Mentor’s Comment:
Answer can be framed simply in three parts.
First, brief introduction of the phenomenon.
Second, explanation of underlying factors of coral bleaching.
Third, description of effects of El Nino on corals, with examples.

Answer:

Lakshadweep is the major area of coral formation in India. Unfortunately it is facing decline in coral reefs
as reported that till 2010, the live coral reef cover in the island was recorded at 27 per cent, which
dropped to 11 per cent in the subsequent year because of the May 2010 bleaching. This decline is
presenting the serious threat to marine ecosystem and livelihood prospects of local community.
The various environmental and anthropogenic factors that are contributing to coral degradation are:

(i) Environmental
• Climate change: the rise in sea surface temperature due to El-Nino phenomenon during 1998
caused extensive coral reef bleaching impacting over 40 to 90% of live coral cover.
• Coastal erosion: It is a serious problem faced by the islands every year resulting in loss of land.
• Increasing sedimentation and pollution of water is disturbing the delicate balance of coral and
their survival need.

(ii) Anthropogenic
• Population pressure: Changing demographic pattern and lifestyle, coupled with resource harvest
from the reefs have brought many reefs in the Lakshadweep to various degrees of stress.
• Developmental activities: Overexploitation and mindless mining of coral reef colonies led to
degrading of coral reef.
• Coral tourism: Lakshadweep increasingly being promoted as major tourist destination for sea
sports like scuba diving. This results in environmental pollution particularly of sea water.

El Nino as an anomaly is not well understood phenomenon but it is cites as major threat to coral by
scientists. It raises the sea temperature and sea level disturbing the delicate ecosystem of corals. Further,
it is well established that the last big El Niño in 1997/98 caused the worst coral bleaching in recorded
history. In total, 16% of the world’s coral was lost and some countries like the Maldives lost up to 90% of
their reef coverage