Coral bleaching occurs when coral polyps expel algae that live inside their tissues. Normally, coral polyps live in an endosymbiotic relationship with these algae, which are crucial for the health of the coral and the reef.

Causes of Coral Bleaching

• Extreme climate conditions: Corals decline in high water temperatures as they cannot survive in such conditions. As estimated by scientists, most of the coral reefs of the world will soon decline with the increasing rates of ocean warming.
• Ocean Acidification: Oceans absorb more carbon dioxide due to a rise in CO2 levels. This increases the acidity of ocean water. This inhibits the corals’ ability to create calcareous skeletons that essential for their survival.
• Pollution: Toxic pollutants dumped into the ocean raise seawater nitrogen levels, poisoning coral reefs and causing algal overgrowth.
• Sedimentation: Construction along the coasts and islands lead to soil erosion, increasing the sediments in the river. As a result, it can smother corals by depriving them of the light needed to survive.
• Infectious Diseases: Vibrio shiloi is a bacterium that inhibits the photosynthesis of zooxanthellae. This bacterium becomes more potent with an increase in sea temperatures.
• Coastal development: Development of coastal infrastructure and tourist resorts on or close by these coral reefs causes significant damages.
• Human activities: Over-fishing, coral mining, development of industrial areas near coral ecosystems etc. impact coral ecosystem.

Impact of Coral Bleaching

• Ecological Impacts: Bleaching leads to reduced species diversity, coastal erosion risk, and alterations in coral communities impacting dependent organisms.
• Socioeconomic Impacts: Local human groups rely on the ecosystem services that coral reefs offer, but degraded coral reefs are unable to provide these services.
• Bleached coral reefs can quickly lose aesthetic appeal, impacting their importance for reef tourism. As a result, there is a loss in tourism revenue.
• It has the potential to cause major changes in fish populations. Fishers targeting reef fish species catch less fish as a result, affecting food availability and accompanying economic activity.
• Pharmaceutical substances are abundant in coral reefs. Degraded or dead reefs are less likely to provide vital therapeutic resources.

Security Measures

• The Ministry of Environment and Forests offers financial assistance to Union Territories/ Coastal States to help with coral reef and mangrove guarding and maintenance.
• It is listed as Schedule I of the Wildlife Protection Act of 1972 which grants it the highest degree of protection that is possible
• The United States has protected areas for marine life, including coral reefs, under the Wildlife (Protection) Act, 1972.
• The Wildlife Crime Control Bureau was created to enhance the enforcement of laws to fight poaching and the illegal trade in wildlife.

Frequently Asked Questions related to the bleaching of coral reefs:

Ques 1. What causes coral bleaching?

Ans.Prolonged or extreme heat exposure causes corals to expel symbiotic algae, leading to coral bleaching due to rising ocean temperatures. This leads to the loss of the colorful algae, turning the corals white or pale.

Ques 2. How does coral bleaching impact coral reefs?

Ans. Coral bleaching has detrimental effects on coral reefs. Without the symbiotic algae, corals become more vulnerable to stress, diseases, and death. Bleached corals can suffer reduced growth and reproduction, impacting the health and resilience of the reef ecosystem.

Ques 3. Can coral reefs recover from bleaching events?

Ans. Coral reefs can recover from bleaching events under favorable conditions. Corals recover by regaining symbiotic algae and health when stressors causing bleaching are reduced or eliminated. Severe or repeated bleaching events hinder recovery and increase the risk of long-term reef damage and degradation.

Read Also : Threats To Coral Reefs