Category: Coral Reefs

Coral Reefs

Source: Section 3.2.3.5; Karki, et al., http:// https://www.ipbes.net/assessment-reports/asia-pacific

  • Coral reefs are the most diverse coastal ecosystems on earth and of disproportionate ecological, economic and food security importance to the Asia-Pacific region which has an inordinate proportion of the world’s healthy coral reefs.  Coral diversity is highest in the Asia-Pacific region.
  • The death of reef-forming corals undermines resilience of coastal communities, and can lead to the collapse of important coastal ecosystems.
  • One third of reef- building corals in the region are threatened.
  • Loss of habitat quality, heavy damage to entire reefs are major threats in the region. In the case of El Niño event in 1998, 16 per cent of the world’s coral reefs and 50 per cent of those in the Indian Ocean were destroyed
  • Increase in sea temperature and ocean acidification have been projected as major drivers of change along coastal environments which may lead to decline in coral reefs.
  • Increasing outbreaks of crown of thorns starfish, a native predator that has boom bust cycles linked to environmental pollution from farm lined estuaries affected The Great Barrier Reef.
  • Coral bleaching events are also increasingly devastating to the northern two thirds of the reef over the last few years where coral-algae associations are disrupted by high sea temperature.  Habitats and communities in the Great Barrier Reef ranged from poor to worsening at the end of 2015, although some species like green turtle populations improved.
  • Among the most serious emerging threats to coral reefs are coral diseases, which have devastated coral populations throughout the Caribbean since the 1980s and accompanied the mass coral bleaching there in 2005 and 2006. Over 90 per cent of the main reef forming corals in the Caribbean have now died due to coral disease with the severity of disease outbreaks commonly correlated with corals stressed by bleaching.  Coral diseases are also being observed more frequently on Indo-Pacific reefs in heretofore unrecorded places such the Great Barrier Reef, areas of Marovo Lagoon in the Solomon Islands and the Northwestern Hawaiian Islands. The outbreaks seem to be related to bacterial infections and other introduced disease organisms, increasing pollution, human disturbance and increasing sea temperature, all of which have put reef-forming corals at serious risk.