Climate Change and Corals: Why We Need to Care and Conserve
Coral reefs are underwater ecosystems that serve many purposes for the various inhabitants of the local environment. Human-driven climate change is causing coral bleaching, which is the process by which corals eject their mutualistic zooxanthellae, resulting in a "bleached" appearance of the corals. These photosynthetic dinoflagellate algae provide corals with sugars and oxygen, while the corals provide shelter and nutrients to the zooxanthellae. This mutualism ensures that both the corals and zooxanthellae are maximizing use of environmental resources while minimizing individual energy spending. However, this dependency quickly turns rotten in adverse climate conditions. A slight increase in water temperature (due to climate change) causes the zooxanthellae to photosynthesize incorrectly and produce toxic byproducts. In a self-protective frenzy, the coral expels the algae, rendering the coral colorless and "bleached." More importantly, the coral is no longer with its symbiotic partner, and therefore is more prone to stress and mortality.
The left image is a normal coral with the zooxanthellae intact. The right image is a coral that has been bleached due to environmental stressors such as warmer water temperatures.
Fish and other commercially important marine wildlife rely on reefs for food and shelter. For example, the northern red snapper (Lutjanus campechanus) feeds on various small fish and crustaceans that live in the reefs. The reefs also depend on their inhabitants. For example, Florida's climate-stressed coral reefs are being grazed by sea snails (Coralliophila galea). Artificially increasing the presence of native spotted spiny lobsters (Panulirus guttatus) into the reef ecosystem is being explored as a method to combat the destructive snails, since the lobsters feed on them. This will prevent grazing and therefore reef damage. The intimate interdependency of coral reefs and their dwellers illustrates the ecological importance of reefs. Coral reefs also function as anchors, preventing erosion at coastlines. Severe erosion can cause devastating events like the Dust Bowl of the 1930s. Coral reefs thus prevent coastline catastrophes by reducing erosion. Additionally, coral-derived substances provide many medicines, including those to treat heart disease, viral and bacterial infections, cancer, Alzheimer's disease, arthritis, and more. Thus, coral reefs and their products have been instrumental to human and ecological well-being, so it is important to reduce climate change to conserve these beneficial organisms.
Here is some cool further reading on this topic:
https://oceana.org/marine-life/northern-red-snapper/ - Facts about the northern red snapper.
https://www.ecowatch.com/coral-reefs-florida-lobsters-snails-2654288199.html - Information on Florida's snail/lobster reef crisis.
https://www.history.com/topics/great-depression/dust-bowl - An overview of the Dust Bowl.
https://www.pbs.org/kenburns/the-dust-bowl/photo-gallery - A photo gallery of the Dust Bowl highlighting the horrible impacts of the catastrophe.
https://www.noaa.gov/education/resource-collections/marine-life/coral-reef-ecosystems - An overview of coral reefs.
https://oceanservice.noaa.gov/facts/coral_medicine.html - An overview of the medicinal uses of coral products.
https://oceanservice.noaa.gov/education/tutorial_corals/media/supp_coral02bc.html - An overview of the mutualism between corals and zooxanthellae.
https://oceanservice.noaa.gov/facts/coral_bleach.html - An overview of coral bleaching.
