Impacts of ocean acidification on growth and toxin content of the marine diatoms Pseudo-nitzschia australis and P. fraudulenta

This paper present the effects of ocean acidification on growth and domoic acid (DA) content several strains toxic Pseudo-nitzschia australis non-toxic P. fraudulenta. Three each species (plus two subclones australis) were acclimated grown in semi-continuous cultures at three pH levels: 8.07, 7.77, 7.40, order to simulate changes seawater from plausible future levels. Our results showed that lowering current level (8.07) predicted 2100 (7.77) did not affect mean rates some (FR-PAU-17 L3-100), but affected other either negatively (L3-30) or positively (L3.4). However, significantly decreased with lowered 7.40 (by 13% for L3-100, 43% L3-30 16% IFR-PAU-17 compared 8.07). In contrast, fraudulenta by changing 8.07 7.40. The produced DA all levels tested, highest particulate concentration normalized cell abundance (pDA) was found 8.07. Total (pDA dissolved DA) higher (7.77), exept one strain (L 3.4) where no difference found. At lower 7.77–7.40, total similar, except L3-100 which had lowest 7.77. diversity responses highlights inter- intra-specific variation response acidification. When exploring environmental using cultured cells, only strain-specific also culturing history should be taken into consideration, as light under cultured, afterwards both maximum content.