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The
disruption in the ocean-atmosphere system in the Pacific region effects
weather conditions around the globe. An example is the increased rainfall
across the southern region of the US and in Peru, which in turn caused
destructive flooding. Another example is drought in the West Pacific, which
is sometimes associated with devastating fires in Australia.
ENSO
Modern scientists now use a new term ENSO –
“El Nino Southern Oscillation.” Observations made in the early 1900s by
a British scientist Gilbert Walker showed that when atmospheric pressure is
low around Australia, it is high to the east of Tahiti and vice versa. This
behavior of air pressure is termed as the Southern Oscillation.
It has its effect on the weather conditions in other places. As the
warm air from the Pacific region spreads eastwards, big tropical
thunderstorms that are fuelled by warm humid air from the oceans move along
with the air. El Nino occurs at irregular unpredictable intervals. The
interval could be as varied as two years to a decade.
The
ill effects of El Nino as felt in India
Many ill effects of El Nino have been found by
scientists. One main resultant ill effect has been termed as bleaching. When
a coral is subjected to bleaching there is a rapid loss of pigmentation.
This happens because photosynthetic activity (main source of food for the
corals) by the corals is reduced. When
bleaching occurs, the corals lose their color. The color may be regained
if the bleaching action stops after a short duration, but continued
bleaching kills the corals.
Some of
the ill effects according to a study conducted by the Centre for Ecological
Research and Conservation in Mysore, India are -
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Bleaching of |
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Nearly 11
per cent of the corals in the Gulf of Kutch reefs
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82 per cent
of the coral cover in lagoon reefs of Lakshadweep
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89 per cent
of the Gulf of Mannar reefs
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Death of |
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This kind of mass
bleaching could adversely affect the economy of a place that is
heavily dependent on sea life with activities such as cottage
industries based on products from the sea, and fisheries. |
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