5 Main Causes of Coral Reef Destruction

Fishing line on corals

Fishing line on corals

The threat to the ocean’s coral reefs is apparent. As coastal construction increases and global temperatures rise, an estimated 33% of coral are in danger of going extinct. Marine studies have shown an 80% decline in some forms of coral over the last decade. Coral reefs are the unseen backbones of the Earth’s ecosystem. With almost a quarter of sea life making their homes in coral reefs, coral reef health is key to a robust ecosystem. Many of the contributors to this kind of habitat destruction are preventable, but awareness on a massive scale is necessary to implement changes that will be long lasting. Here are 5 main causes of coral reef destruction.

Reef Bleaching

Reef bleaching occurs when water conditions cause coral to expel the internal microorganisms that give corals their vibrant colors. Bleaching events are caused by a number of factors including an increase in water temperature. As global warming warms the planet, ocean water temperatures are also on the rise. With warmer waters, bleaching events have become more common.

Poison Fishing

It is unfortunately common practice to use cyanide and other poisons to fish for coral reef dwelling creatures. The poison is not designed to necessarily kill the desired catch, but is used to stun fish that will then be used in domestic salt water aquariums. Although many fish can metabolize the cyanide and are only temporarily harmed by its effects, the same is not true for coral polyps. When the cyanide is released in the nooks and crannies of the reef, the coral often dies in the cloud of poison.

Water Pollution

Water pollution is perhaps the most obvious cause of coral reef destruction. Reefs are harmed when oil, fertilizer, human and animal waste are dumped in the area. Not only do these elements change the chemical make-up of the water, waste can also block life-giving sunlight to the reef. Large floating trash can cut young coral polyps off from nutrients they need to grow into a thriving reef.


Tabletop coral broken at trunk

Tabletop coral broken at trunk

Construction and mining along sea coasts can create a great deal of silt and soil run off. Particles that enter the ocean can smother coral reefs, depriving them of sunlight and nutrients. Fish are unable to feed and coral polyps are unable to grow leaving the area inhospitable to reef life.

Careless tourism

Much destruction to coral reefs could be prevented with just a bit of education for those who want to explore these interesting natural creations. Divers, snorkelers and other sea lovers often inadvertently damage the reef. By simply touching coral the oils on human fingers can kill whole areas of coral reefs. Boating and fishing can also damage coral reefs with carelessly dropped anchors or lines.

Images via tiswangomattk1979


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