Sambhav-2025

Approach Highlight the increasing pressures on aquatic ecosystems due to climate change. Explain the phenomenon of coral bleaching. Discuss the causes of coral bleaching and its impact on marine biodiversity and coastal economies. Conclude with the need for urgent action to mitigate these impacts.

Introduction

Coral reefs, often called the "rainforests of the sea," are essential for marine biodiversity and coastal economies. Despite covering less than one percent of the ocean floor, they support around 25 percent of all marine life. However, aquatic ecosystems, including coral reefs, are facing increasing pressure due to human-induced climate change, with coral bleaching being a significant consequence.

Body

Coral Bleaching: Coral bleaching occurs when corals expel the symbiotic algae (zooxanthellae) living within their tissues, which provide the corals with nutrients and their vibrant colors. This results in the corals turning white or "bleached."

The primary causes of coral bleaching are:

• Rising Sea Temperatures: While reef-building corals thrive in waters between 23°C and 29°C, temperatures above this range, even by a small margin, can trigger coral bleaching, where corals expel their symbiotic algae, leading to a loss of color and nutrients
• Ocean Acidification: Increased CO₂ emissions from human activities lead to more acidic oceans, weakening coral structures.
• Pollution: Agricultural runoff, oil spills, and plastic waste increase stress on corals.
  • Marine plastic pollution has been found in over 60% of coral reefs globally, causing significant harm by increasing disease risk, damaging coral tissues, and disrupting reef ecosystems
• Overfishing : UNEP reports that unsustainable fishing practices, including blast fishing (using explosives), have caused substantial damage to coral reefs, destroying habitats and ecosystems.
• Unsustainable Tourism:The high demand for recreational activities like snorkeling, diving, and boat tours often leads to physical damage to coral reefs

Impact on Marine Biodiversity

• Weakening of the Corals :Coral bleaching weakens the corals, reducing their ability to provide food and shelter for marine species.
• Loss of Species: Marine species that depend on corals for habitat and food are forced to migrate or face extinction.
  • For example, parrotfish, clownfish, and seahorses depend on healthy reefs for shelter, but bleaching causes these species to lose their habitat.
• Disruption of Food Chains: The collapse of coral ecosystems leads to a cascading effect, disrupting entire food webs.
  • For example, The Great Barrier Reef, a UNESCO World Heritage site teeming with diverse marine life, has experienced significant biodiversity loss due to widespread coral bleaching events in 2016 and 2017, impacting over 70% of its reefs. .

Impact on Coastal Economies

• Tourism Loss: Coral reefs attract millions of tourists, and bleaching reduces their aesthetic and ecological value.
  • For example, the Great Barrier Reef, a key tourism destination, contributes $6 billion to the Australian economy annually.
• Fisheries: Bleaching leads to fish migration, declining fish stocks, and loss of livelihoods for fishermen.
  • According to the World Wildlife Fund (WWF), coral reefs provide $6.8 billion annually from fisheries, and bleaching threatens these incomes.
• Coastal Protection: Healthy coral reefs act as natural barriers against storm surges and coastal erosion. Bleached reefs lose this function, leaving coastal areas more vulnerable to natural disasters.

Global initiatives aim to protect coral reefs:

• International Marinelife Alliance (IMA): Promotes sustainable marine resource management and works with governments to restore coral reefs.
• Coral Triangle Initiative (CTI): Involves six Southeast Asian countries to protect marine biodiversity and promote sustainable fishing.
• Global Coral Reef Monitoring Network (GCRMN): Monitors coral health worldwide, providing vital data for conservation.
• UNFCCC Adaptation Fund: Provides financial assistance for coral restoration and climate adaptation strategies.

Conclusion

Measures such as reducing carbon emissions, promoting sustainable fishing, and enforcing marine conservation efforts are essential to mitigate further damage and ensure the long-term survival of coral reefs. Without these efforts, we risk losing not only marine biodiversity but also the economic benefits coral reefs provide to millions of people globally.