Steve Nicol’s Antarctic diary (2006)

Better understanding of climate change and setting accurate, sustainable catch limits for krill were two of the benefits that came from data collected in the 10-week ‘Baseline Research on Oceanography, Krill and the Environment — West’ (BROKE-West) voyage on RV Aurora Australis.

Scientists from the Australian Antarctic Division, Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC) and Deakin University studied ocean currents, phytoplankton, krill, seabirds and whales in a voyage that left Fremantle on 2 January 2006.

You can read twice-weekly reports from voyage leader Dr Steve Nicol as he sailed adjacent to a rarely-visited stretch of the Antarctic coastline, between 30° and 80° east, and in an oceanic region overseen by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR).

You can also learn more about the projects of this marine science voyage and how studying the Southern Ocean can benefit our understanding of climate change and living populations.

6 January 2006

We had a rather peculiar beginning to this voyage, mostly a result of our departure from Fremantle. Although I had a complete listing of arrival times for everyone flying into Perth, ensuring that everyone was aboard the ship at 1400 on the 2^nd of January was quite another matter. Even insisting that all our people slept on board on the night of the 1^st did not fill me with great confidence because come 2230 hours on the first, several people had not yet been sighted, one plane was delayed, most people had disappeared to the nearest hostelry and I was pacing the deck largely alone. Much to my surprise and delight I did encounter all of my shipmates on board at 0830 when we began the briefing with an appropriately kindergarten-like roll call.

Leaving Fremantle was made more difficult by the hordes of media who descended on the docks eager to misquote us. New Year’s Day was slow in WA — the competing story was a scuffle in Kalbarri — so not only did we get TV and newspaper journalists on the dock insistent on knowing how we were single-handedly going to discredit the Japanese scientific whaling program, but also we were escorted out of the Swan River by a helicopter borne news team eager to film our first bout of seasickness. The noisy helicopter caused great angst amongst the hordes wandering around the helideck trying to sustain mobile phone contact with their loved-ones — a 21^st century equivalent of the paper streamers of yore.

Since sailing things have been proceeding — but slowly. It takes a while to slow down to the pace of life on the ship and to become accustomed to its rhythms and cycles — largely revolving around meal times. Several meetings have been held discussing the mechanics of extracting the maximal amount of scientific data from a limited suite of instruments over a 71-day voyage. There seems to be sufficient consensus that we may well be able to squeeze the planned research into the time available given ideal weather conditions, superhuman efforts on the part of all aboard and an appropriate level of human sacrifice. Given that it is some nine days before we conduct our first sampling in anger we are currently putting our faith in the prevailing good weather, resting up in anticipation of the efforts ahead and will hold off on the sacrificial offerings unless the weather gods demand them.

The first few days at sea are always a bit strange; many people are feeling queasy and most people are tired so one encounters one’s cohabitants sporadically and infrequently. Getting to know the names of 85 people is also a major task, especially for one of my advanced age and in the present company I certainly do feel somewhat geriatric — the average age is 32 and several of us fall outside two standard deviations of that! This learning process is not aided by the people who insist on wearing different clothes every day — I have just got used to associating the white T shirt with someone called John when he goes and puts on a purple one and my system is thrown into confusion. Luckily, Toby (who I do recognise no matter which T shirt he is wearing) is prowling the corridors with a digital camera allegedly collecting mug shots which will be displayed on the ship’s website so that I can check and find out that the person I have just called Sandra is in fact Bruce.

We have had benign conditions since setting sail which has helped immensely — but we cannot bank on it, so are making all speed while we can. Our first real sampling site is at roughly 62°S and 80°E, some 2000 nautical miles away from Fremantle, though between here and there we will be ejecting the odd oceanographic buoy, towing some sampling gear and collecting underway data. We aim to make a couple of stops to test our gear before we arrive at the first real sampling site so that we have some time to fix it should it malfunction. We are also conducting a plethora of activities on this voyage so it is as well to examine how feasible our theoretical workplans actually are when out at sea. Next week will see the survey begin in anger as we begin the long oceanographic transect along the 62^nd parallel between 30°E and 80°E and then we will feel we are truly under way.

10 January 2006

We’ve been at sea for a week now and routines are beginning to be established. As we approach the first sampling site more and more people are adjusting to being on shiftwork. The wee hours of the morning used to be the peaceful preserve of a small but dedicated group huddling in the instrument room but now a wander around the ship at three in the morning (I am told) will reveal a whole tribe of industrious individuals engaged in work or other activities to keep them awake such as eating, exercising, eating, arcane discussions (often involving the topic of handcuffs) and eating. By Wednesday when we start the oceanographic sampling in earnest we will have almost all of the scientific party on shift work which means that the point density per unit time drops and it is only at meal times that anything like the whole ship’s company comes together. This makes it very difficult to schedule activities for the few hours of recreation time that fall between meals, sleep and work and it is now that the creativity of our Party Organising Officer (POO), Sarah, becomes most tested. To date we have enjoyed a quiz night which gave all aboard the opportunity to publicly air their ignorance and an iceberg sweepstake which went up only minutes before the first iceberg was sighted. But wait, there’s more. Suggested activities have included salsa dancing with a genuine Colombian instructor, hackey sack on the helideck if it is ever clement enough to venture outside, stretching/flexibility lessons which have led to a certain amount of speculation and viewing of the first 23 episodes of “Desperate Housewives” which has led to even more, unfounded, speculation.

Over the last week we have had a mix of weather. The first few days out of Fremantle were remarkably easy on us so many people were able to settle in to life on the ship — although we have had our fair share of reasonably undulating conditions more recently which sent many people scurrying back to their cabins. The latest meteorological forecasts are quite remarkable in their accuracy so Scotty, the Captain, can plot a course that weaves between low pressure systems and allows us to reach our destination as quickly and as comfortably as possible. We can also plan our activities several days in advance knowing that the projected conditions are something we can bank on.

The trip down has not all been sleeping and eating, however. We have been deploying a number of instruments as we go and have been setting our equipment and the ship up to undertake a long and hopefully unbroken period of research. All the laboratories are now fully functional with the exception of the wet lab which still has a number of large oceanographic buoys occupying prime real estate. These buoys get set loose into the ship's wake every degree of latitude and then begin their journey around the Southern Ocean diving to depth, then rising to the surface every so often to report their position and the recorded water properties. We have also been towing a continuous plankton recorder (CPR) behind the ship to record the different oceanic communities that we are passing through. The ship's sensors are also recording atmospheric and oceanographic data as we sail so we can determine when we cross the major oceanic barriers such as the Polar Front – which we did yesterday indicating that we are in the real Southern Ocean now, not in some oceanographic abstraction. Also recording as we sail are the whale and seabird observation teams though neither have had too much joy so far in a wide blue and rather featureless ocean. Now that we have crossed the Polar Front things should start to pick up.

We had a single stop along the route to test the apparatus that will be deployed from the ship when we are on station including the main oceanographic instrument — the CTD which records the properties of the water as it is lowered up to 4 km into the ocean, and assorted nets, water samplers and underwater gizmos which will allow us to definitively characterise a large chunk of the Southern Ocean. All tests went well so we are looking forward to beginning to use the instrument suite to collect real data. Once we begin work early on Wednesday morning we will be flat out 24 hours a day for essentially the next 7 weeks with only a short break at Mawson station in mid February. Sleeping on the way home may well be as easy, or easier, than on the way down.

13 January 2006

The scientific juggernaut that is BROKE-West finally emerged from its slumber and started to gain momentum on Tuesday at the first sampling station on the southwest edge of BANZARE Bank. The bank was unexpectedly awash with icebergs and was shrouded in fog. A heavy swell made progress difficult but at 2000hrs on the 9^th of January the ship shuddered to a halt and sampling gear was lowered into the ocean from almost every conceivable angle. The process is coming to resemble a well oiled machine; the main oceanographic sampling instrument (the CTD) is lowered, and then a suite of instruments is deployed from the rear deck as the CTD slowly grinds its way to the ocean floor. Meanwhile a pump is struggling to send water into the helicopter hanger where experiments eventually will be run in large tanks, once they have stopped exploding and Klaus and Karen have come out of trauma counselling. This will be complicated still further in a short while when the big net is wheeled out and begins probing below the water’s surface, at which point the hordes of krill enthusiasts will have to rehash their justifications for failing to catch more than a handful of what is reputed to be the most abundant animal on the planet.

Keeping track of where we are and what we are doing is the province of our data domanatrices, Bec and Belinda, whose task is made more difficult by the plethora of numbering systems used by the various scientific groups aboard. Setting the foundation stone of difficulty in place were our oceanographic brethren who insisted on naming the first CTD station Number 2. That in itself would not be an insurmountable problem except that during the planning of this voyage a major regional conflict was avoided by agreeing that certain of the scientific factions could have access to water collected at the even numbered stations and others could have the precious liquid collected on the odd numbered stations. Now, if Station One was indeed really Station Two then where does this leave our water distribution system and the fragile truce that it allowed? This is obviously a problem that can be easily fixed by a number of intercontinental telephone calls and several meetings to which all parties are allowed to bring mediators, however, it is only the tip of the iceberg. Station Two might amicably be redefined as Station One but where does Site One fit in, and what about Event Number Two. Luckily we have a number of mathematically endowed brains aboard who have been spending the last ten days applying complex systems analysis to the problem and just when they were approaching a rather elegant solution Bec stamped her foot and laid down the law – so we do it her way from now on. Now we have pages of rather agreeably described entries, colour coded in attractive shades of pastel, and if we deviate from the master plan we will receive a severe nagging.

If the nomenclature system was a problem that required urgent solution then the acronym jungle was a positive minefield. Instructions from the bridge often suggested pulling in the CPR, opening the CTD door, lowering the FRRF and the ACS and while you are at it how about getting a GPS on the last ARGO before we deploy an XBT. In various corners people are measuring DMS or PCO2, collecting samples from the POOZ or surveying whole CCAMLR areas. Luckily some biologists are natural taxonomists and Stevie Davenport was to be found earnestly wandering the laboratories with a notebook in an attempt to define most of the common acronyms, but surprisingly, some defied translation even by those whose research depended on the offending instrument. At least this time we do not have to struggle to make sense of the voyage acronym as we spend an entire voyage doing that ten years ago and the process left us so exhausted that most of us are content to accept that we are indulging ourselves in Baseline Research on Oceanography, Krill and the Environment (West).

16 January 2006

The survey so far has largely been an oceanographic affair, although there has been considerable activity on the part of those looking at the microscopic elements of the marine ecosystem and at the other end of the food chain, the charismatic megafauna — the birds and whales. Later this week we will begin the north-south transects which is when the more intensive sampling will occur, where we start to deploy the net and really put the echosounders through their paces. The area we have chosen to survey is actually a management area designated by CCAMLR — the Commission for the Conservation of Antarctic Marine Living Resources — the body that manages the fisheries of the Antarctic region. This large area is known as Division 58.4.2 and is bounded on the West by 30°E, on the East by 80°E and to the North by the 62°line of longitude. CCAMLR manages fisheries by setting catch limits in its statistical areas based on estimates of abundance of the target species. For the purposes of our survey we are interested in the abundance of krill which is the subject of the largest fishery in the Antarctic region. There is a standard way to estimate the abundance of krill and this consists of using the echosounders on a number of transects that run perpendicular to the coastline, ground-truthing the results obtained from the sounders with a number of net tows and then using some very fancy statistics to come up with the biomass of krill for the region. Coincidently enough this sort of survey design is also pretty close to that required for a detailed oceanographic survey which explains the rather unholy alliance of oceanographers and ecologists on the voyage. Combining the efforts of the two groups has benefits, other than those derived from extreme social engineering, and these include being able to build a complete picture of the entire ecosystem of the region from the ground up. This will allow us to better understand how it functions and how it might be affected by pressure from increased fishing or as a result of climate change.

But right now we press westwards along the north of the survey area dropping CTDs into the water about twice a day and collecting underway data as we steam between sampling sites. There is obviously a deep yearning amongst the biological contingent to start making a contribution and unconfirmed sightings abound. These include a giant squid attacking the CTD one night (hallucinated by Tim the second mate), surface swarms of krill (thanks Jason, you can go back to bed now) and large numbers of whales which seem to disappear as soon as anyone other than the whale team are on the bridge. Strange things are also showing up on the echosounders and Toby, our acoustician, has his itchy finger hovering over the red button. Pressing this button will initiate a target trawl at which point the entire ship’s company drops what it is currently doing, the ship executes a speedy U turn and the net is stealthily manipulated into the object of interest that has been detected on the echosounder — obviously not something done lightly but a procedure that we will be following some 50 times over the course of the next six weeks.

We have been regularly deploying a smaller net at the CTD station and the aim of this sampling is to collect appendicularians — small, delicate creatures that are highly abundant, but which are rarely seen because of their fragile nature. But if the animals are fragile then the collecting net proved to be equally so and returned after its first sortie minus its bottom which made its usefulness doubtful to say the least. Luckily our science support officers Kelvin and Tony view such incidents as personal challenges and in no time they managed to crochet a new cod-end using nothing more than a passing bucket, some two-by-fours, a set of thermal underwear and a rivet gun. The result was stunningly effective and Margaret was to be seen this morning, grinning more widely than ever, clutching a brand new appendicularian courtesy of this custom built sampler — this is the sort of teamwork and ingenuity that allowed Scott to succeed, let’s have more of it.

Links

• CCAMLR
• Krill
• Echosounders
• CTD

20 January 2006

On Thursday the 19th of January we finally reached the end of Leg 12 which is the long East-West transect that defines the northern boundary of our survey area. At this point we turned the ship South and started the first of our intensive sampling lines, but not before we had conducted the first of our regular trawls with the big 8 square metre net. These trawls are designed to obtain a representative sample of the animals living in the top 200 metres of the water column; the net is lowered slowly to depth then retrieved and there is great interest in discovering what it has caught. Out here in deep water there are a variety of animals which are common but we are fairly far north of where we might expect to find krill — or so we thought. For the last few days we have been encountering orange-brown patches on the surface throughout the day and we are relatively sure that these are krill swarms, however, the krill are doing their best to evade detection. They tend to avoid the ship so towing the big net at the surface is unsuccessful and as they are at the surface they cannot be detected by the echosounders which are mounted on the ship’s hull some 8 metres down. The only tantalising hints on their composition we have had come from Margaret’s little ring net, which theoretically should be incapable of catching krill, but which has yielded a number of small juveniles in hauls made when there are swarms about. If there is a population of juvenile krill out here, and it is difficult to quantify, this may cause us problems when trying to estimate the overall distribution, abundance and biology of the krill in this region. We are trying to devise a way to sample these swarms when we return to this area between legs 2 and 3. But a great deal will happen between now and then.

On the transects, the sampling stations are much closer now and as we approach the continental shelf they come thick and fast. This is the area which is of key interest to all aboard so intensive sampling effort is put into the southern stations. The payback for this increased workload will be that once we have reached the base of the transect we turn east and sail along the ice edge for 5 degrees before heading north up the next transect. This should be the most scenic part of the voyage though it is not clear how close we will be able to get to the continent because there is still some residual sea ice, particularly at the bottom of transect one. We are getting regular satellite pictures of the ice concentration so that we can begin to plan our route through the ice and avoid having to break ice which will hold us up and use precious fuel.

Because this is a very long voyage we have to watch our fuel consumption and what applies to the ship also applies to all those aboard. The food on the Aurora is quite spectacular and long queues at meal times form to investigate the wonders that have emerged from the kitchen daily. With the ship operating 24 hours a day there is a constant demand for food and people will be sitting down to breakfast with those having their evening meals and with those, such as Jason, whose diet appears to consist entirely of steaming vats of oleaginous coffee. There are consequences to having good food available constantly and these show up largely in the waistline area. Those who have extensive experience in these types of voyages are wise enough to pack elastic–waisted trousers, baggy tops and a rash of excuses. The potential to over-indulge has resulted in a rash of activities partially designed to reduce this inflationary tendency. The now under-utilised bar is now the home for Maria’s Marengo Matinees, and Warwick’s morning torture sessions where young contortionists appal those somewhat older and less flexible by tying some rather complex nautical knots with their supple limbs. We are assured that by the time the ship docks in Hobart we will all be so well stretched that we won’t need a gangplank but will be able to languorously drop from the ship’s railings into the waiting arms of our loved ones and assembled debt collectors. But that event is a long way away yet.

23 January 2006

On Saturday we had our first encounter with pack ice. The first hint had come from the bird observers, Adrian and Andrew, who claimed to have seen ice-loving snow petrels, but ornithologists are notoriously excitable creatures so no one really paid them any mind. However, shortly afterwards they were vindicated when a thin white line appeared on the horizon to port and as we settled into another CTD cast we could see the barrier of ice to our south. The satellite imagery we had been sent suggested that there would be a tongue of ice covering the base of Transect One but because of cloudy conditions our most recent images were some five days old and conditions can change rapidly at this time of year. Because this transect extends furthest to the south, one of our concerns has always been that we might not be able to make much progress in this region because of consolidated ice in late January.

We are trying to get up onto the continental shelf on all of our transects and this means going to 69° 18’ S on Transect One. So far the ice conditions have been fairly benign with loose pack making progress relatively easy and not impeding data collection. In heavy ice it is difficult to find an adequate parking space for the CTD and trawls become tricky as ice floes can snag the wire. Additionally, ice banging against the hull can ruin the acoustic signals, and thick ice can make progress painfully slow. The weather has been in our favour though, with seas so calm that there have been complaints from some extreme oceanographers aboard who claim they only signed up because of the notoriously mountainous seas found in this area.

The light as we moved into the sea ice was magical with sunlight filtering through the low clouds and, coupled with the mirror-calm sea, the conditions for viewing wildlife were nearly perfect — had there been any wildlife to view. An occasional whale blew in the distance but the surface of the water lay mainly undisturbed — if a single krill had breached we would have known about it.

However, as we moved into the ice, krill became apparent on the sounders and a quick trawl brought several hundred aboard and they are now to be found happily growing away in So Kawaguchi’s custom built krill Hilton. As we begin to move up the continental slope and towards the shelf we ought to see more krill and hence more krill predators such as seals, whales and penguins — but then such theories have a way of being discredited when tested out on the water.

The sea-ice zone is thought to be one of the powerhouses of Antarctic productivity. Algae are trapped in growing sea ice in autumn and, as they are held near the surface in good light conditions, they grow and form communities which can be so dense that they stain the ice brown. These communities can form pastures that are grazed by herbivores in winter and spring and then, when the ice melts, they are released into the surface water and begin to grow. The melting ice is fresher than the underlying seawater so tends to float on it and the algae are trapped in the well-lit surface layer where they multiply rapidly. This is the bloom that feeds the herbivores of the region, particularly krill, and ultimately is the source of energy for all the animals of the sea-ice zone.

All around us are ice floes with conspicuous layers of algae ranging from yellow to brown. As the ship brushes them aside they turn over to reveal their heavily pigmented underside and occasionally a startled group of krill which had been feeding on the algal layer until their breakfast was rudely interrupted by the passage of the Aurora.

As we head down Transect One the fruits of our labour on the preceding Transect 12 (yes, those inscrutable oceanographers have been at it again) are beginning to emerge. The wall in the mess is now decorated with plots derived from the CTD in gaudy primary colours (to appeal to the biologists) and this has prompted stimulating discussion.

Simon Marsland was heard resorting to polysyllables as he tried to explain how finding no significant difference in either temperature or salinity across vast sections of the Southern Ocean was, in itself a significant difference. Not to be outdone, Toby has appropriated a whole corridor to advertise the results of the acoustic survey in a no-holes-barred, blow-by-blow account of every krill that he has pinged. So far there is one, postage stamp sized echogram positioned at a height that anyone who is shorter than Toby (that’s 83 of us) cannot see without binoculars and a stepladder.

Those concentrating on the more microscopic end of the food chain are reporting spectacular successes in their ground-breaking research but are refusing to disclose them on the grounds that this will severely compromise their commercial potential, might preclude them being published in ‘Nature’ and besides they are too busy collecting data and watching re-runs of ‘Alias’ to conduct any analyses. Others are more secretive still and although the abundance of whales and seabirds could easily be calculated from the number of delighted squeaks and yelps from the observation teams, no hard data have yet emerged — resulting in some furious eyelash-batting by Bec.

By the middle of this week we will have completed this transect and will have enough data to construct a few more theories which we will be able to demolish on our next sampling line, Transect 3 — or will it be re-named Transect 17?

27 January 2006

Early on Tuesday morning we completed the first of the meridional transects at 69° 18’ South in the shadow of a continental ice shelf, and the ship headed eastwards for the first time to find a route through to Transect 2 at 35°E. Transect 1 was a great success; we achieved all our sampling requirements and collected volumes of valuable data that are being worked on feverishly, and turned into wallpaper as we make our way eastwards. After the hectic sampling schedule at the bottom of Transect 1, where the stations were spaced as little as 2nm apart, the long transit period to Transect 2 was a welcome break for most aboard. And it was an extremely scenic break. For about the first time since Fremantle, the skies cleared and we sailed through fields of giant tabular bergs in the brilliant sunshine looking for a clear passage East. There was quite some pack ice in the area but the Aurora cut through that easily and with Scotty, the Captain, making a few ascents to the masthead checking for leads ahead, we found open water close to the continent and an easy passage through. At around midnight we threw the net into a patch of open water and began Transect 2 with a catch of the coastal species of krill which were found exactly where they should have been, leaving another theory intact for a few more days. The sun almost set over the bergs then rose again as we began our first northwards leg.

These legs are not sampling transects and the ship steams at 10 knots collecting data, particularly acoustics data, as we progress northwards. Occasionally the ship is turned around to investigate an object that has been identified on the sounders, and a trawl is carried out. These trawls are useful for confirming that what we can see on the sounder is krill but are probably more useful when they inform us that the echosounder records are, in fact, from fish or other pelagic species and we can then subtract these records form our krill biomass estimate. Each of these acoustic sections will take about two days and gives people who have been working on the CTD data time to catch up before we start coming down the next southwards transect and they have to begin sampling again. So by Thursday night we will have completed a complete cycle — comprising the two longest transects and the connecting legs — only another five of these to go.

It is strange being back into the open water again but the ship settles down into its easy rhythms and life aboard continues its routines. Life on the ship is a very auditory and tactile experience and after a few weeks at sea it is possible to understand what is going on just from the sounds and feelings of the vessel. The underlying rumble of the ship’s engine is the foundation pulse upon which all other sensations build — if the engines are shut down everyone notices and questions are asked. There are two engines and there are subtle differences in feel when the big engine is being used as opposed to the small one and you certainly know it when they are both being used, particularly on the trawl deck which rumbles and bangs impressively when the ship is at speed. Around the ship are other constant sources of noise and vibration — the funnel, the cooling vents, the air conditioning and you become used to a high level of ambient noise. Even the vacuum flushing toilets can break the sound barrier and everyone knows for several cabins away when one has been activated — there are no secrets on the accommodation decks! You also begin to be able to pace your work by the sounds of the machinery — the CTD winch has a subtly different note to the whine of the trawl winch, and when you can hear the CTD coming in it’s time to go and prepare for a trawl. The trawl is deployed from a gantry that makes an ear-splitting impersonation of a London underground train under heavy braking and this signals the time for the krill buckets to be readied, unless So Kawaguchi is doing the sampling in which case one very small bucket is all that is required!

Today is Australia Day and luckily most people will not be sampling, which means that they can take some time to relax a bit and have a few traditional lemonades over a BBQ. This is the first Australia Day celebration since the ship went dry, and there are some rumblings about it being positively un-Australian to celebrate our national day without a beer to assist the process, but celebrate we will. Social life aboard is somewhat fractured because of the shiftwork but it is possible to have some relaxation time and this exercises the mind of our Party Organising Officer (POO), Sarah. So far we have had a quiz night, a backgammon tournament, an interesting-hair night and even a guess the krill biomass sweepstakes — we do live dangerously out here at Australia’s most western outpost. Birdo Andrew has an amazing assortment of obscure rock documentaries which he rations out on Friday nights and Toby has also organised surf movie evenings which for some obscure reason attracts a crowd who like to watch people sliding down vast walls of water whilst we sit on a ship sliding down vast walls of water. Still, it keeps Toby away from the instrument room where his trigger finger has been even more twitchy over the last couple of days to the point where the officers on the bridge flinch each time there is a call from the instrument room for fear it is a cheery request for yet another target trawl. Another member of team acoustics, Natalie, hit the local headlines with her inaugural involvement in the krill sampling effort. First the net failed to open, then on her second attempt the cod end broke and we were treated to the bizarre vision of Luke using a dustpan and brush as a sampling device. It was obvious from his performance that Luke has little experience in using these delicate pieces of scientific equipment. A consequence of this fiasco is that Nat has been exiled to the instrument room and there is general agreement that statisticians should never be allowed near a data-collection device again.

31 January 2006

After a few days exiled out in the grey open ocean we are once again back in the sunlit sea-ice zone. The advantage of this sort of survey is that you are guaranteed a dramatic change of scenery at least once a week. At this point in the voyage we are into a nice easy rhythm and mark the passing of the days by the regular lowering and raising of the CTDs and the other instruments. Days pass and the stations on the route map slowly get ticked off and suddenly you realise that you have been at sea for 4 weeks — and we must be enjoying ourselves because time is flying. The question now is not so much how much more must we do, but rather have we enough time to do all the things we need to?

We are now approaching the coast at 40°E in an area close to the Japanese base of Syowa and we have been informed that the icebreaker Shirase is there and is likely to leave shortly. Because of time constraints, however, we will merely be able to wave as we go past and move on to the next transect at 45°E.

Much of the work that we are doing out here is to try to build up a composite picture of the ecosystem in this vast area of ocean. This is a remarkably difficult undertaking given that we are only able to sample in a very restricted number of places. We need to be able to get information on the abundance on organisms and be able to relate this to the oceanographic conditions, but perhaps the more difficult task is determining the productivity of the plants and animals because it is this which determines how much energy can be passed on to the next level of the food chain.

For the algae, the grass of the sea, we have a couple of techniques that give quick indication of what state they are in and how much carbon they are taking up. But this is only part of the microbial puzzle because some of the unicellular life forms are actually predatory on others and even more confusing still, some of them can act like either plants or animals depending on the ambient nutrients and light. What becomes available to the herbivores is a mix of what is left once the microbes have finished with the plants, and of course the microscopic animals themselves are a food source in their own right. Determining what is being produced by which element of the microbial community requires a combination of complex instruments, experimental manipulations and a highly focussed if somewhat explosive group of scientists. We have a series of large, slightly flammable vats in which a brew of the local microbial community is grown and manipulated so that their production and dynamics can be better understood. In some, herbivores such as krill are added to see what effect grazing has on the community structure. As krill is a major focus of this voyage there are also convoluted efforts to understand their productivity.

Some of this information can come from preserved animals, which provide insights into the previous growth and development through the distribution of size classes present in the population. But to find out more about the growth of the krill under local environmental conditions we need to conduct experiments and this is where the krill Hilton comes in.

Krill grow by moulting, and every month or so they throw off their old shells and grow into a new one so it is possible to determine how fast they are growing by measuring the size difference between the old shell and the new one. It sounds easy but because moulting occurs only once every month, and Natalie has ingeniously calculated that only one in 30 krill will moult every day so, to get a good handle on how fast the population is growing, we need dozens of measurements, all taken within a few days of capture so that the exhibited growth reflects local conditions. This means keeping hundreds, and often thousands, of healthy krill in individual jars in our container laboratory on the trawl deck and checking them daily for moults. So, when a trawl bulging with krill comes aboard the krill crew are to be seen heading for the container with buckets of experimental animals and they spend the next few hours bottling krill and placing them in the elaborate facility designed by Rob King who, realising the labour intensive nature of the apparatus he designed, wisely stayed behind in Kingston. The hard work will pay off though with the best ever description of the condition of krill over such a wide area of ocean and a better understanding of how the production of these key herbivores is related to the overall productivity of the ecosystem.

On board the Aurora, Australia Day was well-celebrated with a traditional BBQ, several entertaining krill trawls and some inventive fun and games. Chief amongst these games was the charity head-shaving which resulted in the raising of some $4000 for Camp Quality, and some rather unsettling changes to the appearance of quite a few of the local detainees. To the horror of many Bolsheviks aboard, Simon metamorphosed from an ersatz Rasputin into a passable imitation of a trainee bank manager. In contrast, Jason is taking so seriously his transformation from California flower child to goatee-sporting thug that he is to be found lurking belligerently in dark corners of the mess muttering sinister threats to the health of whoever designed the numbering system for the sampling stations. The local deforestation has also added a new, shiny and somewhat spiritual perspective to the morning’s stretching classes led by Sensei Warwick “The Rack” Noble. The baldies will hopefully be donning headgear for both thermal and aesthetic purposes tomorrow as we ply the tourist route along the coast — no one wants their iceberg photos ruined by unpalatable foreground glare.

7 February 2006

Between Transects 3 and 4 we had another stunning day sailing eastwards along the continent through pack ice and past massive icebergs in sparkling sunshine. The wildlife put on a special display with sightings of Ross and Leopard seals, orcas and minkes and flocks of small grey birds that kept the ‘birdos’ in such a state of over-excitement that the doctor was nearly called to help sedate them. Unfortunately, Cath had just seen her first ever Ross seal and was in no state to administer calmatives to anyone but herself. At one point the wall of a nearby iceberg collapsed precisely at the only moment during the entire voyage when no cameras were present on the bridge leading to a matching avalanche of colourful language. The sunsets were, however, a highlight and as the sun slowly lowered itself to the horizon between the bergs all aboard slowly fried their retinas waiting for a green flash that never came, but with the wonders of digital photography doubtless there will several images from that night purporting to represent this sought after phenomenon.

Most people when they think of the Southern Ocean think cold and wet but especially, cold. To oceanographers it is these things and more. Some definitions of the Southern Ocean have it starting relatively far north at a boundary called the subtropical front but for many, the true Southern Ocean starts south of the Sub Antarctic Front. This boundary, also referred to as the Antarctic Convergence marks the point where the cold polar waters flowing northwards dive beneath the warmer northern waters and there is often a distinct and noticeable drop in temperature associated with crossing this system from north to south. There is also, as with many boundary systems, a localised increase in biological activity in this area. Once within the ring of the subantarctic front one enters the Antarctic Circumpolar Current (ACC) which is the world’s largest current system and the only truly global ocean current as it flows eastwards around the Antarctic continent in an unbroken stream. In some sectors of the Antarctic, such as south of the Pacific the current is very wide, but in others it is squeezed between the Antarctic continent and other land masses. The best example of such a pinch point is at the Antarctic Peninsula where the entire ocean flow is compressed into a very narrow opening south of Patagonia with an associated increase in speed. In the region where we are conducting our survey the ACC is mostly fairly wide but it does get constricted as it passes over the Kerguelen Plateau. The ACC is also affected by a number of large-scale gyres and the one that affects the BROKE-West survey area is the Weddell Gyre which touches on our western-most legs with its southward flowing flank.

Perhaps the most dramatic feature of the survey area, though, is not the wide oceanic river of the ACC but is the narrow (<50 Km wide) current jet that flows towards the west just offshore of the continental shelf break. Instead of the sluggish eastwards offshore flows of around few centimetres per second we see here, speeds of between 10–20 cm sec^-1. This westward current flow has a marked effect on both the physics and the biology of the region. The flow rates of these currents are measured in a number of ways. Data from the CTD allow calculations to be made of sea-surface height (or pressure) in the ocean, and because water flows along lines of constant pressure, just like in weather maps, the strength of flow can be estimated, and this is particularly useful for basin-scale estimates of water transport. More directly, satellite tracked buoys can periodically send data on their position and this can be used to detect ocean movements and these are showing up the complexity of the eddy structures in the upper ocean. Recently, acoustic current profilers have been used and these provide direct measurements of velocity from the particulate material in the water – generally the organisms living there which gives oceanographers an indirect interest in biology – and these measurements can provide us with horizontal and vertical profiles of current speeds. The detail of the information from these acoustic instruments (and the CTD data) gives us new insights into the structure of the ocean and how the animals and plants are distributed relative to the oceanographic landscape. Putting all these data together over the entire survey area will result in a three dimensional picture of the structure and movements of the water masses of a whole ocean basin in the sort of detail that has not been attempted before.

Part of the scientific process is making predictions and it is easy to see how this gets perverted into gambling. The tonnage of krill that will be detected on the voyage is already subject to a sweepstakes that has spread far beyond the confines of the ship but the contents of the net are always fair game for a discrete wager. Toby, rather prematurely, bet his life on the identity of a particular acoustic target and was proved disastrously wrong. Esmee and Ruth are now the proud owner of a slightly used acoustician and are wondering what other function this specialised creature could be put to. Luckily there are 82 others aboard only too willing to offer helpful suggestions and these discussions will help to sustain us as we complete our next loop up to the grey and bumpy north and then back into the sunshine and calm waters near the continent.

8 February 2006

We thought we had the system well worked out down here – we sail along in the open ocean working hard and experiencing some mildly undulating weather then once a week we head southwards into the sea ice zone where the sun always shines and the sea remains as featureless as the cling film covering the cat food at the rear of the fridge. Then we head north again and put up with grey skies and the occasional roll and pitch before once again returning to the blissful south. This system was soundly based on a perfectly adequate sample size of two, but any scientist worth their salt will tell you to stop at two because once you get into sample sizes of three or more you unerringly encounter variability and have to wheel in the statisticians. So imagine our collective surprise at entering the first inklings of the sea ice zone on Sunday only to encounter sullen grey skies and whitecaps on the water. Things escalated from this point and although by Monday morning the sun had come out, the wind had picked up as we picked our way through the few floes that littered the coast at 55E and freezing spray was flying in a wind chill of −30°C. Turning northwards we headed into the gloomy open ocean with the wind gusting to 50kts and a decidedly angry looking sea which got more and more surly as the day progressed. It was a great pity because the coast that we left behind was remote and very scenic.

Mountains peeked through the ice cap giving us the first glimpse of rock since we waved goodbye to Fremantle 5 weeks ago and icebergs did their usual sterling job of providing interesting foreground and collapsing when no one was looking. The area (known either as Cape Ann, Cape Close, or something indecipherable in Russian, depending on the chart being used) is the furthest north section of coast on the whole survey, extending into the balmy latitudes of the mid sixties, and was largely ice free though there were a number of patches of sea ice in our path. On the last of these encountered before we made our left turn we stumbled across a condensed Antarctic megafauna experience with three species of seals and two species of penguins occupying a single very small patch of real estate. If you add these to the humpback whale that seemed to be scooping all the krill out of the net the night before we couldn’t feel too cheated on the wildlife front, but it was no real substitute for the hours of sightseeing on the previous two eastward passages along the coast. Despite sleep deprivation, everyone appears to feel rather sanguine about the weather; this is an acoustics leg so the sampling is not too compromised, but we did have to endure an uncomfortable night and a rather meandering survey track as a result. It is, however, the last northwards leg before we head into Mawson to terrify the locals and do some acoustic calibrations so spirits are somewhat more elevated than they might be following a night of enforced tossing and turning.

We are now almost exactly at half way through both the survey and the voyage having completed 35 days at sea and five and a half of the 11 transects – although because our physical colleagues insisted on indulging themselves in an extra long transect even before we started the north-south legs, we are actually well past the half way point in terms of the science program. For reasons that are apparent to some, this point is referred to as Hump Day, a nomenclature that caused not a little confusion to some, but no lasting damage that cannot be addressed through intensive psychotherapy.

The general consensus on the science so far is that it is all going to plan – which is actually a matter for considerable amazement because the original plan was referred to as “ambitious” – an often-used synonym for “impossible”. This is no time for complacency, though because, as this week has showed us the unexpected can happen and our biggest adversary is the weather and the effect it can have on our very tight time budget. Other unexpected events have been occurring on the decks of the Aurora as we enter the midlife crisis of the voyage but these will have a limited effect on our science effort although they may be of use in future psychological studies. Jason (once again) has been experimenting with a variety of facial hairstyle, each more baroque than the last but none of them could match his vibrant trousers which violated several international conventions on visual pollution, cruelty to animals and shipboard fashion sense. More furtively, one of the numerous Andrews aboard (surname withheld to implicate the innocent) was generous enough to celebrate his inadequacy at darts with a nude perambulation of the bridge – it being a Sunday night and everyone being at worship, no one noticed. Similar odd behaviours have pervaded the galley where competitive potato peeling dominated the agenda when the boys took their turn, replacing the gentle art of gossip over the peelings when the girls put the potatoes through their paces the week before. And throughout the ship the sound of violent death rings through quiet spaces as Brian consolidates his reputation and the Killer king of the Aurora, amply making up for his shift’s recent abysmal record on the krill capture front.

14 February 2006

Excitement is rising on the Aurora as we head down Transect 7 towards Mawson. Station visits are a much welcome break for most aboard on these long science trips, but for some they are the period when the most intensive work is carried out. One of the main reasons we are visiting Mawson is to calibrate the ship’s echosounders; they work rather capriciously in cold water and the instrument readings tend to drift, so we need to moor up in a location where the ship can be held firm in deepish water and run them through a series of tests. The acoustics team then suspend small metal balls beneath the ship (I’m not making this up) at different points in the echosounder beam and relate the signal they detect to the known depth and position. Even less believably, this precision operation is facilitated by the use of servo-operated fishing rods, which move the balls around at Toby’s whim and, failing any major upsets, this operation takes around 36 hours during which sleep-deprived acousticians become progressively less calibrated as the instruments become more so.

Unfortunately, upsets can include ship movement — and the katabatic winds at Mawson are notorious for their strength and ship-moving ability so the work has to be factored in around the weather. Meanwhile the majority of those aboard will be welcoming the first opportunity to put their feet on dry land in nearly six weeks and the prospect of seeing old friends and new faces. There is also the attraction of the first open bar since we left Fremantle some 4500 nautical miles ago. There are 84 people aboard the Aurora, which is about three times the number of people at Mawson so it promises to be a rather overwhelming experience for the station-dwellers. The station personnel are also mostly men so it will be a great relief for most of the blokes on board to have a chance to sit down with other blokes and have good blokey conversations after having to put up with the company of so many women on the ship — and we feel sure that the chaps at the station will feel the same way.

Scientifically, things have progressed well with little drama to report and the data continuing to pour in, much to Bec’s delight. The oceanographers got a bit excited the other day when they thought they had found something they didn’t expect but then Nathan assured them that they had in fact expected it and he made them do another CTD as a punishment for imagining that the ocean was not entirely predictable from models. The krill remain enigmatic and are refusing to toe the party line on where they should be found, and what they are allowed to do on the odd occasion when they are found. In fact, both shifts have been having difficulty finding sufficient krill to populate the Hilton as the nets bring up organisms that the acoustics claim do not exist, rather than the krill that we all need, want and love. All is not lost on the krill front, as So and Toshi appear to have demonstrated that female krill, like females of so many other species, relish each other’s company and reproduce far better in a maternity wing than in the normal hotel suites where they can be pestered by males.

Up on the swaying superstructure the whale observers continue to amaze by being able to identify black spots using a highly definitive classification scheme which includes terms such as: “like minke”, “possible humpbacks”, “not dissimilar from fin whale” or “I’m buggered if I know but let’s call it a blue whale”. The seabird observers are a great deal more scientific in their approach and counted no less than 720 wandering albatrosses on Tuesday after a lone wanderer lapped the ship once a minute all day — Adrian and Andrew were so dizzy afterwards that they had to lie down and be shown obscure rock videos for an hour or two before they could resume their vigil. Meanwhile the phytoplankton squad are gleeful having discovered a new way to purify in the water their minicosm tanks — just add krill and stir — the unfortunate by-product is, however, an Augean stable of krill poo to remove at the end of each Herculean experiment.

14 February 2006

At the ungodly hour of about 7 O'clock on Sunday morning a very excited shipful of people entered Kista Strait and were in full sight of multi-coloured Mawson Station. As the ship moored, the cameras clicked and the anxious residents no doubt wondered what was about to hit them. After a briefing on board by Ivor Harris the Station Leader, the eager masses were let loose on the Antarctic Continent and their feet touched solid ground for the first time in 5 weeks.

Watching from the shore, the station began to resemble an anthill as dozens of brightly-clad people swarmed across the rocks photographing everything that moved and most things that were either anchored to the ground or floating in the harbour.

The weather was good with only light winds and this allowed the acoustic calibrations to begin almost immediately and proceed for the next 30 hours or so, establishing a record for both the speed with which they were completed and the comprehensive nature of the readings that were recorded. While all this was going on the ship’s company were revelling in the superb hospitality offered by the residents of Mawson that included a sumptuous banquet, which re-introduced us to fresh vegetables, washed down with adult-strength beverages. To cap the night off Ivor allowed a number of people to stay the night at the station, which for many, including several seasoned scientists, was their first night on the seventh continent and will be one of the highlights of the voyage. The smiles on the faces of those returning to the ship on Monday morning said it all. A totally exhausted Team Acoustics were let off the ship for the shortest of strolls as the ship began to reel in the mooring lines before they went to bed for 18 hours of well-earned sleep. As we sailed out of Horseshoe Harbour the team we left behind looked so few, especially since we took away five of their residents with us.

And now we are back out at sea and have spent the best part of a day dodging storms and icebergs as we obliquely approach Transect 8. As we sailed east we were some distance from the coast so in a somewhat Zen-like approach we started Transect 8, a northerly transect, by going south bringing us almost to touching distance of the ice sheet fringing the continent. Finding no more water that was not solid, we turned around and followed a trench leading back to the transect in a process that pleased the oceanographers (who began hurling expendable sampling instruments over the side like there was no tomorrow) and puzzled everyone else. Not to fear, we are now back on our proper northerly track and the unpleasant weather system that has been lurking in the wings has moved on. We now just have to get ourselves back into working mode for one last push, which will last about two weeks.

One of the key events on any voyage is the design of the T shirt and this usually proceeds in a truly democratic fashion with everyone aboard being able to submit designs. Once we have a field of entries a vote is taken and we submit the winning entry to the manufacturers and pick up the resulting product when we return to Hobart. It seems like a simple process but on each successive voyage it appears to become more convoluted, contentious and fraught.

On BROKE–West we have had an excellent field of designs submitted, ranging from the highly obscure through the puzzlingly abstract to the compulsively detailed, so we have not been spoiled for choice. Unfortunately, democracy is a fickle process so what seems like a simple exercise brings out the bush lawyer in everyone:

“What happens if I want design A on the front and design B on the back but with a different colour scheme on an extra large polo shirt in a shade that isn’t available?”

“I still think that design Y is the best — can we get two different designs made up with several options of colours, styles, fronts, backs and matching underwear?”

“We really ought to be allowed to make more than one choice — why can’t we use Hare-Clarke proportional representation rather than the long-discredited first past the post system?”.

If only people had put as much thought into their science there would be a ship full of Nobel Laureates returning to Hobart next month. On future voyages everyone will be issued with a white T shirt, one size fits all, indelible marker pens in three colours and will be told to get on with it and construct their own individual piece of voyage memorabilia and to hell with democracy and group unity.

17 February 2006

It seems like a long time ago that we left Mawson yet it is only 3 days. This is not because we have been particularly busy but maybe because we have not. Our trick of heading south rather than north at the start of Transect 8 appears to have paid off and we completed the line today after experiencing little more than an awkward rolling swell rather than the 45 kt winds we might have faced had we headed due north on Tuesday.

The sun even came out yesterday which resulted in a number of smiling faces venturing out into the open air — we have seen precious little sunshine out in the open ocean all voyage. As the sun twinkled on the ocean surface humpback whales frolicked around the ship stealing the krill out of the mouth of our trawl and prompting calls for intervention from some of the less politically astute on the krill research team. Other than this interlude, the transect passed much without note, and with few krill, as people either settled back into ship-based life or braced themselves for the last two sampling transects, the first of which begins tonight.

Making sense of the spectacular mound of data that we are collecting is not going to be easy and there have been meetings aboard this week to stimulate discussion on what patterns any of us might think we are seeing. A survey of this type is really like a giant jigsaw puzzle and it will be difficult to make head or tail of it until it is complete. Additionally, some of the critical data will not be available until after the voyage when the samples have been analysed. None the less, it is still possible to tease out some features from the raw information that is already available. The oceanographic team are leading the charge by producing large numbers of plots of both vertical and horizontal sections of a wide range of properties, some of which are comprehensible. Some datasets are so large that processing them for later analysis is hugely time consuming. Toby is fond of pointing out that the echosounders are producing four metric pings of data every second and so far his computer has captured every one of the 15.5 million returns from a reluctant ocean which explains why it is now suffering form a bad case of electronic constipation.

There is a push to get as much data out and available as soon as possible and this has meant long hours measuring krill on a rolling ship, countless eons filtering seawater or listening to interminable Grateful Dead CDs and pretending that they are the elusive song of the Southern minke whale. Capturing the essence of all this morass of information and synthesising it for public consumption becomes important as the voyage enters its final phase of sampling and a call for one or two short paragraphs describing key findings that would be of general interest generated a range of responses. These ranged from five pages of florid explanation of why it was premature to release any findings at this point in time, through to pages of detail that would floor an expert — and I even got one or two short paragraphs describing key findings that would be of general interest.

Strange psychologies take over at about this point in a long voyage and few are immune from behaviour that is amusing or entertaining — but most of which is downright irritating. This is the point at which homicide often appears as an eminently reasonable response to a spilled coffee, and the gregarious become reclusive whilst the wallflowers bloom. Conversations take on an Alice in Wonderland quality and the most mundane aside can develop into a serious discussion. For example, an animated discussion developed on the bridge as the ship sailed through some of the world’s most devastatingly beautiful scenery and the proponents earnestly argued the taxonomic difference between a cookie and a biscuit, totally oblivious to the sparkling sun playing on the icebergs passing nearby and the flocks of animated birds fluttering over the dappled water. Suddenly the conversation spread like a bushfire to encompass the etymology of chips, French fries, crisps and nachos — and in a prodigious logical leap, to the defining features of apple crumble and the appropriate filling for pies. Luckily, at this point the Captain closed the bridge…

22 February 2006

After what seemed like an inordinately long Transect 9 we have made it to Prydz Bay and face the prospect of having to complete one more up and down — a mere 800 nautical miles — before we call it quits, pack up our expensive toys and go home. Although the ninth transect was largely uneventful and fairly short, fatigue has set in and at times the ship resembled an out-take from Dawn of the Living Dead, except with rather fewer overt displays of cannibalism.

We ended the line on Fram Bank which is a highly recommended place to finish any transect with thousands of designer icebergs, chic pack ice and considerable concentrations of elegant wildlife. Another clichéd sunset ended the day as the moon rose majestically and later, as the moonlight glowed off the silver bergs in a display of opulence, an aurora lit the sky to compensate the night-shift for missing the earlier floorshow. These experiences really helped to lift spirits, dispel zombie impressions and encouraged a collective loin-girding as we press on into the last lap. But first, we had to complete some unfinished business.

We are estimating the abundance of whales using two different techniques on this survey and this hasn’t really been tried before so the results should be of great interest. The first method is the standard visual abundance estimate which depends on a team of observers who scan a defined sector of the ocean for whales in a specified way. This is not as simple as it sounds and there is considerable research that has gone into the best way of conducting sighting surveys and into analysing the results. It also takes a sizeable team, and we have a wonderfully international group of seven people from five countries and as you might imagine communication errors are not always a function of radio interference — only superb co-ordination by Sarah and Paul prevents the monkey island from becoming the Tower of Babel. Observations can only proceed in daylight hours whilst the ship is on transect so sometimes the hours are long but at other times, when things get out of phase, we end up on station during daylight hours and are in transit at night so observations are frustratingly curtailed.

The second way we are counting whales is using passive acoustics. Whales make noises and if you count the number of noises around the ship you get an idea of how many whales there are in the vicinity. If you also know what noises each species of whale makes then you can also begin to work out which type of whale is found where. We do this using small devices containing microphones that are regularly dropped into the ocean; they pick up whale sounds and relay them back to the ship where they are recorded. Additionally we have a couple of other gadgets (ARPs — acoustic recording packages) that record whale sounds and these are dropped onto the ocean floor where they are left for a year then picked up — or not. The tricky bit is to retrieve an instrument once it has been sitting on the seafloor under a couple of kilometres of water for 12 months.

The instruments have releases that can be triggered by a pulse of sound and they then come slowly to the surface whilst Jason, their custodian, paces the bridge muttering darkly and making arcane calculations. This is why we spent yesterday evening on the bridge with every semi-functioning pair of eyes trained on the grey ocean under a threatening sky as dusk approached looking for any sign of a series of yellow buoys that signified the surfacing of the recording package. We had decided that the current weather was too good to last, and the forecast was bad, so if we wanted to recover the ARP (and we did) then we had to act fast so we fought our way through a field of loose ice to get to the site before darkness fell. Luckily we made it in time and despite the pessimists amongst us we did manage to find the buoys, which were somewhat ironically spotted by Paul who is in charge of the whale visual observation team. However, his use of the “Big Eye” binoculars on the monkey island was deemed by some to disqualify him from winning the spotters fee. Jason now has to download the data and he will have a whole year’s worth of cetaceaous squawks which ought to keep him happy for several months.

Listening to recordings of underwater sounds is not the only evidence of behaviour aboard that might be viewed as strange were it not happening on an icebreaker far from the trappings of civilisation. Weird and the wonderful things that once would have been cause for comment occur on a daily basis. Socks are worn with sandals, fruit juice is poured on breakfast cereal and people are even eating prunes. It’s time to think about going home.

1 March 2006

At 11.15 on Tuesday morning the gantry screeched to a halt for the last time and the net was lowered into its box at 65 51S 80E signifying the final act on station 16 of Transect 11 on BROKE-West, this year’s largest ever interdisciplinary survey of a significant acreage of the Southern Ocean by a single orange icebreaker. The oceanographers donned thermal superhero suits, and a bottle of fake champagne flowed into several paper cups whilst the protagonists stood around, contemplated their achievement and commiserated with one another for having to put up with each other’s single-minded behaviour over the last eight weeks.

Even as the net dripped its last saltwater tear onto the trawl deck the ship was making an unprecedented turn to the southwest and was heading towards Davis. Over the last 47 days we have surveyed over a million km² and the ship is now groaning with the data that we have collected. It feels like a titanic achievement (possibly the wrong phrase in these waters) but for most of us the reality of the survey’s completion is yet to sink in—it has been our life for all of 2006 so far.

Transect 10 was eventful because of its featurelessness. We steamed for nearly 300 nautical miles and failed to detect any significant quantities of life on the echosounder and certainly nothing worth putting a net into. Unexpectedly, Transect 11 turned out to be remarkably scenic throughout most of its length which kept us going as we tried to maintain focus in the dying days of the survey. In the north, in the vicinity of BANZARE Bank, there were numerous icebergs and many of these were jade bergs and the occasional deviation from the transect line might have been associated with their appearance. To cap it all the sun emerged, bringing out hordes of photographers who were unused to seeing either icebergs or sunshine this far north. As we sailed south we encountered pack ice and the last two stations were conducted in leads surrounded by ice and curious penguins.

We have spent the last few days in almost exactly the same way that we have occupied ourselves over the last 2 months—dropping large pieces of expensive sampling equipment over the side of the ship and steaming slowly between imaginary points highlighted on the ship’s navigational computer. The work has continued and there were even surprises right up until the end. Elephant and fur seal were observed, completing our collection of Antarctic pinnipeds. A rash of novel whale species appeared to brighten up the whaleos’ (those scientists obsessed with whales) days. The krill night shift appalled themselves, and everyone else aboard, by catching 40kg of krill on Sunday night which sent So scurrying to check whether he had exceeded his permitted quota or if he was going to have to apply for a commercial fishing licence. The night shift responded in a far more subtle way by catching modest numbers of four different species of krill in a single haul. Jason surprised himself by retrieving the second of his moorings—which resulted in a much reduced demand on the ship’s dwindling supply of Valium. And to top it all, the oceanographers collected an interesting salinity reading!

6 March 2006

With the last transect finished on Tuesday all that remained of our business was to meander down to Davis whilst searching for elusive minke whales for Jason to record, and then effect the final end-of-summer pick up from the station. Despite finding minkes in abundance in the pack ice near the bottom of Transect 11, we were unable to extract a single squeak from them—a lone failure in the sea of triumph that has characterised this voyage.

As we enjoyed a celebratory BBQ on the helideck, we moved slowly to the west through more magnificent glacial scenery with scattered wildlife for company. We arrived at Davis at noon on Wednesday and as the ship’s crew conducted lifeboat drills the incarcerated hordes leant over the rail gazing mournfully at the green fields of Davis where people were free to walk on dry land, stretch their legs, and drop into the bar for a last drink before joining us on our temperance crusade. Most people aboard did, however, get a quick spin around the icebergs as part of a safety exercise organised by the Captain and this proved most popular.

Helicopter operations began at 8.30 on Thursday and we rapidly began to fill the ship with new people and their gear. By lunchtime it was all over; we had put the helicopters to sleep in their hangar and had repositioned the laboratories on the helideck and were ready to sail again at 1500. The decks were crowded as everyone turned out to bid a fond farewell to Davis and to say thanks to John Rich and his small group who can now settle down to their winter together undisturbed.

We headed North in beautifully still conditions with light hearts and the satisfying throb of giant diesels beneath our feet. We had three small tasks remaining to complete and these passed almost uneventfully. Filling the minicosm tanks went by so quickly that no one noticed it had even been done. We sheltered in the lee of a gigantic iceberg as 40kt winds blew and completed our last (?) oceanographic task. True to form Nathan recalled an otherwise forgotten discussion several months previously where he had pointed out that this last CTD calibration was in fact two CTDs and not one—and no one was at all surprised. All that remained was one small krill trawl to fill the tanks so that we could bring a few hundred live krill back to stock the aquarium in Kingston. Of course, with a massed audience, and both shifts of crew and scientists to assist the trawl, it nearly went horribly wrong. As soon as one of the densest aggregations of krill we have ever seen wandered onto the echosounder screen, the computer that has faithfully opened and closed the net all voyage decided to take leave of absence. The whole procedure went on hold as cables were inserted into any available computer port in an effort to display the simple interface that says “Open net”. Finally, following divine intervention by Kelvin, the net was lowered, opened, closed and then brought aboard with a bumper crop of about 30Kg of krill caught in just 3 minutes—not quite the record but more than enough for the krill team to declare it absolutely, finally and honestly the very last trawl of the voyage.

We've now got to that part of the voyage where the nautical equivalent of “are we there yet?” is a constant refrain from the back seats. Yes, it’s time to play “when will we get to Hobart?” a game that all aboard can enjoy. Unfortunately the arrival time is always in the lap of the weather gods, and our speed at any one time is determined by the wind and the sea state so predicting an ETA is a fine art best practiced when already in sight of Hobart. Fortunately, however, we do have an advanced underway-data display system that can provide hours of amusement and which, when programmed correctly with the desired ship’s speed, can come up with exactly the answer required. It’s great fun; for example, when we stopped to do a CTD it predicted that we would be in Hobart in 500 days time but during a brief turn of speed out of Davis it somewhat erroneously suggested that we might have been in Hobart yesterday. All good clean fun and a fine way to while away an afternoon when all there is to look at outside is a low grey sky and snow flakes the size of pillows.

9 March 2006

Since leaving Davis all our thoughts have been concentrated on willing the ship towards Hobart – not that we don’t like the Aurora, it’s just that everyone has had a long period away form home and is looking forward to seeing loved ones, trees, vegetables and the occasional adult-rated drink. The weather is the main trick to getting speedily home and, having inherited a platoon of meteorological types from the stations, it was inevitable that the weather gods, who have smiled on us for the last 2 months, would turn against us – and they did. On Sunday we experienced the stormiest weather of the voyage with 50kt winds and associated large swells. Although this did not slow us down greatly it did make for an uncomfortable 24 hours and sent many, including several seasoned seafarers, to their bunks for a period of enforced horizontal contemplation. But now we are into a more amenable weather system with a following wind and sea and the ship is barrelling along at close to 16 kts, juddering and shaking as it eats up the miles. Our ETA is now set for Sunday afternoon at 1600, two days earlier than originally planned, which has put a smile on the faces of those aboard – and apparently on the weather gods.

As the voyage draws to a close it is time to thank all those who helped us to realise what seemed at the outset to be an almost impossible task. The irrepressible ship’s crew have been superb – the deck crew have made the scientific deployments dependably efficient, the galley crew have kept us amazingly and creatively well-fed for months, the engineers have kept everything working fantastically, the officers have ensured that we have made the best available of the time at our disposal, and Scotty the Captain has made the whole business a pleasure. Ruth, the Deputy Voyage Leader’s unassuming competence and eye for detail has underwritten the success of the voyage, and the Marine Science Support officers Tony and Kelvin have made an art of ensuring the science proceeds. The 61 strong scientific party (including our voluble communications officer who has been awarded honorary scientist rank for his contribution to voyage statistics) has continued to amaze with their dedication and hard work, their enduring good humour and their susceptibility to bribery with only moderate amounts of chocolate. Were I to sail again I would wish it were with you! Thanks should also be given to all those who have allowed themselves to be caricatured in these diary entries with no available avenues for recourse—any resemblance to people living, dead or moribund was entirely intentional. Thank you too to Mawson and Davis stations who willingly subjected themselves to our tight timetable, and in the case of Mawson, our tight presence too. The returning expeditioners from both stations have patiently stood by (or reclined) whilst we finished our work and made the trip back so pleasantly uneventful. The people at the AAD in Kingston who have been at the end of numerous bothersome e-mail requests and phone calls and who have largely left us unmolested deserve significant praise. Finally, to our families and friends who have put up with our absence for what seems to us (and hopefully for them too) like an astonishingly long time.

As a parting gesture, some useful, amazing and just plain idiosyncratic statistics gleaned from one of the Australian Antarctic Program’s least inscrutable voyages are reproduced for posterity below. We hope that you have enjoyed reading about our antics as much as we have enjoyed being part of this monumental and at times transcendental undertaking.

BROKE-West January 2nd – March 12th 2006

Voyage statistics

Total distance sailed: 12,300 nm, 7,500 nm actually on the survey itself. The area surveyed is between 1 and 1.5 million km² – depending on who is doing the estimation, what software is used and how much sleep Toby has had.

Demographics of BROKE-West scientific team (including doctor, comms officer and voyage management) — thanks to Natalie for her sterling work on this.

Mean age overall: 32.92

Mean age (female): 32.2

Mean age (male): 33.46 (skewed age profile not entirely due to Voyage Leader)

Sex ratio: 43% female (not significantly different from a 1:1 ratio — a first for the Australian Antarctic Program?)

No significant difference in participation rate by star sign or birth month, however, significantly more of the voyage participants were born on a Friday or Saturday. Now, what about day of conception?

Exactly 100 713 photos have been taken, this is equivalent to 1.16 frames per minute. If printed to standard print size and laid out in a line they would stretch for 14.6km.

Over the course of the voyage we have made 639 satellite phone calls from the ship, or one every 2.5 hours.

There have been 374 email transfers—sending 25 989 email messages for a total of 84.6 MB (compressed) receiving 46 885 email messages for a total of 152.1 MB (compressed). We were obviously far less prolific than our friends and colleagues.

One person alone (we'll refer to them simply as A/Prof B — not his real name) was responsible for 1203 received email messages at a total of 60.7 MB (uncompressed) and 1309 sent messages at a total of 34.0 MB (uncompressed), representing almost a quarter of all transferred email traffic!

We have read 2520 pages of news, with approx. 74% or 1865 pages of it seemingly bad news.

The whaleos drank almost 300 litres of tea on the bridge and have lost track of the number of biscuits they devoured.

The total depth of water sampled by the CTD was 358 067 metres. Shigeru circumnavigated the CTD 1257 times whilst sampling it, a total distance of 11.8km — he earned two days off from the gym as a result.

The amount of water brought to the surface was 26.4 tonnes — the amount spilled onto CTD room floor was ~ 2640 litres. Attributed cost of spilled water approximately $70 000 — this will appear on Nathan’s next credit card statement.

The Acoustic Doppler Current Profiler (ADCP) produced 6 048 000 pings and the software crashed a paltry 19 times. Only one of these crashes can be directly attributed to Esmee sitting on the off button.

Total number of krill caught = 315 760 equivalent to roughly 0.2 krill per litre of fuel consumed.

Number of viruses sampled: 17 360 000 000 individuals, with a combined length if laid end to end of 0.937 nautical miles.

We started the voyage with 1.6 tonnes of fresh vegetables – we now have none.

We consumed 2.39 tonnes of meat despite the presence of several determined vegetarians.

We consumed almost enough chips (594kg) for everyone to attribute one kilogram of their cumulative weight gain entirely to their intake.

On average, one egg was consumed every 4.7km

We only caught 110 very small fish but consumed 240kg – this is obviously unsustainable.

The Captain showcased 66 nightly episodes of the highly dubious TV series ‘Alias’ in his cabin; we spent 69 days at sea which was uncannily well timed—what would we have done if he had had access to the third series? Was SD6 involved?