THE TRAGIC PHENOMENA OF CORAL BLEACHING

For years, the ocean has absorbed earth’s excess heat (predominantly caused by the burning of fossil fuels). Now, ocean temperatures are rising and have reached an increase of approximately 2 degrees celsius. This number may appear small, but

“for marine life this is like living with a constant fever”

(Chasing Coral 2017). This is the leading cause for coral bleaching.

Coral bleaching is used to describe the phenomena of dying corals.

PANTONE ‘Living Coral’ by Yen-Yi Lee

#GlowingGone⁠ @glowinggone

Healthy, thriving coral reefs have warm, natural colours. Coral polyps are marine animals (not plants). They are responsible for forming the diverse and familiar structures in coral-reef ecosystems.

Being the “rainforest of the sea”, around 25% of marine life is dependent on healthy corals. Their structures protect coastlines from storms and erosion. They are an important source of novel medicine, food and jobs, particularly for the local communities surrounding them. “Over half a billion people depend on reefs for food, income, and protection” (National Oceanic and Atmospheric Administration).

Corals are not self-sustaining because they cannot make their own food. As such, they share a symbiotic relationship with algae-like species called zooxanthellae which reside in coral tissues. The zooxanthellae photosynthesize to ensure that the coral receives organic products, while also producing oxygen and removing waste. They are responsible for healthy, thriving coral reefs.

As ocean temperatures rise, corals ‘panic’. We can see this first stage of coral bleaching as the corals’ colours turn into vibrant neon purples, blues and yellows.

“When you first see it, you think perhaps that it’s beautiful, and suddenly you realize...it’s tragic”

- Sir David Attenborough, ‘A Life On Our Planet’ (2020).

#GlowingGone @theoceanagency @glowinggone

PANTONE ‘Glowing Blue’, ‘Glowing Yellow’ and ‘Glowing Purple’ by @theoceanagency captured during the @Neflix Original Documentary @ChasingCoral

As the corals are under severe stress, they expel the zooxanthellae as an emergency survival response. This response is short-lasting and leads to the next stage of bleaching where corals turn chalk white. Corals can temporarily survive without the zooxanthellae on the stored organic matter, and may regenerate if circumstances allow. However, the more common outcome is that the coral begins to starve without the zooxanthealle. As it starves, the coral begins to lose its colours and only the calcium carbonate skeletons remain.

These skeletons will soon be covered by new algae which will hinder any hope for regrowth.

Image by Brett Monroe Garner

for Greenpeace

Coral Reef Ecosystems are severely threatened, although the burning of fossil fuels (and climate change) are the predominant threats, they are also subject to natural threats (such as storms, predators and diseases), and other man-made threats (such as pollution, unsustainable fishing, and poor-practices in the tourism industry). Image by the Ocean Agency

So What Now?

What can you do to positively contribute to this issue?

1. Inform Yourself & Get Involved:

If you’ve come this far, we’ve got to say that it is a wonderful start to tackling the issue. Our society is one of many groups that you can engage with to get a better understanding and help raise awareness about issues like these. This blog is just a start, but if you’re interested in learning more, we recommend the following documentaries:

• Chasing Corals by Jeff Orlowski

• The Great Barrier Reef by David Attenborough

• Our Planet: How to Save Our Coastal Seas by David Attenborough

• Blue Planet II by David Attenborough

• Desert Seas by Dominic Weston, Mark Wheeler & Simon Nash, starring David Attenborough.

• Can we save our Reef? By Adam Geiger.

2. Cut-Out or Choose Sustainable Seafood:

We recommend the Good Fish Guide by the Marine Conservation Society.

3. Check your products for active ingredients:

See oceanservice.noaa.gov/sunscreen

Can’t Get Enough? Check out NOAA’s infographic below for more suggestions, and stay tuned to our society’s posts and events.