Dive site topography in Lhaviyani Atoll – Part 1

The underwater topography of the Maldives is dramatic, varied and perfect for exploring. Scuba divers visiting the Lhaviyani Atoll in particular have a huge variety of reef formations awaiting them on the dive sites – the first glimpses of which can even be spotted from the seaplane window. In this, the first of a three part series, the underwater islands of giris and thilas are explored.

What is a giri?

Giris are shallow underwater islands with a top reefs lying at around 5 meters and appearing as blueish-green spots when viewed from the seaplane window. Typically found inside the atoll, they are perfect for beginner divers and macro lovers.

One of Hurawalhi’s favourite giris is Maa Giri. It means Flower Island and it is usually described as ‘fish soup’. On the front of the giri are thousands of lunar fusiliers catching food in the gentle currents that flow around the dive site. Once the divers descend a little deeper they can explore small overhangs and crevices where nurse sharks are sleeping or moray eels are getting cleaned. All around the giri are schools of yellow snappers, humpback snappers, and sweetlips. Occasionally, at the right time of the year, there is a glittering swarm of glass fish that divers can swim into the middle of – this is an enchanting experience that will be remembered for a very long time. Along the walls there are macro creatures like the mantis shrimp, whip coral shrimp and nudibranchs.

Picture by Ray van Eeden

On Tinga Giri, close to Hurawalhi, there is currently a large red frogfish that can often be seen fishing with the lure, which comes out from the top of its head.

What is a thila?

A thila is a deeper underwater island usually starting around 12-14 meters. Two of the Hurawalhi team’s favourite and most fascinating thilas are Anemone Thila and Fushivaru Thila.

Picture by Ray van Eeden

Anemone Thila gets its name from the incredible amount of anemones that have made themselves at home there. It is a very small thila and can be dived all they way round its circumference 2-3 times in one dive. This site is great for underwater photography and experimenting with macro photography. The most spectacular part of the dive is towards the end when divers arrive at the shallowest part of the thila and see the clownfish swimming above all the anemones along with bright blue and pink damselfish. For a good part of the year this site is also completely covered in ‘baitfish’ – so many that visibility can be reduced to 1-2 m with the fish parting to make way for the passing divers.

Picture by Ray van Eeden

Fushivaru Thila is a manta cleaning station and from November to January divers can witness the spectacular sight of the majestic mantas as they cruise in and hover over the station as small cleaner wrasse come and cleanse them of parasites. When the mantas are elsewhere, Fushivaru Thila is just as beautiful with huge schools of snappers and hunting grey reef sharks, nurse sharks sleeping under coral blocks, and large stingrays on the sand.

Picture by Ray van Eeden

There are many underwater island dive sites in Lhaviyani Atoll waiting to be explored. In Part 2 of the Dive Site Topography series all will be revealed about the differences between East and West sides of the Atoll.

 

PADI’s guest blogger Paige Bennett introduces herself:

I am an American Scuba diving instructor who has been living in the Maldives for the past 2 ½ years. I have been travelling and working for the past 6 years and have been to Koh Tao Thailand, Playa del Carmen Mexico, Marsa Alam Egypt and have now settled in the Lhaviyani Atoll working with Prodivers Diving center. I love the abundance of textures and patterns in the ocean and am very interested in underwater macro photography. I also have been involved with several conservation/restoration projects such as ReefCI in Belize, Eco Koh Tao in Thailand, and the coral transplantation project for the 5.8 undersea Restaurant on Hurawalhi Island Resort.

 

Paddle against Plastic

On Global Recycling Day, Sunday 18th March 2018, a team of our best watermen and women from Gili Lankanfushi completed a 14km Stand Up Paddle to raise awareness about the overuse of single-use plastic. During the endurance event, the team collected all floating litter they encountered along the three-hour paddle. The majority of the haul was plastic, so our message is clear: If we can SUP 14km around our island; you can give up using single-use plastic in 2018.

At Gili Lankanfushi, we encounter a large amount of ocean plastic arriving with the tide every day. Some arrives with the current from distant countries, but a lot appears from neighboring islands and the capital Male. Despite Gili’s No Plastic Policy and the plastic recycling program we have in place with Parley, we still face a tidal wave of plastic over the year. Our team wanted to tackle this problem head on.

The event began at day break as we hit the water at 7:15am stocked up with high energy food, water and cameras. The conditions were extremely favourable with low wind, little swell and high cloud cover. The first quarter of our paddle took us against the current, so it was slow going but this allowed us to collect as much floating plastic as possible. We found the majority of marine litter in the corners of Himmafushi Harbour so we set about collecting as much as we could carry. Those working at the harbor watched us approach and a few men jumped into action and helped us collect plastic from the water. They gave us a few extra bags when we ran low. These positive reactions made our hard work feel extremely valuable.

As we turned the corner behind Himmafushi Island, we had the wind and current with us, so we completed almost six kilometres in just over an hour. Being out on the open ocean and looking down to see the fish and coral beneath our feet was a real highlight. The final paddle back to Gili was the hardest, but we were met with the smiling faces of the rest of our team.


The entire experience was a great example of perseverance and team work. It was a great success and we were able to recycle a lot of litter, yet the overwhelming feeling was that we need to do even more next time. In just three hours we collected 200 items which included 90 plastic bottles, 20 bottle tops and 5 plastic bags and this was just the plastic we happened to paddle close to; a lot has been waterlogged or broken down and is found just below the surface or on the ocean floor.
The seven-man paddling crew was made up of Beau, Tropicsurf Manager and SUP surf champion; Naseef, Ocean Paradise Dive Instructor and marine mammal magnet; Emma, Assistant Marine Biologist and official team photographer; Tula, Head of Security and pretty much the toughest guy I know; Ibrahim, Ocean Paradise Boat Captain and life saver; Clare, Marine Biologist and event organiser and Jinah, Hotelier journalist and newly inspired sustainability supporter.

Despite the obvious challenges of reducing ocean plastic, we have seen such positive reactions to our war on plastic at Gili Lankanfushi. After visiting in November 2017, the inspirational Merle Campbell kindly shared:

“For many years now, I have daily walked the beach and never picked up any litter. Since visiting Gili Lankanfushi Maldives and listening about the importance of keeping plastics out of the waterways, I now walk the beach solely for the purpose of collecting rubbish to contribute to saving our sea life.”
We hope our Paddle against Plastic will inspire others to reduce their plastic dependence by taking small steps to reduce plastic use at home or at work. If we all participate, there will be a huge reduction in the amount of plastic that enters our oceans. Well done to Gili’s Paddle Against Plastic Team and Happy Global Recycling Day to Everyone.


A special thank you to everyone who assisted us in the Paddle Against Plastic! Thanks to Ocean Paradise for the boat, equipment and crew, the culinary department for the amazing food, the Sales and Marketing department for sharing our work and getting up early to see us off, the gardening team for recycling our plastic, Shifzan for the awesome photos, and the Gili Lankanfushi Management team for their amazing support!

 

PADI’s guest blogger Clare Baranowski introduces herself:

I am a marine zoologist from the UK who has worked throughout the tropics researching mega fauna and reef ecosystems in the Caribbean and Indian Ocean. I have experience monitoring and restoring coral and surveying manta, turtle and dolphin populations. I began my career as a science communicator before moving into research and management roles, this is why I incorporate outreach and education into every project I work on and I hope to continue this at Gili Lankanfushi

Quality Management Tips from the Field

Quality Management Tips from the Field

Throughout 2018, we’d like to share tips from PADI staff in the field on how to maintain and improve safety in your professional diving activities. This month we heard from PADI Territory Director, Rich Somerset:

“We are blessed with a career that puts us in contact with the ocean – and the ocean demands our respect. Treat her with respect and she will give you a lifetime of adventures, but underestimate her at your peril. Remember: be prudent in your decision making, put your students’ safety above your ego and – if in doubt – stay out.”

The ocean is a truly awe-inspiring environment, and as divers we experience its benefits every time we enter the water. But as Rich says – the ocean also demands our respect.

All dive professionals should know their limits and will endeavour to stay well within them. This means having an even-handed grasp on the abilities of your students too. Use your judgement when assessing factors such as water conditions, ability of participants, your and your assistant’s personal limitations, and ratios etc.

Ask yourself questions such as:

  • “Am I familiar with this dive site?”
  • “Can I expect bad visibility or perhaps strong currents?”
  • “Can I provide adequate assistance to all divers in the group?”

With all things considered, you as the dive professional have the ultimate responsibility for making the final decision as to whether to dive. If something goes wrong, the question likely to be asked is– “Should the divers have been in the water at that time, in that environment, in those conditions, with their experience?” In these instances, you, as the professional, may well be asked to defend your decision to dive.

Rich couldn’t be more right when he says “be prudent in your decision making, put your students’ safety above your ego and – if in doubt – stay out.”

Earth Hour

Earth Hour is an annual worldwide movement to encourage individuals, communities, and businesses to conserve our resources. Celebrating it is a symbol of our commitment to our planet.

At Gili we celebrated Earth Hour on March 24th with the rest of the world, we hosted a Coral Conservation themed day with multiple events leading into each other. For each event, all guests and hosts were invited to attend and take part.

Our first event was a coral workshop hosted for Marine Biologists and enthusiasts. In attendance were three participants from our local island Himmafushi who have a keen interest in protecting their reef and inspiring locals. Additionally, Marine Biologists from Four Seasons Resort, Bandos Resort, Atoll Marine Centre and Hurawalhi Resort attended. Jinah, a journalist from Hotelier Maldives covered our event celebrations.

Our coral lines project launched in 2014 and currently has 190+ lines, each containing around 50 coral fragments. The aim of the project is to rehabilitate our degraded house reef through direct transplantation of mature corals and through indirect coral spawning from the nursery. The project was the first low-tech and high efficiency coral recovery project that involves rope in the Maldives.
Due to the optimal location and care that goes into the project we had 68% survival after the El Nino event and the crown of thorn starfish outbreak. Due to the success of our project, many Marine Biologists are interested in learning more as they want to launch their own projects or further their current projects in other locations. This is why we invited them to join us in celebration of Earth Hour.

 

We felt that hosting a coral conservation themed day would create a platform for a discussion on possible project improvements and new project ideas. Overtime the coral line nursery will contain heat tolerant coral species, fragmenting these species and planting lines could lead to natural spawning of more heat tolerant species which will increase survival rate in future warming events. This will lead to the creation of more healthy reefs decreasing the pressure of predation, providing a healthier habitat, refuge and nurseries for marine organisms like turtles, juvenile fish and other fish species as well as conserving a key ecological ecosystem.
On the day the visiting Marine Biologists arrived at 14:00pm and a land based presentation was carried out, topics included an in depth overview of the project, project creation, management, challenges and future plans. This was followed by a practical demonstration of making a coral line, monitoring the lines and general maintenance including cleaning and removal of invasive species. To view the coral line made by the Marine Biologists click here. To conclude there was a group discussion on possible project improvements and a question and answer session.

 

Following the success of the coral workshop together with guests, Marine Biologists and hosts we designed and created a coral shape in the sand on Library Beach. In celebration of the official Earth Hour which is between 20:30 – 21:30 we turned off none essential lights and filled the coral shape with sustainably sourced candles – coconuts and used cooking oil. During the official event our coral shape was beautifully illuminated by flickering candle lights and guests, Marine Biologists and hosts were able to enjoy this display whilst attending our Earth Hour cocktail evening.

 

To conclude our Earth Hour celebrations we hosted the documentary Chasing Coral in our Jungle cinema and Host Village. Chasing coral is a fantastic documentary about a group of divers, photographers and scientists who set out on an ocean adventure to discover why the reefs are disappearing and to reveal the underwater mystery to the world. They found that coral reefs around the world are vanishing at an unprecedented rate and documented their discoveries and explained them in a way that is accessible to everyone.
Overall the event was a huge success with all participants learning something new and being inspired to help conserve our resources. We hope that you will join us in celebrating Earth Hour next year!

PADI’s guest blogger Emma Bell introduces herself:

I am a marine biologist and scuba diver from England. I have had the privilege of working in Greece, Seychelles and Maldives. I have worked in an aquaculture research centre where I focused on hormonal manipulation of a pelagic fish species. In addition, I have experience with coral restoration projects including frames and ropes; habitat restoration – crown of thorns, drupella and invasive plant species removal; educational activities and social media updates including blogs. I have also monitored population dynamics of bird, turtle, shark and cetacean species to aid in their conservation. I started my career working in the Maldives and I have done a round trip via Greece, England and Seychelles, I hope to increase my skills set and knowledge further whilst I am at Gili Lankanfushi, Maldives.

Green Sea Turtles hatchlings on Kuredu

Guests at Kuredu Resort recently had a very cute surprise in the sand: a green sea turtle nest hatched! Late in the evening, while walking back to their villa, the guests spotted the tiny turtles making their way quickly across the beach into the ocean. A few hatchlings wandered astray and were collected by resort staff, soon to be released under the supervision of resident Sea Turtle Biologist, Stephanie, along with volunteers from the Prodivers Team.

According to previous reports, it takes green turtle nests 49 to 62 days to hatch here in the Maldives, but the baby turtles on Kuredu were a little slower – it took them 64 days to make their way out of the nest.

To evaluate the hatching success of the nest, Stephanie and a volunteer digging team from Prodivers went to exhume the nest 48 hours after the hatching event. After quite some digging, they successfully discovered the nest and out of 105 eggs laid, only three had failed to develop – that’s 102 more baby green turtles in the ocean! Such a successful nest is great news for the sea turtle population and we hope to see some of the hatchlings back on Kuredu to nest in about 10 to 15 years’ time.

Snorkelling or scuba diving at Kuredu Island Resort Maldives gives a very good chance of seeing turtles – the island is blessed with a large community of green sea turtles that can be seen at Caves, either on a Prodivers snorkelling excursion or dive trip. Turtles can also be spotted grazing in the lagoon.

Want to learn more about turtles? Visit Stephanie at Kuredu’s Marine Center and join her snorkelling on the reef for a turtle tour while she collects valuable data for the Olive Ridley Project.

Common crabs encountered in the Maldives: Part 2

Crabs are an underappreciated species. Whilst living in a harsh and arid environment they dedicate their lives to keeping the beach pristine.

Swift-Footed rock crab Laura Pola

Swift-Footed Rock Crab

The swift-footed rock crab can easily go unnoticed due to its elusive behaviour. It inhabits rocky shores at mid to high tide level and so can be found around beach rocks, boat ramps, rock walls and jetties. These crabs are fast moving and are generally only seen at night, unless disturbed. Then you may observe them jumping from rock to rock trying to find a new refuge.

Their colouration can be mesmerising with a multitude of blue, green, purple, orange, white and black. The crabs encountered on Gili are more blue, green and purple with white stripes. The shell (carapace) can be up to eight centimeters wide and is flattened, compared to other crabs which have shells that are more rounded.

Swift-Footed Rock Crab. Picture by Laura Pola

The crab feeds on algae, detritus, small vertebrates, barnacles, limpets and snails. They use their claws to break into the shells of other animals and to tear off pieces of their prey to be transferred into their mouth. This species is predated upon by a variety of animals including birds, octopus and fish, so it isn’t safe for them in the ocean or out of it!

Fiddler Crab. Picture by Carly Brooke

Fiddler crabs

Fiddler crabs are a small and short lived species of crab (up to two years) and are closely related to ghost crabs. They are found in mangroves, brackish water, mud flats, lagoons and swamps. The colouration of the crabs change in correlation with circadian rhythm – during the day they are dark and at night they are light.

Fiddler crabs are well known for their sexual dimorphism – the male’s major claw is much larger than the females. If the large claw has been lost the male will develop a new large claw on the opposite side, which will appear after molting. The female’s claws are the same size. The crabs use their claws in communication, courtship and combat. The male claw is used in waving displays which signals to the female that they are ready to mate. A more vigorous waving display indicates a healthier male and a larger claw indicates a wider burrow which will provide better temperatures for egg incubation. Females chose their partners based on claw size and the quality of waving. Once a female has been attracted she will reside in the male’s burrow whilst the eggs are being laid. The female will carry her eggs on the underside of her body for a two week gestation period. After this period the female will venture out of the burrow and release the larvae into a receding tide.

During feeding the crabs move their smaller claw from the ground to their mouth. This movement looks like the crab is playing the smaller claw like a fiddle – hence the name, fiddler crab. The smaller claw is used to pick up the sediment which is then sifted through in the crab’s mouth. Algae, microbes and fungus are the preferred diet of the crab. After the nutrients are extracted the sediment is placed back onto the ground in a ball. The feeding habits may play a vital role in preserving the ecosystem as they aerate the soil. The fiddler crab can be seen when visiting local islands, especially in the mangrove area at low tide

PADI’s guest blogger Emma Bell introduces herself:

I am a marine biologist and scuba diver from England. I have had the privilege of working in Greece, Seychelles and Maldives. I have worked in an aquaculture research centre where I focused on hormonal manipulation of a pelagic fish species. In addition, I have experience with coral restoration projects including frames and ropes; habitat restoration – crown of thorns, drupella and invasive plant species removal; educational activities and social media updates including blogs. I have also monitored population dynamics of bird, turtle, shark and cetacean species to aid in their conservation. I started my career working in the Maldives and I have done a round trip via Greece, England and Seychelles, I hope to increase my skills set and knowledge further whilst I am at Gili Lankanfushi, Maldives.

Common crabs encountered in the Maldives: Part 1

Crabs are an underappreciated species. Whilst living in a harsh and arid environment they dedicate their lives to keeping the beach pristine.

The Maldives is rich in life and biodiversity, but the majority of this diversity is marine based. Due to the great distance of the Maldives from large land masses there are relatively few land based species. Crabs, are one of the most common. These shy little critters are abundant, entertaining to observe and vital to the island’s survival.

Hermit Crab. Picture by Laura Pola
Hermit Crab. Picture by Laura Pola

Land Hermit Crabs

Land hermit crabs are completely adapted to life on land, living under leaf litter or in other sheltered areas. A common error made by people is completely submerging these crabs in water, mistaking them for marine animals. Unfortunately hermit crabs can only survive for a few minutes when completely submerged. They are not true crabs because they do not have their own shell. Instead they use shells from dead gastropods in order to protect their soft abdomens. They are a long lived species – sometimes reaching the age of 40 years and older – so they go through a lot of shells!

Hermit crabs start their lives moving through a variety of larval stages whilst floating in the ocean. The larvae spend the first 40 – 60 days of their life alongside plankton until they change into a hermit crab/lobster shape. In this final larval stage they find a small shell and over the period of a month will spend more time on land until they finally molt and leave the ocean for good. By feeding on vegetation, insects, detritus, other smaller hermit crabs and microbes in the sand the crab grows in size. To accommodate this growth their hard exoskeleton must be shed periodically during the year and this process will carry on through-out the hermit crab’s life. As they grow in size the hermit crab molts less frequently and the molt process takes longer, during which time the crab will stay completely submerged in the sand.

When sexually mature the male will knock on the female’s shell to signal mating. Both genders will then extend out of their shells and the male will fertilise the female. After fertilisation the female will carry her eggs around on her abdomen where they are protected from predation. The bigger the female the larger the quantity of eggs. After one month the eggs are fully developed and the colour of the egg will have changed from brick red to grey. To hatch the eggs the female will enter the water at low tide. Upon contact with water the eggs burst open and the larvae are released.

Ghost Crab. Picture by Hans Hillewaert
Ghost Crab. Picture by Hans Hillewaert

Ghost Crab

Another common crab species is the ghost crab which is aptly named due to its nocturnal activity and sandy colouration, making the crab perfectly camouflaged into the beach backdrop. These crabs are found on sandy beaches and live in burrows. The narrower and shorter the burrow the smaller the crab. Their burrows serve a number of purposes: protection from predation, storage of their food, protection from drying out and other extreme weather conditions as well as a place to mate (although not all ghost crabs mate in burrows).

Young crabs and female crabs create burrows with sand scattered everywhere, with young crabs preferring to create burrows nearer to the water, whilst male crabs have burrows with a neat mound of sand outside – the larger the crab the larger the mound. Males produce mating sounds, squeaking noises, in a variety of ways; by rubbing their right claw on their leg, by rubbing their legs together, or by using their gill chambers, which they keep moist with saltwater.

After mating the females store thousands of eggs inside an abdominal flap. She will then venture into the sea when the eggs are ready to hatch. Since ghost crabs cannot swim the female will float upside down in the water allowing the eggs in her abdomen to breathe. Upon contact with saltwater the larvae are released and after two months return to land.

Swift-Footed Rock Crab. Picture by Laura Pola

The exoskeleton of a ghost crab is water tight, which prevents the crab from drying out in the arid and salty conditions on the beach. All ghost crabs have eye stalks with the males additionally having horns. These eyestalks enable the crab to see in any direction and can be stored in groves on their shells. The ghost crab’s eye sight is so good that they are able to catch insects’ mid-flight. They also have a well-developed sense of smell. They are very agile, capable of moving at 10mph, which makes them the fastest of all crustaceans.

Due to the erratic nature of their food supply ghost crabs are very protective of their food and will use their claws in combat displays. Male ghost crabs have one claw that is slightly larger than the other and combat is normally non-contact and ritualistic. Ghost crabs spend the majority of their day looking for food and particularly like to eat fish, seaweed, microbes in the sand, jellyfish, other crabs, snails, turtle hatchings and really anything they can get their claws on.

PADI’s guest blogger Emma Bell introduces herself:

I am a marine biologist and scuba diver from England. I have had the privilege of working in Greece, Seychelles and Maldives. I have worked in an aquaculture research centre where I focused on hormonal manipulation of a pelagic fish species. In addition, I have experience with coral restoration projects including frames and ropes; habitat restoration – crown of thorns, drupella and invasive plant species removal; educational activities and social media updates including blogs. I have also monitored population dynamics of bird, turtle, shark and cetacean species to aid in their conservation. I started my career working in the Maldives and I have done a round trip via Greece, England and Seychelles, I hope to increase my skills set and knowledge further whilst I am at Gili Lankanfushi, Maldives.

Whale sharks of the Maldives

‘What is it? A shark? A whale? Whatever it is it’s massive!’

The whale shark is the biggest fish in the ocean, and therefore is also the biggest shark. It is one of three species of filter feeding shark; also including the basking shark and the mega mouth shark. On the 7th January we were lucky enough to spot Pedro who is a juvenile male at six metres. It was a truly breath taking moment! The best time to look for a whale shark is three to five hours before high tide and a few days before the full moon. However, finding a whale shark cannot be a guaranteed experience.

For many, seeing a whale shark is a once in a lifetime experience, with a place at the top of numerous bucket lists. These enigmatic and gentle creatures can be seen year round in South Ari Atoll, only a short seaplane ride from Gili Lankanfushi. The whale sharks are attracted to South Ari Atoll due to the vicinity of the Chagos-Laccadive Plateau, which provides very deep and highly nutrient rich water. Whale sharks are a pelagic species, able to travel around 100 miles per day and dive to at least 1600m – probably deeper, but this cannot be officially recorded due to tracking tags breaking under the phenomenal pressure at great depth.

Whale sharks are fascinating animals that predate the dinosaurs by 220 million years. All sharks, including the whale shark are cartilaginous fish, which means that their skeletons are made from cartilage, not bone. As with all sharks the whale shark’s skin is covered by dermal denticles, a substance more like teeth than fish scales. The dermal denticles are a couple of millimetres thick and protect the shark’s skin from damage and parasites. They also provide better hydrodynamics. Under this layer of protective armour is a fatty layer, around 10 to 15 cm thick that is most likely used as an energy store and protection from injuries, together with insulation during deeper dives. Whale sharks have over 300 rows of tiny replaceable teeth which are made from a stronger version of dermal denticles. Scientists are still debating the use of these teeth as whale sharks are filter feeders so their teeth are not required for feeding. Another anatomical feature which perplexes scientists is that the whale shark has spiracles. These are a breathing aid for stationary sharks, but the whale shark is classified as a highly mobile shark so what is the use? It could be that the whale shark is very closely related to bottom dwelling sharks, and it is a feature that will eventually disappear through evolution, or it could be used on the rare occasions that the shark is stationary and not feeding.

Whale sharks are known to make seasonal feeding aggregations in 20 countries, including Australia, Gulf of Mexico, Belize, Gulf of California, Seychelles and Maldives. Whale sharks feed on microscopic plankton and small fish that they suck into their one and half metre wide mouths. Their throats are much smaller in comparison; around the size of a drain pipe. They have two known methods for feeding, ram filtration and suction feeding. Suction feeding allows whale sharks to feed on more mobile prey such as small fishes, which they actively suck into their mouths, together with volumes of water that are then expelled through their gills. By comparison ram feeding is passive; the shark swims through the water with their mouth open and plankton filters in. It has been suggested that whale sharks are more suited to suction filter feeding because the gaps between their five to seven gills are small. This small gap is more effective at filtering out plankton when the shark is suction feeding. Whale sharks have very weak eyesight, they can probably only see three meters away, and so rely on their nostrils to find prey. Their nostrils are very sensitive due to their well-developed olfactory capsules; they can detect chemicals in the water produced by their planktonic prey.

Plankton tend to shelter at depths between 100 – 200m. This is the oxygen minimum zone and is not a suitable habitat for many organisms which would prey on them. Whale sharks however are able to feed at these depths and will spend the majority of their time between 50 – 250m. They do venture to deeper depths where the temperature drops to 3 degrees Celsius but scientists believe that due to the infrequency of these dives this is related to parasite removal, not feeding. Whale sharks cannot internally control their body temperature and so return to the surface to warm up and reload oxygen. This is why they can be found in the shallow waters around South Ari Atoll. During this warming and reloading period the sharks can be impaired cognitively and physically which explains their sluggish and relaxed behaviour.

Due to the sluggish behaviour of whale sharks and the shallow depths they travel in they are under threats from boats. It is estimated that 67% of whale sharks have injuries ranging from scratches to amputations. The effects of pollution, poor waste management and increased sedimentation on the whale shark population have not yet been suitably evaluated. Another issue is disturbances to their habitat resulting from tourism – if the guidelines for whale shark encounters are not followed the sharks can negatively be affected. For example, if a large group of tourists are crowding a shark it can cause the shark to dive before it has properly warmed up and reloaded oxygen. Adult whale sharks can also be targeted by great white sharks and orcas, whilst babies have been found in the stomachs of blue sharks and swordfish. In some parts of the world whale sharks are hunted for their meat and fins. In 2010 the Maldives implemented a ban on all forms of shark fishing. However, due to the longevity of whale sharks it will take many years for the population to return to optimal levels.

It is estimated that whale sharks can live between 70 – 100 years, reaching sexual maturity after 25 years at a size of eight to nine metres. Although some people report sightings of whale sharks up to 18 metres in length the largest confirmed has been 12.65m. It is easy to identify a male whale shark because when it has reached sexual maturity their sexual organs have a ragged appearance called claspers which extend past their pelvic fin. The whale shark is classified as ovoviviparous which means that they produce eggs which hatch inside the body. A female whale shark can store sperm for many months and can have babies at different stages of development. For example a female was found with 300 embryos at numerous stages of development. Due to whale sharks storing sperm and having babies at different stages of development the gestation period is unknown. Upon birth the pups are around half a metre in size and weight one kilo.

Whilst whale sharks are regularly sighted, 98% of these sightings are juvenile males with a length of six metres. At any one point it is estimated that there are 200 whale sharks in the waters of the Maldives. The most common behaviour observed of these sharks is cruising, only 12% of encounters are feeding.

We can’t wait to show you these gentle giants next time you are at Gili Lankanfushi. Please ask your Mr/Ms Friday and we can book a trip for you.  When you see one be sure to snap a photo of the checkerboard pattern on their side by their pectoral fins. This can help us with identification and research.

For more information and to upload your whale shark encounters please visit: https://maldiveswhalesharkresearch.org/

PADI’s guest blogger Emma Bell introduces herself:

I am a marine biologist and scuba diver from England. I have had the privilege of working in Greece, Seychelles and Maldives. I have worked in an aquaculture research centre where I focused on hormonal manipulation of a pelagic fish species. In addition, I have experience with coral restoration projects including frames and ropes; habitat restoration – crown of thorns, drupella and invasive plant species removal; educational activities and social media updates including blogs. I have also monitored population dynamics of bird, turtle, shark and cetacean species to aid in their conservation. I started my career working in the Maldives and I have done a round trip via Greece, England and Seychelles, I hope to increase my skills set and knowledge further whilst I am at Gili Lankanfushi, Maldives.

Bioluminescence at Gili Lankanfushi

The sea never sleeps. Even at night it is bursting with a wonder that seems almost magical – flashes seeming to appear out of nowhere when the ocean is otherwise shrouded in darkness

When the lights go out nature doesn’t stop communicating. Similar to our adaptations to cope with the dark, by making light, many organisms have developed the ability to produce light. This is called bioluminescence and is created by a chemical reaction within the organism. It is not the same as fluorescence which results from the organism absorbing light at one wavelength and then re-emitting it at another wavelength. Bioluminescence is therefore an active form of communication, whereas fluorescence is passive communication. Whilst visual light is required to observe fluorescence, bioluminescence can be witnessed in pitch black environments. It is generally blue/green in color and this is due to the shorter blue/green light waves travelling further under water.

Bioluminescence can be found throughout the ocean
It can be found in many different groups such as jellyfish, sharks, fish, algae and worms to name a few. In each group the chemical reaction that produces the light varies, which is evidence that bioluminescence has evolved multiple times. Generally, bioluminescent animals contain the chemicals required to produce light, but occasionally an animal can take in bacteria or a different bioluminescent organism that has the ability to produce bioluminescence. For example, the Hawaiian bobtail squid takes in bioluminescent bacteria which are stored in a special light organ and at night they then work together to produce light. This light acts as a cloaking device preventing the squid from casting a shadow and hence camouflaging the squid from predators.

For light to be produced organisms must contain the molecule luciferin which when combined with oxygen produces light. Different organisms will contain different types of luciferin. Some organisms can contain a catalyst called luciferase which can speed up the chemical reaction. Additionally, luciferin and oxygen can be bundled together to make a photoprotein which can be activated instantaneously when a certain ion becomes present. The intensity and colour displayed can also vary and this is very important for communication.

 
Bioluminescent animals can be found on land and in the water column, from the surface to the deepest part of the ocean at challenger deep (10,994m), and in coastal and oceanic environments. In coastal environments around 2.5% of organisms are bioluminescent whereas in pelagic environments the number is significantly higher. Studies estimate that around 70% of fish and 97% of cnidarians (jellyfish, corals, anemones and hydroids) are bioluminescent. Due to the vastness of this form of communication it could be said that bioluminescence may be the most abundant form of communication on earth. Humans see only a small portion of bioluminescence – we generally observe bioluminescence resulting from physical turbulences of the surface water due to waves or boat hulls. The aggravation of the water triggers a bioluminescent response in surface dwelling bioluminescent organisms. One of the most common bioluminescent displays observed by humans is from planktonic surface dwellers. When blooming they form a dense surface layer, which by daylight is reddish-brown in colour but at night transforms into a light display. We can see bioluminescence at Gili Lankanfushi – turn your torch off on a night snorkel and wave your hands around to disturb the water. Bioluminescence is unpredictable but the best times to observe it are when the moon is waning. 
 
Animals can light up for a variety of reasons:
to defend themselves, to procure mates and to camouflage or hunt. The dark is an unforgiving place and finding food can be life or death. Some animals concentrate their bioluminescence in a lure and dangle it around their mouths. The deep-sea angler fish has this adaptation – its lure is lit by bioluminescent bacteria. Prey are attracted to the light and can be engulfed before they realise it. The Stauroteuthis octopus which lives below 700m has replaced some of its suckers with bioluminescent cells that direct their planktonic prey into their mouth. The production of light by the cookie-cutter shark tricks whales and squid into venturing closer and once close enough the shark takes a bite out of the animal before it escapes.

Long wavelengths like red light are absorbed quickly in the surface waters and it is due to this that many deep sea animals are red – they become invisible. Additionally many organisms have lost the ability to see red light. However, the dragonfish has evolved to emit and see red light. This allows it to see red coloured prey and also they can light up the surrounding water to hunt or look for a mate.

 
Finding a mate in the dark can be a major hardship.
Flashing bioluminescent displays can be used as a signal between males and females of the same species to signify the desire to reproduce. For example, a type of male Caribbean crustacean (ostracod) lights up its upper lips to attract females. 
 
Even though bioluminescence lights up the darkness it can be used for protection and camouflage. Many animals will produce a strong flash of light to confuse predators and swim off whilst the predator is blinded. Some squid can produce bioluminescent ink – upon ejection it can stick to the predator and light it up. This can lead to the predator becoming a meal for something even larger. If a predator manages to take a bite out of a bioluminescent organism the stomach of that predator will glow making it an easy target and giving the prey time to escape
Bioluminescence can also be used for counter illumination. This is where the animal can manipulate light to prevent itself producing a shadow and making it almost invisible. They can use bioluminescence to match the light coming from the surface. This makes it almost impossible for predators below to see their prey. The lantern shark is an example of this – it can make itself look invisible by producing blue/green light to blend in with the background.
It’s surprising how any organisms create light, even in an aquarium you may notice it.
Next time you are at Gili Lankanfushi try and see the bioluminescence yourself. You never know when the next flash of light will catch you by surprise!

PADI’s guest blogger Emma Bell introduces herself:

I am a marine biologist and scuba diver from England. I have had the privilege of working in Greece, Seychelles and Maldives. I have worked in an aquaculture research centre where I focused on hormonal manipulation of a pelagic fish species. In addition, I have experience with coral restoration projects including frames and ropes; habitat restoration – crown of thorns, drupella and invasive plant species removal; educational activities and social media updates including blogs. I have also monitored population dynamics of bird, turtle, shark and cetacean species to aid in their conservation. I started my career working in the Maldives and I have done a round trip via Greece, England and Seychelles, I hope to increase my skills set and knowledge further whilst I am at Gili Lankanfushi, Maldives.

Carpe Diem Maldives Introduces Coral Reef Awareness Campaign in Celebration of IYOR 2018

January 2018: Carpe Diem Maldives Pvt. Ltd. begins a 12-month social media campaign to celebrate International Year of Coral Reefs 2018.

Crystal clear waters teeming with colour and marine life surround The Maldives, making it one of the most appealing and diverse coral reef destinations in the world. The new digital campaign led by Carpe Diem Maldives promotes awareness towards the status of the destination’s coral reefs. Recreational and professional divers are invited to share their underwater images through Instagram and Facebook channels using hashtags #maldivesreefawareness #carpediemmaldives and #IYOR2018 stating information to three related Ds – dive, date and depth – on each image.

2018 was announced International Year of the Reef (IYOR – www.iyor2018.org) for the third time since 1997 by International Coral Reef Initiative (ICRI), an informal partnership between the Nations and organisations that strive to preserve coral reefs and related ecosystems around the world. IYOR is a global effort to increase awareness and understanding on the values and threats to coral reefs, as well as to support related conservation, research and management efforts.

Francis Staub, International Coordinator for the Year of the Reef for ICRI states, “We welcome this initiative embracing modern media and recognising public awareness as an essential element of coral reef conservation. Campaigns such as this ensure that the general public understands the value of, and the threats to coral reefs. Furthermore, the ongoing stream of images through #maldivesreefawareness on social media channels provides marine scientists and other stakeholders around the world access to real time data on coral reefs in The Maldives.”

Regularly visited dive sites across the Maldivian atolls will be captured to show the real time reef status amidst the effects of global warming, while also recording the ongoing recovery and conservation efforts being carried out by organisations such as Coral Reef CPR. At the same time, the digital campaign encourages public engagement and general awareness to the importance of coral reefs globally.

Haris Mohamed, Acting Managing Director for Maldives Marketing and Public Relations Corporation says, “Recently awarded World’s Leading Dive Destination at the 24th annual World Travel Awards, the Maldives attracts divers from around the world to experience the beauty of our underwater marine life and reefs. This initiative by Carpe Diem Maldives highlights the conservation efforts various organisations are carrying out to ensure our reefs remain resilient and healthy for generations to come. We strongly encourage all divers to the Maldives to share their images on social media with the hashtag #maldivesreefawareness.” 

Likewise, PADI Regional Manager for The Maldives, Matt Wenger, explains “Coral reefs are among the most beautiful ecosystems on the planet and PADI works with local communities around the world to ensure that residents understand the value of their local treasure. With close to 1.2 million tourist arrivals a year to The Maldives, initiatives like Carpe Diem’s #maldivesreefawareness are so important to get the message across about the beauty of the underwater world and why we need to do everything we can to protect it. We wholeheartedly encourage all divers to participate in this simple yet effective image sharing campaign.”

The digital campaign, which will run exclusively in The Maldives until December 31st, 2018, will be promoted to guests on Carpe Diem’s liveaboard dive cruises and at the upcoming resort in Raa Atoll. Carpe Diem Cruises welcome up to 60 divers weekly across all three of their luxury liveaboard cruises. Towards the end of 2018, campaign images posted throughout the year can be submitted to a panel of professional photographers, conservationists and IYOR officials, with a chance of winning a 4-night stay in 2019 at the new resort Carpe Diem Beach Resort & Spa.

 

For more information on Carpe Diem Maldives Pvt. Ltd., please visit www.carpediemmaldives.com