The corals of the Mediterranean Sea
- Friendly Fins
- Dec 23, 2024
- 5 min read
Updated: Mar 7
Contrary to popular belief, the Mediterranean Sea is very rich in corals of rare beauty. They are more reserved but with a little attention Friendly Fins, you will discover that both snorkeling and diving, we are surrounded!
How to recognize a coral?
Corals appear to us in many forms and have colonized a huge number of habitats, so it is not always easy to recognize them. In this article we will focus on recognizing the corals that we most frequently find in our recreational dives, that is, those dives that do not exceed 40 m in depth.
First of all, what is a coral?
Coral is generally a group of small animals called polyps that, in addition to carrying out normal vital functions, are also able to build this skeleton in calcium carbonate that will continue to grow even after their death, with the settlement of new individuals.
We must imagine coral as a condominium, in each room lives a polyp that builds its own little apartment and when it dies the floor above is hosted by another polyp that in turn builds its own apartment and so on.
The first distinctive signs, "so to speak" are:
Tree-like shape without leaves of different colors;
Smooth surface or with a “soft” appearance due to the presence of open polyps;
They are in areas exposed to currents;
They do not have pores like sponges;
They have very bright colors, if you illuminate them with a diving torch!
The corals that we can most easily spot in the Mediterranean are gorgonians.
Let's find out who they are!
Red gorgonian (Paramuricea clavata)
It is perhaps the most striking coral in the Mediterranean Sea, it lives on sheer cliffs and more rarely on seabeds from 25 m deep onwards. We recognise it by its imposing appearance, reaching 1 m in height, and by its fan shape as it peeks out from the vertical wall in front of us. It extends perpendicularly to the wall because, like all other corals, it is a filter feeder and therefore needs to intercept the currents to feed. It appears blue to our eyes, in fact for this reason it is often not recognised, but the blue colour is essentially due to the absorption of so-called warm colours underwater: from the first metres of depth, colours such as red, orange, yellow are filtered and therefore we are not able to see them in depth, in any case an underwater torch will be enough to transform the blue into a bright red. Often you can see the polyps outside their case (white dots in the photo) which filter food making the gorgonian with a much softer and “swollen” profile.
Yellow gorgonian
The yellow gorgonian (Eunicella cavolini) is a nice coral that appreciates shaded areas and tries to grow as perpendicular as possible to the wall. They are often found at shallow depths and can even be spotted by snorkeling and freediving for a few meters.
It remains among the smallest gorgonians in the Mediterranean, reaching a maximum width of 40 cm and is clearly recognizable thanks to its yellow color.
If the conditions are optimal, they create really large colonies especially on the ceilings of caves even at modest depths.
White gorgonian
The white gorgonian (Eunicella singularis) is one of the corals that lives at shallower depths, so much so that it is easy to spot it even with a first level certification within 18 m of depth. It grows on rocky plateaus that slope slowly, it is noticeable because it is white with little branching that points upwards. It is not a very large gorgonian though, its height reaches up to 40-50 cm.
The danger of gorgonians
Lately, with the increase in temperatures, these corals are suffering a lot and unfortunately in summer we witness a real die-off of these splendid animals that become rotting brown and a large number of parasites take advantage to colonize the already seriously compromised branches.
The sea is too hot causes an increase in algal activity that creates an overproduction of substances that accumulate on the seabed in the form of more or less thick filaments until they cover the entire seabed. Years ago this phenomenon was limited to the most superficial areas and degraded quickly, now the mucilage reaches up to 20-30 m of depth covering not only the seabed but the gorgonians themselves that no longer have the possibility of feeding and therefore weaken.
Just like us, if we are weak and debilitated, we get sick; they too are exposed to the action of fungi, bacteria, parasites of all kinds that in the long run lead to their death.
Not only sad things though…
Guests of the gorgonians
Besides the beauty of the gorgonians themselves, there are many animals that use them as a home or as babysitters!
Basket Star
This starfish of rare beauty that resembles a gray/silver basket when closed, lives exactly where?
On gorgonians of course!
It is impossible not to notice it because it looks like an ancient and decorated hair clip, positioned right on a branch of the gorgonian. It can be found wrapped around itself or with its arms completely stretched out, showing us all its splendor.
The catfish
Finally, these corals are used as babysitters by catsharks, small sharks of the Mediterranean reefs. These ingenious sharks produce eggs with special filaments that they attach to the gorgonians to seek oxygenation and protection.
They appear to us as little white bags, as you can see in the photo. If we have a flashlight, we can shine a light on this bag and notice the
little shark embryo inside. Obviously, let's try not to overdo it with the flashlight because the little shark is not used to the thousands of lumens that we are shooting at it, so at most we take a look and go, no one wants to be disturbed like that during a nap!
How do we deal with gorgonians?
Despite their robust appearance, gorgonians are not indestructible so it is important to never touch them and above all not to swipe at them. As with all the rest of Friendly Fins, the sea must always be respected in all its forms, only by entering on the tip of our fins will we be able to experience its true essence and that adrenaline that the sheer wall in the blue dotted with these incredible animals gives us!
But the corals of the Mediterranean do not end here, on the contrary! One of the most fascinating, mysterious and precious corals is the protagonist of our next article!
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