Greenhouse gases are wreaking havoc on land and ocean temperatures all over the Earth. The rise in sea and ocean temperatures has caused widespread coral bleaching all over the world. Anuar Abdullah reveals the top 5 reasons why coral communities are dying or flourishing.
DYING
FLOURISHING
OVERFISHING
The killing of too many plant-feeding fish leads to overgrowth of plants, which smother corals, threatening their survival
APPROPRIATE DEPTHS
Relatively shallow (<27 metres), clear waters, allowing photosynthesis; deep-sea corals flourish in dark waters at 6,000 metres
SEWAGE AND INDUSTRIAL POLLUTION
Cuts out sunlight, giving rise to germs and disease; poisons corals directly, killing them
off quickly
NARROW RANGE OF TEMPERATURES
Tropical and subtropical waters between 20 and 30°C; deep-sea corals survive without sunlight on underwater peaks called seamounts
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
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
DREDGING
Dredging-generated sediments smother corals
STABLE WATER CONDITIONS
Require salinity between 34 and 37 parts per 1,000; they do well away from freshwater run-off
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
MINIMAL HUMAN INTERFERENCE
Need we say more?
Check out the rest of this article in Asian Geographic No.111 Issue 3/2015 ) here or download a digital copy here
