What Causes Ocean Acidification & How to Prevent this Problem?

Ocean acidification is often referred to as the ‘dark side of global warming’ or the ‘nasty little brother of climate change’. It is causing huge problems for sensitive marine ecosystems throughout the world’s oceans, and is one of the biggest threats to the continued existence of coral reefs.

Ocean acidification is a chemical process caused by elevated carbon dioxide concentrations in the atmosphere. It is one of the more severe effects of global warming, and has the potential to devastate sensitive marine ecosystems over the coming years.

pH sensitive species such as corals and shellfish are especially at risk, as more acidic conditions reduce their ability to build shells or skeletons. This has led to widespread cases of coral bleaching and negative events throughout the planet’s oceans [1].

Unfortunately, the frequency of these events seems to be increasing.

What is causing the ocean to become more acidic?

Basically, ocean acidification is caused by human pollution. It is one of the less known problems associated with global warming. The oceans absorb a huge percentage of humanity’s carbon dioxide (CO2) emissions.

Around half of the carbon dioxide produced by modern industry and other polluting practices is dissolved in the ocean. Here it reacts with water to form carbonic acid, which lowers ocean pH and reduces the concentration of carbonate ions. Carbonate ions are an essential component for the formation of corals, shells, and other hard skeletal structures [2].

Lower concentration of carbonate ions in the water reduces the ability of corals and shellfish to build their skeletons and shells respectively. The problems caused by ocean acidification are especially evident in the colder waters of the Arctic and Northern Pacific where the negative effect on shellfish is already becoming obvious.

Obviously, the main cause of ocean acidification is the emission of greenhouse gases (namely carbon dioxide) through a number of human activities.

These include:

Fossil fuel emissions

Fossil fuels could be thought of as the ‘evil good’. They have played a huge role in developing society into what it is today. Without them, it is highly unlikely that we would have some of the advanced technology which people take for granted, and it is entirely possible that we would still be living in the age of the horse and cart.

However, burning fossil fuels releases carbon dioxide – a fact which most people would be aware of. Cars, airplanes, factories, and power plants all burn fossil fuels, and therefore all contribute to carbon dioxide emissions.

Therefore, we can conclude quite easily that fossil fuels are a leading cause of ocean acidification [3].

Deforestation

Deforestation is a complex issue. While the obvious effects include the reduction of habitat and loss of biodiversity, a less known effect is carbon dioxide emission.

The large scale burning which usually accompanies deforestation is similar to burning fossil fuels and releases a lot of carbon itself.

However, since forests also act as large ‘carbon sinks’ – they absorb carbon dioxide from the atmosphere and store it – their removal also reduces the earth’s carbon dioxide storage capacity [3]!

Algal blooms

This is a less-known cause of localized ocean acidification. When nutrient concentrations in an area become too high (usually due to fertilizer runoff), algal blooms occur.

After these algal blooms are finished, there is generally a lot of organic matter remaining, which begins to decay. This decaying process releases large amounts of carbon dioxide and can lead to acidifications.

What chemical reaction causes ocean acidification?

It is estimated that the ocean absorbs around 22 million tons of carbon dioxide per day. Yes, per day. Every molecule of this carbon dioxide contributes to ocean acidification, and therefore is harmful to the environment.

The process is as follows:

When the carbon dioxide dissolves, it reacts with water to form carbonic acid (H₂CO₃)

CO₂ + H₂O → H₂CO₃

This carbonic acid then reacts with carbonate ions to form bicarbonate ions (HCO₃^–)

H₂CO₃ + CO₃^– → HCO₃^–

The harmful part of the process is the second step, which involves the removal of carbonate ions, an essential building block for a number of marine organisms [5]. The effects of ocean acidification provide just one more reason for us to act.

How can we prevent ocean acidification?

Everybody has a responsibility to do whatever they can to protect our sensitive and dying oceans. Although people may not realize it, the ocean performs a number of essential functions for the planet, without which, human existence would not be possible.

Atmospheric temperature stabilization, greenhouse gas absorption, food production, and climate control are just some of the things which the ocean does which benefits our everyday lives.

Although we cannot stop the process of acidification from happening, there are a number of preventative strategies which we can implement to reduce the effect of ocean acidification. Most of these center around reducing carbon emissions and addressing the effects of climate change.

Here are some strategies you can adopt in your life to help reduce ocean acidification from becoming worse and worse.

#1 Reduce the carbon footprint of your personal life

Global warming and climate change are adversely impacting the ocean every day. By making informed choices and being aware of your carbon emissions, you can help prevent ocean acidification. Do this though simple actions such as walking or cycling instead of driving, conserving natural resources, and reducing your energy use to when it is really necessary.

By eating less red meat, you are contributing less to farming emissions – which on a global scale are actually greater than transport emissions.

Save electricity and water wherever you can within your home. You can do this by fixing leaky taps or pipes, installing a solar hot-water system, turning off appliances and lights when they aren’t in use, and using energy efficient appliances and light bulbs.

Use less plastic. It is estimated that up to 4.5 percent of the world’s plastic production each year enters the ocean. This equates to around 12 million tons of plastic, or enough to cover every foot of coastline on the planet [6]. Plastic is extremely harmful to a huge number of marine organisms. It is responsible for the deaths of turtles, whales, and other vertebrates every year, damaging the marine ecosystem.

Buy fewer material objects, and reduce, recycle, and reuse things in your everyday life.

#2 Adopt more environmentally friendly power generation methods

As we all know, renewable energy is the ideal form of electricity generation. However, there are also a number of other things we can do. Coal-fueled power plants can be changed to natural gas, which emits half of the greenhouse gases coal does when it is burned.

Emissions can be filtered more efficiently to reduce the amount of pollutants released into the atmosphere. Eventually, all fossil fuel fired power plants should be closed, and other fossil fuel uses – like in cars, boats, and other motors – should be reduced as much as possible.

#3 Reduce fertilizer use

Excess fertilizers usually end up caught in stormwater drains after heavy rain, and make their way to the ocean. This can result in algal blooms which deplete oxygen levels in the water and create a ‘dead zone’ which contains few or no other organisms.

The best example is the Gulf of Mexico, where an area the size of New Jersey is affected every year. Use less fertilizers or, if possible, use none at all.

#4 Educate, educate, educate

The key to knowledge is education. Many people would be horrified if they knew the effects that their polluting lifestyles were having on the oceans.

However, since they don’t know, and have never learnt, they don’t care. You can begin with talking to your friends and family, joining a local ocean conservation agency, or simply talking to strangers over the internet to raise awareness about this hidden issue.

#5 Pressure the government

Ultimately, the government holds the power to make large policy and educational changes to reduce carbon emissions and prevent ocean acidification. You can ensure that you vote for the party which has the best environmental policies and can pressure your local council members to make small changes.

Send emails or letters, join protests, and rally for the ocean to let the government know you care!

#6 Support a good cause

Join a marine conservation group such as Sea Shepherd, the Marine Conservation Society, or Oceana, and follow their efforts to save the oceans.

You can aid their causes by donating, volunteering some of your time at events – either locally or not – and by educating your friends and family about marine conservation and its importance in our lives.

#7 Make smart life choices

When you have time one day, sit down and think about the emissions associated with your life. Do you work in a field or for a company which doesn’t value environmental protection? Does your job involve carbon intensive or unsustainable activities?

If so, then you should think hard about whether you are in the right job, and/or do what you can to make your company less polluting.

#8 Eat sustainable seafood

Global fisheries are collapsing, and around 75 percent of the world’s fisheries are either fully or overexploited.

This is obviously not sustainable and doesn’t support healthy balance in the world’s oceans. Luckily, there is something you can do to help reduce the diminishing health of the world’s oceans.

You can help by ensuring that any seafood you consume is sustainably sourced. Ask restaurants where they source their seafood. Buy ‘line caught’ or ‘sustainably harvested’ seafood. Or even better, look for a mark of approval from a marine conservation organisation.

There is no quick solution to ocean acidification. Nor will we stop the process and reduce its effects until we can bring our carbon emissions under control and stop polluting the earth. However, it is important that we do whatever small things we can to prevent ocean acidification.

We need to reduce our dependence on fossil fuels, reduce greenhouse gas emissions, and save the planet, one step at a time.