This week at Macquarie Island: 18 November 2016

The North Head SMA, which is only open for six weeks a year and exists to protect breeding seal and bird colonies, closes this week.

Those of us that left a visit until the last minute were lucky enough to be rewarded with seeing the season’s first Antarctic fur seal pups.

Macca may have the slowest internet speed in the world but it does have some of the cleanest air, barring a few obvious locations you should try to avoid being downwind of such as elephant seal wallows, the power house, Warren and Hass House after a big Saturday night on the black and tans.

Macca is one of the important Southern Hemisphere sites in the World Meteorological Organisation Global Atmospheric Watch program. CSIRO with BoM and other collaborators at the Australian Nuclear Science and Technology Organisation (ANSTO), University of Heidelberg (Germany) and Princeton (USA) have been collecting air samples and measuring concentrations of greenhouse gases, their isotopes and other related trace gas in the troposphere from the Macquarie Island clean air laboratory since the early 90’s.

CSIRO has collected an invaluable unbroken time series of trace gas measurement data over this period. These results are presented in Figure 1, showing the steady rise of atmospheric carbon dioxide (CO₂) at Macca, rising about 13% since 1991 (~2 ppm per year). The current CO₂ concentration in the southern hemisphere atmosphere has just exceeded 400 part per million (ppm), steadily approaching the often quoted dreaded threshold of 450 ppm.

This data is used in a wide range of global scientific research of the changing atmosphere and the impacts on regional and global climate. This includes the United Nations Framework Convention on Climate Change (UNFCCC) assessment reports that inform global climate agreements such as the recently ratified Paris agreement (COP21), which went into force on 4 November 2016, just after the Melbourne Cup.

I work for CSIRO Oceans & Atmosphere in the greenhouse gas observation and modelling team and this is my fourth visit to the island since 2005 but these visits have always been limited to as a round tripper during the annual V4/V5 resupply voyages.

In 2005 I installed the original insitu analyser developed by CSIRO, the “LoFlo” to measure atmospheric CO₂ continuously and very precisely. This has produced a continuous decade long data set that is currently being used to investigate the potential decreasing efficiency of the Southern Ocean to absorb atmospheric CO₂. I have been busy developing an international collaborative network of well inter–calibrated atmospheric observation sites for this purpose and which Macca and Cape Grim form the hub (Figure 2).

The Southern Ocean is one of the most important natural CO₂ sinks. The global oceans remove from the atmosphere an equivalent amount of fossil fuel derived CO₂ as the terrestrial biosphere does. And here are some more facts and figures for your next trivia quiz night: there is more carbon stored in the deep ocean than in all of the reservoirs of carbon on earth combined… and penguins are one of the only vertebrates that can’t taste all of the five different flavour classes–sweet, bitter, sour, salty and the savoury taste, umami. So when they throw down all those fish they can only taste the salty and sour components.

I am here on Macca until VMI to use all five of my taste sensations for a very short summer, possibly longer depending on how long the L’Astrolabe takes to get here. The main objectives of this visit are to 1) Install a new air sampling mast for the clean air lab and 2) upgrade the ageing CO₂ analyser with a new technology analyser (Picarro, USA), which uses the unfortunately named Cavity Ring Down Spectroscopy (CRDS) technique.

Following in the footsteps of my Lidar obsessed mentor Andrew Klekociuk this CRDS technique is also laser based with just as many potential real world applications as the more fancied Lidar, including the holy laser grail for full body laser sculpturing of Hollywood celebrities.

So the new analyser is in and operating well, currently it is being cross calibrated against the old LoFlo system. And the new air sampling mast has also been successfully installed and is now running after a very long gestation period getting capital expenditure funding and approvals done across three agencies.

A big thank you for everyone on site here who did all the actual work welding, digging, moving and of course the erecting team who took all the glory: Horse, Nick and the Greg family. This shiny new mast has caused quite a stir on the island with signs of tower envy emanating from some circles (there is always one in a crowd). For all the other people on the island, don’t be shy, feel free to come down and get your picture taken with the new island star attraction, a great one for Macca scrapbook (Figure 3).

There was much learnt from putting up this tower and as always an element of personal growth. From the trades team I learnt about important AAD procedural steps such as JHA (job hazard analysis). I also learnt a great deal about new construction concepts such as how when an observed 1 –2mm off a perfectly level surface can be described as “allowing for windage”.

In particular, I learnt a lot from the sifu (master) of stainless steel, Horse. The most significant being the correct terminology for the unistrut spring washers which are used in the mast construction as “Mr. Zeppity’s”, apparently named after a kid’s cartoon character on the slightly psychedelic named “Magic Roundabout” show, a particularly springy one I presume. 

Dr. Marcel van der Schoot

Back in the days before electricity, light was made from burning oil and oil from elephant seals was considered second only to that of the sperm whale. Of course, one had to kill the seal to get the blubber to render it down to oil…

As urban populations in the northern hemisphere grew and demand for resources increased, men had to look further for supplies for these resources and exploratory voyages were made into the Southern Oceans.

Macquarie Island was ‘discovered’ on July 11, 1810 when the Perseverance landed on the island (having missed their original destination of Campbell Island). Finding a place rich in fur and elephant seals, the ship quickly landed a crew and then returned to Sydney for further men and supplies. Word inevitably got out quickly of the new discovery and more sealers arrived.

Initially fur seals were taken for their pelts and it’s believed that the numbers of this species were severely depleted by about 1815 and that they were eliminated from the island by about 1821. Cargo records indicate that just under 200,000 skins were taken from the island during this period. Fur seal breeding was not recorded on the island again until the mid–1950’s.

With no fur seals left to profit from, the sealers now turned their attention to the elephant seals and supplying the oil industry. Up to 1000 kilograms of oil could be obtained from a single bull elephant seal, although the average was probably closer to half that amount. Sealing gangs spread across the island — elephant seals couldn’t be moved easily due to their size so the sealing gangs moved to where they were.

Blubber was harvested from the animal and then boiled down in ‘trypots’ to make the oil that was stored in barrels to be sent home on the next ship. As the male in this species is so much larger than the female (up to four tonnes vs up to 800 kilograms), bull elephants were the target of the industry and this slowed down the decimation of the species. The trade in elephant seal oil from Macquarie Island lasted until about 1832, when there were no longer sufficient numbers of animals to make the visits profitable.

To live as a sealer on the island was a harsh life — they built huts as shelter from supplies brought with them, tussock grass and seal skins, and had to burn oil for warmth as the only wood to be found on the island came either as driftwood or from shipwrecks. They supplemented their meagre stores with what they could find locally, which would have been penguin, Macquarie Island parakeet, and penguin and petrel eggs; and apparently seal flippers were considered a delicacy. For ‘greens’ they ate the local cabbage plant and this probably saved many from scurvy.

Communication with the outside world was non–existent and the arrival of the next ship, with either new supplies or a passage home, would have been unpredictable and a long time coming. Some men spent years here at a time — it must have felt like being dumped at the end of the earth.

'SubAntarctic Wilderness’ by Aleks Terauds and Fiona Stewart & ‘Life on Macquarie Island’ by Alastair Dermer were both used as sources for this article.