“Have you ever heard of bleaching? We hadn’t heard of it until recently, but now everyone here on the reef is talking about it, they say it’s a disease that leads to death. We are very worried…
Take a few minutes to learn more about this disease that is plaguing us, maybe who knows, you could have the solution to this disease of ours.”
Bleaching in corals
It indicates a phenomenon that has appeared in the last 25/30 years. The first record in the Maldives was made in 1998, with a mass mortality of the most superficial corals. Bleaching is just one of the diseases that corals can be affected by, others such as malbianco, malnero, malrosa, malgiallo and so on are other diseases that affect the living tissue of the coral, giving it different colors.
“Unfortunately, these problems of ours are still little studied, there are many hypotheses and few certainties, but we can start to tell you what we know. For example…”
The causes of bleaching
Bleaching is caused by different reasons, it is a sort of reaction of the coral against any stress phenomenon. Among the most well-established causes are:
or the sudden increase in water temperature,
"We know you like the feeling of hot water when you bathe, but this is too hot for us!"
or the increase in ultraviolet light radiation that filters into the more superficial layers
“In fact, the superficial coral reefs are the sickest, they cook!”
or the marine pollution with the release of pesticides and fertilizers into the water compromises the well-being of corals.
“Veniamo sommersi di alghe e parassiti che s’impossessano dei nostri spazi vitali”
or the Ocean acidification due to the greenhouse effect.
“You have surely heard about it on earth, well the effects are felt in our home too!”
or Microplastics, overfishing, coral trade and coastal development, frame this already significantly tested scenario.
“Friendly fins, don't stop reading, we won't just talk about bad things! You'll find some good stuff too!”
Why it affects corals
Some corals have symbiotic microalgae called zooxanthellae within their living tissues. They play an important role in the coral's nutrition, providing it with the products of their photosynthesis.
Most of the corals responsible for building the reef are colonial and host zooxanthellae: it seems that their presence facilitates their construction capacity. Zooxanthellate corals generally have rather delicate and dull colors, precisely so as not to attenuate the light that the microalgae need.
“We are usually yellowish, brownish, greenish, or even green! The loss or alteration of these colors can be the first sign of suffering or disease. Why?”
“We will quickly explain:”
Our zooxanthellae friends are extremely sensitive to light and temperature;
A surge of the latter could kill them very quickly, and we must expel them from our tentacles, thus also losing our color;
From here two paths can branch off:
1. Bleaching can be mild and short-lived, affecting only some areas of the coral or creating a widespread paleness. In this case, the polyps can survive, recover the symbiotic algae and then return to health.
2. If the bleaching occurs permanently:
The corals become completely white;
The polyp becomes sick and the skeleton begins to be affected by parasites such as algae, bacteria and fungi;
Its appearance becomes brown;
It loses its structure and crumbles on the bottom.
This whole journey towards death is not as slow as one might think.
Why is bleaching so dangerous?
Coral reefs represent approximately 1% of the entire planet’s ocean, but they are home to 25% of marine biodiversity.
“With our structure and richness of food, we always have a huge amount of guests who frequent our magical place.”
The bleaching phenomena of recent years have led to mass mortality of corals, literally bleaching entire coral reefs and leading to the death of millions of polyps. The serious problem, however, is that the coral reef is the point of reference for all the species that live within it, if this collapses, the entire ecosystem that has been created will collapse.
“Now you may ask… But what do we humans care about your evil? We already have plenty of it for our own good! But…”
Consequences of bleaching
And now you will expect me to list the reasons why we must safeguard the coral reef and limit bleaching, instead I decided not to talk about it here but in the next article in which we will dedicate ourselves to the consequences and what Friendly Fins can do…
Now I would just like to tell you a little story, my story…
What is the consequence of Bleaching for me, Chiara from Friendly Fins!
I remember it like it was yesterday, my first time on the coral reef, it was 2009 and I was in the Maldives for the first time, at the time I didn't have a scuba diving license yet and I actively participated in the resort's snorkeling trips.
As soon as I entered the water I was literally overwhelmed by the colors and the immensity of animals all busy with their daily chores. I was with a very good Maldivian guide who made me immediately appreciate the crazy variety of organisms in those few meters that we had just explored.
I remember that he pointed out a cushion starfish! I was ecstatic, I didn't even know it existed! Extraordinary!
I had no idea what to expect from the coral reef but I certainly would never have been able to imagine such beauty!
From that moment MY path was clearly outlined, which still today allows me to experience extraordinary emotions.
Today I put my head under water after 14 years and I see the difference: the change and degradation into which this magnificent environment is sliding and my heart fills with sadness and impotence in the face of all this.
Like me, millions of other people who love the coral reef, the sea, diving and snorkeling in tropical seas; feel like witnesses of this faded picture.
If I had to define the coral reef, I would define it as LIFE, because when I am in the middle of this paradise, I feel truly alive. For me this is already a great reason to encourage me to do something for it…
Follow us in our next article Friendly Fins!!!
Can WE do something to save the coral reef?