TOP 5 REASONS
WHY CORAL
COMMUNITIES ARE...
Dying Flourishing
1
2
3
4
5
OVERFISHING
The killing of too many plant-
feeding fish leads to overgrowth
of plants, which smother corals,
threatening their survival
SEWAGE AND
INDUSTRIAL POLLUTION
Cuts out sunlight, giving rise to
germs and disease; poisons
corals directly, killing them
off quickly
SEDIMENT
DISTURBANCES
Corals covered with sediment will
succumb swiftly to tissue loss
and death; Fungiid corals can
actively shed sediment buildup
by inflating and deflating rapidly
DREDGING
Dredging-generated sediments
smother corals
CLIMATE CHANGE
Overly warm waters cause
coral bleaching, making them
susceptible to disease, which
can lead to large-scale reef die-
off; stronger storms harm coral
reefs, translating into less time for
sensitive habitats to recover
APPROPRIATE DEPTHS
Relatively shallow (<27
metres), clear waters, allowing
photosynthesis; deep-sea corals
flourish in dark waters at 6,000
metres
NARROW RANGE OF
TEMPERATURES
Tropical and subtropical waters
between 20 and 30°C; deep-sea
corals survive without sunlight
on underwater peaks called
seamounts
STABLE CARBON
DIOXIDE LEVELS
Increasing carbon dioxide
levels changes water chemistry,
preventing corals from building
their skeletons; also slows down
growth and rate of regeneration
STABLE WATER
CONDITIONS
Require salinity between 34 and
37 parts per 1,000; they do well
away from freshwater run-off
MINIMAL HUMAN
INTERFERENCE
Need we say more?