A global coral bleaching event that began last year has increased to the largest on record resulting in roughly 77% of the world's reed area to experience bleaching-level heat stress.
According to a US agency, a global coral bleaching event that began in 2023 has escalated to the largest on record. The impacted reef area continues to grow. From the start of 2023, till October 10, 2024, as Derek Manzello of the National Oceanic and Atmospheric Administration (NOAA) mentioned to ADP on Friday, “roughly 77 percent of the world's reef area has experienced bleaching-level heat stress.”
Frequently referred to as the “rainforests of the sea”, coral reefs play a pivotal role in preserving the health of the oceans and shouldering diversity in marine life. Coral bleaching is a result of debarring the symbiotic algae (zooxanthellae) living in the tissues of the corals caused by rising sea temperatures. Not only does the colour of the coral get impacted because of this, their survival is also greatly affected leading to widespread ecological consequences.
Although the coral reefs envelope only around 0.1% of the Ocean's surface, it fosters the health and well-being of about 25% of all marine species. This magnificent biodiversity encompasses fish, mollusks, marine mammals, and invertebrates. All of these organisms depend on coral habitats for shelter, breeding and feeding. As of October, 2024, about 77% of the world's reef area has undergone bleaching-level heat stress, as reported by the National Oceanic and Atmospheric Administration ( NOAA). The plethora of species that depend on the ecosystem of corals are greatly impacted by the loss of coral cover. For example, species like parrotfish and clownfish play key roles in reef health. However, their population may narrow down due to the degradation of their habitats. This dwindling in biodiversity can disturb food webs, resulting in a plunging impact on marine biodiversity and ecosystem.
What do you think protects the coastal ecosystems from damage caused by storm and erosion?- they are the coral reefs! They aid in the absorption of wave energy, bringing down the impact of storms and high waves on coastal communities. As per research by the World Resources Institute, healthy corals can considerable safeguard the shorelines by reducing the wave energy by 97%. When coral reefs degenerate because of bleaching, coastal areas become more susceptible to erosion and flooding. This poses a threat to salt marshes, mangroves, and other important coastal ecosystems. This loss can result in escalating sedimentation, which would further harm marine life, especially seagrasses and other organisms which depend on clear and pure water for photosynthesis.
The economic implications of coral bleaching are extreme. This is true particularly for communities that rely on fishing and tourism. It is estimated that, globally coral reefs contribute nearly $375 billion perennially to the economy through coastal protection, fishery, and tourism. In areas like the Caribbean and Southeast Asia, where the economy primarily thrives on tourism, the loss of colorful coral reefs can distance visitors. For example, the UNESCO World Heritage Site, the Great Barrier Reef, which is one of the world's most celebrated tourist spots, has witnessed a substantial plunge in coral health due to bleaching events. This has deterred visitors, reducing tourism revenues and affecting communities which thrive on tourism for livelihoods.
Fishing industries are equally at risk. Coral reefs provide the surface for spawning and nurseries for young fish. With coral bleaching, this lifestyle is disrupted, leading to reduced fish populations. Because of this, commercial fisheries suffer, resulting in job losses and economic disparity in communities which depend on fishing. According to a report by the Food and Agriculture Organization (FAO), about 120 million people depend on fisheries for their livelihoods, worldwide.
