Internal Assessment: The Effect of Ocean Acidification on ShellsResearch Question: Using various pH solutions, what is the effect of different acidities on various seashells, as measured by average percent mass change? Introduction: Background: For years and years humans have been releasing rampant carbon dioxide into the air and it’s finally catching up to us. Rampant carbon dioxide is the result of burning fossil fuels like coal, oil and gas at a rapid rate. About a third of the carbon dioxide that we emit into the air is absorbed by the ocean. As a result of this the ocean is becoming more acidic and the whole chemistry of the ocean is changing. A century ago when the pH of seawater was recorded it was 0.1 higher than what it is today. That 0.1 decrease is actually a 30% increase in the ocean’s acidity (“What is ocean”, 2012). This is because when the carbon dioxide enters the ocean it combines with the hydrogen in the water to form carbonic acid. The carbonic acid then breaks into hydrogen ions and hydrogen carbonate. Many shelled marine life use calcium carbonate to make their shells, however if all the carbonate is locked up in hydrogen carbonate they are unable to build up their shells. As a result, this causes their shells to become bitter and weak, which means the marine life lose their primary method of survival. This is because they rely on their shells for protection against predators. Research has shown that an increase of acidity correlates with the deterioration of shells (“Ocean Acidification”, n.d.). A lot of marine life such as corals, sea urchins and other mollusks do not exist in places with high levels of dissolved carbon dioxide. Considerations: During this lab, the experiment had no ethical considerations because no vertebrate lives were harmed. While doing this lab, safety glasses need to be worn to protect the eyes from possible splashes that could happen while making the solutions of juice and sea water. A lab coat also needs to be used, so that your clothes could be protected from possible stains. This lab had some environmental considerations that included certainty that the solutions were covered overnight to prevent the liquids in the solutions from evaporating. There was also concern about the shells being taken from the beach because they could be recycled by other marine organisms. However, all the shells used were broken and wouldn’t be able to provide a sufficient enough protection for an organism. Personal Engagement: Every animal species, no matter how big or small, depends to some extent on another plant or animal species for its survival. They may seem insignificant but shelled marine life is a very important part of the food web. Many animals rely on these animals for a main source of food and they also contribute to many habitats (Walpole, Davie & Dann, 2011). Mollusks such as mussels, clams and sea snails are vital to the ocean ecosystem. Not only do humans, fish, starfish and seabirds eat mollusks, but they also play a role in recycling the ocean’s nutrients keeping the ocean water clean and healthy for other marine species.. Mollusks are also excellent ecological indicators that tell us how the environment is changing and whether it is a bad or good change. This is because they are very sensitive to changes in environment which makes them more susceptible to shell deterioration. By doing this experiment, we might be able to see the how our actions are affecting the ocean greatly. It might be able to change the way people treat our ocean and give rise to a whole new era of conservation of the ocean. Methodology Design:Independent Variables: 5 Manipulations of pH level- 10% Orange Juice, 10% Lemon Juice, !0% Apple Juice, 3% (M/V) sea salt and distilled water. Dependent Variable: average percent mass change Table #1: Controlled Variable in this Experiment Controlled VariableHow is it Being Controlled?TimeAll of the shells for each trial and manipulation were soaked in the different acidities for a total of 9 days. All trials were soaked beforehand in distilled water for one day before the experiment was conducted.AcidityAll of the solutions were made so that there was 10% of the juice in each solution, resulting in a 10% acidity. This was done by having only 10 ml of orange juice, lemon juice and apple juice for each trial out of a total volume of 100 ml. Materials Used The same materials were used when making the sea salt solutions and the different juice solutions. Although they were different sizes, all trials and manipulations were put in the same type of glass jars, each with a lid. All of the seashells were collected from the same place on a Monterey Bay beach. Each juice also had their own source in which they came from that was the same for each trial. The chalk also all came from the same box and they were all white. The same weigh boat was used each time to weigh the shells from each manipulation and their respective trials. Amount of SolutionsEach solution was a total of 100 ml for each of the manipulations and trials. Each juice solution contained 10 ml of the juice and 90 ml of the sea salt solution. All the sea salt trials contained 100 ml of solution and each distilled water trial had 100 ml of distilled water. Amount of Sea ShellsEach trial for each manipulation all had a total of three shells. StorageAll of the jars were stored in the same place for all 10 days, meaning they all experienced the same amount of height and were at the same temperature. They were also in the jars with the lids screwed all the way on.MethodsAll of the weights of each trial for each manipulation were measured in the same way and they were all measured wet.