What is causing the decline of coral reefs?

And they are dying. Coral reefs are under relentless stress from myriad global and local issues, including climate change, declining water quality, overfishing, pollution and unsustainable coastal development.

What happens when coral reefs get a disease?

Black-band disease, discolored spots, red-band disease, and yellow-blotch/band disease appear as discolored bands, spots or lesions on the surface of the coral. Over time, these progress across or expand over the coral’s surface consuming the living tissue and leaving the stark white coral skeleton in their wake.

What are the 3 stressors affecting the reef?

Ocean acidification, climate change, and other environmental stressors threaten coral reef ecosystems and the people who depend upon them. New science reveals that these multiple stressors interact and may affect a multitude of physiological and ecological processes in complex ways.

What could have caused the decline of corals since 1977?

Coral and fish communities showed dramatic declines from 1977 to 1996 due to massive harbor construction and suboptimal land management practices on the watershed. More recently, corrective measures in the form of watershed stabilization and fishing regulations have been implemented.

How are coral reefs decreasing in ocean?

Climate change leads to: A warming ocean: causes thermal stress that contributes to coral bleaching and infectious disease. Sea level rise: may lead to increases in sedimentation for reefs located near land-based sources of sediment. Sedimentation runoff can lead to the smothering of coral.

How might disease in a coral reef impact the ecosystem?

In particular, coral disease outbreaks are having a significant, negative impact on the structure and appearance of coral reefs, and have contributed to unprecedented declines in live coral cover and productivity of coral reef ecosystems upon which many millions of people depend (Galloway et al. 2009).

When are corals most affected by diseases?

The warmest water temperatures usually occur between August and October. Corals become stressed when sea surface temperature is 1 degree C greater than the highest monthly average. Coral bleaching risk increases if the temperature stays elevated for an extended time.

What threats are coral reefs facing?

The major global threats to the coral reefs are as follows:

  • Climate Change. Climate change is a direct cause of coral bleaching.
  • Pollution.
  • Algae And Bacteria.
  • Increased Sedimentation.
  • Toxic Chemicals.
  • Marine Debris.
  • Destructive Fishing Practices.
  • Irresponsible Tourism.

How does pollution affect coral reefs?

When sediment and other pollutants enter the water, they smother coral reefs, speed the growth of damaging algae, and lower water quality. Pollution can also make corals more susceptible to disease, impede coral growth and reproduction, and cause changes in food structures on the reef.