Science with Mandy

This week, I will be taking a break from my usual posts about biomedical topics and switch gears a bit to marine biology. I have a passion for learning about aquatic life and have learned a lot about the pure amazingness that is the ocean, through both independent research and various courses I was able to take in college. However, given the current state of the environment, I am worried about our oceans and wanted to raise awareness about some vulnerable aquatic species being affected by climate change.

A very important organism in the ocean is coral, an animal species called Anthazoan (1). Corals are considered colonial organisms, as many coral polyps live together in a colony (shown below), and they use calcium carbonate from the water to produce hard exoskeletons. Polyps, interestingly, are actually clear in appearance, and their color comes from algae that live inside them. Corals live in a symbiotic relationship with these algae, which consume the corals’ waste and generate their own waste products that the corals use to grow (2).

https://oceanservice.noaa.gov/facts/coralmadeof.html

Corals are an important marine species that are sensitive to changing environmental conditions. When placed under stress – things like rising ocean temperatures or oceanic acidification – corals will oust the algae providing them color and nutrients, causing the corals to turn white, a process called “coral bleaching,” which usually leads to death of the coral (2). Recently, record-high sea temperatures around the world, including off the coast of Florida, have caused mass coral bleaching events, like that shown below; in the last few weeks, the water in the Florida Keys reached over 100 degrees Fahrenheit, leading to such effects (3). 

https://www.nytimes.com/2023/07/31/climate/coral-reefs-heat-florida-ocean-temperatures.html

Why are sea temperatures rising? When heat is trapped in Earth’s atmosphere, partially due to greenhouse gas emissions, the ocean acts as a heat reservoir. As the Earth, and the ocean, warms, sea levels rise due to melting polar ice and thermal expansion (when water’s volume will increase with rising temperature [4]), and ocean currents and global weather patterns are altered (5); these changes put not only marine organisms like corals at risk, but could displace millions of people from their coastal homes (6).

The health of the ocean affects the health of the entire planet. Corals are an extremely important marine species that support other species, as well, but they are vulnerable to climate change, and the recent heat waves across the world have had drastic effects on coral health. It is imperative that we humans reduce our emission of greenhouse gases to help save the oceans.

Works Cited

(1) https://floridakeys.noaa.gov/corals/coralanimals.html

(2) https://education.nationalgeographic.org/resource/coral/

(3) https://www.nytimes.com/2023/07/31/climate/coral-reefs-heat-florida-ocean-temperatures.html

(4) https://www.jpl.nasa.gov/edu/learn/project/how-warming-water-causes-sea-level-rise/#:~:text=Thermal%20expansion%20happens%20when%20water,warming%20waters%20and%20thermal%20expansion.

(5) https://www.epa.gov/climate-indicators/oceans#:~:text=As%20greenhouse%20gases%20trap%20more,climate%20patterns%20around%20the%20world.

(6) https://coast.noaa.gov/digitalcoast/stories/population-risk.html