One threat to the Coral Reefs is Overfishing. Fisheries in the Caribbean are often open access with few regulations and the location and distribution of the fish can be highly predictable. This means that the Caribbean Coral reefs are particularly at risk to overfishing. Especially in parts of the Eastern Caribbean as there is often more fisheries competing in a larger area. The traps and fishing line used by these fishermen can damage reefs through breaking up corals. Also, fishermen typically target the largest fish on the reef as these are the ones that have the highest market value. The reduction of larger fish then leads to a reduction in the average size of the targeted species, and this will then cause fishermen to fish for lower valued species, removing even more components of the coral reef food chain. The removal of certain species can dramatically alter the coral reef structure. For example, herbivorous fish are responsible for controlling algae growth on the reef. If these fish are removed from the system, algae will flourish and reduce coral cover.
Another threat to this ecosystem is coastal development and reef related tourism. For example there has been a considerable amount of destruction in The Gulf caused by recreational divers trampling the coral and the dropping of dive-boat anchors in the area. Also with increasing populations, and a lack of space it has caused buildings to be built often near and over the reefs. For example, tourist resorts. It is these and tourist related activities such as snorkelling, diving and boating which attract more people into the area to potentially damage the reefs.
However it is not just the human factors like above that post a threat to coral reefs. Some physical factors for example Tsunami’s can also affect Coral Reef systems. Tsunami damage in Indonesia included overturned corals and swathes of broken corals where large tree branches and tree trunks had been washed across the reef as the waves receded. Also the affect of global warming plays a big part in the destruction of coral reefs. Ocean warming can indirectly kill corals by magnifying the effects of infectious diseases, which are one of the primary causes of coral loss, particularly in the Caribbean.
Another threat to coral reefs is the rising sea temperatures due to global warming. The rise in water temperature causes corals to release their alga which causes bleaching. Bleaching is when a certain organism that give corals their color, is released by the corals in an effort to control the amount it contains. This process is normal until too much is released. This means that the excessive amount which is released causes coral reefs to lose their colour and eventually die off.
All in all, a combination of human and physical threats means that the coral reefs are in need of help. More than half of the world's coral reefs will be damaged beyond repair by the year 2100 unless action is taken to halt these many threats they now face.
