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!
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).
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.
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.
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.
Coral reefs for the most part appear to be static environments, despite the presence of ever busy fish life, that is because most of the activities happening within corals are invisible to our eyes. In fact, coral reefs are a dynamic environment where every cm2 may hide beauty or a fight for survival! Among the invisible, corals are surely the most active, by building the amazing structure which allow us to see paradise tropical islands! However, they are continuously fighting for the survival, against predators, disease and environmental changes, and even between them. They are supplied with microscopic needles and venomous tentacles to kill any other corals and ejecting their stomach to digest them. The battle-zones when two different corals are easy to spot, there is often a cleared band between the two where they’ve killed each other off. They use similar tactics when they are fighting off invading algae. On healthy reefs, corals can maintain their territory, often beating back and even killing various types of algae. Here you will notice the two types ….
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 this species of Acropora on your frame, you will notice the white tips on the branches. When corals are stressed by changes in water conditions such as temperature, light intensity, or nutrients, they expel the symbiotic algae called Zooxanthellae, living inside their tissues, causing them to turn completely white, this is also known as coral bleaching. When a coral bleaches, it is not dead yet, but may soon starve if conditions persist, since the animals inside rely on this algae for its energy. If their stress levels are not severe, corals may recover. If the algae loss is prolonged and the stress continues, coral eventually dies. Here in the Maldives, the peak temperature is around March – June, when we also see some of the corals turn white, usually their colors return soon after if conditions don’t persist.
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.
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.
If you remember from your last update, we have mentioned the encrusting corals that were growing on the one side of your frame. In this update you will see the result of the maintenance that has been done. You will notice that we have removed the entire fire coral that was encrusting all the way onto the frame. This was done with pliers and gloves as to minimize the damage to our own hands. After this we replaced the empty looking side with some new coral fragments from the lagoon as you can see from the image. We hope to see them covering the frame soon
Looking at this one side of your coral frame you will see that the metal bars are encrusted in a pale yellow to golden orange color growth. This is actually coral, more specifically an encrusting fire coral (Millepora complenata). Although the name might be misleading, Fire corals are not true corals, they are actually more related to jellyfish and other hydrozoans thus making them Hydrocorals and not stony corals. Fire corals are aggressive and adaptable and can very quickly overtake neighboring corals and their skeleton often resulting in shapes that don’t fit the mold such as this encrusting shape. These encrusting shapes have major advantages over branching corals and are less susceptible to breakage during violent storm conditions. For the survival of your frame we have removed this fire coral as it was taking over some of the live corals. In the next post we will show you the results of this maintenance
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).
We would like to introduce the species Acropora robusta, which is growing massively on your coral frame. Colonies are often irregular in shape with an encrusting bases and thick conical branches in the middle, and with thinner prostrate branches with upturned ends at the periphery. Branches from the central and peripheral part of the same colony have completely dissimilar shapes. This species is usually yellow-brown or cream in color, and common in the shallow reefs of the Indian Ocean, especially reef margins exposed to strong wave action.
We would like to introduce you this species of coral living on your coral frame, Hydnophora microcornus. Colonies are usually massive and rounded with a lumpy surface. The circular bumps are called moniticules, they are about 2-3 mm across and tall. The colors are usually dull cream, brown or green. This species is found in all reef environments, but primarily in lagoons and protected slopes in the Indian Ocean, and wave washed reef flats in the Red Sea.