Why should we care about ocean acidification?

BY LAURA DE LUCA

photo credit: @mads_ocean

Before you begin reading this blog, I would like you to take a few  seconds to reflect on the following questions: what does ‘ocean acidification’ mean to you? Do you consider that stressors such as marine plastic pollution need more urgent attention? How visible or invisible is ocean acidification in your life?

Most of the time when people hear about ‘ocean acidification’, the first thing that pops in their minds is climate change. Indeed, there is no denying that both of them are intertwined by the changing CO2 concentrations in the atmosphere. The ocean is an important carbon sink, absorbing almost a third of the CO2 emissions the Earth produces . Though it helps to reduce the concentration of this gas in the atmosphere, the dissolution of CO2 in the water can make it more acidic. Ocean acidification (OA) is often framed as a symptom of climate change rather than an on-going and concerning threat to the marine ecosystems. Despite the warning from scientists regarding its alarming effects, OA has not been highlighted as an important issue in the political-agenda of governments worldwide.

Why does it seem that ‘OA’ is not a top priority? A study explains that, first of all, there is a lack of public interest which can lead to low levels of action.  Secondly, this could be related to the fact that OA gives the impression of  a non-pressing issue. This is visible in the poor coverage by the media on this threat, which is the opposite for climate change or plastics. Lastly, there also seems to be more ‘tangible’ actions for these threats than there are for OA. 

Finally, the way the narrative of OA is presented to the world has definitely had an impact on public perception. How do we make a narrative that holds public attention and then leads to action? How do we get them to be emotionally and morally involved? These are indeed very difficult questions that need to be answered jointly by the collaboration between different natural and social sciences disciplines. Just to give some examples, conservation biology, environmental psychology, law & policy and communication & media.  

So, why should we care about OA; why is it so important? I would like you to picture yourself 66 million years ago. You are in the Cretaceous period, an Earth ruled by dinosaurs and unimaginable sea monsters. Everything is about to change, as a meteorite is impacting the Earth. But wait, you might be wondering what does this have to do with OA?  The impact most likely caused the vaporization of rocks containing sulphates and carbonates which then produced acid rain and acidified the ocean. This led to a rapid decrease in the pH ocean, wiping out almost three quarters of all the living marine organisms, such as the well known ammonites. 

You can argue that this was an extreme natural catastrophe and this is not what we are experiencing nowadays. But data today shows us that we must take this issue seriously. According to UNESCO, ocean acidity has increased by 30 percent since the Industrial Revolution. Even worse, this decrease in pH has been occurring at alarming rates compared to the last 300 million years of Earth’s history! OA has proven to be completely fatal in the past and it won’t be different now if we do not take action. 

photo credit: @mads_ocean

Our ocean is ruled by so many organisms that depend on calcium carbonate minerals to build their shells and skeletons, from tiny phytoplankton to the iconic tropical corals and deep-sea corals around the world. All of these organisms are in peril when facing OA. Not only will they be unable to build their structures, but slowly will start to dissolve and their physiology and reproduction will be altered. What does this mean for the other marine organisms that depend on them and for us? Corals, for example, are hotspots of biodiversity. In Hawaiian culture, a coral is an akua (god) and the place where all life begins. They are correct because coral reefs are one of the nurseries of the ocean. Corals also provide ecosystem services for humans such as food provisioning, flood protection, cultural and spiritual value and tourism. Without corals, there would be alterations in the food webs affecting the structure and functioning of the ecosystem, a collapse in the fisheries, loss of protection from storms and we would never be able to see the breathtaking coral reefs full of life when diving or snorkeling. Similar outcomes can happen due to the impact of OA on other carbonate-dependant marine organisms besides corals.

photo credit: @mads_ocean

There are still many things that we need to learn about OA but that does not take away the urgency of this threat. One thing is certain; OA is deadly for all living creatures including us. What can we do about this? This is a very complex question, one that sometimes can be discouraging because there is no ‘fast’ action that can solve this problem. First of all, even though it may sound abstract, we need to self-reflect about how desensitized we are from nature and the ocean. What is keeping us from taking action or changing our behaviour? Secondly, another way of helping combat OA is by educating ourselves and sharing this information to people that we know. Last but not least, reducing our carbon footprint is crucial to stop the accelerating OA and at the same time mitigate climate change. 

Do not feel discouraged if not everyone is taking action, though I know it can be really frustrating. The change begins with yourself and by becoming self-aware. You might even inspire people around you! Let’s give awareness to ocean acidification.