Jan 05 - A New Year and Bongo Nets
Noon Position : lat 54 15.2 S, long 38 40.0 W
Bearing: 236T, 26 Nm from Bird Island
Air temperature @ noon today : 5.2 degrees C
Sea temperature @ noon today : 3.7 degrees C
Wind: Direction SSW, Force 3
Happy New Year!!
So here we are bobbing around in the Scotia Sea just south of South Georgia. Despite being only 20 miles or so off the coast we can see nothing but fog, Well, that's mostly true but occasionally the mists clear and we get beautiful glimpses of snowy mountains, groups of fur seals playing, albatross, dolphins and whales. Whenever the visibilty becomes more than a couple of miles there is a general stampede to join the whale watchers on the monkey island and go wildlife spotting. Not a bad way to bring in 2005.
This science cruise is a biosciences cruise and we steam up and down a specific route in the ocean, known as a transect, at pre-determined points we stop (a station) and take samples. These samples are CTD, bongo nets and an optics rig. As you can imagine this occurs day and night and we are due to do some 60 stations so there are always people on day and night shift. Below is a little bit about part of the science, the bongo nets.
On this cruise there are several science objectives. This week we are going to have a look at some of the smallest, but most abundant life in the oceans, the ‘copepods’
(cope-e-pods), affectionately known to many on board as coco-pops. These animals do in fact look a little like coco pops, they grow to about the same size and shape, although they are
transparent in colour, and have antennae and legs sticking out. There are hundreds of different types of copepod living in many different places on the planet, from small pools of water that
collect in plants living high up the trees in the tropical rain forests, to discarded tyres at the side of roads in Africa, to the deepest oceans floors. These animals are thought to be the
most numerous of all on Earth. Taking any sample of sea-water you are likely to find a few of these critters, even in that unplanned mouthful of sea-water you may have swallowed when swimming
in the sea. It is because they are so common everywhere that they supply the food to all other animals in the oceans, either being eaten as they are by things like fish larvae or even whales,
or indirectly, which means that there are a number of links in the food chain before it reaches the final consumer.
But it is the copepods that live in the upper waters in the Southern Ocean that we are interested in on this cruise. We have been sampling the waters around South Georgia for the last 12 years, looking at the abundance of important copepod species, and how fat they are. We have been looking at how their abundance changes with the conditions in the sea, such as the amount of food present or the temperature of the water. These factors are all linked to things such as the amount of ice cover, the amount of light which penetrates into the ocean, or the amount of nutrients available for the plants to grow, all of which may vary from year to year. We are piecing together how copepod populations change from year to year and place to place, so that we can predict how they may be effected if conditions down here change dramatically from those which they are used to. It is hard to believe, but some types of copepod do better around 1 - 2 degrees centigrade, whilst others thrive when temperatures reach 5 degrees centigrade. It all seems pretty chilly if you put your fingers into water that cold, and in fact is about the range in temperature in your fridge at home, but these animals are happier at these temperatures, so any change may be hard for them to adapt to.
To get the copepods out of the water we fish for them with bongo nets, so called because of their similarity to the drums (we think). At each station we stop and put nets with a mesh of 100 microns and 200 microns over the side of the boat to a depth of roughly 200 metres.
When the nets come up the resulting soup contains many copepods and other little things that swim!
Many thanks to Rachel Shreeve for her help in explaining what a copepod is and why it's important.
Whilst everyone back in the UK was having their Christmas break the ship's crew and scientists carried on with scientific work as usual but there was still time for celebrations. It was very strange to listen to the adverts on live radio (via the internet) all telling us the number of shopping days 'til Christmas. Here, where there are no shops and it made a refreshing change not to have the festive season forced upon you. However, some thought I was little too laid back as we only got the decorations and tree out on Christmas Eve. On Christmas day itself there were many people up and about early, the galley staff were up and cooked a fantastic lunch, many thanks to them for that. The watchkeepers had to be on the bridge even though it was a 'holiday'. But the people who had to get up earliest were those with small children back home, due to the three hour time difference any little ones up at 5am called here at 2am! Hurrah for a good telephone system, which meant that all on the ship could phone home .
On Boxing day we started the science in earnest and Christmas was behind us very rapidly. New Years Eve crept up on us and the bar was very sociable that evening. At midnight we followed the old navy tradition. The ships bell (lovingly polished by a cadet!) is hung on the fo'c'sle and at midnight the old year is rung out by the oldest on the ship and the new year is rung in by the youngest on the ship. Keith Rowe, our electrician, was robbed of his chance to ring the bell due to some last minute repair work that needed doing and so Doug Bone kindly stepped in to fill his place. The youngest was Will, one of the cadets.
Above: Doug Bone ringing out the old year (photo L Handcock) and Will Wright ringing in the new (photo P Enderlein)
So a Happy New Year to you all!
Lots of people liked the questions from Pete the other week and I have received a few more, thanks to Max from Gloucester (sorry it took a while to answer!)
Do all members of the crew assist with watch duties? - The bridge is always manned by the officer of the watch and a crew member on watch duty. All of the deck crew except for the bosun and the bosuns mate do watches.
Does she carry a helicopter? - we don't carry a helicopter, if you are interested in finding out more about the ship you could go to the virtual tour and have a look around!
Why is all of the ship not painted red, eg decks, so she can be seen clearly from above, when ice surrounded? - Because it would give us a headache! But seriously, we are quite easy to see from above in the ice even without red decks.
Do the BAS doctors have to have their appendix out before they travel south? - No. In the early days of BAS, all people who travelled south had their appendix out. Nowadays people are
much less likely to have appendicitis and so there is no need for the operation.
That's all for this week. If you have any burning questions that you want answered do send them via the webmaster (email@example.com) and he will pass them on. I'll do my best. Meanwhile we will continue bobbing along through the fog off the coast of South Georgia. 'Til next week.....