Why Are Lakshadweep Coral Reefs Undergoing Severe Bleaching?

Introduction:

• The ICAR-Central Marine Fisheries Research Institute (CMFRI) has recently revealed alarming findings regarding coral bleaching in the Lakshadweep Sea. This phenomenon, driven by prolonged marine heatwaves, poses a significant threat to the diverse marine ecosystems of the region.

What are Coral Reefs?

• Corals are sessile animals with stony skeletons that form the basis of coral reefs.
• Lakshadweep’s islands are predominantly coral atolls, showcasing the importance of coral reefs to the region’s ecosystem.
• Corals create intricate ecosystems, often referred to as “rainforests of the sea,” supporting a myriad of marine species.

Understanding Coral Bleaching:

• Coral bleaching occurs when corals expel symbiotic algae due to warm water temperatures.
• Without algae, corals lose their color and are at risk of starvation and disease.
• The current bleaching event in Lakshadweep has been attributed to prolonged marine heatwaves since October 2023.

Temperature Trends in Lakshadweep Sea:

• Corals experience thermal stress when sea surface temperatures exceed 1 degree Celsius above the maximum mean temperature.
• The Degree Heating Week (DHW) indicator is used to measure accumulated heat stress, with values above 4 degrees Celsius-weeks causing significant coral bleaching.
• Lakshadweep Sea has been experiencing temperatures 1 degree Celsius above the norm since October 27, 2023, leading to unprecedented bleaching.

Regional and Global Context:

• Marine heatwaves are not isolated to Lakshadweep; they are increasingly prevalent in the Indian Ocean, posing threats to marine ecosystems and coastal communities.
• A 2022 study by the Indian Institute of Tropical Meteorology (IITM) reported a significant increase in marine heatwaves, attributing it to rapid warming in the Indian Ocean and strong El Niños.
• The impacts extend beyond corals to include seagrass meadows, kelp forests, and marine habitats critical for coastal communities and fisheries.

Summary:

• Coral bleaching, driven by marine heatwaves, poses a severe threat to Lakshadweep’s marine ecosystems.
• Increased temperatures in the Lakshadweep Sea have surpassed thresholds for significant coral bleaching, endangering the region’s biodiversity and livelihoods.
• Regional and global trends indicate a concerning rise in marine heatwaves, emphasizing the urgent need for conservation and climate action.

FAQ:

1. What causes coral bleaching?
   • Coral bleaching occurs when corals expel symbiotic algae due to warm water temperatures, leading to stress and potential mortality.
2. How does coral bleaching impact marine ecosystems?
   • Coral bleaching threatens biodiversity, fisheries, and coastal communities dependent on healthy marine ecosystems for livelihoods and sustenance.
3. What can be done to mitigate coral bleaching?
   • Conservation efforts, including reducing carbon emissions and protecting marine habitats, are crucial for mitigating coral bleaching and preserving marine biodiversity.
4. Are marine heatwaves a global phenomenon?
   • Yes, marine heatwaves are increasingly prevalent globally, with the Indian Ocean experiencing a significant rise in frequency and intensity in recent years.

Reference link: https://indianexpress.com/article/explained/explained-climate/lakshadweep-coral-reefs-undergoing-severe-bleaching-9311488/