Rising ocean temperatures
One of the main threats to coral reefs is rising ocean temperatures. Coral reefs thrive in warm waters, but if the water gets too warm, the coral can bleach and die. Coral bleaching occurs when the coral expels the algae that live in its tissues. These algae provide the coral with food and color. Without the algae, the coral is more vulnerable to disease and starvation.
Ocean acidification
Another major threat to coral reefs is ocean acidification. Ocean acidification occurs when the ocean absorbs carbon dioxide from the atmosphere. This carbon dioxide reacts with water to form carbonic acid, which makes the ocean more acidic. Acidic waters dissolve the calcium carbonate skeletons of coral, making them more fragile and vulnerable to damage.
Pollution
Pollution can also damage coral reefs. Pollution can come from a variety of sources, including sewage, fertilizers, and oil spills. Sewage and fertilizers contain nutrients that can cause algae to grow on the coral. This algae can block the coral from sunlight and food, and it can also release toxins that can damage the coral. Oil spills can coat the coral in a thick layer of oil, which can block sunlight and suffocate the coral.
Overfishing
Overfishing can also damage coral reefs. When too many fish are removed from the ecosystem, it can disrupt the food chain and allow algae to grow unchecked. Algae can block the coral from sunlight and food, and it can also release toxins that can damage the coral.
Destructive fishing practices
Destructive fishing practices can also damage coral reefs. Destructive fishing practices include dynamite fishing, cyanide fishing, and muro-ami fishing. Dynamite fishing uses explosives to kill fish, and it can also damage the coral reef. Cyanide fishing uses cyanide to stun fish, and it can also damage the coral reef. Muro-ami fishing uses a large net to catch fish, and it can also damage the coral reef.