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Overnight we conducted the usual trawling, CTD and trace metals deployments at way point 307. We then took a deviation to the North-west to the site of the Gribb Bank Whale recorder. This equipment has been sitting on the bottom of the ocean for the last 12 months recording sounds in the hope of picking up whale calls. It is deployed in this particular location for a couple of reasons. Firstly, the water here is relatively shallow as the Gribb Bank rises to about 1800m below the surface. Secondly, it is a location which is commonly passed by the Aurora Australis on the way to Davis and Mawson which means that these whale moorings can be changed over opportunistically without the need to spend valuable ship time transiting to the location.
Still, it’s a major operation to find and recover these moorings. The ship arrived on the site of the mooring about 8am. Whereupon, we shut down all the echo-sounders and disengaged the ships propeller to make it as acoustically quiet as possible. Then it was matter of donning the head phones and pretending we were in the film, The Hunt for Red October as we sent pings down to the ocean bottom to see if the device would answer. Eventually after a bit of re-positioning of the ship, we convinced ourselves that we were hearing faint pings from the mooring and we punched in the release codes. The device takes about 40 minutes to reach the surface. Sure enough, about 40 minutes later, 3rd Mate Freddie picked up a sighting of the mooring from a quite incredible distance away. 2nd Mate Naomi picked it shortly afterwards leaving all the expeditioners on the bridge wondering if they were seeing things. But as the ship swung around, there it was bouncing up and down in the swell.
That proved to be the easy part and the deck crew did an amazing job of getting the device on board in very difficult conditions. As Brian and I watched from the mezzanine, we both congratulated ourselves on a career choice that doesn’t involve quite that much contact with +1 degree sea water.
We deployed the new whale recorder and will continue the observing program in this area before making a beeline to the south-east to pick up the pack ice boundary. All on board are looking forward to seeing more ice. But not too much…
Lloyd and Brett
Map
A map showing Australia and Antarctica. The map shows the journey of one voyage that has occured in the season, with each route highlighted in a distinct colour.