Threats to coral reefs

Blast fishing
When areas have been overfished, people use other methods to try and get the fish that remain. One of these is dynamite, which is dropped into the sea. The explosion kills fish which then float to the surface. It also destroys large amounts of coral reefs.

Poison Fishing
A lot of people who own restaurants and shops like to buy their fish alive. Fishermen therefore spray poison into the water to stun the fish so that they can catch them alive. The poison spreads through the water and kills the coral reefs.

Sewage
Waste from towns and cities often flows into the sea, causing certain types of tiny creatures called algae (said al-gee) to breed in enormous numbers. The algae float in very big groups on the surface of the sea, blocking out the sunlight that corals need to live. This is a very bad problem in the Caribbean where it kills large areas of coral reefs.

Farming
The chemicals that farmers use to help their crops grow can drain from the fields into rivers and streams, eventually ending up in the sea. Like sewage, they cause the algae population to grow, blocking sunlight from the reefs and killing them. Farmers also use other chemicals to kill weeds and insects. These also find their way into the sea via rivers and streams, and kill coral very quickly.

Oil
Oil is transported around the world in very large ships called oil tankers. Unfortunately, these ships sometimes crash into rocks and spill oil into the sea. These 'oil slicks' are very damaging to all marine life, but especially coral reefs. Most animals can swim or float away from an oil slick, but coral reefs don't move and can get damaged very badly.

Development
When people develop land near the sea to make houses, shops or car parks, tonnes of earth and dirt is disturbed and can be washed into the sea by rivers and streams. It often settles near the coast on coral reefs, burying and damaging them.

Tourism
The money that some countries get from tourists visiting coral reefs is important and helps people to earn a living. However, some places let too many people visit, and the tourists break off bits of the reef to take home as souvenirs or damage them with their flippers or the anchors of their boats. Increasing numbers of tourists also leads to places building hotels, restaurants and other buildings in coastal areas, increasing the damage done to coral reefs described in our Sewage and Development sections.

These are just some of the threats to coral reefs. So what can we do to stop the damage and make sure that these amazing underwater worlds survive?