Controls on magnesium, manganese, strontium, and barium concentrations recorded in freshwater mussel shells from Ohio

摘要

Freshwater bivalve shells may record inter-annual fluctuations in water chemistry, which in turn may archive variations in solute load due to pollution or discharge events. Here, using weekly surface water chemistry collected at two locations and shells of Lampsilis cardium grown in the surface water we investigate if the Mg/Ca, Mn/Ca, Sr/Ca, and Ba/Ca ratios measured at high resolution in the shells on an intra-annual time scale consistently reflect the chemistry of the surface water. Two relationships appear highly correlated, Sr/Ca-carb and Sr/Ca-water, and Mn/Ca-carb and temperature. Ba/Ca-carb correlated strongly with Ba/Ca-water in one shell but temperature in another shell yielding inconclusive results. Mn/Ca-carb and Mg/Ca-carb were not strongly correlated with elemental ratios in the water, but Mn/Ca-carb did show variable, weak to moderate correlation with pH. We found consistent partition coefficient (D-Me) values between individual shell samples grown in the same water with mean D-Mg= 0.0006, D-Mn = 17, D-Ba = 0.13, and D-Sr = 0.176. Sr/Ca-carb and Sr/Ca-water exhibited the strongest, most consistent correlation with partitioning coefficients that were consistent with published values, suggesting Sr/Ca-carb can be used as a proxy for Sr/Ca-water in freshwater mussels.