How can atmospheric pollution result to excessive harm in the marine ecosystems?
By: Ioannis Dedes
Tags: Environment, Diversity, Future, Sustainability, Climate Change

How can atmospheric pollution result to excessive harm in the marine ecosystems? Ioannis Dedes Follow Dec 26 · 5 min read

Photo by NOAA on Unsplash

It is obvious that when one discusses how humans disturb and negatively affect the atmospheric system, the focus is based on the pollution and the effect of the excessive quantities of greenhouse gases. However, there’s less or no concentration on how the disturbance of the atmospheric system can negatively contribute to the harm on marine ecosystems.

Regardless of the focus on this connection, this text is a simple guide that can raise awareness and clearly show the impact that generally human intervention and more specifically carbon emissions, can have on aquatic ecosystems since they threaten the ocean and have a negative effect for entire food webs and chains. It’s more than important to understand the correlation of the two systems, the atmospheric and the aquatic, and be well aware of the fact that our harmful actions for the pollution of the air are equally and sometimes even more disruptive for the marine ecosystems and equilibria.

As stated before, the text is dedicated more on the single perspective of burning fossil fuels and generally, carbon dioxide emissions they can produce, along with other harmful activities. At first sight, one might say that oceans work as a mechanism that absorbs 25% to 40% of the carbon dioxide emitted in the air and actually slows the rate of global warming. Please don’t get me wrong; this is a great outcome for the absorption of this polluting substance. It’s considered great, however, until one understands the second part of the ‘story’. The CO2 quantities which are absorbed by the oceans do not disappear; they come together with water molecules, dissolve them, and create an acidic substance called carbonic acid.

Carbonic acid can be easily ‘broken down’ to bicarbonate and hydrogen ions, solutions in which the acidity is found in excessive levels. This is obviously a great contribution for the destruction of marine systems since the increasing acidity levels in the water can seriously harm the diversity of populations, habitats and plants of the oceans. After reading my last article on the environment, which raises awareness on the importance of the Amazon rainforest, one can easily understand how water acidity will work at the expense of marine ecosystems and in this particular case, the diversity of the river.

Another negative mechanism which is caused by atmospheric pollution and it’s attached to the acidic character of the above-mentioned case is the change of the wind patterns; cases of this outcome are particularly found in the Pacific Ocean. A change in the wind patterns can lead to a push of the waters on the surface aside and acidic water can rise up to the shore. Both the previous one and this case may have the negative effect of leading to greater water acidity; the phenomenon of ocean acidification. Ocean acidification is the increase of the acid and the decrease of pH in the oceans, caused by the substance of carbon dioxide. Lower pH means higher acidity, the inability of many organisms to adapt and the disruption of food chains, as shown below.

One example that should be evaluated and which ecompasses both effects of the mechanism mentioned above is the 2005 to 2008 Pacific Northwest extinction of millions of shellfish larvae. It was considered a mysterious extinction and it took way too long for the researchers to understand that the acidity of the waters was damaging the organisms’ population and that that low pH was causing the dissolution of shells. Furthermore, scientists discovered that a big number of marine organisms build their skeletons and shells from calcium carbonate, which is vulnerable to acid and after specifically two months, it completely dissolves and skeletons cannot be built properly in the water of low pH. Despite the fact that the vast deaths of the shellfish larvae urged scientists to research and figure out what happened, this population hasn’t fully recovered yet and as carbon continues to make water more acidic, the more vulnerable the skeletons and the shells will be.

In addition, there are other case studies that show us how the decrease in pH can lead to disturbance of food webs and ecosystems as a whole. Another example is about the organisms of crustaceans, a species being even more affected by the acidity in the water. This species cannot control the dissolution of acid in their shells and as a result they can easily die. This poses a threat for many ecosystems as crustaceans are primary consumers and are precious for many marine ecosystems. This could result in disruption of the reproductive cycle or the complete disruption and disturbance of the ecosystems, as these species pass a great amount of energy from the plants to the consumers when healthy. This comes in accordance with one of my previous articles that it’s based on the positive feedback mechanisms’ effects on biodiversity and is found below (although the focus is on different ecosystems the theory is the same).

As the writer, I would personally advise the reader to dedicate a greater extent of his time in understanding this particular correlation of carbon dioxide in the atmosphere, caused by human activities, which after all, can also doesn’t only affect terrestrial and atmospheric ecosystems but also poses a great threat to the marines; the examples are used to show that this is frequently the case and acidity doesn’t only harm small organisms which are irrelevant to the greater water ecosystem but it can be deadly for precious populations and parts of the greater food chains and webs.