By: Tessa M. Page
When asked to write an article for Hussy Magazine, I immediately thought about the ocean—everyone loves it, yet not many people know much about it, especially when it comes to the health of the ocean. I’m a marine environmental physiologist, so you can imagine how important the ocean is to me. I study how anthropogenic, or human-influenced, climate change will ultimately affect marine animals, and how these animals will respond to future stress brought on by things such as global warming and ocean acidification. My main focus is ocean acidification (OA), so this article will also be about OA—what it is, why it’s a problem, and what can be done.
The emission of carbon dioxide (CO2) gas into the atmosphere has drastically increased—by more than 12% in the last 20 years! Atmospheric CO2 is the largest driver for climate change, and the largest cause of CO2 being delivered into our atmosphere is anthropogenic. With the increase of CO2 in the atmosphere, there is a decrease in the pH of the ocean, making it more acidic. When I say the ocean is becoming more acidic, I don’t mean we’ll soon be swimming in an acid bath or even a huge jug of lemonade, but the decrease in pH could be significant enough to have deleterious effects on marine organisms, especially those that calcify, or form shells. The ocean is said to be a “carbon sink”, readily absorbing half of all man-made CO2 from the atmosphere. When this happens, CO2 binds with a water molecule to go through a chemical process that ultimately causes the pH to decrease and results in changes in the saturation state of carbonate species such as calcite and aragonite, which are important for shell-building organisms.
Why is OA a problem? As the pH of the ocean declines, we are unsure what will happen to marine organisms. Will these organisms eventually adapt? Will they stop being able to form shells? Will species die off? Will more tolerant species become dominate, leading to losses in biodiversity? There are many questions we still have yet to answer, but over the past decade, much work has been done and progress made researching how OA affects organisms. This work has led scientists and policymakers alike to worry about the fate of our oceans. OA has been seen to alter the ability of marine organisms to calcify, affecting things such as shellfish (what we eat!) and coral reefs (what we dream about!). And these are just two examples—the list goes on. Another heart-wrenching tale of OA is the fate of anemone fish, or more commonly “Nemo” fish. Scientists from Philip Munday’s Lab at James Cook University, Australia, have found that OA impacts the behavior of anemone fish, such as their ability to recognize predators and their homing ability. OA has also been found to impair the judgment of anemone fish causing them to be more daring and vulnerable to predators. Poor Nemo!
The ocean is vast, accounting for 71% of the earth’s surface and supporting almost 50% of all animal species on earth. Yet the underwater world remains largely unexplored and largely misunderstood. I’ve always appreciated a quote said by Jean-Michel Cousteau, “We can’t protect what we don’t yet understand.” This is why we as scientists strive for information so as to better understand what we study. Education and the movement of knowledge are the most influential mechanisms in saving our oceans (and our earth in general). I can tell you to stop burning fossil fuels, to cut down on carbon emissions, to go green, and to stop polluting, but although you should do these, they are not actions individuals can easily tackle on their own. Still, educating oneself and others is something we can do, and, we hope, society will move toward conservation en masse and eventually these larger issues will be solved.