How quickly are coral reefs being destroyed?

[MarkLaymon]

How quickly are coral reefs being destroyed?​

The latest reports state that as much as 27 percent of monitored reef formations have been lost and as much as 32 percent are at risk of being lost within the next 30 years.

 

[MarkLaymon]

Environmental issues with coral reefs​

Human impact on coral reefs is significant. Coral reefs are dying around the world. Damaging activities include coral mining, pollution (organic and non-organic), overfishing, blast fishing, the digging of canals and access into islands and bays. Other dangers include disease, destructive fishing practices and warming oceans. Factors that affect coral reefs include the ocean's role as a carbon dioxide sink, atmospheric changes, ultraviolet light, ocean acidification, viruses, impacts of dust storms carrying agents to far-flung reefs, pollutants, algal blooms and others. Reefs are threatened well beyond coastal areas. Climate change, such as warming temperatures, causes coral bleaching, which if severe kills the coral.

Scientists estimate that over the next 20 years, about 70 to 90% of all coral reefs will disappear. With primary causes being warming ocean waters, ocean acidity, and pollution. In 2008, a worldwide study estimated that 19% of the existing area of coral reefs had already been lost. Only 46% of the world's reefs could be currently regarded as in good health [4] and about 60% of the world's reefs may be at risk due to destructive, human-related activities. The threat to the health of reefs is particularly strong in Southeast Asia, where 80% of reefs are endangered. By the 2030s, 90% of reefs are expected to be at risk from both human activities and climate change; by 2050, it is predicted that all coral reefs will be in danger.

Environmental issues with coral reefs - Wikipedia

en.wikipedia.org

 

[MarkLaymon]

Can you imagine a world without Coral Reefs?​

Corals may look like big chunks of rock but they are actually living organisms. The coral reefs that you see in the oceans are all composed of living things –and this ecosystem is being threatened like never before. To date, 27% of coral reefs have been destroyed. If the destruction continues, 60% will be gone in the next 30 years(1). Can you imagine a world without them?

The threat to corals are everywhere. Not all of the damage is deliberate, but rather a combination of different factors.

The World Counts

www.theworldcounts.com

 

[MarkLaymon]

Anthropogenic (Human) Threats to Corals​

Human-caused, or anthropogenic activities, are major threats to coral reefs. Pollution, overfishing, destructive fishing practices using dynamite or cyanide, collecting live corals for the aquarium market, mining coral for building materials, and a warming climate are some of the many ways that people damage reefs all around the world every day.


One of the most significant threats to reefs is pollution. Land-based runoff and pollutant discharges can result from dredging, coastal development, agricultural and deforestation activities, and sewage treatment plant operations. This runoff may contain sediments, nutrients, chemicals, insecticides, oil, and debris.


When some pollutants enter the water, nutrient levels can increase, promoting the rapid growth of algae and other organisms that can smother corals.

Human Threats to Corals: Corals Tutorial

Human-caused, or anthropogenic activities, are major threats to coral reefs. Pollution, overfishing, destructive fishing practices using dynamite or cyanide, collecting live corals for the aquarium market and mining coral for building materials are some of the many ways that people damage...

oceanservice.noaa.gov

 

[MarkLaymon]

Coral reefs face many threats from local sources, including:​

• Physical damage or destruction from coastal development, dredging, quarrying, destructive fishing practices and gear, boat anchors and groundings, and recreational misuse (touching or removing corals).
• Pollution that originates on landbut finds its way into coastal waters. There are many types and sources of pollution from land-based activities, for example:
  • Sedimentation from coastal development, urban stormwater runoff, forestry, and agriculture
    Sedimentation has been identified as a primary stressor for the existence and recovery of coral species and their habitats. Sediment deposited onto reefs can smother corals and interfere with their ability to feed, grow, and reproduce.
  • Nutrients (nitrogen and phosphorous) from agricultural and residential fertilizer use, sewage discharges (including wastewater treatment plants and septic systems), and animal waste
    Nutrients are generally recognized as beneficial for marine ecosystems; however, coral reefs are adapted to low nutrient levels; so an excess of nutrients can lead to the growth of algae that blocks sunlight and consumes oxygen corals need for respiration. This often results in an imbalance affecting the entire ecosystem. Excess nutrients can also support growth of microorganisms, like bacteria and fungi, that can be pathogenic to corals.
  • Pathogens from inadequately treated sewage, stormwater, and runoff from livestock pens
    Although rare, bacteria and parasites from fecal contamination can cause disease in corals, especially if they are stressed by other environmental conditions. Coral disease occurs in healthy ecosystems, but the input of pathogen-containing pollution can exacerbate the frequency and intensity of disease outbreaks.
  • Toxic substances, including metals, organic chemicals and pesticides found in industrial discharges, sunscreens, urban and agricultural runoff, mining activities, and runoff from landfills
    Pesticides can affect coral reproduction, growth, and other physiological processes. Herbicides, in particular, can affect the symbiotic algae (plants). This can damage their partnership with coral and result in bleaching. Metals, such as mercury and lead, and organic chemicals, such as polychlorobiphenyls (PCBs), oxybenzone and dioxin, are suspected of affecting coral reproduction, growth rate, feeding, and defensive responses.
  • Trash and micro-plastics from improper disposal and stormwater runoff
    Trash such as plastic bags, bottles, and discarded fishing gear (also called marine debris) that makes its way into the sea can snag on corals and block the sunlight needed for photosynthesis, or entangle and kill reef organisms and break or damage corals. Degraded plastics and microplastics (e.g., beads in soap) can be consumed by coral, fish, sea turtles, and other reef animals, blocking their digestive tracts and potentially introducing toxics.
• Overfishing can alter food-web structure and cause cascading effects, such as reducing the numbers of grazing fish that keep corals clean of algal overgrowth. Blast fishing (i.e., using explosives to kill fish) can cause physical damage to corals as well.
• Coral harvesting for the aquarium trade, jewelry, and curios can lead to over-harvesting of specific species, destruction of reef habitat, and reduced biodiversity.

Threats to Coral Reefs | US EPA

Coral reefs are among the most biologically diverse and valuable ecosystems on Earth. This web site describes the importance of coral reefs, threats to them, and ongoing efforts to protect them.

www.epa.gov