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2015 Darwin Science Expedition Blog Jump to project background

  • 2015 Darwin Science Expedition

    Follow the activities of the participants in the 2015 Darwin Science Expedition to Chagos in the daily blog below!

  • Day 24 Last day in the outer islands

    The final day on board the research vessel in the outer islands of the Chagos Archipelago. We set sail in the early hours of the morning, the engine throb rousing in the dark early morning before sunrise. A steady 2 hour cruise will take us south of Danger Island, across a short stretch of open ocean and on to Egmont Atoll.

    A stiff north westerly breeze has lifted the swell from that direction and it’s a rolling cruise down before we anchor off with windy and choppy conditions to welcome us for our day’s activities.

    I head ashore with the shore party to Ile Sud Est. I’m looking for elasmobranch satellite tags that have floated off their host and drifted ashore to the lagoon side of this island. Pete and Tom head off around the island doing their bird and island survey work.

    Whilst we are on island the others have been out diving. For some a particularly sharky occasion with several Grey Reef Sharks circling close as they carried out their work. This will be the last dive for many on this expedition as work wraps up before we start packing for the journey home.


    While we contemplate this it is a good occasion for me to pass you over to Pete for his last write up on terrestrial activities for this expedition.

    The Egmont Islands

    The final day at sea saw us sailing early from Danger Island south to the Egmont Islands. The Egmonts are also known as The Six Islands, though this label no longer holds true. Through accretion the six islands are now two large islands. Some seven years ago a sand bar was developing between these two new islands and looked as though it was going to finally join all of the islands together though this has not happened. Instead, channels have broken through the sand bar and a small island, with Scaevola growing on it has formed in the channel between the two complexes. It was here on this only rat-free ground in the Egmonts that I found my first colony of breeding Crested Terns. These nomadic, non-seasonal breeders (in the Chagos at least) can and do nest on rat-infested islands but have opted to nest without rat-hassle on this isolated feature.

    Red-footed Booby are still maintaining a breeding presence on the Ile Sudest complex with some eight pairs nesting during this visit in the relict coastal hardwoods of Iles Tattamucca and Carre Pate. Sadly, due to the rats and the loss of over 90% of the original vegetation little else thrives on land in these islands.

    As ever, underwater, life appeared to be teeming and again, even after walking the shores of Chagos islands for several years, something new turned up to delight and intrigue me. I had always been under the impression that sea snakes were not to be found in the central Indian Ocean and that there had never been a positive sighting of one in the Chagos Archipelago. So imagine my surprise (shock may be a more accurate term) when as I waded through the shallows looking up in to the coastal trees looking for booby nests, I saw a black banded yellow snake-like creature stalking the cracks and crevices of the shoreline.

    Being mildly ignorant of sea snakes and assuming they are all highly poisonous and aggressive, discretion took the best part of valour and I beat a hasty retreat to terra firma, but not before snapping a distant photograph and watching this creature swim directly in to the sand! As I walked the remainder of the survey route I pondered further over this enigmatic creature. Sea snakes had never occurred in the Chagos, I had never heard of snakes swimming directly in to the substrate, this beast had appeared headless….things were not adding up. But, to the amusement of my more ichthyological minded comrades on the ship I blurted out that  I had had a near miss with a highly venomous sea monster, to which they showed me a picture of the harmless Banded Snake-eel and advised I “Stay Calm and Carry On Birding”.





  • Day 23 - Danger Island Coral Gardens and Rubble Beds

    An interesting swim onto Sea Cow Island last night. This is a circular island with steep beaches or rocky shores and the only way to get there is to swim. Entertaining when swells are bending round the island and meeting each other on the other side in a tumultuous blend of waves. The night was still, beautiful and starry.

    Under the canopy it was quiet while overhead the birds were whistling and squawking as they passed the night through before heading off foraging again in the surrounding seas the next morning. Undisturbed Indian Ocean hardwood forests on this island are interspersed with wide grassy open areas. Although they are not as prolific as on some of the other islands the Coconut Crabs we did find here were large specimens. It is evidently a rich environment for those that do make a home here. We ended the night sleeping on the beach and when the moon rose around 11pm it was so bright colours could be made out on the island vegetation at the edge of the beach.

    After a good night’s rest we woke up to the same sound of crashing cross of surf which provided another battering swim out to the research vessels tender that was sent to pick us up. The research vessel herself was already under way to Danger Island. We rapidly caught up in the fast inflatable and were winched aboard for some breakfast. After a short transit we were soon back in the water again to head to the Oceanside of Danger Island. What a beautiful site.

    This is what Eagle Island’s reefs looked like prior to the blight that swept them. Rich beds of coral sweeping on as far as the eye could see. Schools of fish hovering over the crests of coral. Turtle meandering by and sharks occasionally cruising through.

    By contrast the lagoonside of Danger has also been blighted – large swathes of rubble interspersed with live coral heads. Last year when we came through this site had recently been struck by whatever plague affected it and there were extensive stands of branching coral recently dead and covered in algae. This year all of that skeleton has collapsed and is spread across the bottom in a jumble. Encouraging are the frequent interruptions to this of surviving corals livening up the bottom. Certainly hope that in the years to come a full recovery will be made and once again the bottom will be covered in such colour rather than the light hues of degrading rubble.  

    Now as we approach the end of our expedition it is a good time to offer a few words from Claudia who joined has joined us from the Chagossian community in Manchester.

    ‘I have had the rare opportunity and was extremely fortunate to be part of this expedition. Observing, learning and supporting the team was a great experience. The team was very professional,  supportive and you could easily see their passion for their work. Discovering the beautiful islands full of rare tropical birds species and native plants was breathtaking. Helping to conserve these delicate ecosystems, rescuing a turtle caught on nets, overnight coconut crab survey and waking up to a storm on a deserted island were great adventures. It was hard work but so much fun, truly one of the best thing i ever done.

    I was also overwhelmed by the pristine marine environment and what makes it more rewarding is that i was able to identify different marine species ( through the enviromental training i was given prior to the expedition ). I improved a lot in diving and cannot wait to get back in the water. Definitely one of the best experiences of my life.’


  • Day 22 - bleaching and turtles

    It is evident here that sometime in the last few years there was a huge mortality of the large corals. Similar views to be seen in varying degrees off Nelson, three brothers and now here around Eagle Island. It is possible that this could be down to a crown of thorns starfish plague or due to a bleaching event. No one can tell for sure as there is no year round monitoring of these sites.

    What is reassuring though is that the fish life is still thriving and that the level of recruitment of new juvenile coral settlers is very high. Because the fish are still here they graze the algae on the substrate ensuring that it is clear and available for new microscopic coral larvae to settle. The ones that I have been able to see growing in small mushroom like clumps all over dead coral skeletons are already a year or two old. So in due course the reefs will quite likely recover here as they have done from other mortality events such as the mass coral bleaching event in 1998.

    There were some special sights to see despite the lack of extensive coral cover – a small whip coral turned up the first commensal whip coral shrimp that I have seen in the Chagos. A lovely little light green specimen neatly camouflaged in the same colours as the whip coral to which he clung.

    On a completely different scale was the huge green turtle that wafted in from the blue before warily skirting around us. Or the porites bommie that obviously escaped the mortality event and was an incredible 8 meters or more in diameter. An ancient massive coral.

    A great number of sea stars could also be seen draped over the seabed in various striking hues. Some of them had evidence of predation – and also their remarkable ability to regenerate arms when they have been bitten off. The light blue species was sizable reaching a diameter of at least 40 cm.

    Adding further colour was a fluorescent pink species of porites coral that encrusted patches of rock. Eye catching but I suspect a step too far even for the shape shifting chameleon colour changing octopus. An individual we spotted toward the end of our dive initially put on a display to try and scare us off. Flaring his mantle and turning a stark white. When this didn’t deter us he shifted to a dark brown colour and mottled his skin. Quite remarkable to watch them as they mould themselves across the environs of the reef – becoming a part of it as they move across it.

    So although the corals have had a knock here it is evident that the reefs are still very much alive – it will be interesting to monitor this place consistently in the coming years to see how the corals recover.

    Tonight I’ll be heading ashore on to Sea Cow Island with Pete to continue our surveys of the Coconut Crab populations around the archipelago…more to report on that tomorrow!

  • Day 21 - A romantic dance with a mortal end

    Great Chagos Bank Eagle Island 

    This morning’s dive provided us with a fascinating display from a pair of octopus. We dropped to the eastern side of Eagle Island and although the plan was to follow a shallow survey path along the reef drop off I was distracted shortly after entering the water when some movement amongst the coral heads caught my eye.


    On closer examination I realized that a pair of octopus were squaring up to each other a few feet apart amongst the coral beneath us. I circled closer expecting the octopus to jet away or squeeze themselves under the nearest coral head for cover. Octopus are usually shy creatures and tend to retreat as a first resort – although you can occasionally tempt them out as they are very curious creatures too (watch this video of an octopus I filmed in Madagascar to see what I mean).

    On this occasion both octopus seemed completely oblivious to me so I hunkered down a shot distance from them and started filming. Which is when I realized something more was on the go here…

    As I watched the octopus furthest from me became highly energized. Its arms spiralling and caressing its body. At the same time the octopus closest to me was slowly extending an elongated arm toward the displaying partner opposite. It dawned on me that I was witnessing a courtship display.

    The dancing octopus furthest from me was the female signalling her excitement at the males interest as he extended his hectocotylus, an elongated arm equipped with a tube for delivering sperm packets, toward her. The process was fascinating to watch. The male unwinding and lengthening his arm, slowly waving it closer and closer to the female. And then gently touching her and feeling the way up and into her mantle. Here the sperm packets are transferred and the female can store them until her eggs are ready to lay.


    I expected the process to last no more than a few minutes and was waiting for the behaviour to end so that I could film it’s closure but after an hour I had to call time on the dive and return to the surface. Although the female had pushed away the males hectocotylus several times – on each occasion he had extended it again and the female had accepted his advances.

    On reading up a little more on this octopus mating ritual later in the day it was sobering to realize that this is the opening ritual in the final act of an octopus life. Shortly after mating the males reach the end of their life cycle and die. The female lasts a little longer, laying the eggs in a suitable cave or overhang, she watches over her clutch until they hatch and then also reaches the end of her life span and dies. A romantic dance with a mortal end. 

  • Day 20 Tropical downpours and Coconut Crab eggs

    Last night was a particular treat for us as we headed ashore on to South Brother. There we could not help but stumble across numerous Tropical shearwaters as they roosted on the ground beneath the trees. Pete has already told you a little more about the significance of this in yesterday’s blog. Great to see these birds doing so well here. This was not the only interesting find of the evening though as we came across a gravid Coconut Crab toward the end of our surveys across the island. It is rare to observe the crabs in this state as they tend to conceal themselves in burrows whilst the eggs are carried, only emerging to head down to the beach to wash the eggs off into the shallows of the sea.

    A tropical down pour this morning slowed the start right down. Torrents of rain reduced visibility to about 50 meters shutting down dive operations and our pick up from the island for about an hour. Fortunately for us the weather cleared before we got too bedraggled and after swimming off the island and on to the pick up boat we headed back to the research vessel for a much needed hot shower and breakfast.


    The benefit of the early morning rain is that it appeared to clear the water for diving. When we eventually did get to our dive around South Brother the visibility was amazing. The water clarity allowed for astonishing views down the drop off with the bottom still clearly visible beyond 50 meters. The corals on this side of South Brother are in superb health so the combination of crystalline water and lush coral gardens made for a rewarding dive.

    The afternoon’s dive differed somewhat as we headed to North Brother. Although the corals weren’t as developed there was prolific and diverse fish life, several Grey Reef Shark buzzed us while we dived and shoals of Black Snapper hovered over the reef with myriad smaller reef fish darting amongst the coral heads beneath. Another varied and exciting day on the expedition!

  • Day 19 Scorpionfish and shearwaters

    This morning activity centred around the island of Middle Brother on the western Great Chagos Bank. It is one of the most scenic islands in the territory and proved to be equally appealing beneath the surface.

    Nick and Shaun headed ashore this morning to conduct their work on the island and in the beautiful lagoon there. The remainder of us headed to dive off the north western edge of the island. Here the routine of surveys went ahead while I managed to get some great shots of a colourful Elizabeth’s Chromodoris – a nudibranch with bright orange trim.

    The most engaging encounter of the day though was undoubtedly seeing a group of large coral trout hunting with a morey eel. The grouper signal their co-operation with the morey by shimmying their bodies and changing colour (as can be seen in the video clip below). The morey responds to the signal by foraging in the crevices and beneath corals that the grouper can not reach, flushing out prey which the grouper then attack in the open to the mutual benefit of both. Chris watched this for about 10 minutes on his safety stop at the end of his dive telling me as he came out the water. I quickly jumped in and got this footage before the behaviour stopped a few minutes later.

    Another lovely behaviour seen on this dive was a school of fusilier stopping at a cleaning station, all taking turns to present themselves to the cleaner wrasse who feed on dirt and parasites of their visitors to keep them healthy.

    The shore party had a busy day making the most of calm conditions to visit North Brother, Resurgent Island and Middle Brother.

    This evening for me it is on to South Brother with Pete to continue Coconut Crab surveys. While I head ashore I'll leave you with some words from Pete on terrestrial activity to this point.

    The islands of the Great Chagos Bank

    Dawn on the fourth of April 2015 saw the ship anchored just south of Nelson’s Island. This was to be one of the big seabird days of the trip for me and counts start as soon as there is light enough to see birds. This island is fairly unique in the Chagos. It is isolated on the northern rim of the Great Chagos Bank. It was never inhabited and has not been farmed for coconuts. Probably due to its isolation and lack of man’s influence, there are less plant species present than on most other islands. What vegetation is present is sculpted by the salty winds. It is a mecca for breeding and roosting seabirds.

    Before first light I was on the bridge wing of the ship looking and listening for birds. As my eyes adjusted to the cloaked grey of dawn I started to see streams of noddies leaving the northwest corner of the island for their days feeding and foraging. As the light grew better I was able to count the number of birds leaving the island per minute. We were lucky in that a south-westerly was blowing at dawn and most of the birds leaving the island were coming off the island near where the ship was anchored. Two hundred birds per minute as darkness crept in to twilight, 500 birds per minute as daylight broke. As the sun started to rise the frigatebirds and boobies started to leave the island. Frigatebirds soaring high before heading out to sea, spearheads of Red-footed Booby shearing the waves as they departed and, smoky lines of noddies constantly wisping their way to sea. It was an incredible sight and a challenge to try and assess the numbers. For the record, some 20,000 seabirds roosted on the island and headed out to sea in the first light of the day. It was now time for breakfast before heading on to the island to count the breeding birds.

    The visit to Nelson’s Island was successful and despite the difficulties of conducting a breeding seabird census on this island where unlike most of the other islands, the birds nest in the interior as well as the shoreline, figures were extrapolated from plot counts to arrive at overall totals. Despite what the dawn exodus indicated, noddies were not breeding in any spectacular numbers, emphasising the importance of some of the islands as nocturnal roosts as well as breeding sites.

    As the divers returned from their underwater forays the ship weighed anchor and we headed west in to the setting sun. As we sailed away from Nelson’s Island, stringy lines of noddies were returning from their days feeding activities. The daily avian cycle of the island was coming to a close. In amongst the returning noddies flashed the occasional stiff-winged black and white Tropical Shearwater. These were to become the focus of the next two days research at the islands on the western rim of the Great Chagos Bank, starting with the Three Brothers.

    The Three Brothers actually are four islands. Three of these are vegetated and one, Resurgent, is a barren, wave-washed upraised rock similar to Coin du Mire in Peros Banhos. Similar to its counterpart in Peros Banhos, it is home to a colony of Masked Booby and these were present in the highest numbers I had witnessed ever. Gaining land on Resurgent is always adventurous but as the seas were relatively calm I swam ashore and scaled the rocky side to take a closer look at the plateau where the boobies breed. Similar to previous visits, the boobies were at all stages of breeding from displaying pairs to recently fledged chicks. Another salutary reminder that coming to any conclusions about breeding population fluctuations based upon a single snapshot is unsound.

    North Brother was our next island. A wonderful seabird island but troublesome to swim on to due to its conflicting currents and rocky beaches. The swim ashore is generally made on to a 10m wide sandy beach enclosed by rocky walls. This should present no great problems but, this beach is also where three different currents meet and produce some “Phantasia-type” waves that both overhaul swimmers (particularly when swimming with equipment) and throw them off course. Fortunately our swim in was uneventful.

    North Brother holds the greatest number of breeding shearwaters in the entire archipelago and the island is honeycombed by their burrows. Counting nesting birds that are deep in burrows presents challenges to the researcher. First there is the question of occupancy. This can usually be ascertained through a combination of indicators such as feathers around the burrow, signs on the ground of birds shuffling in and out, the occasional bird being visible in the burrow and the smell! Breeding shearwaters (and petrels) have a glorious, distinctive odour that comes from the oil they secrete and preen and waterproof their feathers with. Once smelt never forgotten and possibly mildly addictive! So, much to the amusement of Claudia who had accompanied me, I was regularly poking my head in to burrows and having a good sniff around. (Some photographs do exist of this activity but are not thought to be complimentary to the researcher or the good name of science!).

    The second problem is which species present? This proved to be the surprise of the trip for me. Previous surveys have always assessed Wedge-tailed Shearwaters to be far more numerous than the smaller Tropical Shearwater, normally at something like a 4:1 ratio. The studies I made throughout the day on both North and South Brother held true to this ratio, finding about four Wedge-tails to every Tropical. However, when Jon Schlayer and I camped overnight on South Brother to conduct further Coconut Crab surveys, Tropical Shearwater by far outnumbered Wedge-tails. As darkness closed upon the island the eerie Nazgul-like wailing of Tropical Shearwater was heard all around and birds were seemingly dropping out of the sky in to the natural coconut forest and even in the grassy open areas and scuttling off in to burrows. Very difficult to produce a credible, scientifically calculated total of breeding birds but certainly, there are far more Tropical Shearwaters breeding on South Brother (and I suspect North) than I ever envisioned. In fact, I would go further and say, at least this year on South Brother, there are more Tropicals’ breeding than Wedge-tailed. I suspect that this may be the case in most years and that Tropical Shearwater being smaller, is simply harder to locate when searching burrows in the daytime. Tropical Shearwater also produced another conundrum for me and this teaser was, “what is the true taxonomic status of the Chagos breeding population?”

    Briefly, there has recently been a taxonomic shuffle of the Little and Audubon’s Shearwater complex. These two species have been split in to several new species and in the Chagos we have ended up with Tropical Shearwater Puffinus bailloni subspecies dichrous. Included in this subspecies are three former subspecies one being named nicolae, which was suggested in Peter Harrison’s ground breaking Seabirds book to be the species present in the Chagos. In recent literature, dichrous is given a breeding distribution that encompasses island groups are far apart as Tahiti and Aldabra. However, and here is my point, the illustrations I have seen of the diagnostic underwing pattern of subspecies dichrous do not match any of the Chagos birds I have handled or photographed in flight. With limited literature on board this mystery will have to remain as such until I return to dry land and a more extensive reference library but, I am keen to see illustrations or specimens of dichrous……..

    And so, the final islands of the Great Chagos Bank were surveyed. Eagle Island, the second largest island in the archipelago remains a rat-infested, barren, bird-free island; Cow remains relatively unspoilt, probably because it is a “cow” to swim on to and finally, Danger Island lived up to its name and produced the most challenging swim on due to under currants and rip tides. The reward on Danger were over a hundred pairs of Brown Booby sitting tight on their recently laid two eggs.

  • Day 18 Nelson Island and the Great Chagos Bank

    Darks skies and ominous clouds threatened on the horizon as we prepared for the days dives. A blown fuse on the winch that carries our dive boats off the research vessel and into the sea delayed us and the clouds drew swiftly in and a torrent of tropical rain was on us before we could get started. Knowing the nature of the weather out here we decided to give it some time and sure enough we were off diving when the crane was fixed without rain belting round us.

    Motoring around to the north side of Nelson Island we dropped the divers down and I was on top cover. Seabirds whirled over the island in their hundreds. Free of historical human disturbance this island is rich with several species and they were all out riding the windy tail of the squall. Several lesser noddy drifted over to examine me on my bobbing dive boat contemplating whether to land on the pontoons either side of me.

    Beneath me the divers worked away with the only sign of their presence being the occasional eruption of bubbles breaking through the choppy waves. Their reports on returning to the surface were a contrast to the vibrant thriving life over the island. Here it seems the seabed comprised mostly of dead coral skeletons overgrown with algae. Something had killed them in the last year or two. Reassuringly though there were numerous tiny coral recruits, juvenile corals, establishing themselves amongst the algae on these dead skeletons. Ronan has been looking into this with his research and if you continue reading I've included his words after this short report on the days activities. 


    After a trip back to the research vessel for lunch the lagoonside dive in the early afternoon provided a possible explanation for the large area of dead coral on the opposite shore of the island. Where we dropped in to the lagoon there was a blend of sandy seabed and thickets of branching coral in the shallows. As we headed deeper this turned to a large area of dead coral and coral rubble. As we approached this dead area a crown of thorns starfish appeared. Further along in the dive another, and another. These coral predators are known to have population explosions in areas, for reasons as yet not fully understood, and it seems that perhaps there has been an outbreak here too killing off swathes of coral.

    We certainly hope the reefs here are sufficiently healthy to rebound from a localized impact like this. Although there were dead patches there were also stands of diverse and healthy corals with the large numbers of fish that are characteristic of this MPA. On one of them I noticed an octopus camouflaged on a coral head beneath a shoal of silvery fish. As I approached it felt threatened by a sizable black grouper and ballooned its legs and body whilst changing colour in the blink of an eye to a stark white. The silvery fish exploded outward at this display and the grouper made a retreat. Evidence of the circle of life continuing despite an element of compromise from the crown of thorns.

    Done with the days diving we returned to the research vessel and began our navigation across to the next survey sites around the Three Brothers on the western edge of the Great Chagos Bank. All being well we’ll be there around midnight ready for tomorrows activities. Read on for Ronan's thoughts on the coral mortality we witnessed today.

    A dark squall with wind and rain moving in has prevented launching of the dive boats this morning. The first bit of poor weather – we have been lucky so far on this year’s expedition. Hopefully it will pass quickly so that we can get to this morning’s dive site, which is on the seaward side of the island we are anchored off.

    Many sites we have now visited during each of the last three years, others only once or twice since 2006. Change can happen rapidly on coral reefs, and we are building up an increasingly detailed picture of how the reefs of Chagos are changing.  Most noticeable since 2006 is the mortality of the large colonies of table-shaped Acropora which can reach over 3 meters in diameter. The reasons for this change are not clear – it is possible be that these corals have simply reached the end of their life span, but bleaching due to high temperatures and disease may also play a part – both of which are being investigated during this year’s expedition.

     The squall passes within an hour, and the dive boats are launched one by one from the stern of the research vessel, using the vessel’s A-frame, the whole process taking about a half an hour before all three boats are on the water and loaded with dive kit and research equipment. We work our way around the island to the more exposed seaward side and finally enter the water. It is a dramatic site; with a narrow reef terrace dropping rapidly down to a near vertical slope extending as far as the eye can see. At about 25 m deep where we start our work, the site has a similar appearance to many of the sites we have been diving over the last two weeks, with one major difference – the corals here are almost all dead.

    Dead table Acropora cover most of the reef surface, and are overturned and tumbling down the reef slope. At the shallower depths, the coral returns to life somewhat, but the majority of the reef is dead. What is striking is how complete the mortality is – suggesting that the cause must have affected all colonies at the same time. We know that there was an outbreak of crown-of-thorns starfish observed feeding on the coral around this island observed in 2012, but it seems unlikely that this could be the only cause. The crown-of-thorns were mostly observed on the sheltered lagoon side of the island, so when we drop into the water on the afternoon’s dive, I am not expecting a flourishing reef. I am pleasantly surprised – although there are large patches of dead staghorn Acropora, there are also areas that appear not to have been affected.

    Disturbances and coral death are part of the natural cycle of coral reefs – giving rise to the reef sediment which sustains the islands. The key is really not whether damage or coral die-offs occur, but how the reef recovers from them when they do. For me, one of the most encouraging signs this year is the abundance of young coral colonies, which on many sites are covering much of the available substrate of dead coral colonies. This is a key sign of reef recovery and ultimately a coral reef which is resilient to damage and disturbance. If these young recruits can continue to grow and contribute their full potential to reef development, the future of the coral reefs of Chagos looks very positive.





  • Day 17 On to Blenheim...

    Having wrapped up our work at Salomon Atoll we motored away this morning toward Blenheim Reef, a submerged atoll that reaches all the way to the sea surface but doesn’t have any islands, being completely awash at high tide. The marine life over here is particularly rich with a seabed covered in a diverse blend of soft and hard corals, algae and sponges. Amongst and over a multitude of fish gather. Not to mention the turtles and dolphin that we saw through the day.

    The first dive site was on the western coast of the atoll and the divers returned to the research vessel with reports of macroalgae beds growing up from the depths to about 15 meters and thereafter cyanobacteria carpeting the reef into the shallows. Unusual for this sort of dominance from plants in a place where so many grazing fish and such healthy corals generally predominate – a mystery for certain.

    This was in marked contrast to the second dive on the SW corner. Here the blend of soft and hard corals predominated and beautiful schools of pyramid butterflyfish and surgeons polka dotted the water. A lazy nurse shark cruised by after a turtle had greeted us on arrival into the water.

    A second dive on the SE corner of the atoll proved to be very similar although it offered up some treats. A fine pair of short-head anemone shrimp living on an unusual anemone – cryptodendrum adhaesivum – appeared just beneath courtney’s transect tape. Around them several smaller shrimp – thor amboinensis scuttled around and just above them a tiny nudibranch. Whilst we were admiring this fine collection of tiny inhabitants some far larger ones made their presence known. I was distracted by whistling sounds through the water. I swum to the drop off but this time around that was the wrong direction as I later discovered the Ronan and John who were finishing their dive in the shallows saw the culprits up close and personal. Dolphin! Disappointed to have missed them this time around. They’re always such wonderful creatures to see underwater.

    Nevertheless I wasn’t to be disappointed for long. Back on the research vessel we set a course for Nelsons Island and I fired up the compressors to fill our scuba tanks for tomorrow. As I was watching the horizon between tanks a pod of thirty or so dolphin came gambolling out of the swells to our port. Evidently done feeding for the day they were up for a sundown play in the bow wave of our cruising boat and stayed with us for 20 minutes effortlessly keeping pace with our cruising vessel. These bottlenose dolphin included some large individuals – really impressive to see them jumping and playing within inches of the hull at times. A fine sight for the last rays of the sun to illuminate! After a day on such a productive reef now is a good time to get an update on Chris' carbon budget on...

    Salomon Atoll

    We sailed from Peros Banhos to Salomon Atoll late on the afternoon of Sat 28th March, drifting in over the shallow northern lip of the atoll before nightfall. This is a much smaller, but equally beautiful atoll, ringed by wooded islands of varying size, the largest being Ile Boddam in the south-west. Over the first few days of diving here we worked on the western/north-western side of Salomon, at several sites along the seaward sides of Ile Anglaise and at Ile de Passe. These sites are on the more “sheltered” side of Salomon, and were very similar in character to those on the western side of Peros Banhos; with large tabular Acropora colonies visually dominant, but with a range of other compact, branched Acropora, smaller massive colonies and encrusting coral forms also present. These reefs again support populations of large (in excess of 50-60 cm) parrotfish.


    Over the next few days we also worked on reefs along the more exposed southern/south-eastern margins. Weather conditions were good, but with the long period wave swell that was present these sites were challenging to study, with significant surge making the surveying very time consuming. These sites, at Ile Takamaka and Ile du Sel, were varied in character, but again rather similar to those on the exposed side of Peros Banhos, with low relief or hardground type habitats being characteristic and which were colonised by a range of robust branched or small massive corals.



    A distinguishing feature of the Salomon lagoon is the presence of numerous reef knolls or pinnacles, which rise from the lagoon floor to near sea level. These knolls are relatively steeply sided and, although rather different to our other sites, were included for study due to their numerical abundance. Generally the waters appear relatively turbid, but the knolls have high coral cover and the coral communities are incredibly diverse, with high carbonate production rates measured.


    A major, not entirely work-related, highlight of Salomon was the opportunity to be in the water with dolphins and Manta Rays; whilst surveying at Ile de Passe we were visited by a pod of 6-7 dolphins who came for a look-see, and then a few days later we had 6 large Manta’s come round the boat off Ile Anglais – the opportunity to get in and swim with them being too great to miss …. a fantastic way to end the Salomon part of the trip. We now move to the last phase of the expedition – a set of mostly 1 day stops at various sites as we loop back around the top of the Great Chagos Bank towards Diego Garcia.


    From Salomon we sailed via Blenheim Reef for a single dive on the reefs west side and then down to the Great Chagos Bank the last major area of study. Our plan was to work from sites along the northern side of the Bank, a vast and largely submerged platform, and then via a series of sites along the western margins where a number of reef islands have formed. The Great Chagos Bank proved to be an area of great contrasts in terms of reef health and coral cover, this variability reflecting the different stages that the Chagos reefs are currently in regarding their recovery from recent disturbance events

    Our first study site was at Nelson Island – a rather depressing but very interesting site – dominated visually by large stands of entirely dead table corals, and whilst these were typically covered in juvenile coral recruits, overall coral cover was very low (<5%). All of the substrate at this site showed evidence of intense biological erosion and recorded, by some distannce, the low carbonate budget states of the trip thus far. Many of these corals appear to have died from a combination of disease, which we have observed to be affecting tablular Acropora colonies elsewhere, and from a recent outbreak of Crown-of-Thorns starfish … although we only observed one such starfish on our dive.



    From Nelson we moved on to spend several days at The Brothers, South, Middle and North, where reef condition was much more similar to that observed at some of the better sites around Salomon and Peros Banhos, with wonderful cover of large tabular and branching coral Acropora, but also a wealth of other species on the upper reef terraces. As with all of the sites visited parrotfish have proved to be extremely abundant, and with many large terminal phase fish present at all sites. Diving conditions in The Brothers were challenging for the work that Gary and I do due to strong swell conditions, but between these sites and the Nelson site, the full spectrum of reef states out here can be seen over a relatively small spatial scale.

    After the Brothers we have moved south, taking in various sites around Eagle Island, the western side of which had relatively low coral cover at all sites and a high abundance of coral rubble, then a site on the Danger Island. The weather by know had turned quite rough and very high waves and strong swell limited our ability to work on the western coast, but a site on the eastern side was workable in the afternoon. The unusual site of 16 Eagle Rays swimming in formation greeted us as we swam down to set up our transect lines.

    Our final research day was spent on the Egmont Islands. The windy/swelly conditions have stayed with us, but a final site was surveyed along the north-east of this small atoll. Whilst this site had quite high cover of corals there was also a very large amount of dead in-situ and rubble Acropora present, and a mix of dead and live table corals present. This was another site with a lot of big fish, no sharks (that we observed) but a lot of big grouper, large parrotfish, large triggerfish, and at the end of the dive a chance to watch an octopus foraging in and around the coral rubble fields. 


    Tonight we head back to Diego Garcia for a several days of kit clearing and tidying. It has been a fantastic trip, and a great opportunity to study the carbonate budgets on these really remote reefs. Overall, I guess we have been surprised by the variability we have observed in reef health and thus in the budget state of the reefs, but the sites we have worked on have enabled us to look at the Chagos reefs not only where they occur in states of high and thriving coral cover but also, importantly, where they have been widely perturbed over the last few years by a combination of disease and predation. This will allow us to explore the natural cycles and drivers of coral carbonate production and bioerosion as coral cover rises and falls. Perhaps a key observation is that, almost without exception, we have seen evidence for widespread establishment of juvenile corals and for multiple phases of new coral recruitment at our study sites – an observation that suggests significant resilience within the reef systems here generally. We have, however, also recorded prolonged high temperatures (30oC) whilst diving throughout our 4 week long trip, and whilst they are no widespread signs of coral bleaching the persistence of such high temperatures would be of clear concern. The dataset we have now established will, however, provide a unique baseline for future monitoring of reef budget states, both at sites currently at the “healthy” end of the spectrum, and those that have recently been degraded – hopefully the opportunity for temporal monitoring of these states will arise in the future. 

  • Day 16 Manta & Sea Cucumber Surveys

    As today was deemed a no-dive day in order that our bodies might recover from prolonged saturation from being underwater activities turned to those on the surface. Which is not to say that they didn’t involve getting wet…

    First to head out were a crew to conduct photo surveys around the outside of the atoll of the reefs in shallow depths. A series of 21 photographs had been taken several years before at these points and were to be repeated to measure any changes over time.

    During the surveys some of our members discovered a group of aggregating manta rays whilst motoring along the northern edge of the atoll. As this is one of the ongoing strands of research for the territory we headed out again in the afternoon to see if we could obtain some skin samples for genetic analysis of these gentle giants. This to tie in with research that is being done around the world. Although no longer aggregating the manta were still cruising along the northern edge of the atoll feeding singly or in pairs so we quietly slipped into the water and were successful in collecting a sample or two. Quite apart from just enjoying the time in the water with these amazing large animals…

    Moving from the water to the air some of the expedition participants had brought along a small drone equipped with an HD camera in order to obtain aerial videos of various key habitats around the archipelago. So they headed out to capture various island and reef scapes around the atoll, their little drone buzzing over them and sounding similar to a swarm of bees. (Charles has written about his efforts with the quadcopter so keep reading today's report and see some of his results below!)

    This was the sound that we heard in the late afternoon as we motored slowly around the interior of the lagoon in the shallows towing a snorkeler who was on the lookout for sea cucumbers. These are a prized delicacy in the orient and as a result are heavily fished around the Indian Ocean and the world as they sell for a high price. In the past there has been a problem in the BIOT of poaching for these creatures and these surveys offer a way of tracking whether their numbers are stable, indicating a lack of poaching, or declining indicating that there may be a problem with illegal fishing for them.

    Apart from this days off from diving offer the opportunity to carry out much needed maintenance on dive gear, motors and research equipment…I won’t bore you with the details…


    A successful day for the expedition! Read on for an update from Charles on aerial views of the islands using the Quadcopter...

    Quadcopter over the Chagos

    Charles Sheppard


    There is nothing like a bit of aerial photography to illustrate some interesting features of a place.   I had a quadcopter with an aerial camera with me in 2015, and made use of it where I could between the research dives.  I used it partly for some shoreline and island erosion work, and we had plans for aerial bird nest counts (though the latter proved to be rather tricky) though I recorded a good couple of hours of general scenic sequences too. 


    Below are some stills clipped from some of the videos, with explanatory texts for each. 


    Notes about the machine:  this was a DJI Vision 2+ with a HD quality gimballed camera, and it has exceptional stability.  Today these cost a relatively small £1000 and I predict they will be increasingly used for things such as close reef mapping work.  It certainly should be, in areas such as Chagos.  It fills a niche for ecological and even geological feature mapping too.



    Salomon Ile Anglaise pond.  Here, a low lying part of Anglaise island whose elevation is below sea level (as is the case for much of most islands) is not only flooded but its shallow water shows a tidal rise and fall that matches that of the ocean.  They are smaller tides than those in the ocean and have a lag.  The tide shows how porous the rock is, and the separation from the ocean is only a couple of metres wide.


    Ile Diamante erosion.  This northern tip of an island in Peros Banhos provides one of the clearest examples of being eroded away.  The shoreline has retreated by dozens of metres in the last 15 years.  This bay contains stumps of palm trees from the plantation era that were planted on land that now is flooded.


    Egmont ‘manta ponds’.  Deeply embayed, sheltered and shallow areas in northern Egmont atoll are, as far as I know, the only place from which juvenile manta rays have been reported.


    East of Nelsons Island on the Great Chagos Bank.  The shrubs covering much of this island are the kind of vegetation liked by numerous kinds of seabirds for roosting and nesting.  The shrub’s branch structure nicely holds the nests.  Few of the seabirds like to roost, and even fewer can nest, on the palm trees seen on the left of this scene.


    Sepulchre, Salomon.  Isle Sepulchre is a small island in Salomon atoll, but sometime probably in the last several decades became divided into two.  We don’t know when this happened, but the older charts all show one larger island.  Here the quadcopter is hovering over the main part of Sepulchre and shows the small ocean side portion that is now separated from the rest by bare coral rock that floods and on which vegetation does not grow.  The surf at the top of the picture marks the reef crest, and from here the ocean depths begin to plunge steeply to hundreds of metres deep. 



    The quadcopter being landed.

  • Day 15 - Lagoon Knolls & coconut crabs

    There is plenty to keep everyone occupied on these expeditions. Today saw multiple roles for me and there are several tangents for others too. Firstly safety cover this morning for the first divers of the day as they surveyed the Oceanside reefs of Ile de la Pas. Its hardly a chore to sit atop the boats in the fresh morning enjoying the scenery of the atolls and seabreeze whilst the others get on with work. There was some assisting to be done on their return to the boats as a current had built up with the tide and everyone needed a hand so as not to be swept away whilst removing dive gear.

    Straight on from there it was out for a dive myself to assist Catherine with retrieving some autonomous reef monitoring systems that had been deployed a couple of years before. During this dive we had the absolute pleasure of a dolphin encounter – as we were working away on the shallow reef I heard the high pitched whistling of dolphin. I immediately waved to Catherine and made for the drop off about 20 meters away and there they were. A pod of about 30 bottlenose dolphin feeding just out in the blue, some rising from the inky depths, others circling passed and spiralling down from the surface in threes and fours. Usually we only see spinner dolphin around salomon and they are far more wary than these bottlenose dolphins were. Their curiosity brought them close to us as they examined what we were before effortlessly sweeping back out into the blue away from the reef. It is worth noting that Charles and Anne recovered more of their temperature recorders from a short distance away and Charles has penned a few words on this strand of field work, before that though I'll finish up with the days endeavours.

    So for Catherine and the various people that helped her the afternoon and evening was taken up by processing the ARMS. For me I broke away and assisted Courtney in her dive on one of the lagoon knolls. The lagoon of salomon Atoll is particularly well sheltered with only one significant small break in the reef on the north east corner. The remainder is protected on all sides by shallow reefs that break the surface at spring low tide. As a result the coral gardens are safe from the most violent of weather and all of the corals grow in a mad variety of colour and structure in a jumble that makes use of every spare space. The knolls crowd toward the surface with corals sprouting out of corals leaning on more corals out of the depths until they create a mound that plateaus just beneath the sea surface.

    On one coral head I was treated to the sight of light blue heliopora branches sprouting out of the rosy pink dome of a lobophyllia all crowned with a lace of white seriatopora. A small cloud of jewel like iridescent blue chromis fish shoaled around and between the branches to finish this stunning piece of nature’s art. A turtle offered a close encounter as he lazily rested on the reef allowing my camera within inches of his nose. As I floated up and away to let him carry on with his business three chunky black tip sharks cruised out of the hazy water and circled myself before heading over to investigate Courtney as she surveyed away with her head down to examine the corals, oblivious to the elasmobranch that was investigating her. Return to the research vessel after this lovely afternoon dive did not bring an end to the day…

    …after some dinner I joined Pete to head onto Ile Anglaise to survey the coconut crab populations there. In contrast to the rat free island, Mapou, that we surveyed earlier in the week, this island is well populated by rodents. The contrast in bird life and night sounds is remarkable. Mapou sounded like a tropical jungle with all manner of cawing, cackling and whistling as seabirds jostled in the hardwood branches overhead. Anglaise was silent except for the occasional rustle of leaves betraying the position of a coconut crab or rat scavenging amongst the leaf litter. Fortunately for the coconut crabs the presence of rats has not disturbed their population and they appear to be on fine form on this island. The trophy crab for our surveys tonight was a huge male weighing in at 2.7 kilograms – best not to tangle with the immense claws on an individual like this. Surveys done we returned to the research vessel by moonlight with a slow motor boat ride across the calm windless lagoon. A busy but fabulous day in Salomon Atoll...carry on reading for an update from Charles on the research stemming from his long term temperature monitors. 

    Coral condition and ocean temperatures

    Charles Sheppard

    For several years past, we have mapped the recovery of corals on reefs of the Chagos following the warm water event of 1998 that killed most of them.  For simplicity in presentations I have generally shown the recovery in terms of average coral cover, with data from all sites pooled.  Although we keep much data for sites separately and use that in scientific articles, overall the picture of recovery has been similar enough all over the Chagos Archipelago to permit this averaging.  We have presented graphs showing this almost annually for several years now, with updates published in Chagos News, at the Chagos day conferences, and other places.

    At the same time we have been recording water temperature in several places and depths too, which has shown interesting patterns of rising and falling thermoclines (bands of different temperature water), and we continue to measure these details too.

    Until recently the trends have shown a fairly straightforward recovery from the early 2000s, but I don’t think this uniformity is the case any longer – not for this year anyway.  In some areas we see the continued recovery, not so much in terms of coral cover now because this is around the maximum that such reefs generally have, but in terms of diversity of the corals growing on the reefs.  The initial flush of fast growing table corals is diminishing (with masses of dead tables clearly visible) and these are being replaced by a much greater variety of smaller, boulder shaped corals that are taking their place.  This is a process called succession. 

    Blenheim Reef is an atoll which continues to show thriving and healthy corals in most places.  The initial ‘flush’ of fast growing table corals is being replaced by a higher diversity of corals.

    In many areas continued recovery is still the case in 2015, but in others, there is a clear and marked deterioration.  On Nelsons Island, and parts of Eagle Island, for example, the reefs look devastated, gloomy, with silty water, and the very few live corals cover no more than 5% of the substrate. 

    North slope of Nelsons Island on the Great Chagos Bank.  Almost all the corals here are dead and starting to crumble, with only a very few survivors from whatever killed them over the last year or two.

    Clearly such areas can no longer be pooled with the healthy reefs to show any sort of general or averaged pattern.  Instead, reefs seem to be going in two different directions: on one hand continuing to look good, with increasing coral diversity, but on the other hand, reverting to a state not seen since the immediate aftermath of the very damaging1998 warming event. Why?

    Temperatures may give an answer.  This year they are high.  This has been predicted since the summer of 2014 in fact, when warnings were issued that ocean temperatures would be higher than ever before.  It has not been quite that warm, perhaps, but water is certainly warm in Chagos this year.  Using loggers recording at 1 minute intervals that record to two decimal places of a degree, as well as the temperatures that we can read from our dive computers, water temperatures have generally been from 29 to 30.5 degrees, to depths of 20 metres deep and more.  These are extraordinary values.

    Consequences we can see include some coral bleaching, but really only a little by March 2015.  There is a lot of paling of colour in shallow waters.  It is not only temperature but the time spent at that temperature that is important, and we don’t yet know how long this warm episode will last.  There is also a clearly visible increase in coral disease prevalence, though this is the topic of another blog.

    It might therefore be that some areas are experiencing warmer conditions than others are, or have warm conditions for a longer time than others, in which case this might be the cause of the two different trajectories seen on these reefs in April 2015.  The fact remains that temperatures of around 30 degrees and greater on ocean facing reefs, to over 20 metres depth, are alarming.  To see the consequences of this (if any) we will have to wait several months before we can tell.

    One thing that is clear though is that, during the time of our visit at least, reefs are travelling in two different direction in ecological terms: one continuing their high cover and with noticeably increasing diversity, and one group showing rapid deterioration, showing little more than dead corals and rubble.  We hope that ocean temperature now will cool (we need wind and heavy cloud now!) in time to prevent the healthy reefs going the way of the newly killed reefs.

    PS in late April.  The Living Ocean Foundation participant Professor Sam Purkis, who is currently in the archipelago,  has reported that bleaching is in full swing (  In a month's time we should know whether this will lead to mortality... or to recovery of the corals affected.  It will likely be many months before measurements of live coral cover will be repeated in a manner similar to that described above.

  • Day 14 Mapou overnight & camera recovery

    So to report on last nights activities I think it best to hand over to Pete – needless to say I was impressed to see a coconut crab of 2,5kilogram tip our scales during the transects we conducted!  Pete has written up his activities of the last few days and they follow my short report for today. The moon is on the wax at the moment and offered bright light whilst we were out of the trees on this island. A great opportunity to do some moonlight photography (not to mention the sunset being beautiful!).


    My day started with a dive to recover John’s camera set up this morning after it had broken its tether and fallen to the depths at the end of his dive. Lucky for us Anne spotted the glint of sunlight off the camera's housing toward the end of the search and we came back successful!

    Whilst we were out searching for it the crew that headed Oceanside to survey the reefs off Ile de la Pas had a treat as a pod of bottlenose dolphin passing by stopped to investigate them at work. Whistling and swiftly circling the survey crews they distracted everyone for a couple of minutes before their curiosity was satisfied and they swam off into the blue.

    My own little treat on the camera recovery dive was a small remora that discovered me midway through. He decided my legs would be a great place to attach and I ended up with a companion glued to my legs for the remainder of my time underwater. In fact he only left my leg when I was climbing onto the boat and his head lifted above the sea surface. Disappointed at my disappearance he swivelled sharply and wiggled into the depths.

    The afternoons dive was off the islet of du Sel on the southern edge of the atoll. Here there was a precipitous drop off starting at 12 meters. I enjoyed the sight of an unusual anemone with two chagos anemonesfish bringing some extra colour to this white tentacled beast. If you look carefully at the photograph you can see that they have laid eggs which are clustered on the edge of the rock above the centre of the frame.


    Filling dive tanks is part of our daily routine out here…back to it! More from Pete below...

    Having a protracted stay in the Salomons allowed me to pursue various ongoing projects. First, of course, was the breeding seabird survey. As this atoll is small, it is thought that all but two of the larger islands are rat-infested (read on) and the two largest islands are former plantations where coconut chaos now reigns throughout, the bird survey work would not take too long. This meant I could concentrate on Coconut Crab surveys and the long-running rat question of this atoll and that is, “are rats present on Ile de la Passe?”

    There is of course some history behind this simple rat question. In 1996, the person who conducted the first comprehensive breeding seabird census also conducted a rapid assessment of the archipelago for rats. This excellent baseline study has since been compared against (breeding seabird populations), expanded upon (new species of seabirds found breeding) and amended (what islands have rats or do not have rats). For one person to assess an entire archipelago with some 55 islands in six weeks for seabirds and rats was a Herculean task and it is no surprise that some of the neophobic rat assessments, after the luxury of checking over several years, have proved to be incorrect. The original survey stated that all of the islands in Peros Banhos (with the exception of the rocky Coin du Mire) and the Salomons were rat-infested. This would be a fairly logical conclusion due to human disturbance but, it has been proven wrong over time. The six proposed and designated IBAs of Peros Banhos have all been revised as having no rats and of course, it appears Vache Marine has now joined this elite club. In the Salomons, after three years of observations and several nights of trapping I was confident enough in 2011 in the journal British Birds to say that Mapou was rat-free and this was confirmed by the eradication expert who joined us on the Vache Marine project in 2014. I also tentatively suggested in 2011 that Passe may be rat-free. Having spent many nights rat trapping on Passe with (fortunately) no success and now having vastly more experience of rat detection having worked with an eradication expert for a month in the Chagos, I was determined to gather enough information on this trip to combine with my previous research, to say once and for all, if Ile de la Passe is in fact rat-free.

    But first the breeding seabirds. Mapou was the target island for the morning of day one and a count of all the seabirds on this island is relatively straightforward. It was pleasing to note that breeding Lesser Noddy numbers in the Intsia bijuga (a tall, straggly, native, climax forest tree) stand in the centre of the island are reaching four figures and huge Coconut Crabs are still roaming this small but impressive forested island. Two more nesting Red-footed Booby were individually marked (one ringed by Claudia, not bad for a first bird ringed!) and had trail cameras mounted nearby to monitor their parental movements. It was satisfying that one bird when released flew out to sea and turned straight back and was alongside its chick within two minutes, just above our heads. The afternoon was spent on Passe, checking for breeding seabirds and, as mentioned above, doing a lot of detective work to try and prove the rat case one way or the other. The traps have been set, and now time, diligence and hard work will tell!

    Over the ensuing days in the Salamons every island was surveyed for birds. With the caveat that the breeding season lasts all year for most of the breeding seabirds in the Chagos and therefore all we are gaining is a snapshot, not the whole picture, the seabird populations of this atoll appear to be healthy and maintaining their numbers. The trail cameras mounted over the marked individuals’ nests were successful in producing a time-series of photographs of which of the parents were attending the nests. The photographs also confirmed the brief visual observations of these nests that I was able to make over our stay.

    Two islands were surveyed at night for Coconut Crabs. This IUCN Red Listed species, the largest arthropod in the world, is declining globally through harvesting by man for food. In captivity it is proving to be extremely long-lived but difficult (if not impossible) to breed. This means there is no safety net for this species, once it has been harvested to extinction, it will be gone. This has already happened at all of its (former) mainland sites and it is now restricted to oceanic islands. The Coconut Crabs in the Chagos are thought to be one of the few (only?) non-harvested populations in the world. This is paying dividends as recent research on Diego Garcia has revealed Coconut Crabs at the highest density per hectare on any island researched to date. My task in the northern atolls of the Chagos was to gather initial data on these out-lying populations such as, which islands are they on? In what numbers? Do they have habitat or soil preferences? All information required for management of the species within the Territory.

    So, once darkness had descended Jon Schlayer and I started our work. Walking along a predetermined length line, measuring the distance away from the line to any crabs we encountered. These specimens were then sexed, had their carapace measured and their mass taken. Combined with island size and what habitat the crabs were noted in is allowing a picture of their distribution and abundance to be built up and critically, what their habitat preferences are at the various life stages. For such a well-harvested beast, there has been surprisingly little published on their life history and it is hoped our research will increase our knowledge and ability to protect and conserve this unique and incredible member of the crab family.


    So back to rats. In August 2014, two tiny islands of this atoll, Sel and Jacobin, had rat eradications conducted on them. This was part of an experiment to assess if (or how long until) rats cross water to other islands. Overnight trapping on these two islands has led me to conclude that at least after seven months, they have remained rat-free. And what of the Passe question? However much I would love to declare 100% that this island was rat-free, I believe it is too big and my research not enough, yet, to lay my neck on the line and say it is rat-free. What I will say is all the indications are that, (miraculously if true), this island is rat-free.





    My final memories of the Salomons is not of the beautiful sunsets or the idyllic looking islands circling the atoll rim, nor the hundreds of birds rising from the tiny, forested island of Mapou at dawn or the huge, unearthly Coconut Crabs clattering around the former coconut plantations in the darkness on Anglaise. It is of a Green Turtle that should be called Lucky, or maybe even Super Lucky. The Salomons atoll is very seldom visited and of those who do visit very few make it ashore, let’s say less than 100 people per year set foot on land there. Of those 100 people, 95 of them will only land at the old Plantation Headquarters on Boddam. Of the remaining five people, three may land on Anglaise and of these two may go around the islands’ shoreline both lagoon and ocean-side. And, they may do this at a maximum twice a year.


    “Super Lucky” the Green Turtle had been caught in a net under a Fish Aggregating Device (FAD). The FAD had been washed ashore on the ocean-side of Ile Anglaise. In fact it had been washed ashore about 15 minutes before we walked along this section of the coastline. Super Lucky was tangled by the netting so badly it would never have freed itself. Struggling in the sun I guess it would have desiccated, dehydrated and died within an hour or two. So, what were the odds on that turtle being washed up on that tide at the time peoplewho would free it were walking around one of the least visited islands in the remotest part of the central Indian Ocean? Pretty slim I think!  However, Lucky did live to swim in the oceans again and Claudia who released it back in to the water thought she had won the Jackpot too!

  • Day 13 - Ile Takamaka & Sam's Knoll


    The day started with some tricky conditions for navigation in our small boats. A large rolling swell moving in from the south while the wind freshened from the North…so a northerly chop and a southerly swell. No lee-side to the atoll today so it was a bouncy ride in all directions. We started the day with a  morning dive off Ile Takamaka where I accompanied Ronan and John as they conducted their video transects and data collection on the gentle reef slope off the south eastern corner of the atoll.

    The dive also yielded up a lovely turtle encounter. Two turtle criss crossing right in front of my camera.

    For the afternoon we stuck to the lagoon to find shelter from the challenging Oceanside seas. Sam’s Knoll is just on the inside of Ile Anglaise and offered up the rich towering coral structures and gardens that are so typical of this very sheltered lagoon.


    Corals grow on corals grow on corals here with an impressive variety of form and hue. These in turn offer up a rich environment for fish – such as these Yellow Sweeper (Parapricanthus ransonneti) sheltering amongst the branches of a heliopora coral. On the top of this knoll the coral gardens are incredibly lush, an arrangement of richly varied corals towering toward the surface in a mad cluster of form and colour.

    This evening I’ll be accompanying Pete as he heads ashore to Ile Mapou to carry out some Coconut Crab surveys…more to report on that tomorrow! A beautiful afternoon I’m sure it’ll be lovely on the island…I'll report on that tomorrow, for the moment I'll leave you with some words from Courtney on how her research and expedition is going.

    When you hear the word “Chagos” what comes to your mind? Most people around the world have never heard of this far off place. Those that have instantly think about the politics surrounding the Chagosians. And then there is an even smaller subset of people that picture remote islands swarmed by seabirds, crystal clear water, diverse and healthy coral reefs and fish so abundant that it’s difficult to focus on anything else underwater.

    Last year, I was fortunate enough to join the minority of people that have experienced how special Chagos’s unique ecosystems are. I left last year’s expedition profoundly humbled by Chagos, itching to continue my work on coral health, but just grateful for this “once in a lifetime” experience.  Well, just 10 months later I was invited back to participate in the 2015 Darwin Expedition providing me with an invaluable opportunity to dig deeper into what’s driving the health of Chagos’s coral.

    Much like going to the doctor’s office, assessing coral health and disease levels can provide an early warning of changing reef health that cannot be detected by just looking at the amount of coral on a particular reef. Although coral disease is a natural component of healthy ecosystems it can drastically reshape ecosystem structure and function.

    Last year I conducted the first comprehensive in situ coral disease assessment in Chagos and discovered relatively low disease overall compared to other reefs around the world. However, I was surprised to find that despite the low overall level of disease, white syndrome was locally high at some reefs. White syndrome is a disease that causes gradual mortality of corals and is targeting one of the region’s dominant reef building corals, the table corals. While this disease has been associated with bacterial infections in other Indo-Pacific regions, its causes in Chagos are still unclear.

    In early March, I made the 60 hour transit from Hawaii to Chagos to answer an ambitious list of questions: Has disease level changed since 2014? Why are some reefs more or less susceptible to white syndrome than others? How quickly is this disease killing coral colonies and has this changed since last year?  Are there specific pathogens associated with this disease? What happens to the colonies when they die - do they become a home for new coral recruits (coral babies)? Much like forest ecosystems affected by fires, I also wanted to know how quickly corals are recruiting back onto the reef and how this might affect reef recovery.

    While our days varied widely from the epically calm conditions with dolphins playing in our bubbles to the more challenging 12’ swells and high current, my days generally followed the same routine. I have a strong aversion to being rushed in the mornings, so I generally woke up at 6:15 each day, made my way out to the back deck to set up my kit (aka dive gear for all my American friends reading this post) while the sun was just beginning to rise. After making sure my camera, GPS and other science accessories were sorted, I made my way up to the top deck for some yoga. By 8:00 we were “kitted up” on the back deck and ready to launch the small zodiacs. If all went according to plan, we were motoring out to our first site of the day by 8:30 and underwater shortly there after. My first goals underwater were to quantify the proportion of the coral population was affected by disease, what type of disease were present on that reef, which coral types were affected and how much recruitment there was. I did this by laying out several transect tapes across the reef. If time permitted, I also tagged colonies with disease to determine the fate of these colonies over time and identify which coral species are recruiting onto the dead substrate. On other dives, I also collected a small number of samples from healthy and diseased table corals, which I will be sending to my colleagues who study coral microbes to identify possible pathogens. After our morning dive we returned to ship ate lunch, kitted back up and headed out for the afternoon dive. Rinse and repeat.

    While the presence of coral disease and the resulting mortality we are observing in a remote area like Chagos is concerning, it’s important that we focus on the unique lessons we can learn from this system. First, the fact that we are seeing isolated but high levels of disease in remote areas emphasizes the importance of improving our understanding of global stressors such as climate change and doing our best to reduce our carbon emissions no matter how far you are from coral reefs. Secondly, many of Chagos’s reefs are still incredibly healthy and we should focus on the why. It’s also important to remember that Chagos’s reefs have demonstrated an astounding capacity for recovery. These reefs recovered after just 15 years following the 1998 bleaching event and many reefs recently hit by disease are showing signs of strong coral recruitment. Large marine protected areas (MPAs), such as the British Indian Ocean Territory/Chagos Archipelago provide a unique opportunity to enhance coral reef resilience by minimizing stress and boosting recovery following disturbance events.


    Lastly, I’ve learned that while it’s crucial to improve our understanding of marine ecosystems through science to enhance marine conservation. It’s equally important to let the rest of the world know that these spectacular ecosystems exist and are in dire need of protection. 

  • Day 12 Reaching the Salomon Atoll

    Salomon Atoll Ile Anglaise Oceanside

    This morning involved collecting ARMS from the seabed – these were placed close to the edge of the drop off in about 5 meters of water just off Ile Anglaise in Salomon Atoll. These proved to be a lot easier to find than the ones in Peros Banhos which confounded us. Within a few minutes we’d located the site and were ready to bring in the devices. After levering them off the reef we returned them to our dinghy and motored them swiftly back to the research vessel. There Catherine began processing them…

    This afternoon was Claudias opportunity to return to the underwater world. We plunged in and saw a number of lovely creatures. Got up close and personal with some anemones and Chagos Anemonefish and also enjoyed the lovely blue chromis clouds amongst the branches of acropora coral.


    Fish are not the only creatures that find their home amongst the branching corals. We also enjoyed the sight of several cryptic crabs and shrimps that live amongst the coral branches.

    Rooting around the reef you can really appreciate the great diversity of coral species here. In numerous shapes, sizes and colours. They really make for a vibrant and beautiful reef.


    On our passage back to the research vessel we motored along the outside of the atoll and came across a large pod of spinner dolphin cavorting in the late afternoon sun. It was Claudias introduction to the resident pod off this atoll and the dolphins treated her to a real display. At one point we had an escort of dolphin fin to fin jumping in unison just inches ahead of our bow at least 20 of them alongside each other stretching to our port and starboard. What a fantastic end to the day… 


    From her dive during the day Anne has something to share with us.

    Close Encounter of a Fishy Kind

    The difference between a reef which is a bustling busyness of reef fish and one which is quiet, seemingly lifeless and devoid of fish is startling.  I find myself looking around in bemused happiness when diving on a reef with its proper population of reef fish.  On Chagos reefs this is fortunately the case on every dive, although it is an uncommon occurrence in most of the rest of the world.

    Snappers are common inhabitants of a busy reef and the Bohar is a fairly common species of snapper.  These reach a size of about 60cms and are apex predators, piscivores  which eat other fish.  A few days ago, surfacing with my camera from a photo survey of the reef to seaward of Danger Island on the Great Chagos Bank, I was startled and a little surprised when a fairly large Bohar appeared in front of me and started to nibble the front of my camera.  My first thought was that he could see his reflection in the front of the lens and was going to attack a perceived rival, but these are not a territorial species so this was unlikely.


    My visitor was not aggressive but seemed merely curious.  When I was concerned that his nibbling might damage my camera I waved him away but he merely swam around me and came back to resume his inspection of my camera equipment by nibbling on my camera light.  My fingers round the camera caught his attention at one point so I kept them out of his way. 

    It was the end of the dive and after a while I had to surface.  I was reluctant to leave my new friend and liked to feel that he seemed disappointed to see me leave too!

  • Day 11 - Underwater searches and seabirds on the islands

    Spent the morning looking for Autonomous Reef Monitoring Systems off the island of Petit Coquillage. These systems were secured to the reef two years ago in a similar fashion to two other sets of the devices at other points around the archipelago. At the other sites we have found them in good condition but here they seem to have vanished. So although our dive did not achieve its purpose it did turn into a long duration underwater as we searched for the ARMS. This long swim allowed the perfect opportunity to view a large tract of this stunning reef.

    The majority of the reef bed consisted of porites and soft corals like sinularia. Beds of these mounds and encrusting corals as far as the eye could see in each direction. And overhead a multitude of fish. Through the course of the dive we saw five turtle and four octopus whilst our boat cover crew saw several manta ray in deeper water as they hovered over the drop off waiting for us to surface.

    So although we were unsuccessful in recovering the ARMS from this site it was still a beautiful morning. Fortunately the data from the other two sets of three devices that were also deployed two years ago is more than enough for this particular project to be successful.

    This afternoon the terrestrial team travelled to Ile Yeye before we depart Peros Banhos and make our way across to Salomon Atoll further to the east. It is a while since we have heard from Pete on the terrestrial front so I've included an update from him. Read on...

    Northern Peros Banhos

    On completion of the Vache Marine work I conducted breeding seabird surveys of all of the islands of western Peros Banhos. All of these islands have been environmentally devastated by man. Introduced invasive rats are certainly present on all the islands that were farmed for coconuts and these islands have also had the vast majority of their original vegetation removed and replaced by monocultures of coconut. If environmental triage was undertaken on them, they would be placed in a corner to die. If ever they are to be environmentally restored, the only way to ecologically improve them would be to take them down to “ground zero,” exterminate the rats and then replant them with native trees; a task that would need decades to see fruition.

    Coconuts are wonderful plants, hardy like few other trees, capable of being afloat in sea water for months and still being able to germinate when washed ashore; they are a cornerstone species for island building and the long-term stability of shorelines in the Chagos Archipelago. Naturally, coconut is found along shorelines and occasionally further inland where storm-surges have washed nuts (seeds) further inland. However, in western Peros Banhos man has removed over 90% of the original vegetation from all across the islands (i.e. inland as well as along shorelines) and replaced with coconuts as a crop. The landscape is now akin to the wheat and corn fields of Europe and America, stretching for miles with no other vegetation and very little wildlife. The first very long days’ surveying involved boating along the miles of shoreline, lagoon and ocean-side, staring at lifeless tracts of former plantations.

    The potential of what could happen through environmental improvement of these islands is demonstrated by a large seabird called Red-footed Booby. This warm-weather member of the gannet family is a pan-tropical breeder, nests above the ground and generally prefers to nest on undisturbed islands. The Chagos Archipelago is likely to be unique for this species in that at least since 1996 (when the first full breeding seabird study was undertaken) it has been expanding its’ breeding range and overall numbers. It is thought this is the only Red-footed Booby population in the world that is increasing.

    On the tips of some of the islands of western Peros Banhos are tinyvestiges of the former oceanic climax forest that once covered these islands; often literally two or three trees. In what appears to be a demonstration of the art of the possible, six of these relicts of the past now have Red-footed Booby breeding in them, four of which are new breeding islands that have been colonised since the last survey. Sadly these colonies are unlikely to increase in any significant numbers as the structural architecture of coconuts prevent boobies breeding in them (I have only ever encountered one Red-footed Booby nest in a coconut tree in the Chagos after nearly a decade of survey work).








    After anchoring off the island of Ile Diamant a full day was spent surveying the islands technically and legally defined as eastern Peros Banhos. In the morning I was to look at Passe and Moresby and in the afternoon move further afield to visit Parasol and Longue. Passe is similar to a western Peros Banhos island, it is infested with rats and was farmed for coconuts. It is an environmental catastrophe that holds between 10-15 pairs of Red-footed Booby in the remaining coastal trees that are not coconut. Moresby also has rats and was once farmed as a plantation but this near-unique island in the Chagos holds a secret; it has a mangrove swamp and Red-footed Booby thrive in these, despite the presence of rats.

    After surveying the lagoon-side (former coconut plantation) of the island where, again, a few Red-footed Booby nest in relict hardwoods, I entered the mangrove swamp from the north-eastern end. Small-leaved Mangrove (Lumnitzera racemosa Willd) only grows on two islands in the archipelago, Moresby and Eagle Island. Both of these mangrove stands require management if they are to survive in to the future. Both are being encroached upon and dried out by the former coconut crops and in the case of Moresby where seawater occasionally overflows in to the swamp, it is inundated with what man so readily discards in to the seas; piles of rubbish such as plastic bottles, polystyrene, fishing buoys and flip-flops now line the edge. Fortunately the boobies do not recognise or mind the poison below them and are still nesting in healthy numbers. 







    The afternoon took us further along the northern boundary of Peros Banhos atoll and on to the first of the IUCN listed Important Bird Areas (IBAs) of Parasol and Longue. These two islands exemplify the problems with how IBAs are classified in the Chagos. At present it is based upon individual islands, and there are ten designated and two proposed IBAs. However, not all of these islands meet all of the criteria every year, for reasons that became fully apparent on last year’s scientific expedition and were first suspected in 2009. In 2009 I visited Longue as part of the British military working out of Diego Garcia. I noticed many deserted Sooty Tern nests and several dying and dead chicks in amongst what had been a few weeks earlier a thriving Sooty Tern. I examined some of the dying chicks and they all had avian ticks attached. Last year the same phenomena was found on Parasol where some 32,000 pairs of birds had deserted the island and the vast majority of the remaining chicks were again infested with ticks, some with a load of over 20 of these parasites. This was evidence enough that periodic desertions of these islands was occurring and was caused by the tick-load of the island tipping the balance in favour of the ticks, not the survival of chicks. Knowing Longue was abandoned for at least two years after the 2009 infestation, if the breeding cycle of Sooty Tern coincided with our visit (they do not breed on a 12 month cycle in the Chagos), I did not expect Sooty Terns to breeding on Parasol. They were not, neither were they breeding on Longue. I have recorded island desertions by Sooty Terns on the Bois Mangues and Coquillages too but did not investigate whether ticks were the cause but suspect so).

    So my point on IBA classification in the Chagos Archipelago is it should be amended from individual islands (in most cases) to groups of islands. Had an ornithologist been surveying these islands for the first time with no knowledge of the breeding phenology and distribution of Sooty Terns, both Longue and Parasol would not have been recognised, yet, at a period as yet undetermined, likely to be about three years, these islands provide rat-free havens for thousands of the highly communal breeders. For Peros Banhos I have proposed elsewhere that this IBA be called the Eastern Peros Banhos Island Group and constitute all of the islands that fall under the Strict Nature Reserve ordnance under BIOT Law (forbidding anyone without permission to land on them) and runs from the recently rat-cleared Vache Marine east encompassing the rat-free Coquillages, Bois Mangues, Parasol and Longue and, significantly, the rat-infested islands of Yēyē, Manōel, Moresby and Passe. The latter four ornithologically poor islands being included in the IBA to signify their importance as islands requiring ecological improvement (by removing rats and managing the former coconut plantations).

    Longue did provide one pleasant, if expected surprise and that was an increase in the Brown Booby breeding population. Throughout the Indian Ocean, if not the world, this species is in decline, primarily through human interference of some sort. Not so in the Chagos where again, since the first comprehensive counts in 1996, this species has been increasing in numbers and expanding its breeding range to new islands. In 2014 it was recorded as breeding for the first time on Ile Longue with a single pair. This year there are two pairs. Brown Booby in the Chagos does appear to have any set breeding period and on Longue, one nest contained two eggs and the other a 10 week old chick. Unlike Red-footed Booby, Brown always breeds on the ground and, as such, rat-free islands are a prerequisite for colonisation.





    The following day saw a long boat transit across the top of the atoll to the paired islands of Petite and Grande Bois Mangues (loosely translated as woods of the mangos). Both islands are rat-free and both qualify as IBAs. Similar to Longue and Parasol, these islands periodically host Sooty Tern breeding colonies, though none were present at the time of our visit. The Bois Mangues speciality are their Pisonia grandis glades and associated with them, massive numbers of breeding Lesser Noddies. At the time of our visit Petite Ile Bios Mangue held about 1100 breeding pairs and Grande about 11,000. The Pisonia stands on Grande Ile Bios mangue have been described as “Lesser Noddy churches.” This is due to the way the branches of the veteran trees intermingle to form domed-likestructures and, all along the branches are nests and roosting Lesser Noddy. The noise produced by chattering birds; the acrid smell of centuries of accumulated guano underneath the domes; the incredible site of thousands of birds in a confined area, some inquisitive enough to hover very close by like huge dragonflies as they inspect you, all taking place in amongst storm-smashed and broken trees is one of the unforgettable experiences of the Chagos Archipelago.

    Pisonia has evolved with seabirds and is reliant upon them for seed dispersal. It does this by having sticky seeds that when a breeding or roosting seabird brushes against them the seed sticks to the feathers of the bird and eventually the stickiness wears out and the seed drops of in a new location to germinate. On this visit I counted 53 Lesser Noddy under the nesting glades totally covered in seeds and adjoining twigs. These were doomed and it was only a matter of time before the land and hermit crabs moved in to devour them. Whilst I had heard and read of bird mortalities associated with sticky Pisonia seeds, I had never witnessed it and the numbers involved in this event appeared high (actually ˃ 0.1% of the island breeding population). It is a natural phenomenon and the seemingly high numbers are likely due to large numbers of breeding birds coinciding with a bumper crop of seeds.








    The penultimate day in Peros Banhos was spent surveying the rat-free and near natural Grande and Petite Coqillages. Both of these islands are IBAs on account of breeding Sooty Terns but as elsewhere in this atoll, the terns were not having a breeding episode during this visit. It was still an absolute pleasure to circumnavigate the island counting the breeding seabirds; the speciality on Grande Coquillage being breeding Great Frigatebird. To see the males displaying on their flimsy twig nests is another Chagos treat; they raise their huge wings out to their sides and fan-wave them, inflate their crimson gular (throat) sacs to balloon like proportions and then give out a wonderful “Red Indian war cry” to try and attract a female.










    The final day in Peros Banhos was spent on rat-infested Yēyē. The total lack of breeding Red-footed Booby on this island is something of a mystery to me. From previous research in the Chagos it has been demonstrated that Red-foots preferentially breed on islands without rats, though, on islands that have stands of mature climax forest trees on the coast, particularly headlands, they will nest. The surveys of the previous few days where birds were found colonising rat-infested islands in western Peros Banhos being examples of this. Yēyē is a quite large for a Chagos island (c. 60 ha.) and its shoreline holds several stands of mature Takamaka Calophyllum inophyllum and Guettarda speciosa, both readily nested in by these arboreal booby. It has windy headlands and sheltered bays, again, both favoured breeding haunts if the right trees are present. So, why, on this island nestled in amongst six IBAs that all hold breeding populations of boobies, is there not a single pair? There are several possible solutions. A super-abundance of rats? This is thought unlikely and, the breeding stronghold of Diego Garcia has a rat population assessed to be as high as on any island in the world. An undiscovered relict population of cats left over from then this island held a very small human settlement? Again unlikely, Diego Garcia still has a tiny population of cats and these do not appear to impact the breeding boobies to any great extent. The most likely theory is human disturbance. Research towards my Masters showed that islands with little or no disturbance such as Nelson’s and Danger Island are preferred for breeding sites over islands that have regular human disturbance around the breeding colonies. Yēyē has had poaching camps sited on it over the last decade and it may be that boobies were killed for food by poachers and this is the reason they have not colonised this island.

    As we left Yēyē heading back to the mother-ship we stopped to take a brief visit to a tiny unnamed island some 150m of Yēyē’s shores. I first landed on this island in 2008 and it had certainly grown over the ensuing seven years. There was evidence that as in 2008, Black-naped Terns breed on the coral rubble that forms the island and the spit running northwest out from it. This species had been joined by Crested Tern as a breeding bird. Three Madagascar Fody, an introduced species that has colonised the entire archipelago, were foraging on the Scaveola that was emerging out of the substrate. But, it was the amount of washed up plastic that has given me my lasting memory of this island. The inner ring enclosed by the coral rubble resembled a commercial rubbish tip. This was a sad reminder that even these truly remote oceanic islands cannot escape the nightmares man is inflicting upon the planet. After an uneventful sail from Peros Banos in calm waters and very light winds we anchored in the circular lagoon of the Salomon Islands as the sun was spectacularly setting. 

  • Day 10 - The Coquillages...

    Peros Banhos Petit Ile Coquillage Blog

    The Coquillages threw up some treats today – for the terrestrial crew there were tours around these pristine tropical islands. Complete with hardwoods and grasslands and oodles of nesting and roosting seabirds. We took the Trekker around Petit Ile Coquillage and the interior of the island is a steady grassland interspersed with copses of coconut palms and patches of scaevola and clumps of hardwood. Look forward to seeing this one on street view.

    In the water the team split between Grand Coquillage, where Nick and Shaun pursued there connectivity studies between island vegetation and wildlife and reef nutrients. The remainder of us headed to the Oceanside of Petit Coquillage where we encountered some beautiful and rich marine life. In a short snorkel and an hours dive I encountered 5 turtle and 3 octopus amongst myriad fish species. Whilst waiting on the surface for the remainder of the divers to come up several manta wafted by beneath us clearly visible in the crystal water. One of the dive boats encountered five or so more of these big winged wonders on the short boat ride back to the research vessel.

    So another beautiful and successful day on this Darwin Science Expedition. This is our last stop in Peros Banhos we wrap up here and move on it is a good opportunity to give you more detail on the work that Chris and Gary are doing out here. 


    How fast are coral reefs growing in the Chagos Archipelago

    Chris Perry & Gary Murphy, University of Exeter

    Coral reefs are experiencing an unprecedented decline in their abundance, diversity, and habitat structures. These changes are not only impacting upon reef ecology, but also now are starting to change the amounts of calcium carbonate that are being produced and eroded on reefs, calcium carbonate being the material that coral skeletons and reef sands are made of. This is an especially critical issue because the balance between the amount of carbonate that is produced and eroded (what we term a ‘carbonate budget’) has a major impact upon the rate at which a reef can grow and on the ability of reefs to maintain their complex surface structures. We measure these biological carbonate budgets through detailed surveys of corals and other calcareous organisms, such as coralline algae, and surveys of the abundances of parrotfish, urchins and other biological eroders that collectively break down the substrate.  The overall balance between the amount of production and erosion thus provides us with a measure of reef “health” from a reef growth perspective. Whilst work on reef budget states, from various heavily degraded sites in the Caribbean, is now emerging, we have very little understanding of reef carbonate budget states from sites that are relatively remote from major human disturbance. Few areas of the world offer the possibility to examine such issues, but Chagos is one of these.

    Diego Garcia

    Our field surveys started on the reefs surrounding Diego Garcia, and we have spent the last 3 days working on a number of reefs around the northern and north-western sides of the atoll. Compared to many reefs we have studied recently in the Caribbean these have what appear to be relatively thriving and diverse coral communities within our target habitats (~10 m depth), with the coral communities typically dominated by the branching corals Acropora and Pocillopora, and the mound coral Porites. Our initial estimates suggest positive carbonate budget states at all sites (meaning that rates of carbonate production exceed rates of biological erosion) and with coral cover and carbonate budget states about 50% higher than the averages calculated from multiple sites across the Caribbean. Interestingly, however, we note variable evidence of active reef structural development at these sites, with the corals often growing on older limestone surfaces. The reefs around these areas of Diego Garcia are, however, quite narrow and relatively steeply sloping and our assumption is that a significant amount of the coral substrate that is produced is periodically stripped off during storms and lost into deeper water. Nonetheless,  given the proximity of these reefs to the only inhabited island in the Chagos Archipelago, and given that coral populations have been hit in recent years by bleaching and disease events, these numbers are impressive.  We await with excitement to see what the more remote atolls are like.  


    Peros Banhos

    An overnight steam has brought us to the large and beautiful Peros Banhos atoll, with the boat initially moored up in the south-west corner allowing us to access a range of reefs along the relatively more sheltered western side. We were told that the sites on the seaward side of Ile Poule, Ile Anglaise and Ile Fouquet were stunning and so this proved. Wonderful clear waters and the reefs covered in large table-like and branched colonies of Acropora and a myriad of other mound, branched and encrusting species.


    Immediately obvious to us also were the large numbers of very large parrotfish, a key grazer of algae on reefs and an important eroder of the substrate – parrotfish scraping and removing thin layers of  coral skeleton as they search for algae.

    This activity not only helps to keep a reef “healthy” and free from weedy algae, but also results in the generation of large amounts of sand – the fish excreting this in huge amounts once it has been processed in their stomachs. A large amount of the sand on the beaches and in the islands is likely derived from this parrotfish feeding.















    Next stop were sites in the north-west of Peros Banhos, with surveys conducted on the seaward sides of Ile Diamant and Ile de la Passe. Again, impressive sites with good coral cover and abundant parrotfish populations, but perhaps the most impressive dive was to survey the lagoon reefs inside Ile Diamont, a stunningly complex reef surface provided by the high cover of branching Acropora corals and, most especially the large platy whorls of the coral Echinopora. A great dive.














    Our final stop in Peros Banhos was on the eastern side of the atoll, with a chance to work on two “exposed” reefs at Petite Coquillage and Grand Coquillage. These two reefs were visually very different and dominated by mound shaped Porites colonies and robust branched Pocillopora. Parrotfish numbers were also again high and we observed a large school of about 70 Greenthroat Parrotfish busily grazing across areas of large dead table Acropora.

    What can we say about the Peros Banhos reefs? Well carbonate production and bioerosion rates were both higher than on the reefs we visited around Diego Garcia, with overall carbonate budgets about 50% higher again and with net budget states close to double those measured at equivalent depths in the Caribbean – this despite all of these reefs being in various stages of post-disturbance recovery. Even more encouraging is that there is evidence of widespread coral recruitment and of the active growth of new corals from multiple coral recruitment events, which suggests the potential for rapid increases in carbonate production rates over the next few years. We leave now for Salomon Atoll ….

  • Day 9 Tiny shrimp and turtle wrestling

    The northern edge of peros banhos offered up its treasures today. The dive off Ile de la Pas provided some beautiful spectacles. There is a species of coral here in Chagos, physogyra, and on some of the colonies of this species you can find a particularly elusive commensal shrimp Vir philippinensis. 

    I was lucky enough to see one today. As the body is transparent and very small, perhaps only a centimetre long, the only evidence of these tiny creatures is their long purple antennae protruding out like fine hairs from between the corals bubble like polyps.



    I’ve been taking an interest in small crustaceans on this trip and frequently find trapezia crabs in amongst the branches of pocillopora corals. The story goes that these crabs find a home amongst the coral and in return protect it from predators such as the crown of thorns starfish. When the COTs comes along the crab nips at the underside of the starfish as it tries to engulf the coral which deters the starfish into retreat.

    After diving for the morning I joined the terrestrial team for the afternoon to take the Trekker camera around Ile Petit Bois Mangue. This island is particularly special for its glades of pisonia grandis. These majestic trees are home to thousands of breeding noddy terns. And are also a potential threat to the birds that make them their home. Their seed pods are burred and sticky…and in the case of noddies can be deadly. They’re designed to stick so that they will be carried by the seabirds to fresh land masses – but in excess they bind the birds hopelessly and many were on the floor of the island fading away in a tangle of seed pods.

    On the way back to the research vessel we see a pair of green turtle mating off Ile Manoel. The third such pair that I have seen in the various trips I have made out here. These islands are a haven for these large reptiles and no matter what time of year you walk the beaches here you will find signs of fresh nesting activity. But it all starts in the water with what looks like a wrestling match between two large adults on the surface. Not wishing to disturb the two that we have seen we move on after snapping a few photos.


    On completion of the days activities we get underway in the research vessel and are on the way to the coccilage islet pair as I write this...

  • Day 8 A day off from diving...islands await!

    On this day some of us took a break from being in the water which is recommended to allow ones body a rest from being saturated at pressure while scuba diving. I made the most of this opportunity to carry the Google Trekker camera on to Ile Grand Mapou and Ile Petit Mapou. These adjacent islands in the north west of Peros Banhos are very scenic but were also once coconut plantations. As a result they are vegetated with a coconut monoculture and also inhabited by rats. This combination is not very favourable for seabirds who find it difficult to nest and roost in the unstable palm branches and also do not like being harrassed by rats. For me this meant less seabirds to view while I went round the islands but for Nick and Shaun it is an important aspect of their research. Shaun outlines the thrust of their research below.

    Seabirds such as red footed boobies, sooty and fairy terns are common around the Chagos Archipelago where they can be seen gliding above the sea often diving into the water and plucking out small fish for their supper. These birds can also be seen on many of the islands where they roost and nest. Whilst on islands droppings from the nesting and roosting seabirds slowly accumulate, enriching the typically sandy island soil with nutrients.  On some Islands the introduction of rats and changes in vegetation has however drastically reduced bird numbers. This has important and obvious implications for bird conservation, but reduced bird droppings will also affect nutrient levels on the island which may have flow on effects to the adjacent coral reefs.

    Our project is investigating if the nutrients that seabirds aggregate onto islands from their droppings are transferred into the reef system. We expect that Islands with seabirds should have nutrient signatures in the soils and plants that differ to those without seabirds. If the nutrients are being transferred onto the adjacent coral reefs, the nutrient signatures from terrestrial plants should be similar to those of the algae, sponges and fish on the nearby reef flats and crests. We also assess the composition of the reef habitats and estimate the abundance of fish to see if nutrients from seabird droppings influence coral and fish communities.  Our results should improve understanding of how changes in land based management influence both birds and the flow on effects for reefs. For example, removing rats from islands may have the potential to not only improve bird numbers, but also enhance the productivity of surrounding coral reefs.

    Seabirds above and on Grand Coquillage

    Coral reef fish represent some of the most diverse vertebrate assemblages in the world. Within these assemblages small bodied species are particularly abundant, however small size, colouration and behaviour make many of these fishes cryptic and difficult to study.

    The slaraiin blennies are a major part of this cyptobenthic fish assemblage on coral reefs. They are commonly known as the combtooth blennies, due to their elongate, flexible teeth which they use to brush loose detrital material (decaying organic matter) from the reef surface. With the exception of a few species, detritus makes up most of a combtooth blennies diet and because blennies are often in high abundance on shallow reefs, they are important consumers of detrital material in this area. Moreover, as most blennies have short life spans (less than a year) and are eaten by larger predators, they represent an important link between reef detritus and higher levels of the food web.

    On the reefs of Chagos 25 species of blenny have been recorded, although only 14 of these are comb tooth blennies. We are currently estimating the abundance of these blennies on the shallow lagoonal reefs that surround islands with or without birds in the Chagos Archipelago. This is an extension of the above project that explores how nutrients from bird droppings may be transferred to the adjacent reefs. Blennies are of interest because detritus enriched with nutrients from bird droppings might support larger numbers and bigger fish.


    Blennies of the genus Cirripectes are common on the shallow reefs of Chagos




  • Day 7 Gabriel and Danger

    Charle’s has tried out  a drone flight over some of the archipelago today. This should be great for recording aerial views of the shallow reefs – this test flight was fairly inconclusive as the sunlight was so bright the screen of the app for operating the camera on the drone could not be viewed by the pilot. So we’ll have to find some shade for the next attempt.

    Diving operations are far more practiced now though with dive teams zipping in different directions to dive sites around the atoll. A couple teams headed outside of Ile Gabriel to a gently sloping coral garden. Catherine sampled a couple of coral heads for cryptofauna whilst Nick and Saun pursued their fish surveys.

    The afternoons dives offered up something different. Within the Peros Banhos lagoon there are numerous knolls that slope up from the lagoon floor to within a few meters of the surface. Dropping in on one of these the coral gardens are phenomenal and the fish life overhead was abundant. An endless column of fusiliers of different species flowed by throughout our dive here whilst a large snout spotted grouper glared at us watchfully as he lurked between coral hideaways.

    Another stunning day although the wind has picked up a little. The weather over the last few days has lent itself to work on the islands. Pete has a written a few more paragraphs to fill you in on the details...

    The overnight passage north from Diego Garcia to Peros Banhos was very calm and accompanied by a beautiful sunset. It also afforded me the opportunity to gather more records of seabirds at sea and cetaceans. In addition to the constant stream of Red-footed Booby, Brown Noddy and Fairy Terns (Gygis alba) heading south to Diego Garcia to roost, three Bulwer’s Petrel were encountered foraging over the glassy sheen of the tranquil seas. It was surprising seeing this species in the Chagos at this time of the year when theoretically it should have returned to its breeding islands in late March / early April; the nearest thought to be Round Island, Mauritius. As the sun finally dropped below the horizon a pod of 10-20 Common Dolphin came to ride in front of the ship. A wonderful ending of the first day at sea.

    As the sun rose again the following day the ship was nearing the rocky island of Coin de Mire. This elevated, sparsely vegetated limestone outlier of Peros Banhos atoll, along with the similar Resurgent Island on the western rim of the Great Chagos Bank are the only islands that the magnificent Masked Booby breeds on. Both Resurgent and Coin de Mire are exceedingly dangerous to land on but, with calm seas offering a rare opportunity to conduct an accurate census of the breeding seabirds, Jon Slayer and I thought we would try our hand. Jon thought he would add to the challenge of getting on the island by bringing along his Google Trekker recording equipment!

    The Masked Booby colony was faring well with 24 occupied nests, nearly all having laid their two eggs. Bridled Tern, another rare breeding species in the archipelago had 21 breeding pairs present, the highest count of any island ever. As a fitting finale there was a single pair of Roseate Tern present that were protecting a nest or chick. A beautiful species in breeding condition with the glaring whiteness of the birds being complimented by pink suffused underparts, less than 10 pairs breed annually in the Chagos.

    After anchoring in the southwest of the atoll the most important task of the expedition was facing me. In August 2014, accompanied by a professional mammal eradication expert from New Zealand and a small team of military volunteers from the British Forces on Diego Garcia, the small island of Vache Marine had its’ introduced invasive rats removed. Conducting this type of operation on tropical islands is still fraught with possibilities of failure and worldwide teams doing this type of work are managing about 80% success. My task whilst while the ship was anchored for three days in the southwest of this atoll was to conduct a first check to see if our work had failed. With some trepidation I set off for Vache Marine to set traps and conduct visual observations. I am glad to say that after three days of checking including one overnight stay with observations being made throughout the night, I saw no sign of rats. It is too early to say the eradication has been successful but, pleasingly, I can say there is no reason to date to believe it may fail. Further checks around August 2016 will reveal the final verdict.

    Claudia again joined me ashore on Vache Marine for some of the time. Together we removed the bait stations that were left on the island (a hard and hot task!) as part of the eradication project and before we left, Claudia planted a small native tree. This tree was grown from a seed collected by a British soldier, nurtured on board by the crew of the BIOT Patrol Vessel for twelve months and finally planted by a visiting Chagossian. It was a poignant and symbolic gesture of how with goodwill and coordination terrestrial environmental improvements can be made in the Chagos Archipelago and was a fitting end to this part of the expedition.

  • Day 6 Invasive rats and coral gardens


    What an evening…on arrival to Ile Vache Marine we circumnavigated the island and discovered what appeared to be an exhausted green turtle stranded in the undergrowth next to the beach. We decided if she had not moved by morning we would carry her back to the water. While we were contemplating this we noticed a ghost crab scuttling about awkwardly stumbling over something in its claws. On closer inspection we saw that it had caught a turtle hatchling. This little one stopped at the first hurdle in survival…it will never make it back to this beach as an adult.

    As dark fell we did another circuit around the island looking for rats. This was the site of a pilot invasive species eradication scheme aimed at ridding the small island of rats. We see none but this does not mean that the island has been freed of this pest. We will have to carry out another check in a years time to be sure that none remain behind. Hopefully they will be gone for good allowing the seabirds to return and nest in numbers here. After the check we sleep under the stars on this cool tropical night.

    In the early hours of the morning we get picked up from just off the beach and race back across to the research vessel in time for breakfast and a swift turnaround to join the morning dive.

    The coral gardens off Ile Poule are the highlights today. They are stunning, coral growing over coral growing over coral all spread in a vibrant smothering of fish. Turtles are there in the mix and a couple of shark cruising through. I watch Gary and Chris as they work, carrying out detailed surveys of the benthic life of the reefs for their carbon budget studies.

    Not to be outdone this afternoons dive was rich with little things to look at in amongst the more weathered corals of the southeast facing reefs outside Ile Fouquet. And more dolphin! A pod being playful with us en route to the dive site this afternoon. Having a great time playing in front of our bow.

    Incredible conditions once again offering up the most spectacular day in Chagos. 

  • Day 5 On to the outer islands...

    After a very gentle overnight trip (the weather is still a faintly rolling calm beneath the boat) we arrived at Peros Banhos Atoll shortly after sunrise. Sundowners were a treat last night with calm seas to the horizon of low puffy clouds lit red by the setting sun. This morning was equally appealing. Such light weather conditions offered a rare opportunity to get ashore at Coin du Mire.

    This uplifted shelf of fossilized reef offers sheer rock for the oceanic swell to break against and as a result is off the visit list in all but the most serene seas. Although unapproachable as a regular destination for people the opposite is true for a number of bird species graced with the ability to glide over the waves crashing with full force against the rocks to land on the emerald green grass that carpets the top of the shelf. There Masked Booby and various terns make their nests.

    So on this day of lovely weather we made the most of the opportunity and stepped straight off one of the small expedition dive boats onto the top of the shelf with only a gentle roll to sway us. The rock is only about 100 meters across and a few hundred meters around but is home to at least 100 nesting pairs of birds of various species. The greenery sprouting all over the central plateau comprises four species of grass and surprisingly, a healthy population of grasshoppers. How did they get to such an isolated outcrop of stone? A mystery.

    The day continued with interest from there…for the remainder of the morning and into the afternoon I accompanied Courtney on snorkelling surveys around some of the lagoon knolls of southwest Peros Banhos. With water like glass we watched small fish flitting amongst the corals in water 15 meters deep. As we were snorkelling we surveyed shallower depths than this and revelled in the beautiful vistas of coral fading into blue in all directions.

    Whilst doing this exploratory work we discovered a coral pinnacle jutting abruptly up from a depth of about 15 meters all the way to within a few meters of the surface. It was crawling with soft corals and alive with fish – a great discovery. Just as we were examining this we heard whistling behind us and turned to a pod of dolphin cruising by. What amazing experiences to be had in this fantastic marine protected area.

    After a few more snorkel surveys that turned up a number of other fantastic coral gardens (and a turtle hiding under an acropora table) we headed down south to Ile du Coin for a dive just inside of this island. Again, coral gardens sweeping as far as the eye could see (or fin could swim) in each direction. Anne and Charles successfully recovered their temperature logger from this site…usually they’re quite difficult to find but on this occasion they practically dropped on top of it. More data to add to this large set of information on temperature fluctuations in the waters of the territory.


    As if the day didn’t hold enough great experiences I’ll now be heading ashore to Ile Vache Marine for the evening to set out rat traps with Pete. There has been a trial rat eradication effort on this island in the hope that removing these invasive animals will allow the seabirds to return and nest. I’m sure there’ll be more to report on the wildlife of this island when I return to the research vessel tomorrow! (I’ve already heard that there is a turtle nesting there as I write this…better get moving!) 

  • Day 4 Psychedelic shrimp

    Diego Garcia Cannon Point and Horsborough Bay

    We couldn’t have asked for better conditions to start the expedition – motoring out of the lagoon this morning the water was flat calm and mirror smooth. This makes for really easy whizzing around on the surface – what a pleasure the day has been!

    First thing this morning we were into the water Oceanside of Diego Garcia to get more surveys done and retrieve some temperature loggers. There was a big smile on Anne’s face when she returned from the dive with both loggers from 15 and 25 meters. A smile that was echoed by Charles as he successfully downloaded all the data from the last year to add to his data set from the last 9 years at this site.

    This dive off the NW coast of Diego Garcia was alive with larger fish. There was a strongish current so whilst swimming alongside the boat we had the opportunity to watch the marine life as it drifted by. Napoleon Wrasse (with a lone Jack escort), Eagle Ray and an aggregation of Snapper not to mention the odd shark or two…


    The research vessel picked us up off the coast and we were soon under way round the north of Diego Garcia and on to Horsborough Bay.

    There we had quite a fascinating dive. I was shallow diving with Courtney and the coral heads on this reef were crawling with life. Small shrimps were the highlight for me. On one coral head a series of snails (Drupella) were predating the coral whilst the shrimp (Saron sp.) moved in to scavenge the leftovers after the snail had been through…the first time I have seen this very colourful species of shrimp in Chagos.

    After a successful dive to round off the day we’re off to Peros Banhos atoll! Looking forward to getting ashore and underwater there. Whilst we have been busy diving Pete has been continuing his work on the islands. An update from him below on his day's activities...

    A small part of the research I am doing this year is looking at Red-footed Booby “parenting”. In particular, I am interested in how long the parents spend away from the nest and chick. This is a preliminary study looking at a bigger picture of where this species feeds and forages in and around the Chagos Archipelago and eventually, in to understanding what, if anything drives birds to feed in what areas and does this influence when they breed? Back to the basics though, my work over the last two days has been to capture, affix an individually inscribed metal ring and mark birds so as to be recognised again without being disturbed. The latter being achieved by applying a small amount of non-toxic coloured dye to the bird’s white plumage. This was achieved with the minimum amount of stress to the birds, though the same could not be said for those handling the birds, who came out with several scratches and bites!

    Marking the birds was the first and, what transpired to be the easiest part. The follow-on phase was to mount self-operating cameras besides the bird’s nests to monitor how often the parents returned to feed and tend their chick, something akin to CCTV on tropical islands. This proved to be far more challenging than I originally envisaged. I had not fully appreciated the full range of factors that need to be taken in to consideration when siting a remote-sensing camera on a tropical island and planning to leave it there working by itself for three weeks. First there is programming. Ideally, one should have thought through what type of data was required and how to capture this on film and then it is a simple matter of feeding that information in to the device. I had but, the camera did not want to comply with my orders! So, eventually realising I was fighting a losing battle with both time and technology, I sought assistance from my fellow expedition members. And none of them could enter the programme either. It took us sometime to realise the first camera was not functioning to specification!


    So, two reserve cameras were brought out, our technical issues were solved and today these were deployed next to the nests. Deploying the cameras gave the first opportunity for Claudia Naraina, the Chagossian Environmental Student accompanying the expedition, to assist with the terrestrial field work and, she was a natural at being around breeding, aggressive seabirds as well as siting cameras to gain the best angles. As we start to gain information, questions arise. At nest one, the same originally marked bird has been present throughout the day for over 48 hours. At the second nest being monitored the parents have swapped over every 24 hours. As we are now underway for the northern atolls we will have to wait until we return to Diego Garcia in three weeks to see if there is any pattern to by who and how often these exceedingly resilient chicks are fed by.



  • Day 3 Barton Point and East Island

    Barton Point and East Island

    Getting into the science of things. Today the program has really got under way. Everyone’s dive gear is now out and working and the work program has started in earnest. To reel off a few elements of the days work – Charles and Anne have been off replacing temperature loggers, Chris and Gary have started their carbonate budget surveys, John and Ronan have been doing their video transects, Courtney has started her coral surveys, Pete has done island surveys and deployed camera traps and Nick and Shaun have been on islands to collecting samples.

    All the boats are up and running now and compressors are firing away keeping our air fresh for scuba.

    ARMS processing is going to be one of the more time consuming elements of this expedition.  Catherine, Claudia and Courtney have been really busy in the lab carefully recording all the life found within the monitoring systems. Ronan lent some muscle in collecting the heavy ARMS off the seabed this afternoon.

    Claudia’s dive skills have also been progressing well as she entered the water for a second time on this trip. On her dive we saw a beautiful octopus and several Nemo’s.


    It has been amazing weather again today. Off Barton Point there was a flat calm and gorgeous sunshine for our dives. 


  • Day 2 - Getting in for the first dive

    Getting in for the first dive

    The lead up to some of the activities on these expeditions is impressive – on our first dive of the expedition today we were out looking for reef monitoring devices that were set out more than 2 years ago. Now they’re ready to be collected. This involves dropping in for a dive, searching out the buckets sized blocks, now overgrown by algae and coral and looking just like a part of the seabed, removing them from the secure bars holding them to the reef, then lifting and transporting the heavy load back to the research vessel for processing. And that is still going on late at night while I write up the days activities…more about that later.

    Before any of this is possible all of the gear we shipped out, everything stored on shelves for this expedition needs to be unpacked, set up and readied for action. A laboratory has been furnished, four dive compressors set up on the forecastle, 27 dive tanks filled and 13 sets of scuba dive equipment have been assembled – not to mention each individual persons science or research or camera equipment.

    With the incentive of some great diving around the lagoon mouth of Diego Garcia all of this activity was given a great deal of effort this morning. Shortly after lunch we headed out into the bright sunshine around the lagoon and made for the Oceanside of Middle Island. This is where the Autonomous Reef Monitoring Systems (ARMS) were set up two years ago.

    After two years it took a long while to find the devices – one of them is overgrown with a layer of acropora and looks a lot like a mound of coral on the seabed. Catherine retrieved one of them to process tonight so that is now back on board the research vessel and is being examined as I write.

    While she was looking for them I took Claudia, our Connect Chagos graduate, on her first dive in the territory. Amongst other things we saw one of the huge sea cucumbers that are characteristic of the waters around Diego Garcia and also came across a large free swimming Morey Eel. As we approached he went to hide under a ledge but this didn’t stop him from peering out and examing us very closely. Something to be weary of with that big mouth and the accompanying sharp teeth.


    She thoroughly enjoyed the experience and there will be plenty more opportunity to get under water and enjoy the sights out here!


    After a great dive we headed back to the research vessel. We’ve now got everyone out the water and there are some Gremlins to work out of the system. Boat repairs to make and dive gear glitches to rectify. As we’re finishing up with this it looks like the ARMS processing is just getting started though…the devices are made up of numerous plates into which the small reef life creeps and lives. The idea is to separate all of the plates and examine what communities have established themselves in this cryptic fashion. There should be some really interesting inhabitants…time to put down the computer and go and see what discoveries they have made!!

    Additional to the marine work we are doing on this expedition Pete Carr is leading research around the terrestrial habitats of the archipelago. His reports will be included in the daily one's entry below...

     Diego Garcia

    After arriving on Diego Garcia late on Tuesday night (17th), the following day was taken up with the necessary pre-sailing administration. Working parties were busy all day retrieving stores that had been cached on the island, acquiring the necessary stores for the expedition such as fuel and checking that all the participant’s personnel equipment was functioning and ready to be put in action. Unlike the rest of the expedition members who all had dive equipment to check over, my kit list is fairly simple; binoculars, camera and notebook are my essentials. Rather than checking these out on the ship berthed alongside a jetty, I decided to test them in the field. This proved to be a good decision as I found three pairs of Red-tailed Tropicbird breeding semi-colonially in their traditional site on the island. Bizarrely, they nest directly behind a regularly used soccer goal. This site, first noted in 2003 by Nestor Guzman who works on the island as an environmental advisor, is the only known regularly used area on the only island in the Territory this species is known to breed on!

    Today was the first day of true census work on the internationally important breeding seabirds of the Chagos Archipelago. Being berthed in Diego Garcia for three days before sailing is offering a rare opportunity to count the Important Bird Area and Ramsar site on this, by an order of magnitude the largest island in the central Indian Ocean. The three islands, East, Middle and West, in the mouth of the atoll lagoon were surveyed today, not just for birds, also to ensure that rats have not invaded these seabird sanctuaries from the mainland. Miraculously all three islands have remained rat-free, despite East Island once being inhabited. The good news being they are still rat-free and East Island remains a superb example of an oceanic climax forest, in this case dominated by the Native Pisonia grandis trees.  The seabirds are faring well too with thriving populations of Red-footed Booby on all three.

    Red-tailed Tropicbird photographed breeding on Diego Garcia

  • Day 1 - Arrival and...well done Pitcairn!

    After arriving in the wee hours of last night we’ve transferred the expedition crew straight across to the research vessel for a jetlag fuelled nights rest. No room for resting on the laurels though and everyone is up first thing in the morning to collect expedition equipment and start setting it up for action!

    Boats to get ready, labs to set up, boxes to unpack and compressors to run – not to mention moving into cabins on board the ship and getting ourselves set up for what will be 3 weeks on board.

    On this day there is barely a breath of wind, let’s hope the weather hold for our dive program in the coming weeks but for today such a still atmosphere makes for an absolutely scorching work day in the burning tropical sun. The deck is baking as people assemble all of our gear for what is going to be a very busy few weeks. Sweat flowing freely the day is productive and by night fall we are having a brief on the following days dive activities and the coming weeks of adventure in what is now the world’s second largest marine reserve. We’ve just received the press release that another British Overseas Territory, Pitcairn, has followed Chagos’ lead and declared their territorial waters a Marine Reserve.

     Well done Pitcairn!!!!

2015 Darwin Science Expedition

This expedition (Darwin 2015) is the third of three that are designed to help deliver the objectives of a Darwin Initiative project to Strengthen the World’s Largest Marine Protected Area, Chagos Archipelago, funded by Defra (UK Department for Environment, Food and Rural Affairs).  11 of the 14 participants have taken part in previous Chagos expeditions and consequently the team is experienced, and the research is well developed.  The Principal Investigator of this project is Dr John Turner (Bangor University) with Prof Charles Sheppard (Warwick University) and Dr Heather Koldewey (Zoological Society of London, ZSL) as Co-Investigators (all also of Chagos Conservation Trust), with the British Indian Ocean Territory (BIOT) Administration the main project partner. The three year project aims to strengthen the Chagos Marine Protected Area by providing scientific knowledge for effective management, and develop a strategy that engages the support of potential stakeholders through outreach, education and engagement. The legacy will be sound management and increased value of what is currently the world’s largest no-take Marine Protected Area and a unique and globally important reference site.



Dr John Turner

 School of Ocean Sciences,  Bangor University, UK

Chagos Conservation Trust

Darwin Project Leader and Darwin 2015 Expedition Leader

Profile: John Turner has expertise in temperate and tropical marine environments and the interaction between human impacts and the aquatic environment. He has over 25 years of experience in a wide range of projects involving Coastal Habitat Survey, Marine Protected Areas (MPA), Environmental Impact Assessment (EIA), and Integrated Coastal Zone (ICZM) in a range of countries and contexts. He has undertaken large scale biological surveys for UNDP-GEF Projects on Sustainable use of Biodiversity of Socotra Archipelago, and Coastal Ecosystems of the Andaman Islands, and EIAs for major industrial developments (eg. LNG terminal, Oman; effluents, Mauritius). John's research advances techniques for integrating spatial biodiversity data in marine systems for the purpose of assessment of state, for establishing Marine Protected Areas (MPAs), and for long-term monitoring and investigating change. He is a field biologist, experienced in undertaking manipulative experiments, survey and monitoring on coasts and underwater. Current interests focus on the establishment of MPAs (Cayman Islands, Chagos); Reef resilience to human impacts and climate change (Cayman & Indian Ocean islands); and Coastal Zone Management and Sustainable Development (East African coast).  John has visited the Chagos four times (2006, 2008, 2013 and 2014) and is an Executive Member of the Chagos Conservation Trust.  John currently/recently  leads three DEFRA Darwin Initiative projects: Darwin Initiative to strengthen World’s largest MPA, Chagos 2012-2015; Darwin Initiative to enhance an established marine protected area system, Cayman Islands 2010-2013, Darwin Initiative Assuring Engagement in Cayman’s Enhanced Marine Protected Area System 2013-2014.


Lead, Research Project 1: Coral Reef community monitoring by video archive (with Ronan Roche)

Coral cover on Chagos reefs has been assessed for greater than 20 years, providing a valuable long term record of change over time in response to major environmental variables, such as warming events and bleaching induced mortality.  Although photographs of many reef communities exist, what has been lacking is a video archive of the structure of communities which would allow documentation of change and the identification of features that may not previously have been recorded in counts because their significance was not evident at that time.  A video archive enables new generations of scientists to revisit reefs visually, and the video can be reanalysed to identify changes and to address questions of resilience and response.   10 minute sequences of video were recorded over 5 m depth ranges (5-10, 10-15, 15-20, 20-25m depth) at seaward and lagoon sites on all atolls in 2006, and these are being repeated during the 2013 -2015 Darwin Initiative expeditions.  Initial analyses indicate that primary framework species that grew rapidly at shallow depths following the 1997 mortalities, are now being replaced by more diverse secondary framework species, which can be expected to increase in biomass in subsequent years unless affected by further impacts. There are already indications of new events occurring, such as mortality of lagoon corals below 15 m depth in Salomon lagoon; and loss of banching Acropora on lagoon reefs of Eagle Island and Danger Island due to Crown of Thorns starfish outbreaks, and coral diseases.   



Professor Charles Sheppard

 Biological Sciences, University of Warwick and Chair of Chagos Conservation Trust, UK



Project Co Investigator and Darwin Expedition 2015 Co Leader


Profile: Charles Sheppard has been working for several decades on the marine ecology of tropical seas.  He focuses on the corals, their abundance and identity, and changes that have occurred over the years in key environmental parameters. Because ocean warming and climate change are so important, he relates community changes to climate change, especially to warming pulses that damage reefs.  He is editor of a major marine  environmental science journal, and has written and edited numerous books and papers on this subject including on the remarkable Chagos archipelago, but focusing as well on tropical areas from the Caribbean to Australia.  Regarding Chagos, for 10 years was BIOT Commissioner’s scientific advisor, before giving up that position and becoming Chair of the Chagos Conservation Trust. He has lead many expeditions to Changos, including the first of the current 3 Darwin expeditions.


Lead Research Project 2:  Coral Reef Monitoring (with Anne Sheppard)

In 2015, Charles Sheppard will focus attention again on the status of the corals which build the Chagos Archipelago.  Factors such as coral cover, juvenile coral density and mortality of older colonies will be investigated in order to assess the ‘health’ of the reefs.  Arrays of underwater temperature data recorders will also be retrieved, data downloaded, and replaced.  We hope also to investigate further the huge seagrass beds that were recently discovered far from the islands, and also will re-examine the area where a crown-of-thorns outbreak on the Great Chagos Bank 2 years ago killed almost all corals on a portion of reef, to determine recovery potential in the archipelago. Charles will fly the aerial camera to obtain good aerial images of reefs and islands for habitat mapping.   With colleagues, he has found that the natural resilience of Chagos reefs was relatively fast compared with areas that suffer stresses from most human induced kinds of exploitation, such as sewage, over-fishing and shoreline disturbances.



Professor Chris Perry

 Geography Department , University of Exeter, UK



Profile: Chris Perry is a marine geoscientist with >20 years research experience relating to tropical sedimentary systems and carbonate nutrient interaction. He has published 85 peer-reviewed articles and book chapters, and is Geoscience editor for the disciplines main journal Coral Reefs. His research relates especially to the controls on tropical marine carbonate nutrient interaction and on quantifying rates and patterns of coral reef growth. This has included extensive NERC funded work on coral reef growth within the inner-shelf environments of Australia’s Great Barrier Reef, and at sites in the southern Indian Ocean and in East Africa. Of particular relevance here he led a 2009 Leverhulme Trust Research Network piloting the development of a census based methodology to measure carbonate budgets on Caribbean reefs, has undertaken extensive work on reef carbonate nutrient interaction at sites in the Caribbean and, more recently, in the Maldives, and currently leads a work package on carbonate nutrient interaction in East Africa under the ESPA-funded SPACES programme.



Lead, Research Project 3: Coral Reef Carbonate Budget (with Gary Murphy)


Coral reefs are experiencing an unprecedented decline in their abundance, diversity, and habitat structures. These changes are not only impacting upon reef ecology, but also now are starting to change the budgets of carbonate nutrient interaction and erosion on these reefs – a critical issue since these budgets have a major impact upon reef growth potential, on the maintenance of reef structural integrity and hence will strongly influence the future capacity of reefs to sustain ecosystem service provisioning. A carbonate budget is a measure of the amount of carbonate produced by corals and other calcareous organisms, such as coralline algae, less that eroded by biological activity (e.g., through fish and sea urchin grazing) and by physical disturbance. Whilst work on reef budget states, from various heavily degraded sites, is now emerging, we have very little understanding of reef carbonate budget states from sites that are relatively remote from major human disturbance. Such  data would, however, be of immense value in terms of the attaining some understanding of natural (pre-major human disturbance) budget baseline conditions. Few areas of the world offer the possibility to examine such issues, but Chagos is one of these. In this context our aim is to undertake an assessment of contemporary reef carbonate budget states across a wide range of fore-reef habitats at sites around Chagos. This will not only provide an understanding of the existing overall budget state at different sites, but also provide data on the key drivers of carbonate nutrient interaction and erosion at different sites and, uniquely, an opportunity to establish a set of baseline survey sites against which future changes could be assessed – for example following future major bleaching events. Thus the proposed work has both current and future research relevance.  Our field methodology will follow a census-based approach, using methodologies developed and tested at sites in the Caribbean through a 2009 Leverhulme Trust International Network Award, and more recently adapted and tested at other Indian Ocean sites (Kenya, Mozambique and in The Maldives). In addition to the manual recording of species abundance and cover data necessary for the methodology (we aim to collect data from 4-6 replicate transects at a depth ~8m at each site) we will also collect video data from along each transect as an archive. We anticipate generating a set of highly novel dataset on reef budget states and on carbonate producer and eroder abundance from this location, data that will have important conservation and management relevance as an alternative metric for measuring and monitoring reef functionality. 




Dr Nick Graham

Principal Research Fellow, ARC Centre of Excellence for Coral Reef Studies, James Cook University.  Australia.


Profile: Nick Graham’s research tackles large-scale ecological and social-ecological coral reef issues under the overarching themes of climate change, human use and resilience. He has worked extensively on the ecological ramifications of fishing and closed area management and has assessed the long-term impacts of climate induced coral bleaching on coral reef fish assemblages, fisheries and ecosystem stability. He has studied the patterns and processes by which degraded coral reefs recover, and how this can be incorporated into, or influenced by, management action. Increasingly he works with social scientists and economists to assess methods of linking social-ecological systems for natural resource assessment and management. Nick was on the 2006, 2010 and 2012 Chagos expeditions.



Lead, Research Project 4: Rat induced terrestrial-marine nutrient cascades (with Shaun Wilson)


The difference between islands with rats present and those with no rats is striking in Chagos. Islands with no rats are teeming with seabirds, whereas islands with rats have very little bird life. From a conservation standpoint, de-rating islands is an obvious objective to enhance the number of important bird areas in Chagos. However, there is very little research on the implications of rat removal and subsequent high bird numbers for the terrestrial, and related marine ecosystem environment. It is hypothesised that the very high abundance of seabirds on small islands will transfer nutrients from the marine environment, as they feed in surrounding waters and their guano will enrich the nutrient content of soils. We intend to assess this nutrient enrichment effect, and assess processes whereby it may be further transferred from the terrestrial back to the marine environment.  Collaborating with Pete Carr, we will select a series of Islands with and without rats, and assess seabird populations on these islands. Other important information will also be quantified, and where possible controlled for. This will include island size and vegetation types on the islands. Shallow (1-3m) reef communities will also be surveyed immediately adjacent to the islands. This will include benthic cover of corals, different types of algae and the abundance and identity of reef fish assemblages. We will assess possible nutrient enrichment and how it passes through terrestrial-marine pathways, using nitrogen and phosphorus to carbon ratios, and stable isotope analyses. At each replicate island, we will sample new growth on a common terrestrial plant, soil (within 30m of the high tide mark), benthic marine algae (Ulva), organic detrital matter in marine sediments, and a common small herbivorous fish (territorial algal feeding damselfish). With these data, we will compare nutrient enrichment pathways between islands from birds, through terrestrial plant and soils, to marine plants and finally up into the reef fish community. This work has not been done previously, and as such would provide a very novel approach to understanding the importance of removing rats from remote islands.



Dr. Courtney Couch

 Postdoctoral Fellow, Hawai‘i Institute of Marine Biology, USA


Profile: Courtney is a postdoctoral fellow at the Hawai‘i Institute of Marine Biolo gy at the University of Hawai‘i at Manōa. She is a coral disease ecologist and epidemiologist working with the BIOT scientists, Papahānaumokuākea Marine National Monument and The Nature Conservancy to build capacity to address rising coral disease and the develop management strategies to promote coral health across the Indo-Pacific. During her postdoc, Courtney is implementing a coral health and disease monitoring programs for a number of Big Ocean sites (such as BIOT), addressing local environmental drivers of coral disease through targeted research in the Main Hawaiian Islands, and building capacity and facilitate communication between marine resource managers and scientists to improve reef resilience planning.


Lead, Research Project 5:  Coral Disease (supported by Jon Slayer & Gavin Colthart)

Outbreaks of coral disease, acting synergistically with other stressors, have reshaped the structure and function of reef ecosystems, even in remote reefs. Courtney participated in the 2014 BIOT cruise to conduct the first in situ coral disease assessments and found that while disease prevalence is low overall, diseases such as white syndrome are starting to affect several regions. During the 2015 expedition, Courtney will continue her comprehensive coral disease surveys across the Archipelago and devote additional effort to assessing the extent, severity and rate of progression of white syndrome. This study will not only allow us to better understand how global stressors affect coral disease dynamics and reef ecosystems in the absence of local anthropogenic inputs.


Catherine Head (Doctoral candidate)

 Department of Zoology, University of Oxford, UK


 Profile: Catherine is studying the biodiversity of shallow water coral reef cryptofauna, the small often hidden animals that live within the reef structure, and how this component of biodiversity is impacted by human activity.  She is particularly interested in how biodiversity affects ecosystem function, the evolution and ecological processes that underpin community structure, and how human disturbance acts on these processes.  To investigate these topics she  use both morphological and molecular methods to identify species richness. Her PhD builds on her experience working in coral reef conservation over the last seven years.  In order to help managers and local communities improve protection of  reefs and increase reef resilience to global impacts,  it is vital that we understand how all components of biodiversity respond to human disturbance and the mechanisms behind this. Study sites in Chagos allow Catherine to set a baseline against which she can compare other reefs of varying health from across the Indo-Pacific.

Lead, Research Project 6: Coral reef cryptofauna biodiversity /ARMS/Coral colony growth (with Professor Morgan Prachett of ARC Centre of Excellence for Coral Reef Studies, James Cook University.  Australia who is not present on this expedition)  Supported by Gavin Colthart and John Slayer

The majority of reef biodiversity is found within the component of biodiversity termed the ‘cryptofauna’. The cryptofauna is composed of the suite of animals that live within the nooks and crannies of the reef structure, these are mainly invertebrates such as shrimp, crabs, sea stars, and some small vertebrates such as gobies. This component of biodiversity is understudied, partly because it is often difficult to sample these organisms on the reef due to their hidden nature, and partly because they are hard to identify taxonomically. These organisms span all trophic groups, eg. carnivores and filter feeders, and are important to the functioning of the coral reef ecosystem as they contain groups such as the detritivores, which are essential for the breakdown of dead organic matter.  Up to 12 each of dead and living coral heads will be collected to make estimates of biodiversity metrics such as the abundance and species richness of the cryptofauna inhabiting dead and living areas of Chagos reefs. This project will study the community structure of the cryptofauna and the ecological and evolutionary processes that lead to this composition by focusing on the Caridea shrimps which are known to inhabit a diversity of reef habitats and often have close associations with other reef organisms such as the starfish including Acanthaster planci. To do this we need DNA from as many species of shrimp as possible for sequencing to produce a genetic family tree.  

Autonomous Reef Monitoring Structures (ARMS) are standardized habitat units developed by NOAA (National Oceanographic and Atmospheric Administration)  to measure biogeographical patterns of diversity among both sessile and motile non-coral invertebrates.  ARMS have been deployed at many locations throughout the Indo-Pacific, but Chagos is a key location for this research both because of its geographical position in the central Indian Ocean and the relatively pristine condition of the reef environments.  In 2013, 3 replicate ARMS were deployed at 7-12m depth on the reef edge at three locations, i) Diego Garcia, ii) Salamon Atoll, and iii) Peros Banhos at sites with a north-west aspect. These ARMS will be retrieved this year, and motile invertebrate will be sorted and catalogued, followed by storage of all representative groups in ethanol for DNA sampling.. Given the relatively pristine nature of the reef ecosystem in Chagos, we expect to find much higher levels of biodiversity than has been recorded at more degraded locations around the tropical rim of the Indian ocean.  However, it is also possible that the diversity of non coral invertebrates may be lower in Chagos due to the very high number of fishes and macro-invertebrates that prey on these groups of coral reef organisms. This research is expected to contribute to our understanding of the function and trophic structure of coral reef ecosystems in the absence of high fishing pressure.

Branching corals (e.g., Acropora and Pocillopora spp.) provide habitat for many different coral reef fishes, but are also considered vulnerable to climate change. Importantly, branching corals and especially Acropora are the first to bleach and die following extended periods of unusually hot weather. Moreover, gradual increases in ocean temperatures and emerging effects of ocean acidification could be compromising the growth rates of these corals. If so, this will reduce the capacity of normally fast-growing corals to recover from periodic disturbances, including climate-induced coral bleaching, outbreaks of crown-of-thorns starfish (Acanthaster spp.) and severe tropical storms. Growth rates of branching corals need to be measured directly, by quantifying changes in the quantity of carbonate skeleton comprising each coral over time.  40 individually tagged colonies (20 Acropora and 20 Pocillopora) were stained in 2013 within the vicinity of the ARMS devices at Ile Anglaise at Salamon Atoll. All corals that are still alive in 2015 will be retrieved and then bleached in order to accurately quantify how much new skeleton has been added across the entire colony since they were stained. The growth rates of these coral will then be compared to other reef locations around the world, as well as serving as a baseline for subsequent studies within Chagos to assess whether climate change is impacting on coral growth.



Pete Carr (Doctoral candidate)

 Chagos Conservation Trust & Zoological Society of London, UK


Profile: Pete Carr has had a long association with the Chagos having led three ornithological expeditions to Diego Garcia and then lived and worked on Diego Garcia for four years between 2008-2012.  During that time he visited every island of the Chagos and found some 25 new bird species for the Territory.  He was instrumental in establishing which islands became Important Bird Areas, published the book Birds of the British Indian Ocean Territory and has had articles in journals on the birds of Chagos, including British Birds.  Pete has recently completed a Masters by Research degree with Warwick University, the thesis being on Red-footed Booby and factors impacting their selection of islands in the Chagos for breeding and, the implications for future island management plans.


Lead, Research Project 7: Sea bird monitoring, Coconut crab assessments, Isle Vache Marine rat removal. (with Claudia Naraina, Chagossian Research Trainee, and supported by Gavin Colthart and Jon Slayer)

Peter is the focus of the expedition’s terrestrial conservation efforts and will also be continuing his ornithological research in to the breeding seabirds of the Chagos.  In Peros Banhos he will be conducting the first check of the outcome of the rat eradication of Ile Vache Marine in August 2014. If successful, this will give one more predator free island (in amongst six islands that are Important Bird Areas), for the internationally important breeding seabird populations to nest on. In addition, as part of his PhD he will be continuing the long-term monitoring of the breeding seabirds. This includes ringing Sooty Terns as part of study to assess natal site fidelity. Sooty Terns regularly mass desert breeding islands due to avian tick infestations and, as a result, it is thought that they are site faithful to groups of islands rather than specific islands and marking individual birds is an aid to proving this.  In addition, the survey of Coconut crabs (Birgus lantro) will be continued at night when they are active to investigate a possible correlation between island size, vegetation composition and rats.



Dr. Ronan Roche (Project 1)

 Postdoctoral Officer

Centre for Applied Marine Sciences, School of Ocean Sciences, Bangor University, UK



Profile: Ronan is interested in studying how natural systems respond to anthropogenic alteration, using a multi-disciplinary approach, focusing on coral reef ecosystems and their long-term resilience and diversity. He graduated in Biological Sciences from the University of Edinburgh in 2000. He carried out research in 2002 as part of the MSc in Tropical Coastal Management at the University of Newcastle in Trindad and Tobago. Ronan then worked for several years in Coastal Zone Management and Fisheries topics at the Essex Estuaries Initiative in Colchester, England. He then was awarded an IGERT fellowship to study at the University of Rhode Island, where he completed the MMA (Master of Marine Affairs) program focusing on Marine Law and Policy in 2007. His PhD thesis was entitled “A multi-proxy reconstruction of mid-Holocene environmental conditions at a nearshore Great Barrier Reef site: King Reef, Northern Queensland.” This project was collaboration between Manchester Metropolitan University, The Natural History Museum, London, and James Cook University, Australia. He am currently works at the Centre for Applied Marine Sciences at Bangor University, UK. Ronan will be in charge of documenting monitoring site positions and will be working on the coral reef community video archive project (1)


Anne Sheppard  (Project 2)

Research Associate, School of Life Sciences, University of Warwick and Chagos Conservation Trust, UK




Profile: Anne has been a coral reef ecologist on many  research expeditions to the Chagos Archipelago since her first 9 month long trip in 1978, when she was the first woman ever to have dived there.  Her main focus of research is coral taxonomy, monitoring reef health and the recovery of reefs after human impacts.  She has also taken many land and underwater photographs of the archipelago which have used to promote conservation both of Chagos and coral reefs in general.  She is a trustee of the Chagos Conservation Trust and is also editor of CCT’s journal Chagos News. On this expedition she will be continuing the monitoring of reef recovery in Chagos by measuring coral cover (project 2).


Gary Murphy (Doctoral Candidate) (Project 3)

 Department of Geography, University of Exeter, UK


Gary has a broad range of interests in marine ecosystems, particularly in coral reefs.  His first degree was in Zoology at the University of Aberdeen and subsequently he spent six months working on a coral reef fisheries project in Fiji. After some time he returned to university studying for an MSc in Marine Biology at Bangor University. In 2005 he began working on a coral reef biodiversity project in Borneo, where he trained groups of volunteers to survey coral reefs for fishes and corals. After this he swapped the Indo-Pacific for the Caribbean to work with the Cayman Islands Department of Environment on assessing fish biomass. In 2010 he started working as a Research Assistant on a Leverhulme Trust funded international research network which developed a census based methodology for assessing net rates of calcium carbonate framework nutrient interaction on coral reefs at Exeter University with Prof Chris Perry. Using this method, he is currently investigating the relationships between the net rates of coral reef framework nutrient interaction and the animals and plants that control them.  Gary will be undertaking assessments for the carbonate budget: Project 3



Dr Shaun Wilson (Project 4)

 Senior Research Scientist

Western Australia Department of Environment and Conservation. Australia.



Profile: Shaun is a senior research scientist for tropical marine systems where his chief responsibilities are to conduct or co-ordinate research that contributes to managing Western Australia’s marine resources. Shaun’s previous research examined the impact that habitat disturbance and fishing on reef communities, focusing on the effect of coral bleaching on reef fish. His work has examined the role that structural complexity of reefs plays in maintaining diversity, habitat associations and specialization of fish and the impact of different disturbances on reef communities. Shaun has also worked on food webs, in particular the importance of detritus relative to algae in fish diets and the implications that different feeding modes have for reef recovery. He has worked on the reef communities on the Great Barrier Reef, Caribbean, Seychelles and Fiji and looks forward to exploring and working in Western Australia.




Dr. Gavin Colthart


Expedition Medical Officer and Diving Safety Officer (also supporting projects 5, 6, 7)


Profile: Gavin works as a locum GP based in Brighton, UK. Until August 2012 he also worked as a part-time healthcare research specialist for the UK Parliament. His main clinical interests are musculoskeletal medicine, and expedition and tropical medicine. He has completed courses in remote and wilderness medicine and remote pre-hospital management of medical emergencies, and has worked as medical officer for marine research projects in Belize, Madagascar and Cuba for a total of 7 months over the past 3 years. He has 14 years experience in healthcare management in New Zealand and Europe, including roles as an IT management consultant, senior hospital manager, and medical editor. He has a lifelong interest in marine biology, having originally intended to train in this field, and has dived since a teenager and now holds a PADI Divemaster qualification.  He has dived intensively in the Pacific, Caribbean and Indian Ocean. Before entering medical school Gavin was involved in fine art photography, exhibiting in shows in Wellington and Auckland in the 1980s, and has work included in the National Museum of New Zealand collection. He resumed more active fine art practice in 1998 and in 2002 completed a BA in Fine Art (first class honours) from the University of Brighton. He has since exhibited in the UK and a work was short-listed for the Jerwood Drawing Prize in 2004.  Gavin has worked as a sailing and windsurfing instructor, run a mail-order book business specialising in environmental thought and practice, engaged in various forms of environmental and peace activism, volunteered as a Samaritan at music festivals throughout the UK, coordinated the Brighton Peace and Environment Centre, and is a qualified yoga instructor.



 Claudia Naraina  (Projects 5, 6 and 7)

 Chagossian Research Trainee


 Profile: Claudia Naraina is a healthcare professional from Manchester. She is passionate about conservation, loves scuba diving and other water sports. She has been a ZSL trainee in the Connect Chagos Project since 2012. Claudia has developed a lot of skills in conservation as well as learning how to wield a chainsaw. She relishes the opportunity to expand upon these skills to gain more experience in these different facets within conservation. She hopes to contribute towards the team of highly qualified professionals to explore new dive sites and learn about the Chagos Archipelago coral reef and the fauna and flora it supports. She will draw upon the knowledge gained to educate the Chagossian Community and the public at large.




Jon Slayer

Chagos Conservation Trust, UK 

Logistics and Communications Officer (also supporting projects 5, 6, 7)


Jon’s childhood playground was Sea World in Durban, South Africa, where his father is a marine biologist. His first job was assisting with dolphins, seals and penguins at uShaka Marine World and also participating in field trips to survey the coral reefs of Sodwana Bay. His working career has remained adventurous, as an outdoor activities training instructor in a game reserve in South Africa, white water safety kayaker on grade 5 rapids of the Zambezi River and as a Commissioned Officer in the Royal Marine Commandos. He served for 8 years including operations in Afghanistan, Northern Ireland and Iraq, also spending a year in the British Headquarters on Diego Garcia. There he apprehended poachers and commanded British Operation Patrols around the British Indian Ocean Territory including escorting the science expedition of 2006. Since 2008 he has qualified as a commercial scuba diver in order to focus on filming life beneath the surface. His award nominated films have supported several conservation campaigns and have featured in television documentaries. In Belize he has founded a branch of the marine conservation charity Blue Ventures that monitors and researches the remote Bacalar Chico area of the Belize Barrier Reef. He also works as a Security Team Leader protecting vessels transiting the High Risk Piracy Area in the Northern Indian Ocean