Report 14: Hello buoys!
Steve Nicol, Voyage leader
After what seemed like an inordinately long Transect 9 we have made it to Prydz Bay and face the prospect of having to complete one more up and down – a mere 800 nautical miles – before we call it quits, pack up our expensive toys and go home. Although the ninth transect was largely uneventful and fairly short, fatigue has set in and at times the ship resembled an out-take from Dawn of the Living Dead, except with rather fewer overt displays of cannibalism.
We ended the line on Fram Bank which is a highly recommended place to finish any transect with thousands of designer icebergs, chic pack ice and considerable concentrations of elegant wildlife. Another clichéd sunset ended the day as the moon rose majestically and later, as the moonlight glowed off the silver bergs in a display of opulence, an aurora lit the sky to compensate the night-shift for missing the earlier floorshow. These experiences really helped to lift spirits, dispel zombie impressions and encouraged a collective loin-girding as we press on into the last lap. But first, we had to complete some unfinished business.
We are estimating the abundance of whales using two different techniques on this survey and this hasn't really been tried before so the results should be of great interest. The first method is the standard visual abundance estimate which depends on a team of observers who scan a defined sector of the ocean for whales in a specified way. This is not as simple as it sounds and there is considerable research that has gone into the best way of conducting sighting surveys and into analysing the results. It also takes a sizeable team, and we have a wonderfully international group of seven people from five countries and as you might imagine communication errors are not always a function of radio interference – only superb co-ordination by Sarah and Paul prevents the monkey island from becoming the Tower of Babel. Observations can only proceed in daylight hours whilst the ship is on transect so sometimes the hours are long but at other times, when things get out of phase, we end up on station during daylight hours and are in transit at night so observations are frustratingly curtailed.
The second way we are counting whales is using passive acoustics. Whales make noises and if you count the number of noises around the ship you get an idea of how many whales there are in the vicinity. If you also know what noises each species of whale makes then you can also begin to work out which type of whale is found where. We do this using small devices containing microphones that are regularly dropped into the ocean; they pick up whale sounds and relay them back to the ship where they are recorded. Additionally we have a couple of other gadgets (ARPs – acoustic recording packages) that record whale sounds and these are dropped onto the ocean floor where they are left for a year then picked up – or not. The tricky bit is to retrieve an instrument once it has been sitting on the seafloor under a couple of kilometres of water for 12 months.
The instruments have releases that can be triggered by a pulse of sound and they then come slowly to the surface whilst Jason, their custodian, paces the bridge muttering darkly and making arcane calculations. This is why we spent yesterday evening on the bridge with every semi-functioning pair of eyes trained on the grey ocean under a threatening sky as dusk approached looking for any sign of a series of yellow buoys that signified the surfacing of the recording package. We had decided that the current weather was too good to last, and the forecast was bad, so if we wanted to recover the ARP (and we did) then we had to act fast so we fought our way through a field of loose ice to get to the site before darkness fell. Luckily we made it in time and despite the pessimists amongst us we did manage to find the buoys, which were somewhat ironically spotted by Paul who is in charge of the whale visual observation team. However, his use of the "Big Eye" binoculars on the monkey island was deemed by some to disqualify him from winning the spotters fee. Jason now has to download the data and he will have a whole year's worth of cetaceaous squawks which ought to keep him happy for several months.
Listening to recordings of underwater sounds is not the only evidence of behaviour aboard that might be viewed as strange were it not happening on an icebreaker far from the trappings of civilisation. Weird and the wonderful things that once would have been cause for comment occur on a daily basis. Socks are worn with sandals, fruit juice is poured on breakfast cereal and people are even eating prunes. It's time to think about going home.