Air pollution impacting marine health and how!

For all who read/visit the Air Quality Matters blog regularly (and this may as well apply to infrequent site visitors too), it could very well be that you’re familiar with the posts on this site devoted to the aspect of atmospheric carbon dioxide concentration, the potential effect this may have on warming – its global warming potential (GWP), in other words, and how this all may inter-relate.

To provide a bit of background, I have researched this area of scientific study rather extensively. Numerous times in related postings I have presented information on how the CO₂ (carbon dioxide) gas present in the atmosphere at its current concentration of an approximate average 400 parts per million parts of air, has – and is having – a devastating, negative effect on sea water and on much of the life contained within. At this point, some may be thinking or even expressing out loud: “Wait a minute: How can this be?!” or “Did I really read what I thought I just read?!”

Through much scientific observation and study, it has been determined conclusively that there is a percentage of CO₂ in the air, through the process known as “transference,” that enters the oceans. According to information in PBS’s NOVA documentary “Lethal Seas” (the show aired on the Public Broadcasting System network on May 13, 2015), the amount of CO₂ absorbed by the oceans currently stands at about 25 percent.

Meanwhile, it was further stated that initially this was seen as being beneficial from the standpoint that whatever CO₂ was entering major bodies of water like the planet’s oceans, that CO₂ gas that would have been in the air was now no longer there. What oceans are doing, in effect, is behaving like sponges, absorbing the excess or extra carbon dioxide the air isn’t soaking up. The amount of carbon dioxide entering the oceans daily is staggering! In real numbers, roughly 30 million metric tons per day, according to Mark Green of Saint Joseph’s College, a scientific authority providing expert comment in the documentary.

Again, as brought out in “Lethal Seas,” on account of this air-to-ocean, carbon dioxide transference, ocean pH levels are decreasing, all of which means there is a corresponding increase in marine acidity. In fact, average acidity in the oceans is rising at roughly five percent every 10 years. And, this acidity rise is having a detrimental impact on the life within, particularly that which exists at the bottom of the sea-based food web, the crustaceans, in other words, this in addition to coral reefs where affected.

So, what is it exactly about the increasing CO₂ that is causing a substantial lowering of ocean pH and hence advancing ocean acidification at the rate it is?

What the scientific community has discovered or maybe more accurately uncovered, is that the carbon dioxide dissolving in the ocean is reacting with ocean water (H₂O) to form what is known as carbonic acid. Said carbonic acid, meanwhile, as I understand it, interferes with proper exterior shell development in the so-affected crustacean population. Without a properly developed outer layer of protection, the crustaceans in question then become vulnerable with their very survival threatened.

The damage being thus, this is having quite an impact, especially on societies and civilizations that rely on said waters for sustenance as well as on those whose livelihoods depend on a flourishing, thriving, healthy aquatic ecosystem. If life on the lower rung of the sea-based food-web ladder succumbs as a result of this kind of destruction, then it could be said that this could have a ripple effect on life that this life supports and sustains.

The accelerated rise in marine CO₂ might possibly be too much to bear and not allow such affected sea-life to adapt and thus recover.

In the final analysis, when I watched the “Lethal Seas” documentary in full (it’s about 53 minutes in length), one of the conclusions I have reached is thus: Anyone who thinks that carbon dioxide is not a pollutant and at current air concentrations isn’t harmful to the environment, they need to watch this NOVA episode themselves. “Lethal Seas” is an eye-opener and thought-provoker to the say the least.

For more on this matter, see: “Earth Day 2014: ‘Conserve’ is the word” here.

Images: Yumi Yasutake, National Oceanic and Atmospheric Administration (middle); United States Department of Agriculture (lower)

– Alan Kandel

This post was last revised on Apr. 3, 2020 @ 3:09 p.m. Pacific Daylight Time.