Chagos Expedition 2012: Chapter 2

By David Tickler, representative of the Bertarelli Foundation at the 2012 Chagos Expedition.

"Day 18 has been another massive day on the Pacific Marlin: three dives today to make the most of our last day of diving amongst the outer islands, and amongst them an absolute first -  a dive on the seagrass beds south of Danger Island that were only discovered, but not dived, on the 2010 expedition. Needless to say, those of us who rolled over the side for that one were smiling all the way to the bottom.

With over 2 of the 3 weeks of the trip completed, we are all now well accustomed to the rhythm of a day out on the reefs. The teams dive laden with a variety of kit necessary for their particular study – tape measures, cameras, mesh bags of tools, plastic bags and zip-ties for the larger samples, test tubes for the smaller ones, tweezers, waterproof notepads, small weights tied to bits of pink ribbon – so we travel to the dive sites perched on piles of dive gear and survey equipment!

We dive twice a day, typically for 60-75 minutes each time, with teams taking turns to be in the water or keeping watch from the boats. Travel time from anchorage to dive site can often be significant so the dive sets can take 3-4 hours to complete and take up most of the day: as a result sample processing and data entry often goes on late into the night. Some projects are more labour intensive than others, and I’ve spent several evenings helping the cryptofauna (i.e. tiny animals) team pick minute, transparent shrimp out of (dead) coral samples by torchlight.

The main focus of our time here is, of course, the work, but we do allow ourselves time out for a passing manta ray or silvertip shark and every day has had some encounter of note –the whaleshark sighting at Ile Diamant last week, yesterday’s sailfish, today’s mantas – to quicken the pulse.

In addition to the daily work of ‘doing the science’, we’ve also had the opportunity, under the excellent guidance of BIOT’s environmental officer, Pete Carr, to visit several of the islands in the Archipelago and see the amazing seabird colonies that are his passion. Thousands of Red-footed- Brown- and Masked Boobies, Brown- and Lesser Noddy, Bridled- and Fairy Terns,Wedgetailed- and Audubons Shearwaters nest in the trees, and on and under the ground. Notable is the contrast between the ex-plantation islands, which suffer from an overly healthy rat population, and the ‘natural islands’ where the birds abound. Other than the birdlife, crabs are the main inhabitant of most of the islands: in the absence of competition from other species coconut crabs, hermit crabs in a dazzling variety of borrowed shells, ghost crabs and host more do all the ground level jobs.

As if the days weren’t busy enough the group have been taking turns to give evening talks sharing their experiences and discussing the work they’re doing here. We’ve heard from Charles Sheppard, the most experienced scientist here, about the fate of the other reef systems in the region not as well protected as the Chagos; from Nick Graham of James Cook University about the importance of the reef systems here as a stepping stone for species movements across the Indian Ocean; from Jessica Meeuig of the University of Western Australia about her work with the baited cameras, both here and in South Western Australia; Pete Carr has given us an introduction to the conservation challenges for the island habitats and birdlife; Heather Koldewey and Catherine Head talked about the various marine conservation initiatives spearheaded by Zoological Society; and even our doctor, Bob Long, has given us a talk about his experiences working with marine habitats and his dream of living underwater. It has been an education to be part of such an informed crowd.

As we draw near to the end of our time out in the islands, and make ready to return to Diego Garcia and complete out final pieces of work I can honestly say that this has been an amazing trip. Hard work certainly, and challenging in terms of logistics and weather conditions on occasion too, but also life changing and inspiring to a degree I did not expect. This is simply one of the most amazing natural environments on earth."

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