A Hitch-Hikers Guide to Ocean Acidification

By Monica Rabin, WILDCOAST US Oceans Intern 

If you’re anything like me, you have a deep love for the ocean, the environment, and our planet. But when scientific concepts feel too broad or overwhelming, they can be hard to grasp. However, when these ideas are broken down into smaller, more digestible pieces, everything just clicks.

Ocean acidification was one of those topics that suddenly (and finally) made sense when it was broken down. I knew it had something to do with climate change, but I had yet to learn how urgent an issue it was. Ocean acidification is not only related to climate change, but is directly linked to its root cause: increased carbon emissions. 

Carbon dioxide released into the air from human activities is one of the main causes of climate change. Many people do not know that our planet has a natural solution to deal with some of these emissions (the other 45% of emissions not absorbed by the planet stays in the atmosphere. This is what causes climate change). Carbon dioxide is sucked up by the planet in a couple of different ways: 25-30% is absorbed by plants and soils, 25-30% by the ocean, 1% by rocks. When considering ocean acidification, we want to focus on this 25-30% absorbed by the ocean. On average, that 25-30% equates to around three 3 billion tons of carbon a year, and for reference, an average-sized rhinoceros weighs about one ton. 

When all of that carbon goes into our oceans it begins to rapidly change the chemistry of the water. Here, CO2 and water (H2O) mix, forming a product called carbonic acid (H2CO3).

Eventually, our little friend, carbonic acid, breaks down and becomes our enemy. Carbonic acid splits apart to create two products: positively charged hydrogen ions (H+) and bicarbonate (HCO3-)

So now, with this reaction complete, there is a large excess of positive hydrogen ions in the ocean. As these numbers increase (as shown in the chart below), the water becomes more and more acidic.

Before the Industrial Revolution, the pH of the ocean was 8.2, whereas now it is 8.1 due to the abundant carbon that has entered the ocean and caused this chemical reaction. This drop might not seem very significant, but even the smallest changes in an ecosystem can create a chain reaction. 

Marine animals, like corals (yes, coral is an animal!), shelled organisms like snails, and some plankton, need calcium carbonate to build their shells and skeletons. The increasingly acidic water reduces the availability of carbonate ions, making it harder for these animals to grow and maintain their shell. Their structures become smaller and weaker, and because of this, shelled organisms become easy targets for predators, which messes with the food chain as these smaller species are crucial in maintaining entire ecosystems. Additionally, coral becomes fragile and more susceptible to damage, which leads to a decline in fish populations that rely on the reefs for food and habitat. 

To see this in action, drop a piece of chalk (the regular white kind) into a cup of vinegar. Chalk is made out of calcium carbonate, just like snail shells, and vinegar is an acid, so it simulates a snail shell in an acidic ocean. You can watch the chalk dissolve right before your eyes, just as shells would!

Here at WILDCOAST, we are actively working to mitigate many of the impacts of ocean acidification. Our mission is to conserve coastal and marine ecosystems and address climate change through natural solutions. To date, we have improved the protection of 38.2 million acres of protected areas that are home to 1,584 acres of coral reefs and installed 213 reef-protecting buoys in the Mexican Pacific. In California, we have helped establish 545,280 acres of marine protected areas that protect important ecosystems such as kelp forests, rocky reefs, and submarine canyons. 

While ocean acidification is a daunting subject, it is not an issue that lacks a solution. We know the science, we understand why this phenomenon occurs, and it is no mystery as to who is allowing it to continue. We all must come together and face this challenge head-on if we want future generations to enjoy the ocean as we know it today. Here are a few ways you can help!

Be mindful of the products you are wearing before entering the ocean. Reef-safe sunscreen is not just a trend, it is critical to prevent ocean acidification from accelerating! 

– Read the “active ingredient” list on your sunscreen as the term “reef safe” is not regulated and can be misleading. The only active ingredient in your sunscreen should be zinc oxide, NOT: Oxybenzone, Octinoxate, Octocrylene, Homosalate, 4-methylbenzylidene camphor, PABA, Parabens, and/or Triclosan.

Aim to lower your carbon footprint! You can take small steps to lower the amount of carbon emissions you contribute to the environment. (P.S. it will also help you save money!) 

– Try your best to choose greener transportation when possible like public transportation, walking, biking, and carpooling. 

– Be energy efficient with your thermostat: during the winter, the Department of Energy suggests keeping your thermostat to 68-70°F and turning it off or lowering it by 8-10°F while you are not home or asleep.

– Unplug your electronics while not in use! When we leave electronics plugged in while not in use, they often still use power, known as “vampire power” which not only harms the planet but your wallet as well. This includes appliances such as monitors, phone chargers, microwaves, coffee machines and more. 

We invite you to help WILDCOAST in this fight against climate change by donating today!