How do high temperatures affect corals?
High temperatures can have significant negative effects on corals. Here are some impacts of high temperatures on corals:
1. Coral Bleaching: High temperatures can cause coral bleaching. When the water temperature rises above the normal range, corals expel the symbiotic algae called zooxanthellae, which provide them with nutrition and their vibrant colors. Without these algae, corals turn white or pale, leading to the process known as coral bleaching. If the temperature remains high for an extended period, bleached corals may die.
2. Reduced Growth: Elevated temperatures can slow down or hinder the growth of corals. Corals rely on a delicate balance of temperature, light, and nutrients for optimal growth. High temperatures interfere with the coral's ability to efficiently acquire and utilize nutrients, resulting in reduced growth rates.
3. Increased Vulnerability to Disease: Heat-stressed corals are more susceptible to diseases and infections. The stress caused by high temperatures weakens the coral's immune system, making them more prone to various diseases, including bacterial infections, viruses, and other pathogens. These diseases can further contribute to coral decline and mortality.
4. Altered Symbiotic Relationship: High temperatures disrupt the symbiotic relationship between corals and the zooxanthellae algae. As the water temperature rises, corals expel the algae, leading to a loss of nutrition and energy for the corals. Without the algae, the corals become weakened, making them more vulnerable to other stressors.
5. Increased Mortality: Prolonged exposure to high temperatures can lead to coral death. If the bleached corals cannot recover their symbiotic algae or the temperatures remain hostile for an extended period, the corals may starve and die. This can have severe implications for coral reef ecosystems, as corals are vital for providing habitat, food, and shelter for numerous marine species.
It is important to note that prolonged exposure to high temperatures due to climate change poses a significant threat to coral reefs worldwide.