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Recreational and Commercial Activities
Activities like scuba diving, fishing, and sailing can be harmful to coral reefs. As the human population increases, more pressure is put on coastlines where beaches are and more people take part in recreational activities. These activities contribute to the decline in coral when it is physically hit, the decline in fish populations when they are caught, and the harmful gases from combustion of fuel for sailing is not good for the environment. In many coral reefs, animals are being overfished and the coral is being overexploited and taken to be used in jewelry or what have you.
Pollution
There are various types of pollution that humans release into the ocean. Humans discharge pollutants every day thinking that the vast sea is large enough to handle any amount of harmful substance. When certain pollutants are released into the ocean, they can alter nutrient levels in the water. Sewage and agricultural runoff are the main pollutants that increase nutrient levels (3). In a eutrophic, or nutrient-rich, environment, the growth of algae blooms can halt the growth of coral and take over their space. Other pollutants can essentially smother a coral reef by blocking the sunlight through the water. Coral reefs require sunshine to thrive, and when they do not have a steady weather pattern, they are bound to fail. Oil spills are a big threat to coral reefs, as they block out sun and muddy the water.
By 2050, it is estimated that 60% of the world's coral reefs will die completely (2).
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Causes of Coral
Reef Destruction