Professor Olga Lavinda
The Problem of Ocean Acidification
There was once a time where human activity was not such a widespread issue as it is today. However, once we began to use fossil fuels, there has been an exponential increase in the use of said fuel. For the last two centuries we have caused considerable damage to our environment. One such place that has been affected is Earth’s oceans. They have been affected in quite a few ways. There is a lot of garbage and waste in our oceans, there is overfishing which is causing some species of fish to become extinct, and many other problems. One issue that needs a bigger light shined on it is ocean acidification. Our water has become more acidic over time and it is damaging marine ecosystems across the planet.
Ocean acidification is caused by an increase in carbon dioxide from the atmosphere being dissolved by seawater. There have been many studies that show that carbon dioxide emissions have increased because of human activity. According to Eugene H. Buck and Peter Folger’s writing done for the Congressional Research Service which can be found on the American Chemical Society’s website, “When atmospheric CO2 dissolves into the ocean, it forms carbonic acid (H2CO3). Some of the carbonic acid dissociates in ocean waters, producing hydrogen ions (H+)” (1). This carbonic acid dissociation is what causes the increase in H+ ions. The concentration of H+ ions is what determines the pH level of water. “It has been estimated that a total of more than 530 billion tons of CO2 have been absorbed by the ocean between 1800 and 1994, with the average pH of water near the ocean surface decreasing (i.e., acidity increased) by almost 0.1 pH unit” (2). The average pH of the oceans has consistently averaged 8.2, however recently it has become 8.1 and that may not seem like a big deal, but according to the same source, that is a 26% increase in the concentration of H+ ions (Buck and Folger, 2). That is a massive change in the chemical composition of water. Some marine life may be able to adapt, but some may perish because of this. When animals go extinct or become endangered it could be catastrophic for the ecosystem because every species has a role in that ecosystem and that entire ecosystem may collapse if a species that is vital to that ecosystem. Carbon dioxide is much more soluble at lower temperatures, so the water in colder climates would be more affected, however temperature is not the only factor at play. There is also respiration and decomposition that occur and these processes add carbon dioxide to the water as well. Deep ocean water is particularly enriched with carbon dioxide and when that water rises to the surface, it absorbs more carbon dioxide from the air. This can really hurt the sea life in warmer waters, especially coral (Buck and Folger, 2). Since this affects all our oceans, we should be very concerned with this issue. Another potential problem is that and increase in stormy weather could speed up this process (2).
Another problem with the increase in carbon dioxide is that it reacts with carbonate and water to form bicarbonate. Here is an example of this reaction: (CO2)+ (CO3)2- + (H2O) = (2HCO3)1-. This equation can be found on page 3 of the Congressional Research Service report. The lack of carbonate atoms interferes with certain species of marine life. According to the study, certain creatures that form shells are adversely affected by a lack of carbonate atoms (3). The current pH is sufficient as long as it remains above 8, however if there is further increased acidification, which is very likely due to the fact that humans are still using fossil fuels and there is still demand for them, then these creatures will be in grave danger. Corals and pteropods are also affected by this as well as sea urchins and starfish. They need the carbonate atoms to react with other elements such as magnesium and calcium to perform the functions they need for their life cycle.
The study also goes in-depth on how coral reefs are negatively affected by this phenomenon. The study states that, “While ocean acidification may not appear currently to
be killing corals, such acidification is slowing development of coral larvae into juvenile
colonies” (5). The study also claims that the calcification rates have decreased by 21% on the Great Barrier Reef in Australia. This isn’t killing corals, however, the coral is not reproducing at a sufficient rate. If there is less coral then there are many species of marine life that may die due to predation or not being able to find a home in the lack of space that they have. Coral reefs have a very diverse community of fish that live there and if the reefs aren’t providing shelter to these fish then they will be in danger if they cannot adapt. However, it is not all bad news because coral reefs can still grow at lower a pH, the problem is that growth is much slower.
The study goes on to cite that other invertebrates may be at risk as well. On page 6, the study says,
“In the open ocean, some species of phytoplankton (i.e., microscopic floating plant life) may respond positively (increasing their primary production rate) to rising CO2 concentrations in the ocean, while others such as the calcifying coccolithophorids will be negatively affected (decreasing their calcification rate) by lower pH.”What this means is that certain species of plankton are at risk as well. Some may respond positively, which is not a bad omen, however, what we should be worried about are the phytoplankton that respond negatively to such changes. The reason we should be worried is because some fish depend on these types of plankton for food. Once again, if these phytoplankton are gone, the larger plankton will not be able to food, which then moves up the food chain and multiple species are then in danger of extinction.
Phytoplankton aren’t the only invertebrates affected by ocean acidification. On page 6 the study says, In response to ocean acidification, scientists have projected that mussel and oyster calcification, and thus shell strength, could decrease significantly by the end of the 21st century, according one Intergovernmental Panel on Climate Change…” This is dangerous because, once again, a softer shell will lead to a lack of protection for these mollusks. The lack of protection for them will lead to predators overeating the entire species and then the worst-case scenario is extinction of that species, which leads to more species of marine life becoming endangered. Sea urchins are another species at risk. Under lower pH the sperm swim more slowly, leading to a decrease in fertilization rates. In fact, on page 7 of the same study, “Overall, fertilization fell by 25%, and in almost 26% of cases where the eggs were fertilized, they did not survive long enough to develop into larvae.” This study was done with the pH level of 7.7 that is projected to be the average level by the year 2100. That is catastrophic for any species.
All this information may sound alarming (and it should be). However, not all aquatic life will be affected directly by ocean acidification. On page 7 of the study, it states “Although evidence suggests that larval and juvenile fish are more susceptible to changes in ocean water pH than adults, larval and juvenile fish exposed to exceedingly high CO2 concentrations (more than 100 times current levels) suffered little apparent harm.” This is not bad news for species of fish that reside in our ocean. However, this study vastly understates the how these species of fish may be indirectly affected by ocean acidification. Every ecosystem has a food chain. The phytoplankton clean the water, the zooplankton consume them, then fish consume those plankton, then bigger fish consume those fish, and so on. By removing one of these links in the food chain, all of these species may be in danger. As stated previously, certain phytoplankton will react negatively with lower levels of pH in the water. If these types of phytoplankton were to decrease, then there would also be a decrease in the rest of the food chain’s population and the worst case scenario is extinction. This has happened in a few bodies of water where “dead zones” exist. This may not be due directly to ocean acidification but it is sure to play out in the same way if the problem is not solved.
There is not a lot that humans themselves can do aside from reducing carbon dioxide emissions but the report does provide a few solutions that humans can utilize. The paper states on page 9:
“Proposals have suggested the addition of chemicals to the ocean, such as (1) using iron compounds to stimulate planktonic algae growth whereby the increased photosynthesis might capture/remove dissolved CO2, or (2) using limestone to neutralize (i.e., buffer) the more acidified streams and rivers near where they enter oceans and close to sources of limestone or add limestone powder directly to the ocean where deeper, lower pH water upwells.”
These solutions can help with the pH levels of water, but unless there is a global effort, they will only work on a local level. The report also cites that things like habitat restoration and planting seagrass will also help. However, there is another problem. The report states that even if we were to get our carbon dioxide emissions to the level they were at 200 years ago, it would still take multiple millennia for the ocean’s chemistry to be at the same level it was during the pre-industrial age.
This is not the only article written on ocean acidification. There have been many articles written on the topic of ocean acidification. Many of them go more in-depth on certain species of animals or other topics pertaining to ocean acidification, but most of the data is drawn from the Congressional Research Service’s report. This article is very well-researched and should be the first place people look to if they care about this issue. It is presented in a way that is easy to understand, even if a person is not familiar with chemistry.
Another article on ocean acidification is called “Use of a Free Ocean CO2 Enrichment (FOCE) System to Evaluate the Effects of Ocean Acidification on the Foraging Behavior of a Deep Sea Urchin.” This experiment was done by many people and what they did was that they had these fragile sea urchins and they had a control group with normal levels of carbon dioxide as well as a group of sea urchins that had been submerged in waters that were high in carbon dioxide. The reason they used water with high carbon dioxide is because that is what is causing the oceans to increase in acidity.
The study states, “Longer foraging time upon exposure to low-pH waters suggests that future ocean acidification may affect foraging efficiency in deep-sea urchins, with potential consequences for the populations and food webs” (Barry, 9894). The sea urchins spend less time foraging the sea floor. The study does, however conclude that the speed at which sea urchins move does not change. The problem is that since sea urchins spend less time foraging their habitats, it could have effects on the rest of the sea community that also has made a home in that habitat. This is stated on the same page of that study. The author states:
“Food limitation is known to shape population and community structure in deep-sea seafloor ecosystems. Reduced foraging efficiency in these urchins could have negative consequences for growth and survival of individuals during periods when food is scarce, potentially affecting the dynamics of the entire population.”
The lower foraging efficiency of sea urchins may cause them to be in danger when food is not as readily available as it usually is. The sea urchin is not the only one affected by this problem. Since the sea urchin is going to spend less time foraging, the rest of the community will also have less food available, especially those who consume sea urchins. The study also states that sea urchins are “moderately tolerant” to lower pH levels on page 9894. However, the reduced foraging efficiency will cause them to decrease in size and population. The study concludes that sea urchins aren’t in grave danger to acidifying oceans but they will definitely be affected.
The problem is that this is just one experiment. Nature, especially underwater communities is extremely complex. There is no way to tell if the lower pH will cause more problems for sea urchins or any other deep sea marine life. They may not be able to adapt in time to get used to the acidic water because adaptation does not happen quickly. Scientists should conduct more experiments on all types of marine life to see how they would be affected by waters with an increased amount of carbon dioxide.
When doing the research for this topic I found that there was an astounding lack of contrary evidence to ocean acidification or how it may not be as large of a problem as it is made out to be by some people in the scientific community. There are some people who are skeptical of climate science as of late and that is due to political reasons. However, it is quite odd that I could not find one peer-reviewed source that disagrees about this problem. This is since there may be some bias in this field of science as well as some studies not being able to publish their studies. James Delingpole at The Spectator seems to think so. He wrote an article called “Ocean Acidification: Yet Another Wobbly Pillar of Climate Alarmism.” He states that people who are talking about the problem of ocean acidification are being alarmists and the term itself “ocean acidification” is a misleading term and the our waters were simply becoming less alkaline.
In his article, he states:
“The methodology used by the studies was often flawed; contrary studies suggesting that ocean acidification wasn’t a threat had sometimes had difficulty finding a publisher. There was, he said, an ‘inherent bias’ in scientific journals which predisposed them to publish ‘doom and gloom stories'” (Delingpole, 2016).
He was quoting Howard Browman, a marine scientist for 30 years. He also states that the reason the term “ocean acidification” is used is for propaganda and to fearmonger people into thinking it is something far worse than it is because “acid” has a worse connotation than “alkaline.” He also goes on to state that two scientists who were studying this phenomenon stated there was a correlation between carbion dioxide increases and falling pH levels in the water since 1988. He then says another scientist plotted the data including pH levels since 1910 and he reached the conclusion that there has been no reduction in pH levels since 1910 (Delingpole, 2016).
Delingpole provides quite a bit of evidence that a reduction in pH is not as bad as it is made out to be. He states:
“First, marine species that calcify have survived through millions of years when CO2 was at much higher levels; second, they are more than capable of adapting — even in the short term — to environmental change; third, seawater has a large buffering capacity which prevents dramatic shifts in pH; fourth, if oceans do become warmer due to ‘climate change’, the effect will be for them to ‘outgas’ CO2, not absorb more of it” (Delingpole, 2016).
These three claims seem to directly contradict the evidence of these peer-reviewed studies. The problem is there are no peer-reviewed studies that prove his statements, which he also stated could not be published due to the bias of most climate change scientists. He provides a good argument as to why ocean acidification may not be the monster that many make it out to be. His idea that people will not allow studies that show that ocean acidification cannot be dismissed. There are some skeptics to what climate scientists have almost universally agreed upon. They are often dismissed as “conspiracy theorists” or “science deniers” by their peers, and that does not help us advance in the field of science, it stifles humanity’s pursuit of knowledge. If there is censorship of viewpoints, ideas, or experiments, it must stop immediately.
Ocean acidification is something that should be looked at as an issue right now or in the near future, based on the data we currently have. The studies that have taken place show that it may have some alarming effects on our oceans. Coral and sea urchins are just two of the many potential species of victims that could be hurt by ocean acidification. If they are harmed then that could spell doom for entire ecosystems. Human activity has polluted our waters as well as our air significantly and we are working to fix that, there can be no doubt about that. However, if there are scientists that censor certain points of view, they ought to quit being scientists because that goes against the fundamentals of science. You are not supposed to change the results and distribution of those results because it does not agree with your hypotheses or world view. Regardless of whether or not ocean acidification is an actual problem or not, we need to know the truth and we need to protect aquatic life.
Barry, James P. “Use of a Free Ocean CO2 Enrichment (FOCE) System to Evaluate the Effects of Ocean Acidification on the Foraging Behavior of a DeepSea Urchin.” American Chemical Society, 22 July 2014, pubs.acs.org/doi/pdf/10.1021/es501603r.
Buck, Eugene H, and Peter Folger. “Ocean Acidification .” Acs.com, 2 July 2009, www.acs.org/content/dam/acsorg/policy/acsonthehill/globalchallengesdiscussions/acidbath/7-2-09-crs-ocean-acidification.pdf?_ga=2.244476358.2145714789.1524777654-352273542.1524777654.
Delingpole, James. “Ocean Acidification: Yet Another Wobbly Pillar of Climate Alarmism.” The Spectator U.K., 30 Apr. 2016, www.spectator.co.uk/2016/04/ocean-acidification-yet-another-wobbly-pillar-of-climate-alarmism/.