While many agree that climate change is bad, its most detrimental effects are not always evident in people’s daily lives. One example of this is the Great Barrier Reef, specifically the devastation that it has suffered in recent years as a result of global climate change. Increasing water temperatures cause corals to bleach and lose their color. While it is possible for them to recover from this, bleaching can also lead to coral death. Thus, widespread coral bleaching is incredibly dangerous to the health and survival of the Great Barrier Reef. When corals are in hotter-than-normal water, they expel their zooxanthellae, which are tiny photosynthetic algae that live within their tissues. These algae are what are responsible for giving the corals their color, so when they lose these algae, the corals turn white, which is where the term “bleaching” comes from. Since the corals have a symbiotic relationship with these algae, the expulsion of the algae compromises the health of the corals.
The Great Barrier Reef experienced severe bleaching in 1998, 2002, 2016, and 2017. The past two years are the first time that severe bleaching has occurred two years in a row. This is all the more dangerous because the corals do not have time to heal between these frequent bleaching events. James Kerry, researcher at the ARC Centre of Excellence for Coral Reef Studies in Australia, agrees with this in his statement that “it takes at least a decade for a full recovery of even the fastest growing corals, so mass bleaching events 12 months apart offers zero prospect of recovery for reefs that were damaged in 2016.” Furthermore, the process of recovery is not so simple, either. The corals will only regain their color if water conditions return to normal, so a continued increase in ocean temperatures will definitely prevent any recovery and only worsen the corals’ already damaged health.
The 2016 mass bleaching event mainly affected the northern third of the Great Barrier Reef. In 2017, the bleaching was mainly focused on the middle third, but there were areas of overlap. These areas, which “had a double dose of severe bleaching for two years in a row,” are the ones that are weakest and at the greatest risk of dying, especially if a third bleaching event were to occur in 2018. Aerial footage reveals large parts of the reef that have been drained of color in these bleaching events. The continued increase in bleaching will eventually cause the corals to die, an event that would disrupt an ecosystem that is both complex and vital to the health of millions of species and the planet itself.
The importance of saving the Great Barrier Reef, and all coral reefs, cannot be overstated. It is only through reversing the effects of global climate change that we can hope to preserve one of the most beautiful ecosystems on the planet. Of course, coral reefs are only one example of the many ecosystems that have suffered as a result of climate change, and it is up to the humans, those responsible for causing this change, to protect and preserve nature’s endless diversity and life.