Home › Sea Wildlife › Coral Formations › Coral Bleaching
Environmental stresses disrupt the delicate mutualistic symbiosis that exists between corals and microscopic algae, the zooxanthellae that live inside their tissues.
Globally, warming oceans from climate change are considered as being the primary driver of severe bleaching. But other stressors can also make reefs less resilient.
It is widely accepted that most coral formations are disappearing at an alarming rate.
In fact, coral is a living polyp that surrounds a hard shell constructed of calcium carbonate.
But when corals get stressed, they lose their vibrant colouring and turn white (bleached).
Even though new divers may admire this "snow-like" environment, the tissue discolouration is actually a sign of distress.
Coral polyps share their calcium shell with zooxanthellae algae. These microscopic organisms convert energy from the sun into an energy form that coral reef polyps need to stay alive.
The coral polyp is a clear transparent formation. Hence, it's the algae species that live with it that create the bright colours that scuba divers and snorkelers love to see.
But - if that algae dies - the result is a distinct lack of colouration, leaving the skeletal remains of the coral polyps - white and colourless!
Coral reefs have an extremely small tolerance for changes in water temperature, typically (+/-) one to three (3) degrees of change.
In spite of that, and because of it, some of the key causes of coral bleaching and climate change are:
Pro Tip: Other stressors can lead to coral reef destruction, including "wayward" boat anchors and environmentally unfriendly fishing practices. Plus, overfishing and invasive species (e.g., the crown-of-thorns starfish) also increase coral's vulnerability to a deterioration in marine ecosystem health.
We have listed the most common reasons why coral bleaching occurs, some of the most significant threats to coral reefs, and why much of it is preventable.
Put another way:
We should stop introducing waste products (underwater garbage) into seas and oceans. We need more education and awareness about reef conservation and the plight of delicate marine ecosystems.
Many countries have laws banning the emptying of garbage and chemicals from factories into water systems. The production of unregulated greenhouse gases is one of the primary causes of a rise in sea temperatures.
Without alternatives to these preventable causes of coral bleaching, we risk losing a precious multi-coloured world of oceanic coral reefs.
The underwater world needs caring divers and non-divers to conserve the fragile aquatic ecosystems. You can join the actions of concerned individuals by discovering some of the most desperate problems facing these vulnerable underwater environments and ecosystems.
How?
The Project AWARE Specialty course contains some solutions that can help protect our coral reefs. It's informative, thought-provoking, and most importantly, it explains how you can make a difference!
Note: The main section lists 10 simple steps to saving coral reefs and how daily decisions and actions can make a difference.