Ocean acidification is another one of the many problems the oceans of our Earth faces today. Similar to ocean pollution (which you can read about here) ocean acidification threatens the ecosystems and livelihoods of millions of aquatic species, from fish, to crustaceans, to even mammals such as the dolphin. And, as the careful balance of the ocean's ecosystems is disrupted, we begin to see other, arguably "more important" problems take place, affecting millions of humans as well. So what exactly is ocean acidification, and why is it so important?
What is Ocean Acidification?
Put simply, ocean acidification is the process through which carbon dioxide enters the ocean. However, the scope of the problem is a little bit more complicated then that. The oceans absorb about one quarter of the carbon dioxide we release into the atmosphere. As it settles into the water, it reacts with another common element, known as carbonate, to create another element called bicarbonate. The excess build up of bicarbonate causes ocean acidification.
What's the problem?
While it's true that bicarbonate in itself is generally harmless, this transformation has a serious effect on much of the ocean's wildlife. This is because of two main reasons: 1. Bicarbonate makes water more acidic, and 2. Mollusks need carbonate to construct their shells. Let's dive a little deeper into what exactly these two effects mean.
1. Bicarbonate makes water more acidic- just like human blood, the ocean's waters have a resting pH level, which has been 8.2 for the past 300 million years. It is within this pH range that all marine life is able to survive, and flourish within their ecosystems. Today, the ocean's pH has been lowered to 8.1, and continues to drop. Now, you may be thinking, "A drop of .1? That isn't anything to worry about!" Well consider this: in human blood, the resting pH is anywhere from 7.35 to 7.45. In tests, a change of .2 pH in our blood has been found to cause seizures, comas, and even death. Symptoms of similar severity have been seen in ocean wildlife, with only a change of .1. As the water becomes more acidic, marine wildlife has a much harder time functioning. Additionally, the pH scale is logarithmic, meaning that each step (Example: from 6 to 7) is 10x greater than the step before it. Suddenly, a change of .1 doesn't seem so small.
2. Mollusks need carbonate to construct their shells- mollusks, such as oysters, coral, etc. use calcium-carbonate to make their shells strong enough for survival. This calcium-carbonate is only created through the bond of the element calcium and the compound carbonate. Without diving too deep into the chemistry, a carbonate ion is more likely to bind with carbon dioxide then it is with calcium. And, when carbonate binds with carbon dioxide, it creates bicarbonate, which not only makes water more acidic, as discussed earlier, but is also unusable for mollusks. So, as more carbon dioxide enters the water, more carbonate binds with it rather than the calcium, leading to a lack of calcium carbonate. And, with a lack of calcium carbonate, mollusks are unable to create strong enough shells to survive, and they start to die off.
How Does it Affect Us?
While the effects on marine life are bad enough, ocean acidification also affects humans in many ways. The most direct way it does this is through the fish and food trade in coastal areas. Many cities located on the coast rely heavily on the buying and selling of marine wildlife as food. Animals like mussels, crab, and fish are all very popular, and heavily relied on. When these mussels and crabs die off due to their weak shells, fish have no food to sustain themselves, and they begin to die off too. Because of this, these coastal areas have no produce to sell, and their economies are deeply affected. Not only this, but these areas no longer have food to eat, and many people starve as a result.
Additionally, marine mammals such as whales and dolphins begin to be affected, as the ecosystems underneath them begin to collapse. If one organism dies off, like the mollusks, then the animals that eat them die off too, and this trend continues until it reaches the top of the ecosystem. Little by little, ocean acidification destroys ocean ecosystems that have been developing for billions of years.
Why Worry About This Now?
Problems like Climate Change and Deforestation have been in the public eye for decades. However, ocean acidification has only recently been defined as a pressing problem. Why is this? Well, it has to do with how science has progressed in the recent years. Previously, scientists thought that ocean acidification was a GOOD thing. It helped to slow the effects of climate change by absorbing the carbon dioxide that normally would have resided in the atmosphere. However, as our understanding of the oceans and of the problems we have caused evolved, scientists realized that while the absorption of this carbon dioxide helped to solve one problem, it created another problem, one that poses equal danger.
Similar to Climate Change, it has also been asked how quickly this problem will continue to get worse. If the amount of carbon dioxide doesn't slow, then the ocean will continue to get more acidic at a rate faster than marine wildlife can keep up with. A common argument posed against ocean acidification is that the ocean's pH has been known to change. While this is true, changes of .1 to .2 pH happen over MILLIONS upon MILLIONS of years. This gives ample time for species living within these oceans to evolve and change. However, with recent human interference, the ocean's pH level has changed by .1 in just 100 years. This gives no time for species to adapt, and thus, they die out.
And we have already witnessed these effects in our oceans. Many coral reefs around the world, including the Great Barrier Reef in Australia, have been hit hard by the effects of ocean acidification. These reefs have begun to die off, as they no longer have the carbonate ions needed to create vital calcium-carbonate, and as a result their shells are too weak for the plants to survive. Many fish (such as the clownish) and other wildlife who rely on these coral reefs have also begun to die off. As their homes disappear, they are thrust into environments they aren't ready for, and aren't able to survive amidst the other organisms that share those spaces.
Conclusion
However, it isn't all doom and gloom. Ocean acidification is certainly a problem we have to worry about, but it isn't unsolvable. In fact, as we begin to solve climate change, we are simultaneously solving ocean acidification. Both problems are caused by an excess of C02 in the atmosphere. If we can decrease the amount of C02 we release, we not only stop the effects of climate change, but improve the health of the oceans as well. Scientists are currently working hard to find solutions to these problems, and are making good progress, but they need help. Simple changes to our lifestyles can help to minimize the effect we have on the oceans. If you would like to know ways you can help to stop ocean acidification, you can look to my next post, in which I will discuss the ways individuals can help limit their impact on our oceans. Also, make sure to check out the links provided below, as they all give great information on how to help stop ocean acidification. Thanks for reading.
All credit for information used in this post goes to:
https://www.pmel.noaa.gov/co2/story/Ocean+Acidification
http://ocean.si.edu/ocean-acidification
http://science.jrank.org/pages/1121/Calcium-Carbonate.html
https://www.nap.edu/read/12904/chapter/6
Images:
https://sites.psu.edu/blanchardcivicissues/2017/03/23/ocean-acidification/
http://ocean-acidification.net/
https://en.wikipedia.org/wiki/Bicarbonate
https://vimeo.com/93586253
https://www.britannica.com/animal/mollusk
http://thetorah.com/the-plague-of-dead-fish/
https://store.churchonthemove.com/products/why-worry
http://isha.sadhguru.org/blog/yoga-meditation/demystifying-yoga/on-the-fast-track-do-the-evolution/
https://www.thinglink.com/scene/789120378965327872
http://www.brighthome.com/blog/how-insulation-can-reduce-co2-emissions-and-improve-health
https://twitter.com/co2_reduce
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