Question

Keppel Island is completely bleached mainly due to the expansion of
1. Starfish
2. Blue whale
3. Octopus
4. Sea horse

Answer 1

Correct Answer - Option 1 : Starfish

The correct answer is Starfish.

• Keppel Island is located in the Southern Great Barrier Reef.
• Coral bleaching occurs when reef-building corals shed their tiny algae to relieve stress and to increase their chances of survival. 
• A primary cause of coral bleaching on the Great Barrier Reef during summer is heat stress resulting from high sea temperatures and increased UV radiation.
  • A temperature increase of just one degree Celsius for only four weeks can trigger bleaching.
  • Deprived of their food source, corals begin to starve once they bleach.
• Another major reason for bleaching in Keppel Island is Starfish whose population has grown uncontrollably in this region.
  • Normally, the starfish contribute to the reef’s diversity by eating faster-growing coral species, which allow for slower-growing species to thrive.
  • But at outbreak levels, the starfish are able to eat coral, a polyp that builds the limestone reefs on which they communally live, faster than the coral can reproduce.
  • This causes stress on the corals and leads to bleaching.