The ocean makes up approximately 71% of earths surface and is the home to numerous organisms, some of which have yet to be discovered. However, due to the decrease of pH in the ocean the organisms residing in the ocean are put in danger. These changes in the acidity of the ocean are mainly due to high amounts of carbon that is constantly and increasingly being emitted into the atmosphere. With the great surface the ocean takes up, it acts as a major carbon sink and absorbs 9.3 billion tons of CO2 per year1. This harms not only the ocean but also the marine organisms, specifically shelled organisms. Shelled organisms create their shells through the secretion of calcium carbonate (CaCO3). These shells serve as a protection against many threats to the sea creature but it may not be effective against the harm done by ocean acidification. With the rise of the pH level comes the possible endangerment or extinction of these species and many more. Acidity levels that are higher than usual for these creatures can cause the weakening, degradation and destruction of these shells which make these creatures more vulnerable and easier to attack. It will also reduce the availability of carbonate ions which will prevent these organisms from building their shells and skeletons. This would lead to a sudden decrease in their population which will greatly affect the food chain of the ocean.
The purpose of this procedure serves to examine and observe the effect of acidity on CaCo3 shells to apply it to much greater concepts such as the effect of ocean acidification on marine life as a whole. When shells are placed in a solution with a pH level of 0-6, the shell will disintegrate and become weakened by the acidity. In contrast, if it is placed in a solution with a relatively neutral pH level, or one that is the same as their natural environment, then no harm will be done to the shell. If a shell is placed in an acidic solution such as vinegar, then the shells will dissolve2.
Methods and materials
The untreated shells were first removed from their bags and labeled "E" for experimental and "C" for control with a sharpie. The initial observations of the shells characteristics were then recorded into the data table and then placed on a measuring scale to record the starting mass of both shells. After the initial data was recorded, vinegar was poured into a beaker and salt water was poured into a beaker. The pH of the salt water and the vinegar where then tested using pH strips and the color was then recorded after the strips were exposed to the...