What types of disturbances could affect a coral reef at small, moderate, and extreme scales?
Small scale disturbances:
1. Runoff from land-based sources such as agriculture or development can introduce pollutants, sediment, and nutrients into the water, leading to decreased water quality and increased stress on coral.
2. Overfishing can disrupt the balance of the reef ecosystem, affecting the populations of key species and leading to changes in coral reef structure and function.
3. Recreational activities such as snorkeling, diving, and boating can cause physical damage to coral reefs through direct contact or anchor damage.
Moderate scale disturbances:
1. Coral bleaching caused by elevated sea surface temperatures due to climate change can result in the loss of the symbiotic algae that provide corals with nutrients and color, leading to widespread coral mortality.
2. Disease outbreaks among coral species can spread rapidly and have devastating effects on reef health and biodiversity.
3. Natural events such as tropical storms, hurricanes, and tsunamis can cause physical damage to coral reefs, disrupting their structure and potentially leading to widespread coral mortality.
Extreme scale disturbances:
1. Ocean acidification, resulting from increased levels of carbon dioxide in the atmosphere, can lower the pH of seawater and hinder the ability of corals to build their calcium carbonate skeletons, leading to reduced coral growth and reef structure.
2. Mass coral bleaching events, exacerbated by climate change, can result in extensive coral mortality and loss of reef biodiversity on a large scale.
3. Pollution from large-scale industrial activities or oil spills can have catastrophic effects on coral reefs, causing widespread damage and long-term degradation of reef ecosystems.