Coastal Development

  • With the global coastal population expected to double by 2050, coral reefs will be facing increased pressure from unmanaged development along worldwide coastlines.
  • The growth of coastal cities and towns introduces of range of threats to adjacent coral reefs including development projects that may be built on land reclaimed from the sea.
  • Critical habitats which are currently home to endangered and threatened species can be destroyed or disturbed by dredging activities to make deep-water channels and through the dumping of waste materials.
  • Where land development alters the natural flow of water, greater amounts of fresh water, nutrients and sediment can reach the reefs causing extreme damage to the existing fragile marine ecosystem.
  • Coastal construction and shoreline modification disturbs sediments, which smother corals. Since coral reefs adapt to waters with low nutrient content, the addition of nutrients effects local species and disrupts overall reef balance.
  • Reef-building corals, specifically algae which generate energy through photosynthesis, require sunlit waters to survive. Excess nutrients that come from sewage releases and other human sources block sunlight and impact coral reproduction.
  • Nutrient-rich runoff promotes the growth of bottom-dwelling algal competitors and further interferes with coral reproduction.
  • Scientific studies indicate that high levels of dissolved inorganic nutrients, such as nitrogen and phosphorus, can reduce coral growth and calcification rates in some coral species by up to 50%
  • Within the last 20 years, mangrove forests, which absorb massive amounts of nutrients and sediment from runoff caused by farming and construction, have been entirely destroyed.
  • Additional threats such as hot-water discharges from power plants, mine runoff and industrial toxic waste poison coral reefs.
  • Unregulated tourism also poses a major threat as swimmers and divers have been responsible worldwide for trampling the reefs, while boat anchors have created further reef degradation. In many regions, hotels and resorts discharge sewage directly into the ocean, polluting local reef waters and promoting excessive algal growth.