The Effects of Increased Acidity on the Shell Integrity and Body Size of C. virginica

Authors:  Margaret Rudd, Kyle Jennette, Becky Duey, Arnel Selman, and Terri J. Seron.
Date:  February, 2013


Ocean acidification is the process by which the world’s oceans absorb carbon dioxide and results in the formation of carbonic acid, which decreases the level of pH.  This process increases the acidity of the water and threatens many different calcifying organisms such as corals, sea urchins, whelks, crabs, and oysters. This study evaluated: (i) the difference between specimens of Crassostrea virginica (whole organism mass and length and tissue mass) in two natural pH conditions consisting of an area considered to be polluted and the other not, with respect to tissue mass and whole organism mass and pH of the location (ii) the effect of altered pH level in decreasing increments on half shell mass and length of C. virginica in a laboratory setting. The results of the field data of this experiment found no substantial relationship between environmental pH and tissue size ratio. This study also did not find a substantial difference in either location between the average mass and length of oyster half shells in the control pH conditions versus oyster half shells in the experimental pH condition.  Therefore, the data suggests the short-term immediate exposure to increased acidity does not induce a substantial decline in shell integrity for C. virginica.