Increased greenhouse gases from human activities result in climate change and ocean acidification. Climate change = ocean change. The world’s ocean is a massive sink that absorbs carbon dioxide (CO₂). Although this has slowed global warming, it is also changing ocean chemistry.

• Ocean Acidification: The increasing acidification of the ocean occurs when oceans absorb massive amounts of carbon dioxide released into the atmosphere by the combustion of fossil fuels.
• The rise in carbon dioxide levels increases the acidity of ocean water and inhibits the ability of corals to create calcareous skeletons.
• High amounts of solar radiation lead to the decline of coral due to global warming.
• Water Pollution: Water pollution caused by agricultural pesticides and fertilizers, oil and gasoline, sewage discharge, and sediment from eroded landscapes make it difficult for coral to thrive.
• It harms the complex relationships that exist between the plants, coral, and other animals that make up the reef ecosystem.
• Bacterial Infection: The prevalence of coral disease appears to have increased considerably during the last ten years, contributing to the global decline of coral reef communities.
• The majority of diseases are caused by bacteria, fungi, and viruses.
• Because the coral disease has been proven to proliferate after coral bleaching events, the evidence for a link between warmer-than-normal water and coral disease is growing.

• Overfishing can alter food-web structure and cause cascading effects, such as reducing the numbers of grazing fish that keep corals clean of algal overgrowth. Blast fishing (i.e., using explosives to kill fish) can cause physical damage to corals as well.
• Coral harvesting for the aquarium trade, jewelry, and curios can lead to over-harvesting of specific species, destruction of reef habitat, and reduced biodiversity.

Frequently asked questions related to threats to coral reefs:

Ques 1. What is coral bleaching, and why is it a major threat to coral reefs?

Ans. Coral bleaching is a phenomenon where corals expel their symbiotic algae, turning them white and vulnerable to disease. It is primarily caused by rising sea temperatures associated with climate change. Bleaching events can lead to coral mortality and have severe impacts on reef ecosystems, reducing their resilience and ability to recover.

Ques 2. How does pollution impact coral reefs?

Ans. Pollution, such as runoff from coastal development, agriculture, and industrial activities, can have detrimental effects on coral reefs. It can introduce excess nutrients, leading to algal overgrowth that blocks sunlight and consumes oxygen, causing coral stress and death. Pollution can also introduce harmful chemicals and toxins that directly impact coral health and disrupt ecosystem balance.

Ques 3. What are the effects of overfishing and destructive fishing practices on coral reefs?

Ans. Overfishing disrupts the delicate balance of reef ecosystems. Removal of key fish species can lead to shifts in ecological dynamics, affecting coral health and overall reef productivity. Destructive fishing practices, such as using dynamite or cyanide, directly damage coral structures, causing irreversible harm. Both overfishing and destructive practices contribute to the degradation of coral reefs and the loss of biodiversity.

Read Also: Importance Of Coral Reefs