Meeting Abstract
Dissolved CO2 from natural and anthropogenic sources drives pH and other important parameters of carbonate chemistry in marine environments. Acidified conditions can inhibit growth of shells and skeletons in a variety of calcifying organisms. The caenogastropod Crepidula fornicata is a cosmopolitan intertidal and subtidal species that lives in environments subject to wide fluctuations in pCO2 and pH. We have previously shown that larvae and juveniles grow at similar rates over the pH range of 7.6-8.0, but that larval experience of acidification can depress early post-metamorphic growth. In the present study we grew larvae to metamorphosis at ambient pH of 7.9- 8.0, then cultured juveniles for 14 d at pH 7.6 or 8.0 and studied juvenile shell performance by measuring the force required to crush the shells. Mean values of crushing force did not significantly differ between shells of individuals reared at the two pH levels but were more variable within and between replicate cultures at the lower pH. Mean thickness also did not differ significantly between the two groups of shells. In order to investigate effects of larval and juvenile acidification experience on shell performance of younger juveniles, we reared another brood of larvae to metamorphosis at pH 7.6 or 8.0 and then cultured juveniles for 8 d at pH 7.6 or 8.0. Larval pH did not affect crushing force for juveniles reared at pH 8.0. Shells of juveniles reared at pH 7.6 were significantly weaker than those of their siblings that had been reared as juveniles at pH 8.0, even though they did not differ in average length. These results suggest that acidification may affect performance of early juvenile shells without affecting overall shell growth rates. Supported by NSF 1416690 and 1416846.
