|  | Public Health Safety | Environmental Health

Factors Affecting Organisms Living in Coral Reefs

Thousands of species of fish, marine plants and animals make coral reefs their home. Coral reefs are extremely fragile and sensitive. Human activities such as coastal development, pollution, over-fishing, coral mining and global warming are affecting the diverse organisms that make up coral reefs. According to the Global Coral Reef Monitoring Network, about 25% of the world's reefs have been destroyed or severely damaged. Another third of reefs are degraded and in danger of being lost.

  1. Fishing

    • Overfishing and destructive fishing methods threaten the survival of coral reefs. Commercial fishing and subsistence fishing by local populations that depend on the reefs for food are depleting the coral reef ecosystems. When fishermen use cyanide or other poisons to stun the fish for easy catching, the corals and many dependent organisms die. When people use explosives, such as dynamite, to kill the fish, the reefs are reduced to rubble.

    Mangrove Loss

    • Mangrove forests reduce the runoff of sediments, pollutants and fertilizers from the land. Many reef species depend on nearby mangrove forests for nurseries. The construction of shrimp farms caused major destruction of mangrove forests in some areas. The loss of mangrove forests reduces the quality of the coastal water, which impacts the reef ecosystems.

    Coastal Development

    • As populations grow, coastal development has a harmful effect on the reef organisms. Human activities result in increased runoff from sewage, fertilizer, chemicals, and sedimentation. Physical contact from ships, anchors, pipelines and cables can damage the reefs.

    Global Warming

    • Rising ocean temperatures from global warming is the primary cause of coral bleaching. When the algae that lives on the coral dies, the coral starves from lack of nourishment. A white skeleton of calcium carbonate is all that is left.

    International Trade

    • Lucrative international trade in reef fishes and coral reef skeletons for marine ornaments is destroying reefs. Coral skeleton, which forms the base of the reef, and living coral are collected and sold for marine aquaria. Living coral is essential for the survival of species that reside in reefs.

Environmental Health - Related Articles