Sophomore Year 

 

The Undiscovered Mystery On Earth 

        From the stars above to the darkness below, the oceans, an undiscovered and underexplored mystery is seventy one percent of what surrounds us all daily (National Geographic). The world that the human population has lived on for years has been explored longer than outer space, yet the moon and mars have been mapped out more than our ocean floors. There is so much of the ocean that has never been seen by humans that there is an estimated ninety percent of marine species that have yet to be discovered. This ninety percent has scientists estimating that between a few hundred thousand and a few million animal species are waiting to be discovered (National Geographic).  The  world’s oceans are broken up into four specific parts, which are: Pacific, Atlantic, Arctic, and Indian. The oceans are estimated to have an average depth of 12,000 feet (3,720 meters) and hold what is estimated to be about 97% of the world's water (National Geographic). These bodies of water contribute so much to earth’s living organisms and are a huge part of why there is life on earth.  Without the bodies of water, the atmospheric temperature, weather, plant growth, movement of sediments, and concentrations of element levels would struggle to work together to support life and encourage growth here on earth. With each contribution that water has on the environment the more it shows its importance on why we need to care for it. 

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       The ocean is not only the majority of earth that surrounds all populations but is also home to many other species, yet we look the other way like it is non-existent. We throw our trash, sewage, and emit pollutants directly and indirectly into it day after day. The damage humans have caused on the waters is so traumatic that it is causing rapid changes in the environment affecting the water concentrations elementally and causing its pH (the acidic and basic levels) to drop to all new lows faster than it has in the past 650,000 years (Falkenberg). The marine ecosystems that are home to many species that have yet to be found such as corals and seaweed and algae have been degrading at rates faster than researchers can find a solution to the mess that we have created as a human population.

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         In this paper, we will be going over what ocean acidification is, the effects it has on the marine ecosystem of plants, the marine ecosystem of animals, its direct effects it can have on the human population, and some possible solutions to slow the ocean acidification process down, to hopefully give scientists enough time to find a permanent solution to revive the ecosystem within the waters, in order to save the planet earth that the human population likes to call home. 

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Ocean Acidification  

        As humans evade the land on earth, we are deforesting all the greenery around us to create business and are creating carbon dioxide emissions through burning fossil fuels into the atmosphere. Humans depend on burning these fossil fuels to have energy to cook, have light in the dark, travel via cars, boats, and planes, and ultimately live a privileged life. These emissions increased heavily about 200 years ago when the industrial revolution  took place. According to Laura Falkenberg, the author of “Ocean Acidification and Human Health”, stated that “The atmospheric carbon dioxide concentration is approximately 383 parts per million by volume, which is a level not yet seen in the past 650,000 years, and it's been projected to increase by 0.5% per year through the 21st century, which is one hundred times faster than any point in the last 650,000 years. However, the emissions given off by all the machines and power plants are toxic to the atmosphere and poisoning our oceans and its ecosystem around us. The plants that assist the environment in leveling the number of emissions put into the atmosphere are dissipating due to deforestation taking over to provide land for growing businesses. This is causing other animals to suffer and starting a chain of events that harm everything in the long run. 

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          When carbon dioxide emissions are released into the air fifty percent of the carbon dioxide stays in the atmosphere, while twenty percent goes to our greenery and thirty percent goes into the world’s oceans (National Oceanic and Atmospheric Administrations). The thirty percent of carbon dioxide that goes into our oceans causes a chemical reaction within the water. The carbon dioxide (CO2) will react with the water (H2O) and carbonate ions (CO32-) creating a weak acid commonly known as carbonic acid (H2CO3). This reaction will then cause the product to dissociate into hydrogen ions and bicarbonate ions.  (Jagers).  This reaction that creates an excess amount of hydrogen atoms, will cause the pH level to drastically decrease. ​This decrease in pH means that the water is becoming more acidic. Since the industrial revolution, the amount of carbon dioxide released into the ocean has had a 0.1 unit decrease of pH within the waters (Guinotte). “This decrease seems like a small amount, however, pH is a logarithmic unit, this means that each whole unit is actually equal to a ten-fold increase in acidity” (Guinotte). This decrease in acidity is estimated to decrease another 0.3-0.4 units within the next century, which is double the acidity by the end of the century (Guinotte). 

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        The decrease in acidity due to the carbon dioxide levels in the ocean is termed ocean acidification. The acidification of the water in the ocean can be seen affecting other chemical compound levels within the waters, which takes a greater toll on the environment the ocean creates for our sea creatures. 

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Ocean Acidification Effects On The Ocean Water Nutrients ​

         The normal ocean is saturated with calcium carbonate (CaCO3) that sea creatures normally use in order to create their outer shells. The Calcium carbonate is another reaction that occurs within the waters of the ocean. Calcium (Ca) reacts with Carbonate ions (CO3) in-order to create calcium carbonate (CaCO3). These ions are not highly soluble however, the perfect amount of Carbon dioxide will help calcium carbonate precipitate creating crystalline structures of the mineral (Australian Academy of Science). This reaction can be affected by the levels of carbon dioxide in the water. The colder the water the more carbon dioxide there is, the warmer the water the less carbon dioxide there is.

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         The more carbon dioxide there is, the more it reacts with carbonate which creates carbonic acid which means there is less carbonate to form calcium carbonate. Depending on the level of carbon dioxide, the carbonate ion will create a horizon for many sea creatures and sea plants. Within the horizon/ reaction that occurs two different forms of calcium carbonate is created. According to Sarah, who wrote “More Than Just Temperature – Climate Changing and Ocean Acidification” stated that, “The main difference between the two forms made is simply the organization of the calcium, carbon, and oxygen atoms put together. This affects their stability.”  When a calcium carbonate is formed in a certain organization, one of the forms created is aragonite and the other is calcite. Aragonite is the least stable of the two and is easier to dissolve than calcite. The shallow end of the calcium carbonate horizon is favored by many organisms in the ocean who need the minerals in order to grow their outer shells and protection. However if organisms fall below the calcium carbonate horizon then they have a greater chance of dying because they don’t have the extra minerals in the water to build their shells (Guinotte). With the carbon dioxide levels rising this is causing the horizon to appear in shallower depths leaving little area in the deep waters for animals that need the calcium carbonate to live.  

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Ocean Acidification Effects On Marine Animal Life ​

            Though the majority of the ocean’s animal species have not yet been discovered, the ones that have been, are studied in research labs to understand the kind of effects ocean acidification is taking on them. This type of research is very new, and we have not yet found all possible effects of every single marine animal’s species. The research that has been done on marine animals is most of the time compiled together and analyzed to grasp the general idea of the effects that the increase in carbon dioxide and ocean acidification has and can cause in the future. This type of study according to Kristy Kroeker, the author of “Impacts of Ocean Acidification on Marine Organisms: Quantifying Sensitivities and Interaction with Warming”, states that this type of study is called a meta-analysis […] it provides a transparent method to identify key patterns across numerous studies and can be used to develop hypothesis for future research.”  Most of the information talked about in marine animal life, will be found from studies that have used the meta-analysis to find patterns in specific species of animals. 

Animals that live and depend on the saturation horizons (calcium carbonate horizons) for example are typically corals, and shellfish. They rely on the horizon in order to build their structures/ outer shells. As the ocean becomes more acidic the levels of calcium carbonate are decreasing making the coral's outer shell weaker. The rate of calcification for corals has dropped to about twenty-two to thirty-nine percent, while the increase in acidity has also made the corals abundance rate decrease to about forty seven percent (KROEKER). These effects in coral were also seen in mollusks (ex. Clams). 

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            According to Laura Falkenberg, the author of “Ocean Acidification and Human Health”, stated that “Over fifty percent of all species tested in laboratories have shown negative response to ocean acidification.” The reasoning behind such a high number of animals reacting negatively is because of how animals use their energy to balance the acid-base concentration within their bodies. In order for animals to keep a perfect balance they must use their energy toward their metabolic system, and other functions to keep homeostasis and because of this, the energy is taken away from being used for their growth, reproduction, and ultimately their survival tactics (Falkenberg).  

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             Another impact that ocean acidification has is on the sensory function of marine organisms. This is a huge factor because marine animals use their sensory functions in order to get back to their safe environment, get away from predators, find their food and ultimately survive. The main sensory functions affected are chemosensory perception, auditory senses, and vision senses.

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            Chemosensory perception is the most common sense between marine animals; however, it can look different between each species. While some might smell, others have pits that cause a chemical reaction to occur and can alert the olfactory nerve. According to Molly Ashur, the author of, “Impacts of Ocean Acidification on Sensory Function in Marine Organisms”, its found that “Recognition of chemical cue is initiated by the binding of a chemical molecule to a receptor protein on a primary chemo receptor neuron. In all animals, this binding initiates a G protein- based signaling cascade that transmits a signal to the central nervous system.” This signaling cascade is vital for marine animals to detect predators, find home, and find food. A synopsis done by Ashur, compared many types of species at different age ranges, different areas of the ocean, with different amounts of carbon dioxide levels as well as different exposure times to fully grasp the idea of how the chemosensory is being affected. Out of twenty-six studies it was found that the chordata teleost phylum, when exposed to high amounts of carbon dioxide, had a negative effect overall. The predator avoidance decreased, prey detection decreased, antipredator response went down, and the homing ability as well as a few other factors decreased. With the phylum cnidaria, the settlement success decreased. With a decrease in prey detection, predator avoidance and in settlement success, this can cause a chain of events where one species becomes overpopulated. This also means that the survival rate will decrease due to not enough nutrients, as well as being killed by their predators. 

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            Auditory senses in a general definition can be described as a non-contact vibration stimulus that can be recognized by several fish such as: arthropods (ex. crabs), cephalopods (ex. Squid), cnidaria (ex. Jellyfish) and marine mammals (Ashur). Marine animals' auditory work is similar to that as humans, and how we have an inner ear that detects vibrations and sends signals to our brain. However, in each species the organ system/ structures may be a little different. For example, Ashur talked about how lobsters have external sensory hairs, and how shrimp have an organ system called a statocyst that has a mass that leans on sensory hairs to detect vibration. While each structure may be different for each organism, they all do the same thing, sense vibrations. This system can be used for communication between animals’ detection of prey and predators as well as navigation. For many animals the use of the auditory system is key to navigating throughout the ocean to find a habitat to live and survive in. Ashur, the creator of the marine analysis synopsis in “Impacts of Ocean Acidification on Sensory Function in Marine Organisms” stated that “Ecosystem-specific sound, for example, fish vocalization, or crackle of snapping shrimp, and physical wave action can be detected from thousands of meters away and can be a reliable source of information for homing fish as sound transmits through water regardless of water movement.” Due to this being a reliable source of communication and navigation for marine animals, they tend to follow what the auditory system is telling them; however, the carbon dioxide levels have started to affect which vibrations are getting to specific species. For instance, fish larvae use their auditory senses to settle in a reef. Each reef gives off a specific sound, and reef fish tend to go to nocturnal reef sounds and avoid daytime reefs.  However as there is an increase in carbon dioxide the reef fish have gotten confused, and the day reef sounds have been interpreted by the reef fish to be the nocturnal reef. 

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          This is due to when the pH level increases or decreases. As water becomes more acidic sounds become louder, and the basic water creates sounds that are quitter. (Asher). This confusion can cause serious danger for the reef fish larvae and delay the timing of navigation. The confusion of auditory senses can ultimately cause behavioral differences in the organisms as well.

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             Vision senses are different among every species. There are different lenses in each animal which can affect the amount of light needed to see.  There are different amounts of pigment photoreceptors, as well as high functioning eyes that work like a camera (Ashur). According to Ashur, “The physiological basis of vision relies on the photon-activated G-protein phototransduction cascades that is present in nearly every light sensing organism.” This cascade is normal in almost every animal. The vision senses of animals are key to navigation once reaching the destination. The visual sense helps the animals adapt to the new environment as well as scope out any dangers like predators who may be after them. In specific fish larvae it is found that the increased carbon dioxide levels have increased the fish’s ability to “phototaxis” which is a process where the larvae swim toward a light source in order to feed and survive (Ashur). This may seem like a positive factor to an increase in carbon dioxide and ultimately ocean acidification, however, this could also mean that the neurons inside the fish are becoming overstimulated, which could be a potential negative impact (Ashur). 

 

Ocean Acidification Effects On Human Health  

       The ocean provides many with sustainable food, that feeds families and provides some with a living. Over 7.8 billion people live on earth, and 4.5 billion of those people take in about fifteen percent of their protein by eating fish from the ocean [Falkenberg].  According to Falkenberg, the author of “Ocean Acidification and Human Health”, stated that “There are 199 million kids 5 years old and under (68% being in Asia) and 55% are malnourished […] 5.3 million children die from preventable causes, and nutrition related factors contribute to 45% of those deaths.” It should be noted that these numbers aren’t directly related to ocean acidification and the carbon dioxide levels in the ocean, but it shows how important keeping the fish healthy and away from toxins are. 

However, as  humans pump about 22 million tons of carbon dioxide into the ocean making it more acidic than ever, we are, in the long run, poisoning not only sea animals but ourselves (Center of Biological Diversity). If the carbon dioxide rates and ocean acidification rates keep increasing at the rate they are going, the human population's health will be affected in four major ways. The first possibility is poisoning and malnutrition through our seafood. The second possibility is Mental Health degradation. The third possibility is decreased opportunity to develop and obtain medical resources. And the fourth possibility is respiratory issues due to the water quality. 

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Pollutants and Toxins 

            As carbon dioxide is pumped into the ocean, other pollutants are as well. Some of these include very heavy metals such as: mercury, aluminum, zinc, and copper as well as medications. (Falkenberg). These heavy metals and medications become more relevant within acidified water making the metals more readily available for a fish living in the ocean’s ecosystem to eat. These heavy metals, once digested by sea organisms, soak into the skin and muscles of the sea creatures, poisoning them and their predators within the food web, which infect each trophic level, one of which being humans. The poisoning of our sea creatures has affected the safety of consumption of many fish. Falkenberg, mentioned that these heavy metals such as mercury within the ocean are commonly seen in the muscles of smaller fish, which could be directly correlated with ocean acidification.  It causes a decrease in the growth rate of fish as well as degrades the skin of marine animals making it easier for the pollutants to invade the fish. A common example of this found by Falkenberg, was mercury levels within finfish, which showed that it impacted humans by causing neurological damage and affecting developmental health. It was also found that DDT, an insecticide that is colorless, tasteless, and odorless, was commonly found in the liver, adipose tissues, and muscles of fish, and once consumed by humans, had the opportunity to cause cancer, neurological damage and reproductive complications in humans [Falkenberg]. Another marine life that is heavily affected by ocean acidification are shellfish that carry natural toxins and are surrounded by algae that increase those toxins.  According to Falkenberg, some of these natural toxins that shellfish hold can cause four specific poisons such as: paralytic shellfish poisoning, Neurotoxic shellfish poisoning, amnesic shellfish poisoning, and diarrhetic shellfish poisoning. These poisons are often gathered by harmful algae bloom, which grow faster and more readily in acidic ocean environments that have more carbon dioxide in 

them. These poisons that are among the shellfish are then consumed by humans making our seafood a greater health risk. The same algae that affect the oceans shellfish can cause micro bacteria that when digested by humans, can block nerve endings and cause respiratory issues as <well as paralysis among the muscles. In the future if the ocean becomes more acidic, the faster the bacteria will grow [Falkenberg]. 

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Mental Health Degradation 

             The ocean can be used as an area for people to socialize, get rid of stress, feel connected to nature and exercise. For many the blue oceans and waves crashing on the shore is a peaceful area to let go and relax, and for others it’s where their living is made, by catching fish and selling it to vendors. Falkenberg states, “Approximately 300 million people find their livelihood associated with marine fisheries, and ninety percent of those are in small-scale, artisanal fisheries” However, the more acidic the ocean becomes, there is less to see, fish to be caught, and rather more to fear. It has been found that as the ocean acidification increases the more the coral reefs bleach, making an ecosystem that used to be so lively and filled with animals a more simplistic habitat making many marine animals must find a new home. This causes the quantity of fish caught by fisheries to decrease and creates a problem where many will lose their livelihood and can create a fall in the fishery industry [Falkenberg]. The bleaching of the corals creates a more simplistic environment which not only affects the marine animals, but also the humans that use scuba diving and snorkeling as a way of relaxation and nature connectedness and it* normally creates “positive well-being” [Felkenberg] . Another factor that ocean acidification causes on the environment is the senses of fish (talked about above), creating a migration of marine animals into areas not normally seen. For instance, Falkenberg talked about how “key foundation species in decline under ocean acidification and topicalization of temperature coasts have been replaced by the movement of poisonous organisms around the Iberian Peninsula and the proliferation of Irukandji and box jellyfish along the North Australian coast.”  These areas have not yet become familiarized with these poisoned marine animals and are not equipped with knowledge needed to care for injuries caused by these animals [Falkenberg]. This migration of poisonous animals causes fear within populations which makes people turn away from the beaches, and rather stay at home. This will decrease

the amount of positive impacts the ocean has on humans, but rather degrade the mental status of many. When humans become afraid of the water, they will not want to associate with the waters, which will make it even harder to educate them on the importance of cleaning up the oceans. 

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Decrease Medical Opportunity 

          As the majority of the ocean has yet to be discovered, scientists are not sure about the abilities of the ocean with aiding in medications. However, Falkenberg states that “Of the 34,000 molecules of medicine or cosmetic interests in existence today, only 10 have been developed from ocean-based organisms.” With scientists only knowing about ten percent of all marine species, this means that many more cosmetics as well as medicines could be developed by looking at the unknown biodiversity. However, ocean acidification has been affecting biodiversity in a negative way. For example, coral reefs are used for marine made products, but as the water becomes more acidic the diversity of coral has decreased and have negatively impacted other marine species environments. This effect can cause unknown species to die off, which means our possible medical innovations found within the ocean are slowly dissipating. This also means that there are some medications that could possibly be found in the ocean that may help with the four major human health factors of ocean acidification [Falkenberg].  

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Respiratory Aerosols

              As the waves crash along the shore, water droplets are dropped into the air, these are called aerosols. These aerosols tend to have toxins in them that cause upper and lower respiratory irritations in humans. The toxins come from very similar algae blooms that triggered poisons in shellfish, these specific examples that will be talked about are “blooms of the dinoflagellate Karenia brevis which are characterized as Florida red tides” [Falkenberg].  These blooms produce neurotoxins specifically called brevis toxins and are spread through the atmosphere when the algae is broken on the waves of the shore and put into aerosol droplets. These toxins within the atmosphere are negatively impacting human health by affecting the respiratory tract. Though the irritations are self-resolved it can be dangerous to those who have asthma or any respiratory infections.

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Ocean Acidification Effects On Marine Plant Life 

          As carbon dioxide is put into the ocean and increases the acidification of the water, the carbon is taken not only by the sea but by photosynthetic plants such as green and brown algae that can also take in some of the components like bicarbonate which is created in the reaction where ocean acidification occurs. However, red algae are not one of the plants that can take in bicarbonate, but rather just carbon dioxide. To fully understand the impact that ocean acidification had on the plants in the marine environment, Janet Kübler, the author of Predicting Effects of Ocean Acidification and Warming on Algae Lacking Carbon Concentrating Mechanisms, gave results on an experiment. The experiment conducted was to see how the plants, specifically the red algae, would photosynthetically react to an increase in carbon dioxide levels, temperature, as well as amounts of light. Normally while in the ocean red algae is found in dark or shaded areas, where light is not commonly found. An example of this would be under the end of a cliff within the water (Kübler). When looking at the results found and given by Kubler, there was a significant increase in growth for algae. This result could be positive, considering that the increase in ocean acidification is caused by the increased uptake of carbon dioxide. However, this increase in growth may be seen as a positive as it may be able to slow down ocean acidification by taking in some of the carbon dioxide. It also helps the algae bloom that carry toxins, (talked about above), increase in growth rate as well, which could also cause more respiratory issues.

 

Delaying the Issues of Ocean Acidification 

           As plants are trying their best to adapt to the amounts of carbon dioxide within the ocean, calcifying corals are as well. While many coral reefs are dying because the increased rate of acidification is too high for adaptation to take place, there is what scientists like to call a super coral also known as lophelia. This coral is one that grows some of the largest reefs and has been able to withhold against the constantly dropping pH levels. Scientists don’t quite understand exactly how it withstands the constant stress and rapid changes of PH. However, In a documentary called Acid Horizon directed by Ivan Hurzeler, there were scientists who studied the ocean and had the opportunity to do some studies on lophelia to try and understand its ability of survival and exactly how much stress it could handle. The group of scientists had found that in the lophelia they had a gene where it could stand a pH level of 7.6 acidity which was one of <the lowest pH’s they had seen a coral survive. Due to the fact that this coral can withstand such low pH’s many objectives of scientist and marine biologists is to produce as many lophelia corals as possible in hope to delay the effects of ocean acidification, until a more permanent solution can be found. 

Conclusion 

           Ocean acidification is caused by the massive amounts of carbon dioxide emission put into the atmosphere and soaked up by the ocean. The acidification process of the ocean’s ecosystem will continue to degrade and if humans do not find a solution to the emissions being produced severe consequences will be had. These consequences can range from impacting the marine animals physically, mentally and their habitats. The effect of the animals’ lives will move towards affecting humans physical and mental health, as well as their jobs which can ultimately affect the economy. Through all the carbon intake in the ocean the plants are the only ones that have been found to benefit from it. While not all the plants can take in the bicarbonate product given off when ocean acidification occurs, it still allows some of the carbon to be used during photosynthesis giving the calcifying organisms of the ocean a chance to live. Scientists have found that a super coral called lophelia may be the earth’s temporary solution until a permanent one can be made. In order to save marine life and ourselves we must cut back on fossil fuels and anything that produces large amounts of carbon dioxide into the atmosphere, to limit the rate at which ocean acidification is increasing.

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References

• Alden, Andrew. "Calcite vs Aragonite." ThoughtCo, Aug. 27, 2020, thoughtco.com/calcite-vs-aragonite-1440962.

• Ashur, Molly M et al. “Impacts of Ocean Acidification on Sensory Function in Marine Organisms.” Integrative and comparative biology vol. 57,1 (2017): 63-80. doi:10.1093/icb/icx010

• Falkenberg, Laura J et al. “Ocean Acidification and Human Health.” International journal of environmental research and public health vol. 17,12 4563. 24 Jun. 2020, doi:10.3390/ijerph17124563

• Guinotte, John M, and Victoria J Fabry. “Ocean acidification and its potential effects on marine ecosystems.” Annals of the New York Academy of Sciences vol. 1134 (2008): 320-42. doi:10.1196/annals.1439.013

• Hurzeler, Ivan, director. Acid Horizon. Amazon Prime/ Acid Horizon, https://www.primevideo.com. 

• Jagers, Sverker C et al. “Societal causes of, and responses to, ocean acidification.” Ambio vol. 48,8 (2019): 816-830. doi:10.1007/s13280-018-1103-2

• Kroeker, Kristy J et al. “Impacts of ocean acidification on marine organisms: quantifying sensitivities and interaction with warming.” Global change biology vol. 19,6 (2013): 1884-96. doi:10.1111/gcb.12179

• Kübler JE, Dudgeon SR. Predicting Effects of Ocean Acidification and Warming on Algae Lacking Carbon Concentrating Mechanisms. PLoS One. 2015 Jul 14;10(7):e0132806. doi: 10.1371/journal.pone.0132806. PMID: 26172263; PMCID: PMC4501704.

• “Ocean.” National Geographic Society, https://education.nationalgeographic.org/resource/ocean/. 

• “Ocean Acidification.” National Oceanic and Atmospheric Administration, https://www.noaa.gov/education/resource-collections/ocean-coasts/ocean-acidification. 

• Sarah. “More than Just Temperature-Climate Change and Ocean Acidification.” Curious, Australian Academy of Science, 5 June 2018, https://www.science.org.au/curious/earth-environment/ocean-acidification. 

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