Marine Park Issue

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.

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. Marine Debris How can you help? The following are useful ways you can help to decrease the amount of litter being discharged into our oceans: Dispose of all litter and waste appropriately. Remember that storm water drains flow straight into our waterways - keep them clear and do not use them as rubbish receptacles. If you go fishing make sure you take your entire rubbish home with you. Do not wash your car on the road or driveway because the detergent and oil will wash down the storm water drain and flow into the ocean. Reduce the number of plastic bags and packaging you receive when buying goods and make sure you reuse your plastic bags. Pass on the message to others about the dangers of rubbish to marine animals and encourage them to dispose of litter properly. Recycle your household items. Ask your Local Government what you can recycle in your area. Get involved in "BEACH CLEAN UP AND AWARENESS PROGRAMME" and other community events. Report sick, injured, stranded or dead marine animals like seabirds, dugong, turtles, whales or dolphins to Marine Park Office.