November 2102 Expedition - Week 1 successfully completed
Well, we’ve now been at sea for a week on the Pacific Marlin and it has been a productive and busy time. On a daily basis, we have at least 5 research activities occurring using three vessels, no mean feat to coordinate. As we’ve now settled into our research groove at sea, I can describe a typical (good weather) day for us.
Starting at 4 am, well before dawn, the shark taggers are hard at work chumming, and by 5 am, deploying their longlines, then commencing checks at first light to see if they’ve captured any of our priority species for tagging. Critical here is that the lines are checked regularly so that animals are not spending extended periods on the line to ensure that they remain in good condition. By 7 am, as the taggers check their line, the acoustic team of Martin and Phil deploys in one of the Marlin’s Fast Rescue Craft (FRC2) and the video team starts deploying a longline of 10 camera systems (SISSTAs). By 7:30 am the SISSTAs are in and the acoustics team has started running transects around them so that we can correlate what is “seen” by both approaches (see Phil’s blog for more details). By 8 am, as the Marlin trails our longline of cameras, Lewis is dropping his oceanographic equipment to build profiles of salinity, temperature and productivity down to 200m. By 9:30 am, the taggers are back in FRC1 having been constantly monitoring their longline since 6:30 am. Morning tea means delicious cupcakes and cookies from the Marlin’s chefs that fortify us to haul in the 2 km longline with 150 kg of cameras dispersed along it that we deployed, starting at 10:30 am. It is a testimony to the skill of our captain, Neil Sandes, that he is able to beautifully reverse the Marlin down the longline for the team to recover the 10 longlined SISSTAs from the sea. And by team, I mean team. On the back deck, Marlin crew members work side-by-side with the scientists to safely recover each camera system. Managing this much line is an art and I can tell you that our expedition doctor, Jasjot, and Chagossian communications coordinator Rudy, are also now rope coilers and splicers par excellence. By 11 am, the acousticians are back and we break for lunch. We then repeat most of this in the afternoon. And throughout this entire day, like clockwork, our ornithologist Pete has been doing 30 minutes on – 30 minutes off seabird transects from 6 am to 7 pm.
In terms of locations, we started our week at Sandes Seamount NW of Diego Garcia where we spent the first day as a “shake down” to make sure all the kit was working well. Following 2.5 days of sampling, we transited to the southwest corner of the Chagos but overnight we found ourselves in the middle of a large storm from the north, complemented by increasing swells from the south. As it was still raging late morning and looked to be so for days, we transited to the northeast of Chagos. Following three days of work in this area, which included deploying our first series of camera systems linked via a longline stretching 1 km, we then moved on to some of the Northern atolls, where we continue to work.
Our research activities are highly weather dependent (neither the acousticians nor the taggers can work in rough seas). Indeed, we’ve had squalls, wind gusts up to 30 knots, prevailing winds at 15-20 and even a bit of horizontal rain. These highly changeable conditions have made organising each day’s activities a bit challenging in regards to efficient and safe use of the Marlin’s time. Which brings us back to the Marlin crew – all week they have been helpfully available as we shift and rearrange activities, and ably assisting us to these ends.
We are trialling brand new methods in a very remote region of the world about which we little is known, including basic bathymetry. To this end, we are truly doing exploratory research on this expedition and couldn’t do it without our fantastic crew.
Jessica Meeuwig, Expedition Leader