31 December 2003
I can't begin to tell you how exciting it is at the moment. Whether its the dawn of the New Year or that we have had spectacularly great conditions in recent days and are on the verge of beginning the predator/prey experimental sampling, it doesn't matter. We are abuzz.
I am penning this ("poking at the keyboard" doesn't have the same romantic ring to it) while everyone is preparing for a big "do" for New Year's Eve - fancy dress. We will be celebrating 5 hours behind you lot.
Since the storms not long back, the seas have been very kind. It's great not having to walk through the restaurant acting like a pendulum as you shift from leaning one way and then the other in order to counter the roll of the ship. It also means that we can sleep in our bunks once more - in seas like that it is much easier to wedge yourself between bunks on the floor so that the lazy roll increasing to a sudden "fling" doesn't leave you spread-eagled on the floor. Not surprisingly, one relaxes better when you don't have to continually brace yourself for the rolls away from the wall.
We have concluded the broad-brush sweeps of the main areas likely to be feeding grounds for seals and penguins and come up with some really interesting views of the way the sea works down here. It seems that all the action for small mesopelagic (midwater) fish is to the east and southeast of the plateau area. There doesn't seem to be much action to the northeast. The data on ocean temperature and salinity tells us there might be currents sweeping around the south of the island as well as from the north west, which makes for some interesting eddies and other features that might keep the small fish in one place. We will be trying to get more information to tease out what is happening.
With such good weather and almost calm seas, we have "dropped" the underwater video in three more times. Well, what sights there have been! Two were in deeper areas and one on a place named Gunnari Ridge, so-named after one of the main commercial fish in the area because of the abundance of fish found in the early surveys by Dick Williams (Champsocephalus gunnari). Dick Williams is our voyage leader this voyage and like a child in a lolly shop (though Dick doesn't have a sweet tooth), he was ecstatic about the visions of mackerel icefish and Patagonian toothfish - they were spectacular. Very clear, showing the real colouration and postures of the fish. It was a special moment because mostly we work on what we see that comes to the surface in trawl and longline fisheries and have only imagined what they have looked like in their own world. Even in daytime, it is dark, relatively fast flowing and, in some areas, flat and featureless while in others it is a rocky and hilly domain with lots of other creatures waving in the current. The current was noticeable in these videos with the powerful lights highlighting the marine snow drifting past and some of the stalked anemones leaning over in the "breeze". The toothfish just sat there pointing into the current - great if you wish to act as a trout in the stream capturing food as it passes. The icefish were quite mobile, giving us plenty of opportunity to see how they swim, sit on the bottom and orient themselves in the water.
The video camera has been fine-tuned by Tony, Kelvin, Andrew (Pud) and others giving us great footage for most of the hour that the film in the camera allows. We've seen plenty of other life as the camera sweeps over the bottom at just over 1 knot. In the last drop, there were plenty of skates, sea urchins, and sea anemones. We have also seen whip tails, other types of fish, and octopus. It's mesmerising!
We did have a false start on the first of the three recent deployments, finding that one of the electrical plugs in the electronics pressure housing had leaked and flooded some of the gear. The talents of Tony and Kelvin came to the fore in weaving their magic over the electronics boards and fittings to set everything back in train. To Dick and I, our solution of spraying everything with WD-40 would not have worked. We'll stick to handling the bigger stuff.
In the last 48 hours, we have been rapidly bringing all the data together that we have collected to date in order to design the first "predator box". The parties on the island have been putting trackers on macaroni and king penguins, fur seals and albatross. We have now identified three boxes that each of the three species have been active in. Combined with the acoustic (fish finder) data, we have been able to speculate on "foraging areas" and "non-foraging areas" in each of the boxes. The Aurora is now only one hour away from beginning the intensive sampling program in the macaroni box. This program will be completed in each of the three boxes. Each box will take about one week to complete.
This intensive sampling is intended to try to understand generally why the predators (penguins and seals) seem to concentrate their feeding (foraging) in particular locations and why they spend the time they do there compared to other areas. Is it because they are the only places you find food or do they go to those places because they are easy to find or because those places are at the limits of their range of swimming or some other reason?
Thus, the specific aims of the intensive sampling are to try to answer questions for each box:
- Are there differences in the density of food between foraging and non-foraging locations? In other words, is there more food in the foraging areas?
- Are there differences in the locations of food in the water column between day and night and are those differences the same in the foraging compared to non-foraging areas? In other words, is the food more accessible in the foraging areas and when is it more accessible, during the day or during the night?
- Are there differences in the types of fish (food) species between the foraging and non-foraging areas? In other words, could the predators be finding more preferred food in the foraging areas?
- Is the food found in patches or is it widely distributed in the foraging areas and how does that compare with the non-foraging areas? In other words, could the food be easier to find because it is more widespread in foraging areas?
As we prepare for the New Year and first intensive study box we are sailing on calm seas past Heard Island only 12 nautical miles distant with a luminous grey sky. Although the top half is covered in cloud (as one would expect) the main glacier on the south west is basking in sunlight. We are very close to where the main land party is working (they should be able to see us). It is a glorious and clear sight. We have a "sched" this evening with the land party to confirm our plans and then we will be in the thick of it. (I will tell you more in the next instalment).
It has been great standing on the bridge watching the island and reflecting on how much we have managed to achieve already. It has been a great pleasure working with Dick and Tim Lamb (the Deputy Voyage Leader) on this voyage. They have worked very hard to keep everything ticking over smoothly. And then to have such wide ranging discussions on how this part of the world works. Dick has had 14 years experience in the area and it is great to see some of his and others ideas that have evolved over the years be explored in the detail we are able to on this voyage. Although this program is an adaptive program - as they say, suck it and see - it is very exciting the way that it is already evolving.
We have finished phase one in good time and now moving into phase two with all the promise of this being successful. We will certainly be trying hard. It has been a great credit to all on board.
This is the last of my notes for the year. I wish you all a wonderful celebration this evening and a Happy New Year.