Our Changing World

Thursday 19 January 2012, with Alison Ballance, Ruth Beran & Veronika Meduna

Welcome to Summer Science, a special edition of highlights from 2011

Audio from Thursday 19 January 2012

Not all audio is available due to copyright restrictions.

  • Kermadecs - Fish Collecting ( 12′ 59″ )

    21:06 Biologists explain what's so unique about the Kermadec Islands fish life while they collect fish from rock pools

  • Rumen Methanogens ( 12′ 20″ )

    21:20 AgResearch scientists hope to reduce methane emissions by changing methanogens in the rumen of cattle and sheep

  • Sleep Apnoea ( 25′ 29″ )

    21:34 Overnight sleep studies to detect sleep apnoea, and the use of CPAP machines to solve the problem

On This Programme

Fish Collecting on Kermadecs

kermadec

Ged Wiren netting fish at the outlet to a rock pool on Meyer Island, and the HMNZS Otago (left) and the Braveheart at anchor with Raoul Island just visible to the left (images: A. Ballance)

The Kermadecs Biodiscovery expedition headed to New Zealand's remote sub-tropical Kermadec Islands in May last year for three weeks of surveying and collecting, based on board MV Braveheart. Led by Auckland Museum fish biologist Tom Trnski, the trip involved 13 scientists from Auckland Museum, Te Papa, the Australian Museum and the Department of Conservation, with expertise in fish, marine and terrestrial invertebrates and botany. The idea was to carry out a comprehensive survey and collection of coastal marine species around each of the archipelago's four groups of islands, and complement that with invertebrate and plant surveys on as many of the islands as possible.

Alison Ballance was on board to record events and discoveries, write a blog, and help out with fish collecting. In the first episode of the Kermadecs series, she talks with NIWA's Malcolm Francis about the island group's unique mix of fish species, finds out about the expedition's aims from Tom Trnski, and then joins the 'fish team' as they use rotenone in a rock pool to collect fish. Australian Museum's Mark McGrouther, and Auckland Museum's Ged Wiren and Stephen Ullrich don their wetsuits and join Tom in the rock pool.

A group of artists also visited the Kermadecs in May 2011 - click here to find out more about their trip, and their new book Kermadec, featuring art works developed as a result of the trip.

kermadec

Mark McGrouther putting rotenone into an intertodal rock pool, and seabirds wheeling over the island (images: A. Ballance)

Reducing methane emissions

Peter Jannsen, left, and Graeme Attwood.

Peter Janssen, left, and Graeme Attwood are investigating several species of methanogens in their research to reduce methane emissions in the rumen. (images: AgResearch)

Among developed countries, New Zealand has an unusual profile of greenhouse gas emissions. Agriculture produces almost half of our total emissions (compared to less than 10% in other developed countries) and methane accounts for a third. In recognition of the problem, several research organisations have formed the NZ Agricultural Greenhouse Gas Research Centre, hosted by AgResearch, in 2009 to investigate ways of mitigating emissions of greenhouse gases other than carbon dioxide.

This story was part of a series and focused on methane produced by ruminant animals such as cattle and sheep. The rumen is the first and largest part of the multi-chambered stomach of grass-eating animals. It acts as a fermentation vat where microbes break down the cellulose in the plant material to make it more digestible. One group in the rumen microflora, methanogens, takes up surplus hydrogen and produces methane. Researchers are currently pursuing six strategies to reduce methane production in the rumen: They are investigating the ecology of the system and the genetics of methanogens; they are exploring the natural variation in ruminants and different types of feed to identify animal lines and pasture grasses that produce less methane; and they are developing vaccines and inhibitors that will specifically knock out methanogens but leave the rest of the rumen microbial community intact. In this interview, AgResearch scientists Peter Janssen (pdf) and Graeme Attwood explain how important methanogens are in the rumen and which of the strategies are showing the most promise.

Harry Clark, director of pastoral greenhousa gas research centre

AgResearch chairman Sam Robinson, left, the director of the NZAgricultural Greenhouse Gas Research CentreHarry Clark and Agriculture Minister David Carter at the recent opening of the NZ Ruminant Methane Measurement Centre, at AgResearch in Palmerston North.

Sleep Apnoea

Maui Stuart before, and with Jessie Bakker after

Maui Stuart before his diagnosis of sleep apnoea (left), and after (right) in the room where he had the overnight sleep study with Jessie Bakker (images: Maui Stuart and Ruth Beran)

In this two-part story, Ruth Beran meets Maui Stuart who was recently diagnosed with sleep apnoea after an overnight sleep study at WellSleep, a sleep investigation centre based at Wellington's Bowen Hospital.

Jessie Bakker from the University of Otago, Wellington who worked at WellSleep explains what sleep apnoea is, how it is diagnosed, what happens during a sleep study, and demonstrates the gold standard treatment - a continuous positive airways pressure (CPAP) machine.

CPAP machine and leads used in sleep study

A CPAP machine and leads used in overnight sleep studies(image: Ruth Beran)

Jessie Bakker recently led a study analysing why some people in the community are less likely to continue with CPAP treatment. The first part of the study was based on a questionnaire of 127 patients living in the Greater Wellington area, and found that ethnicity did not independently predict compliance with CPAP after measures like socioeconomic deprivation and education were factored in.

The second part of the study involved three focus groups where eight New Zealand Europeans, five Maori and five Pacific patients, and while discussions did touch on culturally-specific aspects, all groups discussed common problems like financial barriers to CPAP use, feeling overwhelmed with the CPAP educational material, and the importance of role models.

Maui Stuart benefited from the discussion group, and has been changing his life ever since he was diagnosed with sleep apnoea. He has continued with CPAP treatment, has changed his diet, and is now doing regular exercise. He has lost over 25 kilograms so far, and his goal is to swim Cook Strait.

Scott’s Last Journey

On 19 January 1912, as Scott and his companions begin the long march back from the South Pole, the men pick up the Norwegians’ black flag and use the staff for their sail. “That is the last of the Norwegians for the present,” Scott writes in his diary on that day.

While it is easier to be marching with the wind, the men feel the cold more then they did during the march south. When a blizzard strikes two days later, they have to spend most of the day in their tents. Night temperatures drop to minus 30 degrees, rising to minus 20 degrees during the day and although the sail helps to pull the sledge, the journey is “dreadfully tiring and monotonous”. To make matters worse, Evans suffers from serious frostbite on his nose and fingers, and Oates’ feet get so cold he struggles to walk. Then another gale forces them to stay at their camp site.

“This is the second full gale since we left the Pole. I don’t like the look of it. Is the weather breaking up? If so, God help us, with the tremendous summit journey and scant food. … I don’t like the easy way in which Oates and Evans get frostbitten,” Scott writes on 24 January. A day later, they spot the red flag that marks their Half Degree Depot. They pick up provisions for seven days, but face a 90-mile march to the next depot.

Next Week

Our Changing World launches its 2012 season of programmes.