Coral Reefs in Danger
Athip (Oat) Twinvitoo ’25
Sydney Robinow ’25
Although many are aware that coral reefs worldwide are suffering from the effects of climate change, the discussion often seems to end at that point. Without any practical measures implemented to address this issue, coral reefs may become extinct, beginning the domino effect of ending marine life. To come up with solutions to solve the detrimental impacts that climate change has placed on corals, one must have a complete understanding of the issue.
From tourism to fishing communities, coral reefs support an estimated 2.7 billion dollars in goods and services. However, they serve far beyond a financial role. They also help protect coastlines from storms and supply food for humans (Einhorn, 2021). Scientists have predicted that by 2050, over 90% of corals could be gone (WWF, n.d.).
Increasing ocean temperatures caused by climate change is a stressor on corals to eject beneficial algae, zooxanthellae. This algae provides corals with their color and nutrients, meaning that the ejection of the algae causes the coral to “bleach” when it is released. If the algae do not return, corals will eventually starve to death. This issue has already created significant consequences, with half of the Great Barrier Reef killed in a series of mass coral bleaching events between 2015 and 2017 (WWF, n.d.). Not only do increased temperatures cause bleaching, but they can also result in other effects, such as an increase in both the severity and frequency of coral diseases (Gaddis et al., 2022).
Similarly, climate change has resulted in precipitation around the world increasing at a rate of 0.1 cm/decade since 1901, potentially causing devastating effects on coral reef ecosystems (EPA, n.d.). While signs of a healthy reef include low amounts of nutrients and sediment, rainfall prevents this environment from existing (Fong et al., 2020). Runoffs from rivers caused by excessive rain increase sediment and nutrients, triggering algal blooms and lowering oxygen levels in the water after the death of algae (GLISA, n.d.; US Department of Commerce, 2015). The rainfall also prevents sunlight, preventing zooxanthellae, the coral’s symbiotic algae, from photosynthesizing (Sundararaju, 2019). Situations demonstrating the severity of increased rainfall include the algal bloom in the gulf of Oman leads to the complete depletion of the corals Poxillopora and Acropora spp (Bauman et al., 2010).
Although there are several more negative impacts climate change has placed on corals, it is clear that climate change can wreak havoc on not only coral reefs but all types of important ecosystems on this planet. Climate change is no longer a distant possibility but a reality we face today.
References
Einhorn, C. (2021, October 5). Climate change is devastating coral reefs worldwide, major
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Coral reefs and climate change: From cradle to an early grave. WWF. (n.d.).
https://www.wwf.org.uk/coral-reefs-and-climate-change
Gaddis, K., Turner, W., Estes, M., Brophy, M., & Kunerth, M. (2022). Ecological
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US Department of Commerce, N. O. and A. A. (2015, March 3). How does climate change
affect coral reefs? NOAA's National Ocean Service. https://oceanservice.noaa.gov/facts/coralreef-climate.html
Sundararaju, V. (2019, October 28). Why there is an algal bloom in Gulf of Mannar and how
it affects livelihood. Down To Earth. https://www.downtoearth.org.in/blog/india/why-there-is-an-algal-bloom-in-gulf-of-mannar-and-how-it-affects-livelihood-67461
Algal blooms. GLISA. (n.d.). https://glisa.umich.edu/resources-tools/climate-impacts/algal-blooms/
