LIFE IN A HIGH CO2 WORLD: ASSESSING THE EFFECTS OF OCEAN ACIDIFICATION ON THE SURVIVAL OF THE BENTHIC FORAMINIFER BOLIVINA ARGENTEA

The world’s oceans act as a major sink for the current rising atmospheric CO₂ levels. Ocean acidification results from the formation of carbonic acid during oceanic uptake of atmospheric CO₂, thus affecting the oceans’ carbonate system. This investigation attempts to quantify the effects of decreasing ocean pH on the survival of Bolivina argentea, a calcareous species of benthic foraminifera collected from the flanks of the Santa Barbara Basin off the coast of California (430 meter water depth). A six-week long experiment was conducted at 5,000ppm CO₂ simultaneously with atmospheric controls (~385ppm CO₂). Foraminiferal survival was assessed using an Adenosine Triphosphate (ATP) assay. Test (shell) measurements and water chemistry were also recorded. A rebound treatment was included at each time point to target the possibility of individuals recovering from the experimental conditions. Results will be presented on the survivorship of specimens after the first, second, and sixth week of experimental incubation. We will also present light microscopic and SEM level observations indicating the presence or absence of test dissolution on the high CO₂ treatment specimens compared to the control. These and similar studies may provide insight on how ocean acidification will affect the ocean’s carbonate reservoir, as well as help decipher effects of past pH excursions on microfossils.