Author: Ojaswee Chaudhary
Have you ever wondered about coral reef, one of our most majestic aquatic creatures? How do they get their beautiful color? What are they made of? And how long can they last in our fading world?
Let’s use the last question, arguably the scariest one, to answer the rest of them. One culprit of Earth’s deterioration is global warming. When our oceans warm to unnatural temperatures, coral reefs expel the algae they need to produce their vibrant colors, leaving them an empty white color; this is called “coral bleaching”. But coral reef, and many other marine organisms also face the wrath of global warming’s ruthless sibling, ocean acidification. To answer, “What are they made of?”, reefs consist of a calcium carbonate skeleton. Sadly, ocean acidification is this skeleton’s worst enemy, and let’s learn why.
“Ocean acidification”. Sounds like a complex term, right? Well turns out, as long as you don’t go too deep into the chemistry, the process is pretty simple. Ocean acidification is caused by the increased CO2 levels in our oceans, making the ocean more acidic and taking away necessary nutrients for marine life, specifically calcium carbonate.
Detailed explanation: Both global warming and ocean acidification are fueled by the major increase in carbon dioxide on Earth. But while global warming is caused by the CO2 in our atmosphere, ocean acidification is caused by the CO2 that gets sucked into our oceans, hence the first half of the name. Now let’s understand the second, more daunting half of the name: “acidification”. When CO2 combines with the H2O in the ocean, it ends up forming two important particles: hydrogen ions and carbonate molecules. Our ocean loves and needs carbonate molecules because, when combined with calcium ions, they form calcium carbonate, and calcium carbonate makes up the skeletons and shells of marine organisms. The issue is that hydrogen ions swoop in and steal this carbonate! And not only do these hydrogen ions steal a necessary molecule, carbonate, but they also increase the acidity of the ocean. Acidic conditions are fatal to organisms, both land and sea.
So which marine organisms are affected? An article by the EPA breaks it down like this. Ocean acidification affects…
Life forms with carbonate-based shells and skeletons
Starfish, coral reef, plankton, and even sea butterflies are just a few examples of this category. When ocean acidification affects their homes, their bodies become brittle and dissolve. Not only do “adult” organisms lose their shells and skeletons, but when reproduced, the “baby” life forms’ bodies are weaker than before. Another EPA article states that coral reefs provide a home for 25% of marine life, including clams, crabs, oysters, sea urchins, starfish, and many types of fish. So you can only imagine the damage an ecosystem faces when its coral disappears. The scariest part is that “by the end of this century, coral reefs may erode faster than they can be rebuilt” (PMEL Carbon Program).
Organisms higher up the food chain that feed on these sensitive organisms
One change to any part of a food chain can be devastating. Phytoplankton and zooplankton are the foundation of marine food chains, and since their calcium carbonate bodies are disintegrating, the entire marine life food chain is suffering, too. Sea butterflies have a similar situation. First of all, because your curiosity level is probably peaking, this article depicts a sea butterfly in action (who doesn’t want to see an underwater butterfly?!). Second, these mystical creatures are dying due to ocean acidification. Many organisms ranging from tiny krill to whales to salmon depend on sea butterflies for food.
How can we help our marine life? How can we protect the sea butterflies?!
Though we may not be able to bring our ocean back to pre-industrial-revolution conditions, we can slow down the harm. The National Ocean Service provides a list of steps we can do:
Reduce our greenhouse gas emissions (so that less CO2 can enter the oceans)
Hopefully this article gives you a better understanding of one of the most dangerous facets of climate change: ocean acidification. Spread the word and take action, because without it, our marine life will face the consequences of our mistakes. The ocean is beautiful and alive, and let's keep it that way.