Study on Coral Cover

Study on Coral Cover : Recently, a comprehensive 24-year-long scientific study has brought to light a stark reality about coral cover in the Lakshadweep archipelago.

o It shows that coral cover has declined largely due to repeated marine heatwaves caused by global climate change.

• Key Highlights : Study titled “Local Environmental Filtering and Frequency of Marine Heatwaves Influence Decadal Trends in Coral Composition”, published in Diversity and Distributions.

o Introduces a predictive framework to identify: Vulnerable reefs

- Potentially resilient reef zones across the Lakshadweep archipelago and possibly beyond.

o Coral cover in Lakshadweep declined by ~50%, from 37.24% in 1998 to 19.6% in 2022.

o Primary cause: Repeated marine heatwaves, especially during El Niño years (1998, 2010, 2016), worsened by global climate change.

o Local conditions like wave exposure and reef depth play a critical role in shaping bleaching impact and recovery.

• About Coral : Sessile marine animals that attach to the ocean floor. They live in symbiosis with zooxanthellae (algae) that provide nutrients via photosynthesis.

o Corals also capture food using tentacle-like structures.

o An individual coral animal is called a polyp, and many polyps form a colony.

o Hard corals have limestone skeletons and build coral reefs over thousands of years but soft corals do not.

o Coral reefs are known as the "rainforests of the sea", existing for over 450 million years.

o They are critical marine ecosystems, supporting thousands of marine species.