QUES . Assess the impact of global warming on coral life system with examples. UPSC 2019 G S MAINS PAPER 1
HINTS:
Climate change is the greatest global threat to coral reef ecosystems. Scientific evidence now clearly indicates that the Earth’s atmosphere and ocean are warming, and that these changes are primarily due to greenhouse gases derived from human activities.
The varied effects of global warming and climate change are changing the ocean; these changes dramatically affect coral reef ecosystems.
• A warming ocean: causes thermal stress that contributes to coral bleaching and infectious disease. Bleaching is a phenomenon in which corals lose their distinctive color as a result of the loss of zooxanthellae algae. These algae reside in a symbiotic relationship with corals, and thus, their demise also results in the mortality of the corals. For example: Bleaching observed in the Great barrier reef of Australia.
• 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.
• Ocean acidification (a result of increased CO2): causes a reduction in pH levels which decreases coral growth and structural integrity.
• Changes in precipitation: increased runoff of freshwater, sediment, and land-based pollutants contribute to algal blooms and cause murky water conditions that reduce light.
• Changes in storm patterns: leads to stronger and more frequent storms that can cause the destruction of coral reefs.
• Altered ocean currents: leads to changes in connectivity and temperature regimes that contribute to lack of food for corals and hampers dispersal of coral larvae.
Loss of phytoplankton: Phytoplankton serves as a primary source of nutrients for corals, enabling them to thrive in optimal subtropical temperatures. Without the presence of these organisms, corals would be unable to survive.
Low levels of magnesium and calcium: Due to increase in global temperature corals are losing their mineral contents which are useful to sustain the life of corals. Increased temperature reduces the percentage of magnesium and calcium, making it difficult for corals to survive due to low levels of these mineral contents in the ocean.
Taking urgent measures to reverse global temperatures is the need of the hour. This entails implementing methods for reducing carbon emissions. It is crucial to decrease the burning of fossil fuels and the release of harmful gases like CO2, NOx, and SOx into the atmosphere. Additionally, efforts should be made to reduce pollution near water bodies and to ban the use of non-biodegradable products in oceans and lakes. Artificial reefs can serve as a solution to prevent the erosion of islands.
