Thank you for signing up to keep in touch with the Coral Conservation Project. Pictured above, you will find your coral frame as it was few days after construction. Your personal page will allow you to see more regular updates and amazing facts about the corals and animals living on your frame. By now having all the updates on one page, seeing the progress of your frame will be much easier and convenient. If you want to satisfy your curiosity even more, you can take a look at our Marine Blog Life and videos from the Marine Lab Diary or connect with us for more information.
Here is the start of a healthy coral reef relationship!
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.
What is biodiversity? Biodiversity is the variety of living species that can be found in a particular place, for instance the number of coral species on your coral frame. Coral reefs are said to have the highest biodiversity of any ecosystem on the planet—even more than a tropical rainforest. In this particular image you can see two species of the Acropora genus, one of the fastest growing species of coral. Since we collect broken fragments from the bottom and not original colonies, the biodiversity on the frames is often between 1 and 4 species of corals, depending on location of collection. You will see that these small pieces have already grown quite a bit in the one year since construction. Of course we always try to keep the diversity high between all of the frames and during maintenance we often add new pieces onto the frame. Hopefully soon we will see lots of different marine species occupying your frame, which is the goal of our Coral Conservation Project.
In some unfortunate cases, much like we can see in nature, there are some dead fragments on your frame such as this one pictured. This is often the result when corals undergoes very high level of stress where they cannot seem to recover. This is not because your frame isn’t suitable, but since all the fragments were collected from the sand they already received lots of stress before attached onto your frame, so it happens from time to time that fragments might receive further high stress levels due to increased water temperatures and they lose the symbiotic algae Zooxanthellae that they need to survive. They will turn bleach white and if stress conditions persist they will die completely since they have no more animals for feeding or defending the corals and then they are often competing with invasive algae that grow over the polyps when this happens they will also die off. During the maintenance these pieces of dead coral is usually removed while the live part remains attached.
Check out this intriguing creature we found on your coral frame… this is called a hermit crab, one of the 1110 species found today, so we cannot be too sure about the specific species. These specific groups of animals are called marine hermit crabs and they spend most of their life underwater. Most species have long, spirally curved abdomens which are soft, unlike their calcified relatives. This soft abdomen is protected from predators by a salvaged empty seashells usually abandoned by other gastropods. Often times they will use the shells of sea snails or other hermit crabs. Like all hermit crabs, as they grow bigger, they require bigger shells and often times when resources are limited there can be some competition between crabs for new shells. Their diets consist of algae and plankton but they are also omnivorous and depend on a reasonable amount of scavenging. They find the easiest ways to collect the plankton is by utilizing their claws to guide food into their mouths and suck in anything that is within reach.
The Dascyllus aruanus, known commonly as humbug damselfish, has found in your coral frame its home. This particular fish is known by multiple common names, such as three stripe damselfish, humbug dascyllus, or black and white damselfish. They only reach an adult size of 3-4 inches (7.6-10 cm). Sporting three broad black stripes on a white body, the humbug damselfish has a zebra like appearance. The stripes run slightly off vertical through the eyes and mouth, midbody and bisecting the caudal peduncle, making it half black and half white. There are several contestants for the title of most important reef fish family, but the Damselfish are certainly one of the front-runners. Not only are there numerous species, but also many of these species are present on Maldivian reefs in prodigious numbers. The humbug damselfish that you can see in the picture is associated with isolated coral heads in sheltered inshore habitats. Like all damselfish, they can be territorial and aggressive, especially as they get older.
This is your 6 month frame progress update. Your frame is doing fantastic!
Looking at your frame, we can see lots of new growth, especially of the acropora corals (the branching & fast growing corals). We can see some of the corals are competing for space, which is a good problem to have, it means your frame is thriving. We can also see that your frame is contributing to the overall health of the coral ecosystem. We see lots of life such as little fish, crabs, worms and mollusks around your frame. Overall your frame has survived the warm months of March, April and May just fine, unfortunately some of the other frames in our colony weren’t so lucky.
Over the following months we will continue with maintenance to keep harmful algae and predators off your frame and to give your frame the best chance for successful growth.
Have you ever wondered how do corals grow bigger or how their branches are getting longer? Coral reefs are mainly built by stony or hard corals, together with their endosymbiotic algae (algae living into the corals), zooxanthellae. To give you some information on how the calcification process works. The main elements needed to build the skeleton are Ca2+ (Calcium ions) and DIC (Dissolved Inorganic Carbon). Both these elements are transported into a specific area of the coral called the “calcifying region”, which is situated under each single polyp. Here, the calcium carbonate (CaCO3) is formed throughout a chemical reaction. Finally, the calcium carbonate (or technically crystals of aragonite) is deposited to form the skeleton. The process involves the polyp’s cells and the zooxanthellae and by the mutualistic work of these two counterparts the skeleton is formed. However, if for any reasons (i.e. high temperature) one of the two parts is not working properly the process stops and the coral may die.
Looking at the side of your frame, you will see this amazing species of coral, they are classified as table corals because of their round and flat shapes. They all belong to the Acropora genus which is the fastest growing species with up to 145 species already described. The role of table corals in the reef is quite important as they provide vital sun protection for new and smaller corals but also larger fish. Some scientific evidence suggest that without this important shade (in which they escape strong UV-light), larger fish which include predatory species will ultimately leave the reef. Predatory fish such as groupers, emperors or even sharks are important to maintain a healthy balance within the ecosystem. Unfortunately due to their size and support base, they often tumble over due to strong seas or hurricanes and this species is put under more pressure. The addition of this table coral on your frame is doing really well as you can see and already provide some shelter for juvenile fish during the day
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.
Humans get a sun tan – corals become more colourful.
As you can see from the picture, your coral frame are colonized by some little, brown and green organisms called Ascidia. The species is called Didemnum molle (also known as the green barrel sea squirt or the green reef sea-squirt.) and is very common in the Indo-Pacific area. Ascidia is a filter-feeder, feeding on suspended plankton and detritus and its green color is given by the algae living in symbiosis with them, in this way the algae is protected by the predation and the Ascidia can receive energy from its little hosts. Luckily they don’t possess any threat to the corals when they are few in numbers, however they can colonize quite quickly on the frames through asexual budding, as such they are regularly removed to minimize competition with growing corals.
Your frame seems to be an attraction for baby corals, such as the small, 2 cm, coral colony in the picture. Most of the coral species reproduce by ejecting sperm and eggs in the water that subsequently merge and form planula larvae which can swim and is naturally attracted by chemical substances and light. After a couple of weeks, planulae fall back to the ocean floor and attach themselves to a hard surface. An attached planula makes the metamorphosis into a coral polyp and begins to grow—dividing itself in half and making exact genetic copies of itself. As more and more polyps are added, a coral colony develops. Eventually, the coral colony becomes mature, begins reproducing, and the cycle of life continues.
Looking at your frame, you will see that it is doing amazing and the corals are really growing well since the last update even after the heated months and some stormy weather. We have done some recent maintenance on all the frames which include cleaning them, removing the invasive algae and coral predators to maximize growth. In the upcoming post we will show you close-ups of your frame and the coral fragments, with some interesting facts and findings about those that are on your frame. After 6 months you will see a similar post showing once again the progress of your frame.
We want to give you some information about this Acropora humilis that lives on your coral frame. This species forms digitate colonies, meaning the branches are shaped like fingers of the hand. The axial corallites (which tend to be shallow and are found near the tips of the branches) are very large compared to the radial corallites (on the sides of the branches) which are small and tubular. It may have many colors, but most usually cream, yellow-green, brown, purple or blue with blue or cream tips. It is mostly but not exclusively found in shallow and turbulent water where it can be common, and sometimes a dominant species.
