Coral Bleaching

Coral Bleaching

Coral bleaching and Climate Change

When you hear or talk about a coral reef you picture a beautiful underwater sanctuary, filled with bright colours and sea life. However, around the world coral reefs are suffering firsthand to an ecosystem effected by climate change and ocean acidification. Coral bleaching has struck almost every tropical coast worldwide, impacting up to 75% of reefs from 2014 – 2017 and that is only a 3-year period!

On Australian shores alone The Great Barrier Reef has suffered 7 major bleaching events which were recorded over a 2-decade period from 1997 – 2017, with 90% of these being a direct result from increased temperature fluctuations.

What are the causes of coral bleaching?

Coral bleaching can occur from a range impacting events with increasing temperatures being at the top of the list.

  • Extremely low tides – Exposing the corals to the atmosphere and direct sunlight.
  • Acidification – Caused by increased CO2 in the atmosphere which generates an imbalance in PH levels.
  • Extreme weather events – Destructive cyclones and flooding. Flooding can be extremely impacting as it creates freshwater bleaching and pollution run off.
How does It happen?

Our coral reefs are all interconnected – an ecosystem with each living organism playing an extremely important role in its own survival. Zooxanthellae is a microscopic algae which provides coral with its vibrant colours and up to 90% of the corals energy. Without these algae the coral will die off and never return. When coral bleaching occurs, it expels the Zooxanthellae which lives inside the tissue of the coral into the ocean, leaving the coral white like it has been bleached of all its colours.  The coral can survive without these algae for around 3 months before it dies completely and will not recover.

Its not all bad news, coral has an 80-95% survival rate if the event that caused the bleaching returns to normal conditions within those 3 months.


The consequences of widespread bleaching can be devastating of the ocean’s ecosystem. If our coral reef systems were lost, the thousands sea creatures that rely on the reefs would be without shelter, spawning grounds and food sources. This would have dire effects on not only the marine life that live in the reef but the birds and fish that depend of the reef to provide food. Entire species could be wiped from existence.

These consequences do not just stop with the marine life, they can also dramatically effect humans. Reefs provide barriers from surging oceans; economic security – tourism and commercial fishing, food sources and more.  

How can we help?

There are many ways we can all help protect our oceans ecosystems.

  • Using eco-friendly products – Using these products can greatly assist our reefs by reducing green house gases and pollution
  • Donating to environmental or conservation groups – these groups are mainly non for-profit groups which dedicate their time to protecting and conserving the environment
  • Collecting rubbish – You may think, what does this have to do with our oceans? But the amount of rubbish that gets washed down our drains and contaminates the ocean is devastating!
  • Help by spreading awareness – Awareness is a powerful tool in the fight against climate change and suffering eco-systems.
  • Sustainable fishing – If you’re a fishing enthusiast like me we can fish sustainably by only taking what we need. This has a great impact on not overfishing coral reefs and allows them time to regenerate.
  • Keeping Anchors off the reef – If you love getting out on the boat ensure you find a sandy place to anchor. Anchors can easily destroy a coral reef.