Biome Meltdown: Coral Bleaching on the Great Barrier Reef

Over 500,000 years old. As large as the country of Germany. Visible from space, and home to more than 1,600 species of fish, 30 species of whales and dolphins, and 130 species of sharks and rays. The largest living structure in the world- by far. What is it? It could only be: Australia’s magnificent wonder, the Great Barrier Reef, a living city founded on over 3,000 individual reefs of coral. This underwater world is a universe unto itself, with a self-sustaining ecosystem that allows for thousands of different water-dwellers to not only live but to flourish. But today? Today sees a rotting death touching each corner of this watery paradise. Today, the health of the grand Great Barrier Reef is slowly sinking, and sinking under a miserable illness caused not by cycles of nature but by the gradually increasing temperatures of the surrounding seas. In a word: global warming.

 

What Is Coral Bleaching?

Coral bleaching doesn’t mean humans have dumped too much bleach into the water at last (although not for lack of trying). Coral “bleaching” refers to the draining of color from the coral, and its eventual and final death. It happens specifically when coral is in far too warm of water for far too long. The coral polyps become stressed due to the temperature and expel the algae that lives inside of them. Since the algae is what gives the coral its vibrant color, the coral then becomes transparent to the point where the white skeleton is visible underneath. Thus, “bleached” coral.


Why Is Bleached Coral Bad?

Albino coral is not a sign of a new and exciting species. Bleached coral is dead coral. Why? Because the algae that the coral spit up was what provided 90% of the coral’s energy. Without the algae, the coral begins to starve, and without a return to normal water temperatures the coral will die and be swiftly overcome by a suffocating carpet of seaweed. It can take over a decade for coral to recover from a catastrophe like this, and that’s without considering other detrimental factors like pollution.

 

Why Should We Care About Coral?

Coral provides fundamental structures for underwater ecosystems to survive and thrive. If coral dies, the whole ecosystem must undergo a radical change; imagine if your house’s foundation was suddenly ripped out from underneath it. In the case of bleached reefs, once the coral dies fish can no longer use the coral as shelter. The seaweed blanket is too thick for the fish to penetrate, fish which might feed on it, use it as a hiding place, or eat the algae on it. Once these fish perish, so will the larger fish that feed on these fish. The cascading effect spirals downwards from there, moving all the way from the coral to birds to human beings themselves.


The Great Barrier Reef’s Demise

If you don’t care too much about the perpetuation of the underwater and above-water species utilizing the Great Barrier Reef, consider at least the effect on the humans that rely on its well-being for their own. Worldwide people rely on reefs for food, income, and shelter from waves- and that goes for the Great Barrier Reef, too. More importantly than this, the rotting death of the Great Barrier Reef jabs an accusatory finger at the rise in global temperatures that most scientists agree is due to human-related activities. More than 22% of the Great Barrier Reef is dead, and roughly 93% is dying. While coral bleaching has been seen in small pockets around the world over the centuries, nothing on this scale has ever been recorded. The Great Barrier Reef is dying. And we are to blame.

 

What Now

Can the Great Barrier Reef be saved? Australia seems to think so. With a staggering 93% of the coral structures affected, however, and pollution at record highs, it’s perhaps more realistic to think otherwise. Global warming is causing a rise in the temperature of the oceans as well as a change in their acidity levels. If it’s not warm water now, it might be overly-acidic water tomorrow, and even more likely it might be a downed ship full of oil the day after that. Earth is suffering under the heavy burden that humanity has hefted onto its shoulders and we are now seeing its steps falter underneath the weight. We would do well to take heed, as a nation, and as a global community, of these warning signs.