The ocean is home to many of the most prominent, yet commonly looked over, indicators of anthropogenic climate change present in society today. Often these indicators are in connection with many other obvious, more recognized factors such as the emission of greenhouse gases or the drastic change in global temperatures. More specifically, ocean acidity can be looked at very closely to determine the severity of the situation of climate change, and how it is consistently affecting our planet’s marine ecosystems in a negative manner.
Many studies have been conducted throughout the years in order to bring awareness and alert to this situation through the use of facts regarding carefully collected and analyzed data. Ocean acidity may be one of the most alarming and long-term effects of the burning of fossil fuels. Figure 1: Bates, 2016; Gonzalez-Davila, 2012; Dore, 2015 The rapidly rising levels of acidity in the world’s oceans are due to the extremely high new levels of carbon dioxide being emitted into the atmosphere everyday.
The burning of fossil fuels purely for the benefit of humans, such as in factories or powering an automobile, has caused the oceans to absorb approximately 28 percent of the total carbon dioxide it has produced over the past quarter of a century. (Environmental Protection Agency, 2014) On a daily basis, the oceans absorb about one third of carbon dioxide emissions from humans, which averages to about 22 million tons. National Geographic Society, Unknown Year) This can be seen by using the pH scale, which measures the levels of acidity in the water.
The scale runs on a 0-14 range which means that each tenth of a point on the scale represents about a 30 percent difference in acidity. Today the pH level of the oceans averages to about 8. 1. According to a study run using data collected for the past couple hundred years, the oceans’ pH has dropped by about 0. 1 pH units, which means a terribly drastic increase in carbon dioxide levels in the waters. National Geographic Society, Unknown Year)
Another study calculated that these numbers will only continue to rise and damage the main sources of water that humans rely on for survival everyday, predicting another 0. 5 point pH increase during this next century. However, as the ocean absorbs these harmful gases, it prevents them from seeping into the atmosphere and causing more issues in the ozone layer that could negatively impact humans. These newly heightened levels of carbon dioxide affect not only the water used to maintain human life, but also the lives of millions of different species of marine life.
The way carbon dioxide reacts with sea water produces carbonic acid that exists mainly near the surface of the water, which makes it extremely difficult for some creatures, such as different species of coral and plankton, to produce the mineral they need in order to create their exoskeletons or shells, calcium carbonate. (Environmental Protection Agency, 2014) Any pH level less than 5 can severely impact populations of fish, either by affecting reproduction or directly causing death. Small factors and events that occur in ecosystems can lead to a much larger impact on the environment overall.
This in turn, could affect the whole habitat that is the oceans by setting off a chain reaction on a much larger scale, which could affect other ecosystems and the earth in general, as well. Many people rely on the ocean’s sea life as their main source of protein, and there are many coastal countries and areas across the world that rely heavily on their fishing industries, which cannot survive without healthy marine life. Although some species of plants may actually benefit from these higher carbon dioxide levels, such as algae and seagrasses, the majority will not and will definitely die off eventually.
In a recent experiment conducted using carefully collected spiny damselfish from the reefs off Lizard Island on Australia’s Great Barrier Reef, scientists spent three weeks studying the fish’s behavioral impairment and brain chemistry when exposed to elevated levels of carbon dioxide. The control of the investigation was water with normal CO2 levels. The behavioral test was put into action using a two-option flume setup, where the fish were given the choice between control seawater or water containing a chemical alarm-cue.
The chemically-concentrated water was typically avoided by the fish due to the smell it emits that resembles an injured fish of its own species. The experimenters discovered that the fish that were exposed to extra CO2 levels spent much more time near the alarm-cue than the control fish, which is of course very unusual for an average fish. The research done on the brain and blood chemistry further proved that these CO2 levels majorly altered the fish’s behavior. (University of Miami, Rosenstiel School of Marine and Atmospheric Science, 2016)
Figure 2: Unknown Author, 2013 Anthropogenic climate change as a whole is extremely dangerous and very preventable, but this specific indicator (ocean acidification) is horribly lethal to more than just one ecosystem or environment. With the world’s oceans being the center of many areas of commerce, industry, and food sources, it is very possible that this could be one of the most deadly effects of the burning of fossil fuels and subsequent constant heavy emissions of carbon dioxide gases.
