winter, when there is less invertebrate activity, and there was only a small amount of evidence that the Bug Hotels had been used by insects such as weevils. The most common critters collected were spiders; “it was about six spiders to one insect,” noted Nathan.
While the number of residents was low, Rob pointed out that the hotels were not just for insects, but were there for people as well.
“The Bug Hotels are there to draw people in, give them something to look at, and help them think about the value of biodiversity.”
In a recent Our Changing World story on spiders, Cor Vink from Canterbury Museum showed me how most of the spiders around our houses are introduced species. Since the idea of the Bug Hotels is to encourage native biodiversity, Rob and Nathan were keen to find out if the spiders taking up residence in the Bug Hotels were native or introduced. I delivered the eight spiders found in the two hotels to Cor Vink at the museum, and he identified them as being two native species, two endemic species, one introduced species and three indeterminate (they weren’t mature so it was not possible to identify them). And, since spiders were the most abundant resident in the two Bug Hotels sampled, Cor agreed with me that perhaps they should be renamed Spider Hotels.
New Zealand has about 2000 species of spiders. There are about 70 introduced spiders in New Zealand, and they are mostly found in highly modified habitats. Here is a list of the spiders found in the Bug Hotels:
Garden orbweb spider (Eriophora pustulosa): the most common orb web species in New Zealand. It is a native species that was originally from Australia and arrived in New Zealand by ballooning, using silk threads to float with the wind. It’s called pustulosa because it has five pustules or knobs at the end of its abdomen. As its name suggests, it builds a web, and also builds a messy grey-green egg sac to lay its eggs in.
Australian ground spider (Nyssus coloripes): was probably introduced to New Zealand by people in the 1940s. They are hunters that don’t build a web and are very common around houses as well as in native habitat. They have orange front legs and white spots on their back and back legs.
Cobweb spider (Cryptachaea veruculata): is native to New Zealand and Australia, and common around bush edges and in gardens.
Square-ended cobweb spider (Episinus antipodianus): an endemic species in the family Theridiidae. It hangs upside down on a few threads of silk and catches prey from this position.
Square-ended crab spider (Sidymella spp): are ambush predators rather than web builders and lie in wait for their prey. Cor wasn’t entirely sure what species this was at first glance, but highly likely to be endemic (although there are several introduced species).
Ground spider (Scotophaeus pretiosus): Cor said that we have a number of endemic species, but we don’t know the status of this one. It’s thought to be introduced as it has no close relatives in New Zealand, however it’s also not been found anywhere else.
There were also two native jumping spiders, but as both were immature Cor wasn’t able to identify them – identification of spiders is often based on the genitalia of adult males. There are about 200 species of jumping spider in New Zealand, but although they’re a well-known group only about 50 are described, and Cor says you’d only be able to identify about 12 species based on the descriptions.
Berry Good News for the Brain
By Alison Ballance
“We design foods, or mixtures of food, that have an appreciable effect on mood or cognition. The two main targets were around learning and memory, and anxiety, sleep and stress. We want to find something that can relax people to a degree, without making them stupid. And that’s actually quite a challenge.”
Arjan Scheepens, Neuroscientist, Plant and Food Research.
The Mood Food research programme, run by Plant and Food Research has spent the last few years trying to identify food that has a proven health benefit. And they’ve recently announced a success – blackcurrants. Their research has shown that New Zealand-grown blackcurrants not only increase mental performance, but also reduce the activity of monoamine oxidases.
“We specifically were looking for things that inhibit enzymes called monoamine oxidases. As their name suggests they oxidise mono-amines, and mono-amines are things like dopamine, serotonin and noradrenalin. These are really important neuro-transmitters … they’re the good guys and more is generally better than less.”
Neuroscientist Arjan Scheepens says that serotonin is involved in depression, while dopamine is involved partly in depression and anxiety, but also in movement disorders such as Parkinsons.
“If you can inhibit the enzyme that removes dopamine, then you should have higher dopamine levels and this should be of benefit to people who don’t have enough.”
Previous research carried out in the lab had showed that compounds found in some berryfruits may act like monoamine oxidase inhibitors. The latest research tested the effects of blackcurrant consumption on adults – as it was a food, not a new drug, it was very easy to carry out these clinical trials.
Participants in the study were 36 healthy adults aged between 18 and 35 years. They consumed a 250ml drink prior to conducting a set of demanding mental performance assessments. The participants consumed either a sugar and taste-matched placebo (no blackcurrant), an anthocyanin-enriched New Zealand blackcurrant extract (Delcyan™ from the company Just the Berries) or a cold-pressed juice from the New Zealand blackcurrant cultivar ‘Blackadder’, bred by Plant & Food Research. The assessments showed that after consuming the Delcyan™ and ‘Blackadder’ drinks, attention and mood were improved while mental fatigue was reduced. In addition, blood tests showed that the activity of the monoamine oxidase enzymes (MAO) was strongly decreased after consuming the ‘Blackadder’ juice, indicating the potential for compounds found in ‘Blackadder’ blackcurrants as a functional food ingredient to support brain health or managing the symptoms of disorders like Parkinson’s disease.
Research results have been published in the Journal of Functional Foods: “Acute supplementation with blackcurrant extracts modulates cognitive functioning and inhibits monoamine oxidase-B in healthy young adults.”
Before you rush out in search of the products mentioned, Plant and Food Research say they are not aware of any products on the market containing only juice from the New Zealand cultivar 'Blackadder'. Blackadder is a commercial cultivar is not currently available to the home gardener.
Plant & Food Research also say they have only analysed the cultivar 'Blackadder' for its effect on cognition in healthy young people - although it is possible that other varieties may have a similar effect this has never been scientifically tested. They have not tested the effects of 'Blackadder', or any other blackcurrant variety, in people with cognition or mood disorders, such as Parkinson’s, depression or anxiety, and are not able to comment on potential effects.
Neutrinos - a Poem
‘Neutrinos’ is a poem by Wellington poet and novelist Janis Freegard. It is part of her poetry collection The Glass Rooster, published by Auckland University Press (2015). We featured it on Our Changing World to mark National Poetry Day on 28th August.
We recently featured an interview about Neutrinos with the University of Canterbury’s Jenni Adams.