Meeting Abstract

104.5  Thursday, Jan. 7  Elevated atmospheric carbon dioxide levels affect metabolism and shell formation in oysters Crassostrea virginica (Gmelin) SOKOLOVA, I.M.*; IVANINA, A.; LIEB, N.; KUROCHKIN , I.; BENIASH, E.; University of North Carolina at Charlotte, Charlotte, NC; University of North Carolina at Charlotte, Charlotte, NC; University of Pittsburgh, Pittsburgh, PA; University of North Carolina at Charlotte, Charlotte, NC; University of Pittsburgh, Pittsburgh, PA isokolov@uncc.edu

Ocean acidification due to global rise in CO₂ can afflict marine organisms negatively impacting ecosystem health. CaCO₃-producing marine species such as mollusks can be especially vulnerable to such changes, since elevated CO₂ levels and lower pH lead to a decrease of the degree of saturation of calcium carbonate potentially affecting biomineralization. We determined the effects of elevated CO₂ levels on biomineralization and metabolic physiology of an intertidal mollusk, eastern oyster Crassostrea virginica using atmospheric and CO₂-enriched air (5000 ppm CO₂) corresponding to the current conditions and a IPCC projection for the year 2300, respectively. Elevated CO₂ levels in sea water negatively affected physiology, rates of shell deposition and mechanical properties of the shells of oysters. High CO₂ levels led to elevated juvenile mortality and inhibited shell and soft body growth in oysters. Furthermore, the increase in CO₂ levels resulted in elevated standard metabolic rates in juveniles due to the higher energy cost of homeostasis. The hypercapnic conditions also led to changes in the ultrastructure and mechanical properties of shells, and an upregulation of carbonic anhydrase gene expression in mantle tissue of oysters indicating that elevated CO₂ levels have negative effects on the biomineralization process. These data strongly suggest that the rise in carbon dioxide can impact the physiology and biomineralization in marine calcifiers such as oysters threatening the survival of this species and leading to profound ecological and economic impacts. Supported by NSF, North Carolina Sea Grant and UNC Charlotte.