Reduced impact of ocean acidification on growth and swimming performance of newly hatched tropical sharks (Chiloscyllium plagiosum)

Sharks have been facing unprecedented pressure over the last decades, and ocean acidification may represent an additional threat, particularly during their most susceptible life stages. Hence, the present study aimed to investigate the effects of ocean acidification (controlpCO(2 similar to) 400 atm; highpCO(2)similar to 900 atm) on the growth, swimming performance and cholinergic system of juvenile white-spottedbamboo sharks (Chiloscyllium plagiosum). After 45 days of exposure, we observed that highCO(2)did not affect most of the end-points studied. However, somatic growth rate and the percentage of time that sharks spent swimming was significantly reduced under highCO(2)conditions. Moreover, AChE activity decreased in two of the seven brain macroareas analyzed, the telencephalon and optic lobes. As this near-threatenedshark species showed small sub-lethaleffects to highCO(2)levels, we argue that within a longer time-frame they can potentially reduce individual performance with cascading consequences to shark population dynamics.