Well it has been a long while since we last posted. September has come and gone and Graham and I have now moved on to New Zealand to start our long journey home. Our last month working on the French Polynesian Manta Ray Project was spent in Tikehau where we had no electricity and no internet connection so we were unable to update our blog at all so there is a lot to cover! This is the first of two posts on our time in Tikehau.
Like Bora Bora and the other islands of French Polynesia, Tikehau is the remnants of an extinct volcano; but where Bora Bora’s volcano peaks still rise 727m out of the ocean as a lush, forest-covered island at the centre of it’s atoll, Tikehau’s has entirely disappeared into the sea leaving only a thin ring of islets (motus) above the water’s surface. These palm tree covered motus, with their idyllic white sandy beaches and vibrant coral reefs, surround a shimmering, turquoise lagoon teeming with fish. Tikehau must be one of the most ludicrously beautiful places we have ever seen. Seriously, this place is nuts!
There is a popular dive site in Tikehau that has for many years been a perfect spot for observing manta rays; a cleaning station in less than 5m of water with reliably great visibility where divers would regularly see numerous mantas at a time. It was at this site that Vincent (a dive instructor and talented underwater photographer we met in Bora Bora) took hundreds of photographs of manta rays in 2011 and 2012 from which we have identified 74 individuals. We were excited to get to Tikehau to collect some new data at this site for comparison and of course to meet some new mantas. However before we left Bora Bora, Tikehau Plongee (the company taking us diving) contacted us to let us know that this year the manta rays have almost completely stopped visiting the cleaning station.
We headed out to Tikehau at the start of September, hopeful that the mantas may have returned or that we may be able to find them at a different site. Within a day of arriving in Tikehau we spotted a few manta rays swimming close past the tiny motu island on which we were staying. Apparently this is a common sight and the inhabitants of our island (of which there were five) regularly spot two or three mantas passing by each morning at roughly the same time. Perhaps, we thought, we may be lucky enough to be able to get in the water regularly with these mantas within meters of our bedroom window! So our landlord, a local fisherman, took us out in his small boat to try and get a closer look but it proved too difficult to keep up with the mantas by snorkelling. The waters were a little rough, the visibility dreadful and the mantas were not hanging about, just passing through on route to another unknown destination. Within the space of a few minutes they had vanished again. Photographing their bellies in these conditions would be impossible.
Tikehau Plongee checked the cleaning station for mantas daily but the rays did not return. Instead they took us diving at a site known as ‘The Pass’ where they have seen mantas a number of times before. For Graham and I it was not to be, the mantas didn’t show up for any of our dives but we did see an abundance of other incredible wildlife.
Huge schools of jacks and barracuda swirled over our heads while cumbersome napoleon wrasse cruised by swivelling their bulbous eyes around in their sockets to stare at us strange, gangly, bubbly-making creatures. Tikehau’s healthy, mature reefs are teeming with fish, nudibranchs, eels, octopus, crustaceans and a whole world of exciting macro life; we could have happily spent hours searching just a few square meters of reef with our cameras there was so much to find. On almost every dive we had the pleasure of hanging out with multiple sea turtles, all far more interested in their dinner than they were in us. Check out this video I took of a particularly determined sea turtle feeding on the reef.
So where have all the manta rays gone and why did they leave the cleaning station? We’ll save that for the next post!
Thanks for reading, Bex
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After 5 months in Bora we’re off to Tikehau which is a coral atoll in the Palliser Islands group, part of the Tuamotu Archipelago. It’s a little over 400km North East of Bora Bora and our flight today will take us about an hour. Exciting times!
When we first arrived in Bora we met a dive instructor that had been photographing the manta ray population in Tikehau for years and he kindly let us has copies of his photos so we could start on a population database for the island. We identified 74 different manta rays from 2011 and 2012 and we’re going back now to see which ones are still coming back and which new ones there are. The lagoon at Tikehau is much larger than in Bora and there is no volcano in the middle so it can be a little tricky to find the mantas, but we’ve got three weeks to do it and hopefully we’ll have some luck! We’ll be sure to post again when we leave to let you know how we get on. We’ve had a fantastic 5 months in Bora Bora, not only because of the wonderful marine life but also because of the wonderful people we have met along the way. Bora Bora is truly an island full of friendly and generous folk! We would like to say a particularly big thank you to Top Dive and their staff for their help with the project; taking us out on their dive boats, introducing us to the manta rays and being great company. We will miss you all! I can’t believe that we’ve been in Bora over 4 months already! Between Bex and me, we have dived almost 5000 minutes (almost 85 hours) at the manta spot and encountered mantas more than 100 times. But now we only have 2 weeks left before we’re off to another French Polynesian island called Tikehau which has a separate population of reef mantas (Manta alfredi) to study. We have some population data from 2011 and 2012 and would like to make a start on a comparison for 2016. Should be exciting!... but more about Tikehau in a future post I’m sure. Today, as we’re nearly at the end of our time in Bora, I wanted to write about some of our ‘regulars’ - mantas that we have encountered pretty frequently since we arrived and have quickly become our favourites. It’s easy to anthropomorphise these things I know, but when it’s just Bex and me in the channel and one of the regulars comes by, we do get the impression they recognise us; they come up so close and circle around us and are totally calm and intrigued. Even if they don’t recognise us personally they are at home around the divers and it makes me feel sure that we are not disrupting their way of life at all whilst conducting this research, which is a hugely important thing to consider. First up, and we’ve only seen her once, but ST-MA-0079 was an incredibly pregnant manta we saw in the middle of May, and her story deserves a mention. She was so huge when we saw here that we sent some photos around to some of our manta ray expert friends. It turned out that she was first seen in 2004 as a baby but with a serious injury, most likely from a boat propeller. Her tail was totally severed and she had some bad wounds on her back. The researchers here at the time thought she might not make it but over the next two years she healed up leaving some nasty scarring and some deformity. However, after 2006 she wasn’t seen again and they feared the worse until we saw her in May. Needless to say we were all very pleasantly surprised that not only was she still alive but also pregnant and healthy. Great news! OK so onto the really-regulars who are: ST-MA-0002 “Ziggy” Ziggy is the oldest manta ray in the French Polynesia database. She was first seen 30th May 2001 at which point she was already a big mature female at about 3.5m across. Female mantas mature at around 15 years of age so that means she is now at least 30 years old but most likely older! We think she might be a little bigger still these days! 30 might seem old, and she is certainly getting on a bit, but she is still getting chased around by the male mantas here and we see her as part of ‘mating trains’ quite often. (See Bex’s post here for more info on these.) If she keeps going strong she could live to be 60 or more. ST-MA-0003 “Blacky” Blacky already had her name when the last manta ray scientists started work here in Bora Bora in 2002; she was given it by the locals because her belly is particularly spotty. She was first recorded in the database though on the 10th August 2002 at about 3m in size. This means she is an old timer too but probably not as old as Ziggy. We have a soft spot for Blacky as we have watched her pregnancy progress and her belly grow since we’ve been here. We haven’t seen her for a couple of weeks but last time we bumped into her she was pretty enormous! ST-MA-0110 “Felix” Felix is probably our favourite. He was first seen on the 8th November 2012 at almost 3m and we have seen him more and more regularly as the season has gone one. He is without doubt the most chilled out manta we’ve met. When he sees us he often comes over, banking around and swimming circles around us to have a look. He has come close enough for my eye to be about 30cm from his and for his fin to hit me on the head as he passed by. He’s awesome. I took the photo below the other week and it has not been cropped at all, that’s how close he was to me! If you look closely you can see the reflection of me and my camera his eye! 0110 didn’t have a name before we arrived but he’s too cool to be known as nothing but a number so we chose the name Felix for him. We will miss him. That’s about it for now, thanks for reading as always.
Graham
For the first couple of months of our stay here in Bora Bora, Graham and I were often kept up by the sound of strange, distance drumming in the night. These mysterious rumblings of percussion couldn’t help but inspire in our sleepy brains, images of the first people to arrive in Bora Bora; brave, seafaring adventurers who had traversed the South Pacific in tiny kayaks discovering new territories from Hawaii to Fiji to New Zealand. This drumming, it turned out, was actually the sound of rehearsals for the Heiva Festival which runs from mid-June to mid-July; an annual celebration of French Polynesia’s indigenous culture.
Here in Bora Bora local districts compete with each other in sporting events and through percussion, choir and dance performances in a large arena in the centre of Vaitape. Surrounding the stage are arcades, shops, restaurants and bars to which both locals and tourists flock each night; the smell of BBQs and delicious local dishes fills the air, children are allowed to stay out late and fill up on ice cream and sweets and the uplifting sound of singing and drums echoes across the tiny island. It’s a bustling, vibrant, festive time to visit. The arena and surrounding vendors were erected at the start of June with incredible speed especially for the event and disappeared a few weeks later just as fast. Notably missing from the lineup this year was the usual nightclub as it went up in flames not long after construction and burnt to the ground; Apparently a reasonably common set-back as the whole temporary construction is made of wood, straw and leaves and the stands are filled with BBQs, deep fat fryers and plenty of people smoking cigarettes. Luckily nobody was hurt but sadly for the people of Bora Bora, Graham will have to save his dance moves for another festival.
The arena was only a few minutes walk from our flat so we’ve been able to pop along and take in a few shows, all of which have been fantastic. The large-scale group dance performances in particular are spectacular and accompanied by percussion in such a way as to make the whole experience very hypnotic. The passion and dedication of local people to keep alive these elements of their culture is evident in the unbelievably high standard of their performances; It is stressed to the audience at the start of each show that these are all people with normal day jobs who spend hours every night in intensive rehearsals during the months leading up to the festival.
We were of course thrilled on one evening to spot two giant manta ray sculptures framing the stage as part of the decoration for one of the local district performances! Check out my video below but bear in mind that the poor sound quality does not do the choir justice.
Today the people of Polynesia are incredibly proud of their native manta rays but Polynesian mythology shows that they have not always felt this way; Just as old Western literature portrayed whales as terrifying, savage leviathans of the deep rather than the intelligent, social, sentient beings that we now realise they are, Polynesian mythology demonised the strange and mysterious manta ray. Some legends told of mantas using their huge, cloak-like bodies to smother pearl fishermen and prevent them from getting back to the surface to breath, others of mantas kidnapping children and carrying them out to sea. With their horn-like cephalic fins (the fins on either side of their head which they use to funnel water into their mouth), mantas are often referred to as devilrays in many parts of the world.
Modern day Polynesians know mantas to be beautiful, gentle giants with no track record for stealing children or smothering fishermen. In fact rather than posing any threat, mantas help to attract tourists from all over the world to French Polynesia and its many resorts and so each ray is estimated to be worth over $1million to the French Polynesian economy in it’s lifetime. Protecting manta rays in Bora Bora is not only great conservation, it also makes a lot of financial sense for local people and businesses.
Thanks for reading, Bex
The last couple of weeks we have been trying to expand our manta horizons and spread the word about our project. Our aim was to find a couple of new ways to talk about the importance of conserving mantas and marine ecosystems and we already had some target audiences in mind. Before we came out here we hoped to be able to do two things: create a way to engage those holidaying in Bora Bora with manta conservation and also get some school groups involved in the project. If we could achieve both then we would have raised awareness of the important issues involved in conserving these amazing animals and their habitats with international visitors to French Polynesia as well as with the next generation of conservationists back home.
Part 1 was an easy win actually. We’re constantly taking photos of manta bellies when we’re diving and adding the sightings to our ever growing database. But it’s only us doing it and not many people know what we’re up to. So we’ve made some ‘Manta Watch’ boards and put them up in both the dive shops we work with here in Bora Bora. We update them with our sightings and with info on the mantas we see, such as: when they were first seen, their number (or name if they have one), approximate age and any other notes like scars, injuries, pregnancy etc. We’ve also added a bit about the project and a note to say that if anyone has any manta belly photos they can email them to us and we’ll add them to the database. They’ve gone down really well so far and we’re hoping to get some more photos to process from fellow divers soon.
Next up was to try and get some school kids involved. We were approached by two friends back in the UK who are primary school teachers, one in Bournemouth and one in Southampton. Their Key Stage 2 classes were studying the ocean and they wanted a new way to tell them about it and asked if we could help. This was just what we had been looking for! So we got some of our manta footage together and even made some stop motion animations about overfishing and coral reef damage and created a little video for them on marine conservation. It was a bit of a slog in the end; video editing on an unhappy laptop and uploading on medieval internet but we got there in the end. You can watch the video below.
Bex will be posting again soon on the topic of mantas in Polynesian culture so stop by to have a read of that! All for now though, thanks for reading.
Graham
We’ve had another fortnight of entirely unpredictable, tropical weather; we are never sure whether to the leave the house with shades and factor 30 or our Pac-a-Macs? As the weather changes dramatically, multiple times a day, we generally opt for swimwear which functions well in both scenarios. If like me, you like Pina Coladas and getting caught in the rain, then Bora Bora really is the perfect place for you!
So yesterday’s dive at Anau started out in the same way as most of our dives have this last couple of weeks; descending down the reef and into milky, murky waters with low expectations of seeing very much. At nearly 20m we found the visibility so dreadful we could not see more than a 1m in front of us so we popped back up to 15m where it was a little better and set off on our normal route along the reef. However, after less than 10 minutes of ambling along, a beautiful big female manta swooped past us with three amorous young males in tow. Here is a little atmospheric* footage that I took. *In the context of this post the word ‘atmospheric’ can be interchanged with the word ‘blurry’.
During the mating season females are thought to release sexual pheromone scents into the water to let suitors know they are ready for courting. Males know that the best places to find females are at cleaning stations (like Anau) and feeding sites. Once a male finds a female he tests her receptiveness by following her and stroking her head with his unfurled cephalic fins (the ones on either side of the mouth). If she is uninterested the female will simply bat the male away with her huge pectoral fin, however if she is amenable to his intentions then she will lead him and any other eager males in the area on an elegant dance around the reef which is known as a mating train. Mating trains can get very long with tens of excited males in pursuit all jostling for first place and hopefully the chance to make some baby mantas. The train we saw yesterday was only small but still a wonderful thing to witness; manta rays are as unconsciously elegant as I am ungainly in the water and with the prospect of love making on their minds the mantas barely seemed to notice us gawping at them from below so we really felt like we were getting a sneaky peak behind the scenes.
As if that wasn’t enough we encountered many more mantas the further we went. It felt like each time we turned around another new manta ray materialised from the gloom, however we expect that once we have properly reviewed all of our ‘atmospheric’ footage we will find that we actually saw a handful of rays multiple times; perhaps 7 or 8 including the mating train? So why were there suddenly so many rays on the site yesterday compared to previous days? Well Graham has previously written about Anau being a site that mantas visit in order to get cleaned however yesterday we also spotted several of the manta rays feeding; swooping and rolling with their mouths wide open and gills splayed out; something that until yesterday we hadn’t seen at Anau. So there was obviously a lot of plankton in the water yesterday which would have attracted hungry manta rays.
We have our fingers and fins crossed for some more sunny days and manta mating trains, but yesterday’s footage will give us plenty of IDing to do when the rain does return. Thanks for reading! Bex Le Méridien is one of many resort hotels on the motus (little islands) on the archipelago of Bora Bora. However, we heard this one had set up something called an Eco Centre and that they were positively contributing to protecting and helping sea life in Bora Bora. Obviously we wanted to go check it out and see the kind of work they were doing and hopefully speak to some like-minded conservationists. I’m very pleased to report that they're doing some great marine conservation work over there! We contacted the biologist over there named Melanie and she very kindly invited us over for a visit and a tour. They have a lovely facility based in the grounds of the resort that is doing quite a few different things and Melanie hopes to expand even further soon to do more research on a wide range of cool topics. The focus of their work at the moment is sea turtle rescue and rehabilitation. They are regularly contacted by local people who see injured or ill turtles and the Eco Centre collects them and tries to fix them up, give them some TLC and then when they’re ready release them back into the ocean. Common issues they encounter in the turtles they rescue are infections from wounds, injuries from boat propellers and just simple disorientation and weakness. They work closely with a vet to give them a full health check (and things like antibiotics if needed), feed them up to get them strong again and if possible release them back into the wild. Generally, when they arrive they are not very strong swimmers due to their injuries or illnesses and so they’re kept in a special holding facility where they can be monitored closely and fed properly. However, when they’re ready they are taken to a shallow lagoon for some daily exercise to help them get their strength back and get them ready for release. The Eco Centre also has a classroom with which it runs educational sessions for French Polynesian school groups and resort guests on turtle conservation. At the back of the classroom is a mini museum with some marine artifacts and a display of conservation and sea themed artwork by local artists and kids that have visited. They also have a few little aquariums set up to show not only school groups but also all visitors to the Eco Centre and Le Méridien the amazing marine life that Bora Bora has to offer. This is the area Melanie hopes to expand into next; to do some research into coral bleaching and the problems effecting reefs not just here but across the world. Everything here is set up to add educational value to their guests visit which is great; whether that’s through talks on threats to sea turtles or info up about Bora Bora fish life. All in all, a very positive and inspiring little trip! It was great to see the work they’re doing now and hear about work they want to start. Hopefully we’ll hear from them soon to find out how they get on with their research. Huge thanks to Melanie and her team for showing us around.
I want to start this post by showing you a little clip of another totally awesome manta ray we met this week! On her approach we snapped away with our cameras her trying to capture that all important spotty belly as she passed on by then after she had disappeared into the blue we continued on our merry way. A few minutes later we were lucky enough to encounter another friendly manta who eagerly swam on over to meet us and again we snapped away taking photos. A little further on, what luck! Another very friendly manta ray came gliding out of the gloom, rather intently it seemed, towards us. At this point, upon viewing her belly, we cottoned on to what was happening. We were seeing the same manta ray over again because she was looping around to pass us. This inquisitive ray returned to see us multiple times throughout our dive, at one point whilst we were swimming along we turned around to catch her chasing us from behind like a giant, friendly shadow! She definitely seemed as interested in us as we were in her and I really didn’t want to leave the water at the end of our dive and say goodbye. We’ve decided to name her Boomerang and I really hope we meet her again.
Another much smaller acquaintance we have made recently is a beautiful little Hawksbill sea turtle who has been hanging around the manta site for over a week now, absolutely gorging himself on coral. He is so chilled out and so intent on munching away that he seems to barely notice us hovering in the background and taking pictures. We've named him Prince because he is a miniature maverick!
Encounters with characters like Boomerang and Prince make the thought of losing these incredible creatures even more distressing but it is a real possibility if we don’t take action against the threats that they face. A few weeks ago I wrote about overfishing for the gill plate trade for Traditional Chinese Medicine, this week I want to tell you a little about bycatch.
What is bycatch? Well that’s the name given to animals caught unintentionally by a fishery. Each year a tenth of the world’s global catch is thrown back into the ocean, dead because it has been caught accidentally. That equates to many millions of tons of discarded animals including sea turtles, sharks, sea birds, manta and mobula rays. It also includes many perfectly edible fish that are simply not in demand; aside from the environmental impact this kind of food waste is pretty disgraceful. The problem is that many of the methods used to catch fish are totally indiscriminative, catching anything and everything. Bottom trawlers, for example, can have nets large enough to hold 13 jumbo jets which are dragged across the seabed catching everything in their path and smashing up vital marine habitats as they go. Longlines are laid out by boats, they have baited hooks at intervals to catch big predators such as tuna and swordfish, but there is nothing to stop any other hungry animals from taking a bite too. Each line can be 60miles long and contain thousands of hooks. Tuna is one of the most sought after fish species in the world and sadly many of the fishing methods used to catch it have huge bycatch levels including manta rays and sea turtles.
The good news is that we can all help to stop this by simply eating the right things. So how do you know what’s sustainable seafood and what’s not? Of course going for a vegetarian option is always a fail-safe, commendable way to ensure that you are not eating anything caught using destructive fishing methods. However, if you sometimes fancy some seafood and you want to support fisheries seeking more environmentally friendly techniques then...
Thanks for reading! Bex Two days of non-stop rain means no diving and no new manta sightings but it also means that we have time for a much needed blog post. Today I’m going to talk about the thrilling topic of databases! Also known as “what we spend our evenings doing”. Bear with me here... Every single manta ray has a unique spot pattern on their ventral surface (scientific word for belly). It means that if you can get a photo of it then you can ID that specific manta again and again whenever and wherever it shows up. They work just like our fingerprints. The best way of cataloguing the population of manta rays in an area is to photograph the belly of each one you see and then use the Manta Trust’s database to work out if it has been sighted before, how many times, where-abouts etc. And that is exactly what we have been trying to do in Bora Bora. The database of Bora Bora mantas goes back to 2002 when some of the original research was done on the population here so we have been comparing our belly photos to these. Some of the mantas we have encountered are new to the Manta Trust so we have given them new numbers like our most recent individual ST-MA-0137 (catchy right!) The photo above is straight from the database gallery and shows you that ST-MA-0137 is a female with a long tail. Here we would also be able to log if she has any damage to her fins, tail or body which thankfully she doesn't! Spreadsheets within the database then tell us info like when they were first seen and where, if they've ever been sighted pregnant, their size, life stage and all sorts of other info. It's all very useful and we're excited to be able to contribute to something like this. Some of the mantas we're seeing though have been encountered before. This week we have had two dives with a manta called ST-MA-0003. For those of you that haven’t guessed how the numbering system works this means that this particular ray was the third manta added to the database for Bora Bora. She was first seen way back in 2002, already as an adult and since female mantas reach maturity at around 15 years old then it stands to reason that she is around 30 now! She’s known as Blacky, she travels regularly between Bora Bora and Maupiti (another nearby manta spot) and is well known to manta scientists here. On to Tikehau which is an island (or a motu as they're known in Tahitian) near to Bora Bora and part of an island group called the Tuamotus. We recently met a man called Vincent who has been working with and photographing the mantas in Tikehau for years and had hundreds of belly shots dating back to 2011. He offered us the photos to catalogue and add to a new Tuamotus database and we eagerly accepted. After a few long evenings of staring at photos of manta stomachs we have 71 new individuals logged already! Vincent has some stunning manta photos from Tikehau which we hope to share with you soon as well as persuading him to write a little guest too.
Thanks for reading, Graham
Today marks exactly a month in Bora Bora for Graham and I and I’m pleased to say that the manta rays got the message and decided to join us for a one-month celebration! After a week of barely being able to see the end of our own noses underwater, we haven’t exactly had a great manta to dive-time ratio. That’s not to say that the mantas weren’t there, we’ve certainly seen a few dark shadows in the gloom (Cue internal dialogue: ‘Arrhh! What-the? Please be a manta, please be a manta. What else could it be...? don’t think about that! Please be a manta.’), but we stood no chance of photographing and identifying them. Today however, following a storm free Saturday afternoon and minimal rain in the night, the visibility was far better at over 10m. Clear enough for us to spot manta rays but still misty enough for them to make a dramatic entrance; like cloaked magicians appearing from a cloud of smoke.
Here is a little clip of a manta ray gliding over our heads and nearly blocking out the sun. Please excuse the shaky images, the camerawoman was a little overexcited.
As each couch-sized ray casually swooped past we did our best to capture as much data as possible: size, gender, visible injuries, tail length, species, spot patterns… thank goodness for underwater cameras. There was one ray on this dive, however, which stood out from the others for an exciting reason. A big, beautiful and incredibly pregnant female! This heavy, hampered lady was swimming around in the shallow corals and looked absolutely fit to burst; reminding me of some of our friends when they hit the ‘I just want to get this thing out of me’ phase of their pregnancy. We have our fins and fingers crossed that we might spot her new-born on another dive very soon.
Manta rays have a long gestation period of 12-13 months and only produce one baby at a time. They are ovoviviparous reproducers which means that an egg develops and hatches within the womb and the female later gives birth to a fully formed, mini-manta. It is believed that female mantas only reproduce once in every 5-6 years so they are not at all fast at replenishing their numbers. Not enough is known yet about manta reproduction but what is clear is that with few natural predators, mantas haven’t evolved to cope with the pressure of heavy predation making them very vulnerable to overfishing.
Tonight perhaps a new baby manta will be born somewhere nearby? A comforting thought before bed. Thanks for reading, Bex |
AuthorMarine conservation fanatics from the city of London on a manta ray research adventure in French Polynesia Archives |