EARTH SCIENCE
CLIMATE AND ENVIRONMENTAL CHANGE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
Habitat is being lost as ocean water levels drop.
|
|
|
Ocean water temperatures have cooled to maintain balance.
|
|
|
Photosynthesis happens to a greater extent due to increased sunlight.
|
|
|
The algae contained within some corals are dying.
|
Detailed explanation-1: -Bleaching occurs when prolonged increased sea temperatures cause a breakdown in the relationship between the corals and their symbiotic zooxanthellae (algae). The coral subsequently expel the zooxanthellae, lose their colour (bleaching) and become weak.
Detailed explanation-2: -A warming ocean: causes thermal stress that contributes to coral bleaching and infectious disease. Sea level rise: may lead to increases in sedimentation for reefs located near land-based sources of sediment. Sedimentation runoff can lead to the smothering of coral.
Detailed explanation-3: -The leading cause of coral bleaching is climate change. A warming planet means a warming ocean, and a change in water temperature-as little as 2 degrees Fahrenheit-can cause coral to drive out algae. Coral may bleach for other reasons, like extremely low tides, pollution, or too much sunlight.
Detailed explanation-4: -When water is too warm, corals will expel the algae (zooxanthellae) living in their tissues causing the coral to turn completely white. This is called coral bleaching.
Detailed explanation-5: -If coral reefs disappeared, essential food, shelter and spawning grounds for fish and other marine organisms would cease to exist, and biodiversity would greatly suffer as a consequence. Marine food-webs would be altered, and many economically important species would disappear.