Coral Bleaching
What is coral bleaching?
Coral bleaching is a stress condition in reef corals that involves a breakdown of the symbiotic relationship between corals and unicellular algae (zooxanthellae).
The symptoms of bleaching include a gradual loss of colour as zooxanthellae are expelled from the coral tissue, sometimes leaving corals bone white.
Bleaching stress is also exhibited by other reef animals that have a symbiotic relationship with zooxanthellae such as soft corals, giant clams, some sponges, etc.
Large expanses of coral can be affected during mass bleaching events.
Coral bleaching is a stress condition in reef corals that involves a breakdown of the symbiotic relationship between corals and unicellular algae (zooxanthellae).
The symptoms of bleaching include a gradual loss of colour as zooxanthellae are expelled from the coral tissue, sometimes leaving corals bone white.
Bleaching stress is also exhibited by other reef animals that have a symbiotic relationship with zooxanthellae such as soft corals, giant clams, some sponges, etc.
Large expanses of coral can be affected during mass bleaching events.
 |  |  |
The coloration of a healthy coral (left) is due to microscopic algae called zooxanthellae (center) living within its tissue. When bleaching occurs, the coral loses its zooxanthellae, leaving the white skeleton starkly visible through the transparent tissue (right).
Why do corals bleach?
 | Large expanses of coral can be affected during mass bleaching events. The stress factor most commonly associated with bleaching is elevated sea temperature, but additional stresses such as high light intensity, low salinity and pollutants are known to exacerbate coral bleaching. If the causal stress is too great or for too long, corals can die. |
No comments:
Post a Comment