Coral Reefs

Factors affecting Coral Reefs

Climate Change

One factor believed to be the greatest threat to reefs is climate change. When severe weather events increase in frequency, this causes rises in both sea temperatures and sea levels. The problem with water temperatures rising is that coral reefs need to sustain a sea temperature between 73 and 84 degrees F to sustain growth. 

Pollution

Coral reefs are strongly affected by humans and their pollution. Boating and even coming into contact with coral reefs can cause damage to the ecosystem. Discarding rubbish can cause a huge impact on the environment; turtles can sometimes mistake plastic shopping bags for jellyfish and eat them, causing the creature to starve to death by blocking its digestive tract.

Overfishing and Blast Fishing

Fish might taste delicious but catching too many can be harmful to a coral reef. It can be difficult for a species to sustain life when too many fish are taken from one area. Overfishing of herbivorous fish can also lead to a reef having high levels of algal growth. Another factor affecting coral reefs is blast fishing. This practice involves catching fish by using explosives to blow apart sections of a coral reef.

Disease Outbreaks

Coral reefs are susceptible to disease outbreaks caused by stress, which include the presence of bacteria, fungi and viruses. Some of the diseases found in coral reefs include white-band and black-band disease. White-band disease involves tissue peeling away from coral and the skeleton of the reef being colonized by algae. Black-band disease is caused by bacteria moving along the reef and destroying the tissue.

Location

Coral reefs flourish in shallow areas (less than 120ft, or 37m) in tropical latitudes, or where warm ocean currents flow into more temperate areas. In deeper waters, not enough light penetrates the depths, which means the reef's main food producers, algae and plankton, cannot photosynthesise.