CORAL REEFS IN A DETERIORATING ENVIRONMENT
What’s in news?
An inspection was on corals growing on tables in the Red sea as a part of research carried out by the Interuniversity Institute for Marine Sciences near the Southern Israeli city of Eilat.
- As coral reefs around the world face growing danger from a changing climate, scientists are researching new interventions that have the potential to slow coral reef damage from warming and acidifying oceans.
- A new report from the National Academies of Sciences, Engineering, and Medicine examines these resilience tools and provides decision-makers with a process they can follow in considering whether to use one or more of the novel approaches.
What are corals?
- Corals are a kind of calcareous rock, chiefly made of the skeletons of minute sea organisms called ‘polyps’.
- Though they are very tiny creatures, their ability to secrete calcium carbonate within their tiny cells has given rise to a particular type of marine landform. The landforms are popularly known as coral reefs.
- Coral reefs and atolls are formed due to the accumulation and compaction of the skeletons of these lime secreting organisms.
- Corals reefs are one of the most diverse habitats in the ocean. It is commonly known as the rainforest of oceans.
- There are two major types of corals: hard corals and soft corals, such as sea fans and gorgonians. Only hard corals build reefs. While the majority of coral reefs are found in tropical and sub-tropical waters, there are also deep water corals in colder regions.
- According to the United Nations Environment Programme, there are more cold-water coral reefs (largest cold-water coral reef is the Rost Reef off Norway) worldwide than tropical reefs.
Conditions for Growth of Coral Reefs:
- The surface water temperature of the ocean must not be less than 20 degrees Celsius. The condition virtually limits the areal distribution of corals to the tropical, and sub-tropical zones.
- Corals can live only in saline water, and for their proper growth the average salinity should be between 27 to 40%.
- For the growth of coral the depth of the water should not exceed 200m. Most vigorous growth is confined to shallow water less than 50 m. deep.
- Corals also require sediment-free, clean water, which is disturbed by ocean waves and currents is beneficial for the corals.
- In the open seas it is necessary to have platforms which may act as foundations for the corals. These platforms should not be deeper than 90 m.
Types of Coral Reefs:
The three main types of coral reefs include,
- Fringing Reefs
- Barrier Reefs
Importance of Coral Reefs:
- It is a source of food for millions of marine species.
- It protects coastlines from storms and erosion.
- It is a source of new medicines.
- It assists in carbon and nitrogen fixing as well as helping with nutrient recycling.
Bleaching refers to the paling of coral color. It occurs when
- The density of zooxanthellae residing inside the reef’s declines.
- The concentration of photosynthetic pigments within the zooxanthellae fall.