We would like to give some information about this colony of Acropora digitifera that lives on your coral frame. This species forms digitate colonies; the branches may be 1 cm in diameter and up to 10 cm long. This species strongly prefers shallow water. It is usually cream or light brown in color with blue branch tips, but can also be brown with purple tips. It is common near reef crests’ as it prefers strong water movement and it is very common in the Maldives. The most important known threat is the reduction of coral reef habitat due to bleaching, disease and predation. However, it seems to be strong enough to resist to habitat loss more than other species of corals. However, since the current situation with multiple stresses (mainly rising temperature of the ocean) acting simultaneously the species is considered Near Threatened by the International Union for Conservation of Nature (IUCN).
Look at this amazing visitor to your frame! These are just a few of the species that would often visit the coral frames and are extremely helpful at times when cleaning the frames. This species is called the Moon Wrasse (Thalassoma lunare) a very typical and brightly colored species of fish found in the Maldives. It belongs to the wrasse family which consists of over 600 described species that range on average around 20 cm although the Humphead and Napoleon wrasse can grow up to 2 meters! They are carnivores by nature, feeding on a wide range of small invertebrates such as crabs or snails. Many smaller wrasses follow the feeding trails of larger fish, picking up invertebrates disturbed by their passing.
The coral on your frame is thriving. The fragments attached at the beginning are growing very well. All the fragments of this digitate Acropora are now fusing together. We applied the micro-fusion technique that has been described by the Mote Marine Laboratory in Florida. In particular, when putting fragments of the same genotype close to each other they can stimulate the fusion of these fragments, speeding up their growth rate. When doing coral frame restoration or maintenance we usually apply this technique when we find a huge broken colony. We cut off small branches and then we attach them very close to each other as you can see here.
Here you will see the partial shape of the cable tie that we used to stabilize this particular fragment to the iron frame. In one month we can already see that this Acropora have started to overgrow this plastic tie and will soon be part of the skeleton forever. Plastic cable ties are a good compromise for attaching corals to the structure, since the material is cheap, resistant and the results are great, however we are looking into using different materials to improve our techniques of reducing plastics in the ocean. When this colony have reached the minimum size for spawning it will release its gametes in the water that ultimately leads to the formation of new colonies elsewhere on the reef
Have you ever wondered why some corals are more colorful than others… That is because some corals increase the production of colourful protein pigments (such as these purple tips) when they are exposed to more intense sunlight and this colony, of a branching Acropora, is simply amazing. Scientist have found that these pink, blue and/or purple proteins act as sunscreens for the corals by removing substantial light components that might otherwise become harmful to the algae hosted in their tissue. Corals rely on these light-dependent miniature plants, the so-called zooxanthellae, since they provide a substantial amount of food. Furthermore, these tips consist of a particular polyp called an “apical polyp”. It is responsible of the growth of the particular branch. For instance, it will reproduce asexually by cloning itself, potentially an infinite number of times throughout its lifetime. Here and there, one of the “radial polyps” will differentiate becoming a new apical polyp with its distinguished purple color, driving the growth of a new branch.
Your frame is the start of a new beginning for the Thudufushi House Reef! Your coral frame is part of an experimental trial. We are trying to determine if we can start a coral frame chain that will act as an artificial reef. The “frame chain” is currently located on the sandy seafloor in front of the Main Bar & Water Villa Jetty.
A few concerns we are having with this location are the shallow water, which might make the corals more prone to bleaching due to warm waters. We are also concerned about the stand and possible turbidity that might not allow enough light to penetrate for photosynthesis.
So why did we choose this spot? As we are trying to expand our coral reef and help corals take back areas they used to inhabit before the big bleaching in 2016 we need to expand frame locations past the already existing reef. Furthermore the location is easily accessible for the biologist to monitor and clean the coral frame and react to any changes quickly.
Let’s cross our fingers and hope the corals will adjust to their new location well.
As you can see from your first post, we have already done the first maintenance on your frame which is to remove the ad cable ties and move the frame with the other frames. Some information about the fragments that we put on your frame, most of them belong to the genus Acropora which is one of the fastest growing corals and almost 149 species described. Over the next few months we will show you some close-up pictures of the fragments with some interesting facts and the creatures that now lives on your frame. After 6 months we will show you the progress of your frame in a new post.
