Our Changing World
Thursday 2 July 2015, with Alison Ballance, Ruth Beran & Veronika Meduna
On This Programme
- Life in the World's Oceans
- From False Teeth to Forensics - the Story of Dental Technology
- Liquid Water on Mars
- Losing Weight and Getting Healthy - the SWIFT Study
- Commuting Secrets of Antarctic Orca
- Old Antarcticans Malcolm Laird and Peter Otway
Life in the World's Oceans
by Veronika Meduna Veronika.Meduna@radionz.co.nz
Some 51 per cent of all our marine species are found only in New Zealand. What that means is that we become custodians of that knowledge on behalf of the rest of the planet.
Dennis Gordon, NIWA
Every day, Wellington marine biologist Daniel Leduc comes past a small, popular swimming beach on his way to work. One morning, he decided to grab a handful of sand from the intertidal zone to see what lives in it – and discovered a species of nematode nobody had described before.
These tiny, worm-like creatures are ubiquitous. Some are parasitic and live inside animals, including us, and plants. Free-living species are found everywhere, with the biggest diversity in soils and marine sediments. A square metre of sand or soil is likely to be home to a million nematodes.
“They are quite diverse. You can take a handful of sediment from a beach and you might find a dozen species or so. If you go to the deep sea, the same handful of sediment will probably contain about a hundred species,"says Daniel Leduc.
The newly discovered nematode is one of many new species marine biologists at the National Institute of Water and Atmosphere have contributed to a global effort to combine all existing knowledge of sea life. The World Register of Marine Species, known as WoRMS, recently announced that it has almost completed logging all of the world’s known marine species that have been described throughout scientific history.
Since the initiative began in 2008, more than 1000 new-to-science marine fish species have been described globally – an average of more than 10 per month – including 122 new sharks and rays, 131 new members of the goby family, and a new barracuda found in the Mediterranean.
A NIWA-led inventory of New Zealand’s marine species counted close to 12,500 named marine species for WoRMS.
NIWA taxonomist Dennis Gordon says the rate of discovery is only limited by the amount of time people can put into studying biodiversity, and as far as marine life is concerned, there is still a lot to be found.
“A case in point is when in 2007 we had the world’s first marine BioBlitz, which was focusing on the Taputeranga Marine Reserve on Wellington’s south coast. We had at least 20 new species and half a dozen of those have since been described.”
These new species are not all tiny microscopic organisms.
As we get more and more into the deep sea, we’re finding heaps of new species - and we’re talking here about quite large organisms. We’re talking about sponges, large corals, including black corals. It’s hard to keep up with the rate of discovery.
Dennis Gordon says while naming and describing biological diversity is fundamental to ecological science, the next step is to protect unique ecosystems.
“This is particularly true for New Zealand, because we have a high degree of endemism, in other words, species that are found nowhere else in the world. And this is true even in the marine environment – some 51 per cent of all our marine species are found only in New Zealand. What that means is that we become custodians of that knowledge on behalf of the rest of the planet.”
Globally, in 2014 alone, some 1,451 new marine creatures were added to WoRMS, including 139 sponges and two dolphins (see image gallery above). But apart from adding new species, another task is to tidy up taxonomic redundancies. The champion in this category is Littorina saxatilis, a sea snail popularly known as the rough periwinkle, which has been described and named 113 times.
The most daunting challenge, however, is that researchers with the Census of Marine Life, within which WoRMS is a major component, estimate that up to two million marine species remain to be discovered and described.
“It is humbling to realise that humankind has encountered and described only a fraction of our oceanic kin, perhaps as little as 11 per cent," says WoRMS co-chair Jan Mees.
We fear many species will almost certainly disappear due to changing maritime conditions - especially warming, pollution and acidification - before we’ve had a chance to meet.
From False Teeth to Forensics - the Story of Dental Technology
By Alison Ballance
"Dental technology is the technical side of dentistry. We’re sort of the backroom guys, the oral micro-engineers who design and make things for the dentists to use to treat patients."
Neil Waddell, Faculty of Dentistry, University of Otago
Dentures or false teeth, bridges, tooth caps, orthodontic devices such as removable braces, ‘glass’ eyes, and prosthetic noses and fingertips. If it can be made from polymers, metals and ceramics, and it needs to look and, at least in the case of the teeth, function like the real thing, then chances are a dental technologist will be able to make it.
Dental technology is mainly about creating appliances to improve patients’ appearance, speech or ability to chew. It is taught as a three-year degree at the University of Otago, and students must have a background in chemistry, biology and physics. After training they can register as a Registered Dental Technician.
“The forces in the mouth are very strong, so the materials we use to make the teeth have to withstand very, very high forces. And the mouth is a very harsh environment. The saliva, the enzymes there, are very corrosive,” says Neil. “And then because we eat, we masticate, we clench and our jaws move it’s a fatigue – we cyclically load. Yet at the same time it’s got to look tooth-like in appearance.”
As a result dental technologists need to understand material engineering as well as having artistic abilities to be able to sculpt and paint things such as dentures in a very realistic way.
“Dental technology is very linked to the aerospace industry,” says Neil. “The dentistry industry looks at the aerospace industry and says ‘wow, we could use these technologies and materials and techniques’ but in a dental application.”
Neil Waddell and others from the Department of Oral Rehabilitation in the Faculty of Dentistry have worked with Crown Research Institute ESR to develop a skin-skull-brain model that was used in ballistic testing. PhD student Lisa Falland is currently working to further the use of the model to look at concussive head injuries.
“The question is how much energy would get transferred [to the brain] if you got hit on your head, and you can’t measure that on a real human,” says Lisa. “So I’ve developed this model that has a gelatin brain, a polymer resin skull, and skin made from silicon. Then there are sensors attached.”
The model has been tested so far with swords from the Japanese martial art of Kendo. “A couple of month ago you’d have seen a whole lot of students, using a Kendo sword, beating a skin-skull-brain model to measure the impacts. Once we know what the levels of energy transfer are we can then start to change as a variable the helmet design, thickness, etcetera in light of the forces going through to the brain.”
PhD student Joanne Choi has been developing a moulded device to measure intra-oral pH in the mouth over 24 hours. Acidic conditions in the mouth can lead to dental erosion of both real and artificial teeth, and is common amongst people who have dry mouths or suffer from gastric reflux.
Liquid Water on Mars
By Veronika Meduna
Space scientists have seen a lot of evidence for frozen water at the Martian poles, and water vapour in the planet's atmosphere, but in theory, Mars should be too cold to support liquid water.
Recently, however, NASA’s Curiosity rover discovered deposits of salts, known as perchlorates, which significantly lower the freezing point of water. The findings suggest that liquid water could form below the Martian soil surface on cold winter nights, and evaporate again in the morning when temperatures start to rise again.
The discovery was made while the rover traversed Gale Crater, near the Mars equator, taking round-the-clock, year-round measurements. An international team led by Javier Martín-Torres from Luleå University of Technology then analysed data on atmospheric humidity and temperature from a full Martian year, finding that while it would be impossible to detect the brine directly, the conditions for its formation are right.
Astrophysicist Duncan Steel says water is a prerequisite for life as we know it but the discovery does not mean that life will be discovered on Mars. “We also find organic chemicals there, all but that that means is that the building blocks of life are there. Although it’s exciting to find liquid water on Mars, there really is no way of making an estimate at all as to whether there is any life elsewhere in the universe.”
Losing Weight and Getting Healthy - the SWIFT Study
By Alison Ballance
“This diet, if my wife had come up with it, I probably would have told her it is a stupid idea. But I read about it in the paper and it sounded like what I wanted to do.”
Geoff Keeling, South Canterbury dairy farmer
Geoff Keeling is on a diet and exercise programme – and in just a few weeks he’s already seeing the benefits. The Canterbury dairy farmer seems like an unlikely candidate for a diet, but this is no ordinary weight-loss programme. He’s taking part in the University of Otago’s SWIFT study, a 2-year project that hopes to identify popular and effective diet, exercise and support strategies that people can easily incorporate into their daily lives.
Geoff says his motivation for getting involved came from looking around and seeing other middle-aged, overweight and unfit men. He says his farming lifestyle is probably less energetic than most people would expect – he spends much of his time in meetings or in the office, and often drives a tractor around the farm. The SWIFT study has enlisted 250 participants, more than 30% of whom are male, which is a high proportion for this kind of study.
SWIFT stands for Support strategies for Whole-food diets, Intermittent fasting and Training, and PhD student and medical doctor Melyssa Roy is adamant that weight-loss is just a small part of the study. The focus of the study, she says, is to support people who want to make healthy life-style changes, by looking to see whether “these alternatives that are popular in popular culture are feasible alternatives from a public health point of view.”
Michelle Jospe, another PhD student working on the project, says “you can lose weight following many different diets, but it’s a matter of finding one that works for you. And then we’re interested in seeing how places like a GP practise can help a patient follow the diet and exercise plans that they want to follow.”
The 250 study participants can choose between three diet options and two exercise options, and then they are randomly assigned to one of five support strategies. The three diets are popular diets that haven’t all been well-researched: the well-known Mediterranean diet of whole foods, fresh fruit and vegetables, and low meat; the palaeo diet, which is similar except there is no limit to the amount of meat that can be eaten, and no processed food; and the intermittent fasting or 5:2 diet, in which people eat normally for five days, and then eat no more than 500 calories for women or 600 calories for men on the remaining two days.
The choice of exercise programme was either moderate intensity exercise, which is the current standard recommendation of 30 minutes a day, or high intensity exercise, which is a very sharp intense exercise bout for 5-10 minutes two to three times a week. This has grown in popularity recently as it doesn’t involve much time.
Geoff has chosen to follow the 5:2 diet, as it fits in well with his busy, energetic family without impacting their diet. He chose to follow a moderate intensity exercise programme, as again it works in well with his family – his children swim a lot, so he can either swim with them or take a walk, and he is also trying to make himself walk rather than use the quad bike around the farm.
The third key component of the study is the support strategy that people are randomly assigned to. The control group is current GP care, in which people are briefed at the beginning and then left to their own devices; a more traditional support strategy that involves coming in occasionally for weighing and a chat about successes or failures; daily weighing and reporting-in, with feedback in the form of a monthly email; use of the popular mobile app My Fitness Pal, which you use to log your eating and exercise; and hunger training – during the first four weeks of the programme people gain awareness of when and why they want to eat, by monitoring blood glucose levels to determine if they actually need to eat.
Geoff was assigned to the hunger training support group, and credits this with losing 7 kilograms in weight during the first 5 weeks of the study.
“I was effectively training myself to only eat when absolutely required, which meant that there are no snacks between mealtimes, my meals are generally smaller, and with two kids that loved monitoring what my blood glucose was, watching what I eat and sniping at me [it had] huge effects, straight-away.”
The intensive hunger training system really opened Geoff’s eyes.
“It illustrated that we eat a lot of food needlessly. I got to the stage after a couple of days I knew my blood glucose wouldn’t be in the right level so even though I felt like I wanted to eat I just didn’t even bother.”
The SWIFT study runs for two years, and results won’t be available until after June 2017.
Commuting Secrets of Antarctic Orca
New Zealand and Italian researchers have finally confirmed what scientists have suspected for nearly 20 years - that some of the orca seen around the coast of Northland are in fact orca from Antarctica.
The clincher is photos of the same female orca, taken in both Northland and Antarctica.
Dr Ingrid Visser, from the Orca Research Trust, has studied orca for more than 20 years. She knows most of the 200 or so animals that make up the small New Zealand population by sight.
But, every so often, she sees smaller orca with yellowish white patches and distinctive slanted eye patches - which she suspected were a kind of Antarctic orca.
Dr Visser has been collaborating with Dr Regina Eisert from Gateway Antarctica at the University of Canterbury over the photo identification of orca in New Zealand and Antarctica.
Ekaterina Ovsyanikova, a student supervised by the pair, recently struck gold, finding that the same individual female "Type C" orca had been photographed repeatedly in New Zealand and in McMurdo Sound, Antarctica.
“This suggested that the killer whale had been commuting between Scott Base and Northland,” Dr Eisert said.
For the past two summers, Dr Eisert has been researching orca and their diet in the McMurdo Sound area of the Ross Sea as part of the Top Predator Alliance (TPA) project.
At the same time, Italian researchers Dr Giancarlo Lauriano, from the Institute for Environmental Protection and Research, and Dr Simone Panigada from the Tethys Research Institute, have been studying Type C Antarctic orca in Terra Nova Bay, 360 kilometres north of New Zealand’s Scott Base.
They deployed satellite transmitters on orca to determine where they travelled to, and these have revealed that Type C Antarctic orca are travelling to northern New Zealand, and as far as north as the Kermadec Islands, a journey of nearly 5000 kilometres.
The satellite tags only work for a month, and most of the data collected shows the whales moving north, so it's not yet known how frequently the orca make the return journey.
Orca in Antarctica: Type A to Type C
There are three types of orca recognised in Antarctica. Type A are found in open water around the Antarctic Peninsula and migrate there in summer from further north to prey on Antarctic minke whales. Type B live in loose pack ice and prey mainly on seals. Type C are the smallest and least well-known type, and they forage deep into the pack ice, hunting fish such as Antarctic toothfish in open-water leads amongst the ice.
These are the orca that are being studied in the Ross Sea.
“If Antarctic killer whales roam all the way from Scott Base to the North Island of New Zealand, rather than stay in a relatively confined area as some scientists believe, it crucially changes our understanding of the ecology of these key top predators and the potential threats they may face,” Dr Eisert said.
She said that the the whales’ long commute "would also suggest that there is much greater ecological connectivity between Antarctica and New Zealand than previously thought".
The TPA, of which this work forms a part, is a joint multi-year research programme between Gateway Antarctica, NIWA, Landcare Research and Lincoln University. It is looking at top predators in the Ross Sea ecosystem, including Weddell seals, Adelie penguins and Antarctic toothfish, as well as orca.
“We wanted to determine whether a decline in the Antarctic toothfish fishery in the Ross Sea poses a risk to Type-C killer whales, including finding out how many there are in the Ross Sea and where they feed,” Dr Eisert said.
She said that, although scientists had suspected that Type C orca eat Antarctic toothfish, as well as smaller fish such as silverfish, it was during the 2013/14 summer that the research team finally got photographic evidence of an orca with a toothfish in its mouth.
While some researchers had reported declines in the number of toothfish caught in McMurdo Sound, the TPA has been finding evidence of good numbers of toothfish coming into the sound.
The Antarctic Type C orca have learnt to use the open water provided in the shipping channel created by an icebreaker each summer in McMurdo Sound.
“Killer whales are very smart,” Dr Eisert said. “You have to remember they are about the same size as an elephant and they have a kilogram more [of] brain. They wait for the ship to come in and then they follow the channel right down to [McMurdo] Station.”
The TPA project has also been collecting photos of as many Antarctic orca as possible to add to Dr Visser’s existing photo identification catalogue for New Zealand orca.
Photo identification is one of the main non-invasive research tools used to study orca, as well as other whales, dolphins and sharks. Subtle differences in colouration patterns, nicks on the dorsal fin, and scars on the whale’s body uniquely identify each whale, allowing individual killer whales to be recognised wherever they go.
Compilation of whale images into a catalogue allows scientists to follow individuals in time and space, and even estimate the total size of a population.
Dr Eisert is currently working with Antarctica NZ to investigate the possibility of hosting the orca photo identification catalogue on Antarctica NZ’s new digital asset management platform.
Small tissue samples, collected using a biopsy dart fired from a special gun, will allow the researchers to analyse diet, and confirm how important Antarctic toothfish are as food.
The findings are being presented this week at a meeting of the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).
They are the result of international collaborations between Gateway Antarctica at the University of Canterbury, Italian researchers from the Institute for Environmental Protection and Research and the Tethys Research Institute, the Orca Research Trust and Heritage Expeditions - a Christchurch-based adventure travel company.
Many citizen scientists in Antarctica and New Zealand contributed their killer whale photos and sightings.
In New Zealand, Antarctic killer whale research is supported by the Ministry of Primary Industries, Antarctica New Zealand, the New Zealand Antarctic Research Institute and Canon New Zealand Ltd.
Old Antarcticans Malcolm Laird and Peter Otway
By Alison Ballance
Antarctic geologist and one-time sled dog handler Malcolm Laird died recently. The retired University of Canterbury sedimentologist made more than a dozen trips to Antarctica during his lifetime, beginning in 1960 as a dog handler, and more recently as part of the Cape Roberts Drilling Programme. He also visited a number of times as a lecturer on board cruise ships. In 1978 he was awarded the Polar Medal for his services to Antarctic research. Laird Plateau and Cape Laird in Antarctica are named after him.
At the 2014 IceFest, held in Christchurch, Malcolm Laird shared the stage with retired surveyor Peter Otway, another frequent Antarctic visitor, in a session entitled Old School Antarctic Explorers. The session was chaired by Alison Ballance, and the pair showed slides and talked about the challenges and excitement of working in remote locations, using sleds and sled dogs to travel.