What is the Great Barrier Reef?

About Great Barrier Reef:

 

• Location: It lies in the Pacific Ocean off the northeastern coast of Queensland, Australia, in the Coral Sea.
• It is the longest and largest coral reef system in the world. 
• Size:
  • It extends in roughly a northwest-southeast direction for more than 2,000 km, at an offshore distance ranging from 16 to 160 km, and its width ranges from 60 to 250 km. 
  • It has an area of some 350,000 square km.
• It is composed of over 2,500 individual reefs of varying sizes and shapes and over 900 islands.
• It was designated as a UNESCO World Heritage Site in 1981.
• Much of the Great Barrier Reef is a marine protected area, managed by the Great Barrier Reef Marine Park Authority of Australia.
• Biodiversity: It is estimated that the reef is home to around 1,500 species of fish and around 600 different coral species.

 

Key Facts about Corals:

• Corals are marine invertebrate animals that belong to the phylum Cnidaria.
• Coral Polyps:
  • Corals exist as individual polyps, which are small, sac-like organisms with a mouth surrounded by tentacles.
  • The polyps secrete a hard external skeleton made of calcium carbonate, which forms the basis of the coral structure.
• Colony:
  • Most polyps live in groups of hundreds to thousands of genetically identical polyps that form a ‘colony’.
  • The colony is formed by a process called budding, which is where the original polyp literally grows copies of itself.
• Symbiotic Relationship:
  • Many corals have a symbiotic relationship with single-celled algae called zooxanthellae.
  • These algae live within the coral's tissues and provide them with essential nutrients through photosynthesis.
  • In return, the corals offer protection and a place to thrive in well-lit, shallow waters.
• What are Coral Reefs?
  • Coral polyps secrete a hard skeleton made of calcium carbonate, which over time forms the reefs.
  • Coral reefs are therefore created by millions of tiny polyps forming large carbonate structures.
• Coral Bleaching:
  • When stressed by high temperatures, pollution, or other factors, corals expel their zooxanthellae, leading to coral bleaching.
  • Without their symbiotic algae, corals lose their vibrant colors and become more vulnerable to disease and mortality.

 

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Q1) What is algae?

Algae are a diverse group of photosynthetic organisms that are found in all types of aquatic environments, including oceans, lakes, rivers, and even moist soil. They can be single-celled or multicellular, and they come in a wide variety of shapes and sizes. Like plants, algae are photosynthetic, meaning they use sunlight to convert carbon dioxide and water into energy-rich organic compounds like sugars. This process releases oxygen as a byproduct, contributing significantly to the Earth's oxygen production.

Source: UNESCO recommends to take Great Barrier Reef off danger list, still warns of ‘serious threat’