Report 5: The wild west

The big net comes aboard following the first regular trawl at the North West corner of the survey area
The big net comes aboard following the first regular trawl at the North West corner of the survey area (Photo: Steve Nicol)
So Kawaguchi teaches krill biologyThe first catch - the wrong species of krill!

Steve Nicol, Voyage Leader

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.