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Special Report: Continuous Plankton Recorder

Hello out there!

We finished deploying the new string of sediment traps and current meters late afternoon on Saturday and straight after that Gordon assisted by two crew members deployed the CPR. I believe Brownie told you about those early this year but for those who haven’t heard about it or can’t remember from last time.

I also thought CPR stood for Cardio Pulmonary Resuscitation - but Gordon says no, it is actually Continuous Plankton Recorder. Ok but what is it?

This is a project Gordon is looking after for a couple of the Biologists at the Antarctic Division who are involved in krill and other marine research. What the CPR does is collect plankton from the ocean as the ship is moving along. Plankton is a microscopic life form which is at the bottom of the food chain; an idea of their concentration in the oceans in certain areas and at various times of the year adds to the knowledge of the marine system.

So what happens is that we tow a device like a small submarine behind the ship - this is about one metre long and at the fattest about a metre around and weighs 40 or 50 kilograms. It is sort of pointy at one end like a ship and it has fins and a small propeller at the back. It is dragged through the water on a steel cable about 100metres behind the ship. It operates in the surface layers of the ocean perhaps down to ten or 15metres below the surface. Inside this device is the instrumentation which comprises two strips of silk on rollers. As the instrument is dragged along, water is forced into a special opening and the two rolls of silk wind up and make a sandwich of any plankton in the water; water is forced out the back. The rolls of silk wind on quite slowly - at about five centimetres of silk for each five nautical miles of sailing. We tow the contraption for about 450 nautical miles before bringing it back on board and changing over the internal mechanism to a new one with a new roll of silk. The plankton which has been ‘caught’ and strained is effectively sandwiched between two layers of silk. After taking the silk roll out of the mechanism Gordon labels it and puts it in a jar with formaldehyde and sea water. The scientists back in Australia can then carefully unroll the silk and do plankton counts and correlate the data with information about where the ship was, the sea conditions, water temperatures and so on, all of which Gordon logs at four hourly intervals.

As we write this the first of the CPRs is back safely in the laboratories after a run of some 409 nautical miles. Gordon processed the recovered silks and prepared a new instrument for deployment - it is now sitting firmly in the outer casing waiting to be deployed. We are now at the place where the second set of sediment traps is to be found and pulled in - that will be tomorrow morning Tuesday 10 October. When the new sediment traps have been put into the water the ship will turn and start heading toward Davis station many many days sailing away. Once we start heading that way Gordon with crew support will deploy the second CPR.

The work is not hard but it is interesting; Gordon and the crew have to be careful because the equipment is heavy, the deck at the stern of the ship is usually wet and Gordon has to unscrew and reattach steel plates on the device to get at the internal machinery. A lot of water has been coming onto the trawl deck where we do this work because we had a ‘following sea’. The deck has lots of safety barriers etc and Gordon wears gum boots, overalls, a hard hat and gloves and all sorts of stuff to protect him. The silk rolls are in a formaldehyde and sea water mix which can be dangerous so he has to work safely with gloves and in a place where the fumes can disperse.

But does this make me, Berkley from Husmann Elementary in Crystal Lake, Illinois a star? I told you in an earlier report that a two person team from National Geographic Wildlife Television, Washington DC is on board to make a special program on Leopard Seals at Davis. While on board they are putting together as much footage as possible of anything which happens on a voyage. So, today with the CPR it was our turn.

By the way I don’t think I mentioned before that Gordon has given names to the four CPRs we are putting out during the voyage - the first was OzGold, the next one going in is Berkley, to be followed by Dreena and lastly by Puff.

The film crew took shots of Gordon bringing the CPR and processing it. Both OzGold and I were down there of course having a look so the film people asked about us and why the CPR had been called OzGold. So the filming took another turn - Gordon talked about why I was in Australia and the contact I was having with lots of people around Australia and all my friends back at Husmann. The producer Birgit really loved the concept and the story, so apart from me being on film with the CPR, I am also going to be covered by a special interview and filming - about Betty’s Geobears project and what it means for learning and spreading the message about Antarctica. I’ll also be able to introduce my best pal OzGold. What a thrill this all is.



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