Coral bleaching may sound familiar, a term that many may have heard, especially in recent years. This issue became glaringly apparent last summer when Florida’s Coral Reef experienced its most severe bleaching ever recorded. Despite these events making headlines, misconceptions still abound. Many believe that bleached coral is dead, but that's not entirely accurate. In this article, we'll address common misconceptions surrounding these events and explore ways we can help. So, let’s dive into coral bleaching and why it matters.
What is Coral Bleaching?
In the past decade our planet has experienced record-breaking heat, with 2023 marking the hottest year ever recorded worldwide. As a result, rising ocean temperatures have put marine environments under immense pressure. This rapid warming presents a challenge for many species, which struggle to adapt quickly. Coral reef ecosystems have been significantly affected, experiencing drastic and sometimes fatal stress responses, including mass bleaching events.
A thicket of staghorn coral experiencing a stress response - bleaching. Photo by Jackson Harris.
When picturing a healthy coral reef, one often imagines vibrant colors and intricate shapes. However, it's important to note that the coral tissue that covers their white skeletons, is translucent. The various shades in coral are the colors provided by a symbiotic, photosynthetic algae known as zooxanthellae, that lives inside the coral’s body, and provide the coral with the majority of its nutrients. When corals undergo stress due to shifts in water temperature and other environmental changes, they expel their zooxanthellae, rendering the tissue transparent and exposing their white skeletons. Coral bleaching does not immediately lead to death but greatly increases the susceptibility of reefs to this outcome. When ecosystems face pressures beyond thermal fluctuations – such as pollution and overfishing – corals are more unlikely to survive bleaching events. And when corals die, the myriad species that depend on them are also vulnerable.
How does this Impact the Environment?
A large, healthy colony of elkhorn coral – one of the primary reef-building corals found in Florida. Photo by Jackson Harris.
Coral reefs are indispensable to life on Earth, serving as keystone ecosystems with far-reaching influences on both marine and terrestrial life.
These vibrant hubs of biodiversity beneath the ocean's surface, are essential ecosystems that support at least 25% of marine life, despite covering less than 0.1% of the ocean floor. Coral reefs play a foundational role in the intricate oceanic food web by providing this habitat. Despite their small coverage in our vast oceans, coral reefs have an immeasurable ecological impact.
From microscopic coral shrimp to large goliath groupers, these reefs offer space for marine species to flourish. These species, in turn, serve as a crucial food source for animals higher on the trophic level, such as sharks.
As crucial habitats fostering foundational marine biodiversity, coral reefs underpin the balance of almost all ocean ecosystems. Considering that approximately three-quarters of the Earth's oxygen originates from healthy ocean ecosystems, our very existence is intimately linked to these vital organisms, underlining their profound significance.
When coral bleaches and faces a higher risk of mortality, it diminishes structural integrity and reduces habitat availability for species reliant on these ecosystems. This reduction in coral abundance and health results in diminished shelter and food resources for various fish and invertebrates, affecting predators further up the food chain.
Increasing coral mortality has led to the formation of vast 'coral graveyards' – rubble fields made up of broken, algae-covered coral skeletons. Perpetual bleaching events are decreasing marine biodiversity and disrupting the larger oceanic food web, potentially leading to the potential for mass ecosystem collapse if these mass bleaching events persist.
A diver observing a colony of elkhorn coral on the reef substrate. Photo by Coral Restoration Foundation.
What About Us?
Healthy coral reef ecosystems offer valuable services beyond their beauty and complexity, benefiting millions globally. These ecosystems directly support food security and livelihoods for over 500 million people and contribute to income through fisheries and tourism industries. Additionally, coral reefs provide crucial coastal protection, absorbing up to 97% of wave action and safeguarding communities, particularly in hurricane-prone regions like Florida. It is estimated that globally, coral reefs have an annual economic value of around nine trillion dollars.
However, an increase in bleaching events worldwide threatens to diminish these benefits. Bleaching events reduce the integrity of coral reef ecosystems, making them more susceptible to breakage during strong wave action and diminishing coastal protection. This puts coastal infrastructure and vital coastal ecosystems, like mangroves, at risk. As a result, millions of people face the possibility of various insecurities due to the potential loss of these direct benefits from coral reefs.
Additionally, they offer unparalleled opportunities for recreation and education, allowing people to connect with and learn about marine environments firsthand. Preserving and restoring coral reef ecosystems is therefore crucial not only for sustaining biodiversity but also for fostering a deeper understanding of the natural world and ensuring a sustainable future for all.
How Can We Help?
When talking about things such as coral bleaching, it can be overwhelming - at times feeling like the only news is bad news. At Coral Restoration Foundation™, however, we are providing hope for these important animals and the ecosystems they build. We believe it’s important to focus on the good news coming out of the world of coral conservation and on what we as individuals can do to help prevent the further loss of our planet’s coral reefs.
To address the daunting issue of coral bleaching, it is vital that we put pressure on our elected representatives to take action on cutting carbon emissions and moving towards a carbon negative future. With this year being an election year, it is a critical time to support candidates, parties, and policies that take the protection and restoration of our planet’s life support systems a priority. The most impactful way you can make a positive change for life on Earth is by using your vote.
Individual choices also matter. By educating yourself and reducing your personal carbon footprint, you are also moving the needle for coral reefs. Ocean friendly decisions include reducing your meat intake, using public transport, reducing plastic consumption, and being mindful that all waterways lead to the ocean – avoid using harmful chemicals in your home and garden.
Incredible efforts to save and restore our coral reefs are underway around the world. At Coral Restoration Foundation™, we remain dedicated to this mission, but we can’t do it without you! Please consider supporting our work with a donation, or by sharing this message with your friends and family.
Coral reefs are under threat, but all is not lost – there is still time to turn the tide for these important little animals.
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