Poor Water Quality

Water Quality credit Rory Mulloy


Poor water quality is seen as one of most serious threats to reef health. As well as increasing turbidity and restricting access to light, this can make corals more susceptible to bleaching and disease. Water quality is affected by a variety of factors:

  • Land-based industrial processes and dredging which can increase heavy metal, pollutant and sediment levels in the water.
  • Agricultural processes and the use of fertilisers which can increase nutrient levels in the water, especially after a big rain.
  • Removal of coastal habitats and vegetation which can act as a natural filter system for the waterways.
  • Pollution and waste from urban areas.

Understanding how our decisions and actions on land impact the health of reef habitats is crucial to reducing our impact on marine environments, and to good management and conservation of coral reefs.