Wednesday, June 15, 2016

Week 2/3 as the Marine biology intern.

Hi there! So after my action packed first week that included learning about  El Nino's effects, relocating slow growing coral, removing crown of thorns star fish and the arrival of the manta rays I didn't think things could get much better; how wrong I was! Since then I have been lucky enough to have more incredible manta encounters, rescue a female Hawksbill turtle, partake in our world oceans day activities and conduct growth surveys of the coral lines.


If you look closely there are 7 Mantas in this shot!
Debs and I accompanied some guests on a dive to Lankan Beyru with the intention of seeing some Mantas at the cleaning station, giving me the opportunity to hone my ID photography skills. Nothing could have prepared me for what was to come on the dive! As soon as we descended onto the cleaning station there were a couple of Mantas making use of the station, a good start! Then came another group of 5 mantas, meaning there were approximately 7 mantas all around us on the station. They hung around for a while, allowing me to witness some interesting behavior as well as get some of those all important ID shots! Then as this group moved on, another group of 3 or 4 moved on to the station, and we managed to ID these individuals too! Once back at the desk we were able to sort the Manta photos, which revealed 11 individual Manta rays! 4 of these were on our database, the remaining 7 were ID'd by the manta trust. Interestingly the vast majority of the mantas we saw were females, with only 1 male manta being spotted. What an amazing experience!


Helping the turtle onto the pontoon.
One sunny afternoon a female Hawksbill turtle was spotted in our lagoon that was noted to be behaving unusually, and did not seem to be able to dive beneath the surface. We realised she was in trouble and jumped into the water to try and assist her. She still had some fight left in her and on our approach made an effort to dive away but unfortunately her condition was such that she was unable to move very far at all. She swam in my direction and I was able to take hold of her at the top and bottom of her carapace (shell). We lifted her out of the ocean onto the pontoon where we made the decision to take her to the Four Seasons turtle center immediately. Once she arrived she was giving a dextrose solution to bring her blood sugar levels back up and initially appeared to perk up, however after a day or so it became apparent that there was an underlying problem, and unfortunately she died. During her postmortem examination, several pieces of plastic were found in her digestive tract as well as growths on her liver. This explained her buoyancy issues as well as her low blood sugar levels. This turtles story was by no means unique and really highlighted to me the impacts that plastics have in our oceans.


Fragmenting a colony for a coral line.
World Oceans Day fell on the 8th of June which luckily coincided with my internship here on Gili Lankanfushi. In preparation for the day Josie and I retrieved two metal frames using a lift bag from the one palm island reef that were no longer needed due to the fact that the coral on them had died during the El Nino. These frames were then taken to our
World Oceans Day stall where guests were able to attach new healthy colonies to the frames using a range of species of coral that we had collected from Himmafushi the previous week. In addition to this we also made a pair of coral lines with the help of some eager guests. We chose to use the Stylophora pistillata species of coral due to its fast growing nature as well as the fact that its structure is well suited to the lines. All in all it was a great experience and I'm enjoying having the chance to share what little knowledge I have on corals and our oceans!


Me and Debs measuring coral.
Finally, in the last couple of weeks I have been lucky enough to go on a number of Coral Lines dives in which we have measured the growth rates of the coral colonies on the lines as well as cleaned algae from the lines them selves. In order to measure the colonies we use calipers aligning them with the widest points of the coral and taking down the reading. It was interesting to see just how large some of the colonies had grown as well as seeing how different species grow at different rates. It was also a good chance for me to practice my buoyancy whilst diving, a skill that could always do with working on!

Best fishes,

Dylan.



       

Sunday, June 5, 2016

My first week as the Marine Biologist Intern!

Hi, I'm Dylan, the new Marine Biology intern! 
I'm 19 years old from Wales and will be starting a BSc in Marine Biology at Exeter University this September. I've taken a year out of study to learn more about marine ecosystems around the world, and so far I have been lucky enough to dive in the Mediterranean and visit Indonesia where I dived around Bali! I'm going to be based here at Gili Lankanfushi for 1 month before heading off to the Great Barrier Reef in Australia! I will be writing a weekly blog during my stay at Gili, so stay tuned to find out what I'm getting up to! 


Credit: Hannah Govan
Coral Bleaching is evident on most reefs
During my first week I've had the opportunity to work on a range of interesting and meaningful projects, as I have arrived during an interesting period for the reefs around Gili Lankanfushi! The Resident Biologists have been busy with the ongoing El Nino induced coral bleaching event; the land reclamation that is happening on Himmafushi (a nearby local island), Crown of Thorns Starfish (CoTS) removal, and the arrival of the Manta rays!

The El Nino event is now coming to an end with temperatures beginning to come down after an extended period of warming. However, the effects of the warming is clear to see on both the reefs and the Coral Lines Project, which are showing wide scale bleaching and some mortality. One of my jobs is to log temperature data in the Divestat database, which can give us clues to temperature's effect on mega fauna sightings. It is good to see a recent decrease during dives at different sites from around 30°C to 29°C. We are waiting for temperatures to return to a more normal level before moving some of the Coral Lines out onto the reef, which I hope to be a part of!


We chose the valuable slow growing species to relocate
Meanwhile, on a nearby local island, an area of 22 hectares is being reclaimed to build houses for the locals. The region in which the land reclamation is happening is home to an established coral reef system which will unfortunately be lost in the reclamation process. In an attempt to preserve some of the older coral that is not showing signs of bleaching we have been transporting bleach resistant colonies by hand to the Coral Lines Project site with the aim of relocating them onto our house reef. Hard work but definitely worth while! It seems I have become a pro with a chisel!


I saw Mantas in Bali, but this is something else!!
Finally, there has been the arrival of the Manta rays! While returning from a snorkeling trip to Bandos reef we stopped at Sunlight Thila, which is a known Manta ray cleaning station. There were 6 Mantas all making use of the cleaning station! Unfortunately we were unable to take any ID photographs of Manta bellies as we were only in snorkeling gear and the Mantas were down at 15 meters! My first Manta survey dive had us circled by 6 different individual rays, and today I hope for the same as I head on my second Manta survey dive! The Manta season on the East of the atoll  has definitely kicked off strongly, with the Gili Lankanfushi Manta ray count being 50 at the time of writing - 12 were my sightings ;) 

In summary, I have had a great first week, working on a variety of interesting and exciting things from research based activities such as logging data in the Divestat database and survey diving, conservation based activities with the transport of coral from Himmafushi to Gili as well as the removal of CoTS, and finally just enjoyable things like seeing Mantas. It has been great and I am excited to find out what the coming weeks have in store! 

Best fishes,
Dylan

Friday, June 3, 2016

Here Manta, Manta, Manta!

One of our old favourites - 'Atlanta' comes to clean!
It is with great pleasure that I announce the Manta Season has officially begun at Gili Lankanfushi! Despite being quite early this year, we have already had some fantastic sightings. In less than 2 weeks alone we have had over 50 sightings of these majestic creatures (and it’s showing no sign of slowing down)!

At Gili Lankanfushi we always strive to keep the lowest possible diver to guide ratio; it is very uncommon that we have more than 2 divers per guide. The major benefit of this is that our small groups will have little to no effect of the Manta Rays’ natural behaviour, thus creating some truly sensational encounters. Nothing quite beats the feeling of having to duck out of the way of these gentle ocean giants! In collaboration with the Manta Trust, we have been sending our precious identification belly photographs and have already started to welcome back some old favourites from last season!
When snorkeling or diving with Mantas we encourage environmental awareness and remind our guests never to touch or chase these vulnerable animals, and to always stay 3m from the cleaning station to enable the Mantas to get their daily clean without disturbance.

Pickle's shark bite is healing well- good to see her again this year!
See you soon!
Jon

Tuesday, April 26, 2016

Coral Bleaching Basics & the 2016 El Nino

We have noticed the usual colours draining from our beautiful corals over the last few weeks. This phenomenon is known as Coral Bleaching, and is caused by excessive stressful conditions in the seawater. We have been collecting data to document this event, but before we share our findings, we wanted to help our readers to understand coral bleaching and why it is happening. To do this we must first understand what coral really is…

Tiny coral animals live together in colonies
Coral is made up of hundreds of tiny jelly-like creatures, all stuck together. Like a jellyfish, they have stinging tentacles that are used to catch plankton in the water for food. Their skin is see-through, but living within are thousands of plant or algal cells called zooxanthellae. Not only do these algal cells give the corals their colours (browns, greens and yellows), but they also provide the coral animals with lots of energy. In fact, about 90% of the energy that coral needs to survive is taken from these algal cells as they convert sunlight into sugars through photosynthesis. With this energy, the coral animals are able to build a hard, limestone skeleton by accumulating naturally occurring calcium and carbonate ions from the seawater. This skeleton is white, and this is what we see during coral bleaching events.


Some resistant or shaded corals evade bleaching...
...Others bleach bright white
The current bleaching is happening because of an increase in water temperature. We have all noticed the hot, calm weather recently. This is caused by El Nino- a weather phenomenon affecting the Pacific Ocean which is so influential that the whole world can feel the effects. Here in the Indian Ocean, we experience a rise in temperature. Since 1900, the world has endured 26 El Nino events, and this year’s El Nino is set to be the strongest in recorded history, with sea surface temperatures already rivaling that of the 1997/1998 El Nino, with an average increase of 2.3°C!

Acropora nasuta is almost fluorescent in a bleached state
The beautiful greens and purples are natural pigments usually
hidden by the zooxanthellae
These unusually high water temperatures are damaging the delicate relationship between the coral animal and algae, which live together symbiotically. The animal respires by taking in oxygen and releasing carbon dioxide as a waste product (just like humans), whereas the algae respires in the opposite fashion; by taking that carbon dioxide ‘waste’ and releasing oxygen. Thereby, the coral and algae use each other’s waste and live in a perfect balance. When the temperature increases, the algae start to release oxygen radicals, or bad oxygen molecules, which can damage animal tissues. Because of this, the animal must spit out what has become harmful algae. As the algal cells are ejected, the coral loses its colour. This coral is not dead, rather it is surviving in a stressed state, where it must try to gain all of its energy by capturing plankton. In this bleached state, without those energy making algal cells, coral can only survive for about 3 weeks, by which time the coral starts to metabolise its own tissues and, in effect, it starves. If the normal temperatures return, the corals can capture new algal cells for storage, recovering its colour and its vitality.

In 1998, the previous El Nino event was responsible for the loss of an estimated 80% of the coral in the Maldives! This current event is expected to be worse, where this hot weather will likely continue through until May. If this happens it could take between 10-15 years for many reefs to make any kind of recovery. El Nino events are increasing in severity and frequency- this is a direct cause of anthropogenic Climate Change. If the Maldives loses its reefs, it will lose its fisheries, its tourism and eventually its islands. These reefs are intrinsically linked to Maldivian survival- don't sit by and watch. Do your bit to help the planet. it is so important for us to try and reduce our carbon footprint, both as individuals and within our businesses! Help the planet and our coral reefs (and also your wallet) by saving energy, streaming for renewables, and reducing emissions!