Our Coral Reefs Are Still Dying: Latest Update on Reef Bleaching

Chasing Coral (2016) is a powerful documentary available on Netflix that demonstrates the ferocious damage climate change is inflicting upon the coral reefs of the world. Chasing Carol highlights the effects of reef bleaching, and how our coral reefs are rapidly dying out. But while this insight into coral reefs is well worth your time, there’s a problem with Chasing Coral.

It feels like watching ancient history.

The documentary was filmed in 2015, only a few years ago. In most cases of ecosystem destruction, this would mean the situation is more or less the same. Typically, ecological impacts are slow declines, taking many years to see real and definable change.

But in the case of coral reefs dying, things are different.

The documentary is a testament to the destructive power of coral reef bleaching. Chasing Coral saw a dive team conduct a research project, where they spent over 100 days image cataloguing reefs. When they started, they were swimming through beautiful coral reefs. By the time they finished, they were gliding over graveyards.

If entire reefs of coral can die in just 100 days due to climate change and reef bleaching, what is the state of our oceans now, years on?

The purpose of the documentary was to show the world that, as of filming in 2015, coral reefs were dying. But since the rate of change that occurs in coral bleaching events is so cataclysmic, where does that leave us in 2020?

Why Coral Reefs are Dying: What Causes Coral Bleaching?

Corals, believe it or not, are animals. They might look like plants, but corals actually have digestive systems and biological structures complex enough to classify them as an animal species. One of the most fascinating things you need to know about coral is that they produce their own food. They are filled with tiny plant cells that create energy through photosynthesis, which is why coral is only found in shallow waters in sunny climates.

This energy production feeds the animal.

When the water around the coral gets too hot, the plant cells no longer function. They’re very sensitive to temperature and only produce energy within certain ranges. This is much like how your body has to remain at around 37’C. Too hot or too cold and your biological functions stop working as they should. The same can be said for the plant cells in coral.

As the waters warm, the coral notices that the plant cells are not working properly. In a similar reaction to our immune system, the coral will then rid itself of the dysfunctional plant cells in order to cleanse its body of parts that are not working. The exodus of plant cells causes the coral to go bone-white, as they give the coral its colourful pigment.

This is what is known as coral bleaching.

You’ve probably noticed the problem here. If the plant cells create food for the coral, what is it going to eat if it expels them all? The answer is very little. With no plant cells, the corals slowly starve to death. A bleached coral is not a dead coral - yet. A bleached coral is a coral without plant cells to feed it. The coral can produce more of these plant cells if the water temperature returns to normal quickly, but any sustained rise in ocean temperature means the coral will die.

Right now, around 50% of coral that bleaches dies, but as waters are getting warmer for longer, that figure is set to increase.

It’s not difficult to guess why bleaching is occurring. Climate change is raising global temperatures fast. 2020 saw the highest temperatures ever recorded. A town in Russia, found within the Arctic Circle, recorded a temperature of 37’C. The first time an arctic location has even crossed the 100 Fahrenheit marker.

But while rising surface temperatures are known to be a massive issue, the ocean is actually under a much greater threat. Our oceans absorb 90% of the world’s excess heat, which means as temperatures soar around the world, we’re seeing significant increases in temperatures that are affecting coral’s ability to feed and resulting in mass bleaching.

What is Mass Coral Bleaching?

Sea temperatures vary from location to location, based on a variety of factors including currents and weather patterns. Mass bleaching of coral occurs when large areas of ocean are affected by extreme warming events. If a wide area of reef is subjected to increased water temperatures for a sustained period, huge amounts of the reef can bleach. This is when we see high numbers of coral dying.

Current Levels of Coral Reef Bleaching

Coral reef bleaching events were once a rarity. So rare, in fact, that scientists didn’t understand what was causing them. We’re now alarmingly aware of why coral reefs are dying, but this information gives us little power to stop coral bleaching.

2019 was the hottest year on record for the world’s oceans, which meant we saw unprecedented levels of coral bleaching and subsequent coral death.

Well, it was unprecedented until 2020.

The 2020 coral bleaching event along the Great Barrier Reef saw the highest and most devastating coral bleaching ever recorded. Over 50% of reefs were affected across the entire Great Barrier Reef, with many experiencing severe coral bleaching.

Mass bleaching events are becoming incredibly frequent. Once a small-scale phenomenon observed in isolated incidences spread out over many years, they’re now annual events with the potential to cause high levels of mortality for affected corals.

Reports show that in the 1980s, around 8% of all reefs were at risk of coral bleaching. By 2016, that number rose to 31%. There are no official statistics for what that number is today, but with the frequency of coral bleaching increasing year-on-year, and record-breaking bleaching events recorded in 2020, the likelihood that more and more reefs continue to be affected is in little doubt.

The Future of Coral Reefs

Coral reefs are dying, but it’s not just the current populations of coral that are under threat.

Bleaching events don’t just kill coral, they stop the natural reproduction of new coral.

Coral reefs rely on healthy coral reproduction in order to spawn new animals. Data from recent mass coral bleaching events shows an 89% decrease in the amount of new coral found on reefs following widespread coral death. It’s not just established coral that is dying, but new coral is not being given a chance to grow and thrive either.

The future of coral is a dark one.

With global sea temperatures predicted to only rise over the coming decades, coral has no real defence against the onslaught. It is expected that within the next twenty years, 90% of coral will die.

Without change, coral will become an extinct species in the wild within our lifetimes.

Is There a Chance to Save Coral Reefs?

National Geographic reports on an initiative that aims to save coral reefs. Through a process of monitoring natural reef structures, scientists are removing coral that has survived mass bleaching and breeding them in controlled lab conditions.

The concept is very simple: find the most resilient coral and multiply their genetics. Once bred, the corals are reattached to the reef, with the idea of making reefs more resistant to bleaching.

In short, by finding species of coral that can adapt to rising temperatures, scientists hope to save coral reefs by essentially empowering natural mechanisms of survival of the fittest.

But there is a problem with the methodology.

The theory and practice behind the project is sound. Coral, given the chance, is actually very receptive to change and can move with its environment. It can quite happily move from lab to reef without issue, breed and produce more healthy coral.

However, it is thought that the intense changes to global ocean temperatures will mean this strategy is only going to work for so long. Eventually, the waters will become so warm that even the most resilient coral will die. Genetics and biological resistance can only take a species so far. Eventually, not even the toughest corals will be able to resist the impact of climate change.

This is resistance to heat, not immunity.

We’re facing a race against time. We can shield corals from destruction, but for how long?

It is suggested that by 2100, the oceans will have warmed to such an extent that no coral can survive at all, no matter how resistant it is to warmer waters.

Coral Reefs Are Dying: Can We Save The Reef?

It’s hard to imagine that we as individuals could have any sort of impact on the health and survival of coral reefs. How can we prevent coral reefs from dying when they’re being killed off by climate change? A problem on a global scale.

Simply put, awareness is the first step.

Awareness breeds opportunity. The more people fighting a battle, the stronger that force becomes. Inactivity is the death of coral. The best hope coral has right now is in the scientists attempting to breed heat-resistant coral.

This change has only come about because of awareness.

From saving the elephants to stopping deforestation, change is born through the power of people. The more people helping to shape the future of coral, the better the chances coral reefs stand. Together, we can promote and influence change through increased interest in projects that aim to help coral survive.

Public outcry can lead to new funding for coral conservation. New funding can help develop strategies that save our reefs.

Data also shows us that coral reefs are more likely to die if they’re being exploited for resources, such as fish. Protected reefs are healthier and more capable of surviving and recovering from coral bleaching events.

Again, awareness of the plight of coral helps to convince governing bodies to protect the oceans they control.

But yes, as we’ve established, this is only a temporary reprieve from the ravages of climate change. Ultimately, the health of our coral reefs, and their survival, depends on the temperatures of our oceans, and that’s only going to be reversed through major changes to the global climate crisis.

You can do your part to help reduce climate change by following all the usual best practices for reducing your carbon footprint, yet the reality is if we want to see coral reefs survive for future generations, their fate lies with national climate change initiatives. It’s not simply about saving the reefs, it’s about saving our planet.

Save the planet. Save the reefs.

Get out onto coral reefs before they’re lost forever. Discover the best places to snorkel in the world.