Impact of ocean acidification on growth, onset of competence, and perception of cues for metamorphosis in larvae of the slippershell snail, Crepidula fornicata

Ocean pH has been declining since the start of the Industrial Revolution, and is predicted to continue declining for at least another 200 years. Although the chemical cues that induce larval metamorphosis in marine invertebrates in part determine the distribution and persistence of many coastal marine communities, few studies have examined the effects of ocean acidification on the timing of metamorphic competence or the ability of larval invertebrates to metamorphose in response to environmental cues. Working with larvae of the marine gastropod Crepidula fornicata , we examined the impacts of sudden, short-term (2 h), and prolonged (several weeks) exposure to reduced pH as low as 7.5 on larval survival and growth, the onset of metamorphic competence, and the ability of larvae to perceive inductive cues and metamorphose in their presence. Unexpectedly, although larvae reared at pH 7.5 grew more slowly and took longer to become competent to metamorphose, exposure to acidified conditions did not appreciably impair larval cue perception for metamorphosis.