Coral Bleaching

The effects of coral bleaching around the world

Coral Bleaching – Koh Tao

A recent topic of interest worldwide is coral bleaching with reports suggesting that large areas of the Great Barrier Reef, Australia have been significantly affected by this phenomenon.

But how is our small island, Koh Tao being affected?

With ever changing factors of global warming and other extreme weather incidents, there is no simple answer. In the last 12 months we have witnessed some areas that have shown incredible development and re-growth of the reefs; however, in other areas we are still seeing a slow decline in corals.

Here on Koh Tao extreme weather is a rarity and so our corals generally have good opportunity of growth despite all the human activities going on.

Yet now and then we also experience certain weather events that stress the coral on our reefs. The more frequent this happens the slower the re-growth period in between get, and in turn will not allow the corals time to repair themselves.

What Is Coral Bleaching?

Coral bleaching is exactly what you would imagine when the words come to mind. White, starved and ghostly colours, a total contrast to the colorful underwater world we all know and love.

So these vibrant healthy colours are the result of tiny algae that live in their tissues and live in harmony with the corals and they basically share resources. The tiny algae in questions role in all of this is to provide food for the corals. This is done using the carbohydrates that they can produce during photosynthesis.

Sound perfect right? One thing to understand is that corals are very temperamental and fussy when it comes to water temperatures they frequent in.

Corals have limited temperature range when it comes to surviving. This means when it gets too hot due to rising ocean temperatures they begin to get stressed out.

When this happens the perfect symbiotic relationship the coral and tiny algae once had starts to sour. The tiny algae are told to leave and the corals kick them out.

This results in the washed out white colour that we are experiencing at the moment.

However not all is lost, if the corals choose to re-absorb the tiny algae in the near future, the corals can still survive, they just cannot manage to survive without the algae long term.

Could We Manage Without Coral Reefs?

Across the entire Earths undersea world, coral reefs only make up for less than 1 percent. However this very small number has huge impacts to our daily lives. (Imagine if we had more!)

First off they provide shelter, security and nurseries for around one quarter of the world’s marine species. They create protection for our shorelines and give huge support for the fishing industries.

Without our coral reefs tourism would be affected worldwide and countries such as Thailand would see a huge decline and in turn suffer due to a reduction in the huge cash flow tourism provides. Finally, and maybe the most important, it has a realistic potential to be the next undiscovered medical breakthrough.

Research as we all know is a slow process and for us to achieve any medical aid from our aquatic realm, we need our coral reefs to have long term stability. This is proof of the importance coral reefs offers to us all, whether we know it or not. A decline in healthy reefs is a huge blow to mankind.

What Causes Our Corals To Bleach?

Ever rising water temperatures caused by climate change causes a constant battle for our reefs. El Niño is also another bully towards the reefs causing warmer waters. El Niño was to blame in 1998 for its underwater heat wave that wiped out 16 percent of the worlds corals, and appeared again in 2010 for another global bleaching event that also affected Koh Tao.

Other factors that cause bleaching are….

  • Extra-bright sunlight, especially when combined with the aforementioned extra-warm seawater.
  • Disease.
  • Pollution from urban or agricultural run-off.
  • Changes in the salinity, or saltiness, of seawater.
  • Sedimentation from undersea activities like dredging.

We as humans suffer serious stress when we become more susceptible to having problems with our health, and this is no exception or difference when it comes to corals. They’re just like us!

Conservation & Our Very Own Eco Koh Tao

All this serious talk of coral bleaching disasters may sound daunting, but it doesn’t have to be a death sentence. As we know, not every reef that has come up against a stressful weather event is destroyed.

Some healthy reefs, called “resilient reefs”, are capable of bouncing back.

Here at Crystal Dive we have our in house conservation team, Eco Koh Tao and one their goals is to focus on increasing the longevity of our reefs. They are actively involved with our Divemaster program here at Crystal, and share their knowledge.

It can be anything from Drupella snails and Crown of Thorns Starfish collection that chomp away at our reefs, to coral transplants and creating new coral nurseries.

At our very own dive site, Junkyard, new structures are being put down to create new homes for corals to flourish. You can even enroll in the “Adopt A Coral” program and have your very own coral in the waters around Koh Tao.

If you have serious interest in being the next Eco Warrior here at Crystal, give us a visit and we would be happy to help. Whether it’s adopting your own coral to revisit on your next holiday or a Marine Resource Management Course.

Any effort makes a difference and that is what we are trying to achieve here at Crystal Dive, and more generally within the local community of Koh Tao.

Author: Kieran Hooley (PADI DM #364105)

Crystal Dive Koh Tao

7/1 Moo 2
Tambon Ko Tao
Koh Tao
Surat Thani


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