Lakshadweep Coral Reefs Decline by 50% in 24 Years

Lakshadweep Coral Reefs Decline by Fifty Percent

Why in the News ?

A 24-year-long monitoring study has revealed that coral cover in the Lakshadweep archipelago has declined by nearly 50% since 1998 due to repeated marine heatwaves, worsened by climate change, and reduced recovery after each bleaching event.

Lakshadweep Coral Reefs Decline by 50% in 24 Years

Findings of Long-Term Coral Survey:

  • Coral decline: Coral cover fell from 24% in 1998 to 19.6% in 2022, a nearly 50% reduction.
  • Cause: Repeated marine heatwaves triggered by El Niño events (1998, 2010, 2016) are the main reason.
  • Recovery lag: Although coral mortality decreased in each event, the rate of recovery also dropped.
  • Critical gap: A six-year period without bleaching is needed for coral reefs to recover significantly.
  • Predictive value: The study offers a predictive framework to identify vulnerable and recoverable reefs.

Influencing Factors and Local Conditions

  • Study locations: Coral health was tracked at Agatti, Kadmat, and Kavaratti
  • Environmental filtering: Wave exposure and depth were found to influence reef resilience.
  • Reef response: These local factors determine how reefs respond to climate stress.
  • Heatwave frequency: The number of marine heatwave events directly correlates with coral damage.
  • Monitoring agency: Study was led by the Nature Conservation Foundation.

About the Coral Reefs and ENSO Events:

●      Coral bleaching: Caused by loss of symbiotic algae due to heat stress.

●      ENSO impact: El Niño–Southern Oscillation (ENSO) drives ocean warming, leading to bleaching.

●      Biodiversity role: Reefs are hotspots of marine biodiversity and support coastal communities.

●      Recovery timeline: Coral reefs require multiple stable years for regeneration.

●      Conservation need: Highlights urgency for climate mitigation and marine conservation efforts.