Coral Reef NOAA
 
September 03, 2014  

Threats


  Coral reefs are threatened by an increasing array of impacts—primarily from global climate change, unsustainable fishing, and pollution.

For deep-sea coral communities, bottom trawling is considered the major threat in most US regions where such fishing is allowed. Additional threats include: other bottom-contact fishing gear (e.g. traps and bottom-set gillnets and longlines); coral harvesting; oil, gas, and mineral exploration and extraction; marine debris; submarine cable/pipeline deployment; invasive species; climate change; and ocean acidification. Additional information on threats to deep-sea coral communities is available in The State of Deep Coral Ecosystems of the United States: 2007.

Climate change impacts have been identified as one of the greatest global threats to coral reef ecosystems. As temperatures rise, mass bleaching and infectious disease outbreaks are likely to become more frequent. Additionally, carbon dioxide (CO2) absorbed into the ocean from the atmosphere has already begun to reduce calcification rates in reef-building and reef-associated organisms by altering sea water chemistry through decreases in pH (ocean acidification). In the long term, failure to address carbon emissions and the resultant impacts of rising temperatures and ocean acidification could make many other management efforts futile.

Fishing impacts in coral reef areas, when ecologically unsustainable, can lead to the depletion of key functional groups of reef species in many locations, with cascading impacts on coral reef habitats and their associated species and ecosystems.

Impacts from land-based sources of pollution (e.g. agriculture, deforestation, storm water, impervious surfaces, coastal development, road construction, and oil and chemical spills) on coral reef ecosystems include increased sedimentation, nutrient enrichment, toxins, and pathogen introduction. These pollutants and related synergistic effects can cause disease and mortality in sensitive species, disrupt critical ecological functions, cause trophic structure and dynamics changes (i.e. eutrophic conditions), and impede growth, reproduction, and larval settlement.

Follow the links to see video clips about marine debris and lionfish (an aquatic invasive species in the US Atlantic and Caribbean basin).

Other threats to corals that have been deemed important and relevant across all U.S. jurisdictions include: coral disease; tropical storms; tourism and recreation; vessel damage; marine debris and pollution; and aquatic invasive species.

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More information:

The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2008
Hazards to Coral Reefs / CoRIS essay
Major Reef-building Coral Diseases / CoRIS essay
Coral Disease and Health Consortium
ReefBase Threats / Global Coral Reef Monitoring Network

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