Coral reefs

Definition

Coral reefs are diverse underwater ecosystems made up of living coral polyps that secrete calcium carbonate to form a hard skeleton, creating structures that provide habitat for numerous marine species. These ecosystems are often referred to as the 'rainforests of the sea' due to their rich biodiversity and the vital roles they play in marine life and coastal protection.

5 Must Know Facts For Your Next Test

1. Coral reefs cover less than 1% of the ocean floor but support about 25% of all marine species, showcasing their incredible biodiversity.
2. Coral reefs provide critical ecosystem services, such as coastal protection from storms and erosion, and support local economies through tourism and fishing.
3. Climate change is a major threat to coral reefs, as rising sea temperatures contribute to coral bleaching and increased ocean acidification affects their structural integrity.
4. Healthy coral reefs can recover from stressors if conditions improve, but persistent threats like pollution and overfishing can lead to long-term degradation.
5. Corals are not plants; they are animals that live in symbiosis with algae called zooxanthellae, which provide energy through photosynthesis while benefiting from the corals' protective environment.

Review Questions

• How do coral reefs contribute to marine biodiversity and what factors threaten this biodiversity?
  • Coral reefs play a vital role in supporting marine biodiversity by providing habitat and food for countless species. They serve as nurseries for many fish species and contribute to complex food webs. However, threats such as climate change, pollution, and overfishing pose significant risks to this biodiversity. When corals bleach or die due to elevated water temperatures or acidification, the entire ecosystem suffers, leading to declines in fish populations and loss of habitat.
• Discuss the impact of ocean acidification on coral reefs and their ability to thrive in changing marine environments.
  • Ocean acidification negatively impacts coral reefs by reducing the availability of carbonate ions necessary for corals to build their calcium carbonate skeletons. As atmospheric carbon dioxide levels rise, more CO2 dissolves in ocean water, increasing acidity. This hampers coral growth and makes them more vulnerable to erosion and stressors like temperature fluctuations. The combination of reduced growth and increased susceptibility to bleaching events threatens the survival of coral reefs in changing marine environments.
• Evaluate the effectiveness of current conservation strategies aimed at protecting coral reefs in light of ongoing environmental changes.
  • Current conservation strategies for protecting coral reefs include establishing marine protected areas, restoring damaged ecosystems, and regulating fishing practices. While these efforts can help mitigate local stressors and promote resilience, they may not be sufficient in addressing larger-scale issues like climate change. A more integrated approach is needed that combines local conservation efforts with global initiatives aimed at reducing greenhouse gas emissions and enhancing climate resilience. Without addressing the root causes of environmental change, many coral reef conservation strategies may ultimately fall short in preserving these vital ecosystems.

Related terms

coral bleaching: A phenomenon where corals lose their vibrant colors and turn white due to stress factors such as elevated water temperatures, leading to the expulsion of symbiotic algae.

marine biodiversity: The variety of life found in marine ecosystems, including the different species of plants, animals, and microorganisms that inhabit ocean environments, particularly in coral reefs.

ocean acidification: The process by which the ocean becomes more acidic due to increased carbon dioxide levels, which negatively impacts marine organisms like corals by hindering their ability to build calcium carbonate structures.