Climate Change and The Fate of Coral Reefs

Climate change threatens coral reef ecosystems globally. Scientific evidence shows that Earth’s atmosphere and ocean are warming due to human-made greenhouse gases. As temperatures rise, coral bleaching and disease outbreaks increase. Carbon dioxide absorbed by the ocean from the atmosphere has already reduced calcification rates in reef-building and reef-associated organisms by lowering seawater pH. Ocean acidification occurs. Sea level rise, changes in tropical storm frequency and intensity, and changing ocean circulation will disrupt coral reef ecosystems. All of these influences together alter coral reef ecosystem function and the products and services they supply.

Impact of global warming on coral reefs

Human activities contribute to climate change and ocean acidification because of their release of greenhouse gases. Ocean acidification is directly related to changes in global temperatures. Carbon dioxide is absorbed by the oceans around the planet (CO₂). While this has helped to decrease global warming, it is also altering the chemistry of the oceans.

Coral reef ecosystems are severely impacted by climate change.

The burning of fossil fuels for heat and energy, the production of some industrial goods, the breeding of animals, the fertilisation of crops, and the degradation of forests are all contributing processes that raise atmospheric concentrations of greenhouse gases.

• Coral bleaching and infectious disease can be exacerbated by a warmer ocean

• Reefs near land-based sources of sediment may see an increase in sedimentation as a result of rising sea levels. Coral can be suffocated by a discharge of sediment

• Coral reefs may be destroyed if weather patterns change, resulting in storms that are more powerful and occur more frequently

• Pollution discharge from the land and increasing runoff of freshwater contribute to algae blooms and murky water conditions that limit light penetration

• As a result of altered ocean currents, there is less food for corals and less opportunities for the spread of coral larvae

• Ocean acidification (as a result of rising CO₂): reduces coral growth and structural integrity due to a decrease in pH levels

Impacts of climate change on coral reefs and the marine environment

• To measure climate change’s influence on coral reefs and the marine environment, we must consider expected environmental changes and marine creatures’ adaptability.Models predict a 1 to 3°C rise in sea surface temperature and a 0.18 to 0.79m rise in sea level. Regional weather patterns may shift, increasing storm severity and frequency, especially cyclones. As a result of CO₂ absorption, ocean circulation patterns and pH may change

• Marine species must adapt fast to new environments despite millions of years of evolution. Changes in habitat, food supply, and ocean chemistry will affect marine life. Primary producers, mostly phytoplankton, form the food chain’s basis. In warmer waters, the number of these plants is projected to decline, limiting the nutrients available to creatures further up the food chain. Temperature also triggers feeding, growth, and reproduction in many marine plants and animals. Without synchronization, organisms may arrive after their food supplies are gone. Heat-tolerant species will expand their range northward, while less tolerant species will retreat. This alteration in ocean dynamics could kill non-migratory species. Ocean acidification, or increased CO₂ levels that lower seawater pH, inhibits phytoplankton and coral and shellfish calcification, weakening their skeletons and impairing their growth

• Bleaching due to rising water temperatures is a major hazard to corals. Bleaching happens when high sea temperatures destroy the corals’ symbiotic interaction with zooxanthellae (algae). The coral ejects the zooxanthellae, bleaches, and weakens. Some corals can recover, but many die

Effects of coral reef destruction on the environment

• Since the beginning of the industrial revolution, scientists assume that the seas have absorbed about half of the CO₂ created by human activity. The rising quantities of CO₂ in the atmosphere have an impact on the acidity of the oceans. Many marine organisms are in risk of extinction as acidity rises, and the degradation of coral reefs is at risk as a result. Carbon dioxide levels in the atmosphere are expected to reach 450 parts per million by 2040, according to scientists. Coral reefs are now believed to have reached a stage where they will no longer be able to recover. It’ll be 2100 before coral reefs are extinguished regardless of how we manage carbon emissions

• One of the world’s major reservoirs of biodiversity would be decimated if coral reefs disappeared. Coral reefs help seed the ocean and provide habitat and food for a wide range of species, including humans. Coastal areas are protected from the ravages of the ocean by these natural barriers. Storms, hurricanes, and cyclones are more likely to destroy and flood coasts as coral reefs decline. There will be more CO₂ in the atmosphere if the oceans do not have coral reefs to absorb carbon dioxide

Conclusion

The world’s coral reefs have been devastated to a great extent, despite their enormous ecological, economic, and aesthetic benefits. As a result of human activity, another 24% are at high risk of collapsing, and another 26% are at risk of long-term collapse. It is predicted that 70% of the world’s coral reefs would be lost by the year 2050 if the current rate of destruction continues.

Coral reefs are under threat from the following factors:

• Fishermen are overfishing for food, aquariums, trinkets and therapeutic uses

• As a result of overfishing, harmful fishing tactics such purse seining, fine mesh nets,’moxy’ nets, cyanide-fishing, and blast fishing can cause irreversible environmental harm. Nets such as “moxy” and “fine-mesh,” as well as bottom trawlers, all harm coral reef ecosystems

• Coastal coral reefs in the region are being harmed by marine pollution in the form of oil spills, ballast water discharges, and ship solid waste

• Already stressed coral reefs face a new and grave threat from climate change as a result of human-caused global warming