For the fourth time in six years, the corals of Australia’s Great Barrier Reef are going through another mass bleaching event – a major casualty in the ocean world brought on by the ever-growing climate change crisis.
Coral reefs serve as the fundamental infrastructure for life under the sea. While it mostly serves the ecosystem as a habitat for other marine lives, corals themselves are also living, stationary invertebrates, consisting of small “polyps” that enable them to feed on tiny planktons for sustenance. Because they play a vital role in maintaining the underwater ecosystem, removing them from the said ecosystem would not just drastically alter the living conditions there, but might even endanger several species as well.
If a byproduct of climate change – such as the warming of oceans – does worsen over time, ocean dwellers are capable of finding a more hospitable area to thrive in; whether they find one or not is entirely a different matter. However, being the immovable, stationary beings that they are, corals do not have the luxury of travel and thus have to endure harsh conditions. And this is when the bleaching begins.
As mentioned before, corals are what make up the lively and vibrant ecosystem in the form of reefs, but corals themselves have a roommate of their own as well. Known as “zooxanthellae”, these photosynthesizing algae reside in the coral’s tissue and coexists with its “host” through a symbiotic relationship – the corals offer protection, carbon dioxide, and nutrients, while the algae provide oxygen and organic products, a bit of housecleaning, and even the dazzling colors that make the corals look appealing.
This relationship also benefits the rest of the reef to some extent; the algae is also a valuable food source for fishes, which in turn can be able to help regulate the production of the plant-based species through feeding.
Unfortunately, temperatures have risen four degrees above average in the area – which is particularly concerning as this is occurring during a year when the ocean temperatures in the area are typically cooler (also known as a La Niña year).
The corals become “bleached” by expelling the algae out of their tissues, hence losing their vibrant color in exchange for a ghastly white. These situations can be reversed, however, and a return of these algae could probably restore the corals to their former glory; but if neglected for too long, the corals would eventually die from starvation.
The end result would probably be predictable to notice – a barren sea with the skeletal-like remains of the corals, which would eventually decay into powder. A boneyard of sorts, but for corals and whatever creatures were unfortunate enough to stay behind.
The 2,300km-large Great Barrier Reef is home to about to thousands of different marine species – ranging from anywhere between fishes, mollusks, turtles, and mammals… to corals, sponges, and plants. It is the go-to spot for anyone wanting to embark on an oceanic adventure and serves as a hotspot (no pun intended) for the region’s tourism industry. However, both its beauty and marketability would be lost if the waters warm even further, and it would damage not only the ecosystem but to the tourism industry and the livelihoods of those who depend on it.
The Australian government is working fervently to preserve the reef, while also calling on organizations such as the UN to declare it as an “at-risk” zone and to take the necessary measures on mitigating the effects that pose such dangers to it.
Regardless of the grave impact, this problem poses to the world as a whole, it is still one among many warning signs materializing throughout the world. Ocean warming isn’t just bleaching the corals, it is also leading to melting ice caps, unwarranted migration of marine life and thus causing an imbalance in habitats, and ultimately, an inhospitable environment that could definitely wipe out species from the map.
It all leads back to us in the end. Our overreliance on fossil fuels and blatant destruction of flora and fauna for territorial expansion unleash copious amounts of greenhouse gases that heat up the planet. The ocean can only do so much to absorb some of that heat, but even that is now at the point of endangering its own inhabitants just so that those on land would suffer less. It goes without saying, but we can’t wait around for the ocean to restore its ecosystem on its own just to repeat another bleaching in the imminent future. As it has aided us in absorbing the heat from our atmosphere, we have to engage in sequestration efforts that would help lighten the load. Just like the symbiotic relationship between the corals and the algae residing in them, we have to align ourselves with nature in a concerted effort in mitigating global warming together.