Impact of ocean acidification on the gross dissolution of biogenic carbonates (2013)

Undergraduates: Maite Ghazaleh, Kim Horvath, Isaac Westfield

Faculty Advisor: Justin Ries
Department: Environmental Science

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Anthropogenic increase of atmospheric pCO2 since the Industrial Revolution has caused seawater pH to decrease, a process known as ocean acidification. Ocean acidification reduces the availability of carbonate ions (CO32-) in seawater, which marine calcifiers require for shell and skeletal production. Thus, CO2-induced ocean acidification is expected to impact marine calcifiers’ ability to produce their shells and skeletons. However, several recent laboratory studies (e.g., Ries et al., 2009) on a wide range of species of benthic marine calcifiers have demonstrated that ocean acidification has both positive and negative impacts on net calcification rates (gross calcification rate minus gross dissolution rate). Here, we present the results of experiments designed to quantify gross rates of shell and skeletal dissolution for five species of marine calcifiers (the conch Strombus alatus, the temperate coral Oculina arbuscula, the mussel Mytilus edulis, the coralline red alga Neogoniolithon sp., and the oyster Crassostrea virginicus) under three pCO2 conditions (400, 1200, and 5700 ppm) and two temperatures (10, 25oC). Addition of the gross dissolution rates of these marine calcifiers to their previously determined net calcification rates (Ries et al., 2009) reveals the impact that CO2-induced ocean acidification has on the gross calcification rates of these organisms under various pCO2 scenarios.
Ries, J.B., Cohen, A.L., McCorkle, D.C., 2009, Marine calcifiers exhibit mixed responses to CO2-induced ocean acidification. Geology, 37 (12): 1131.