Keywords: 
• ocean acidification /
• marine fish /
• sensory system /
• behavior /
• review

Abstract: Ocean acidification is the lowering of ocean pH due to increasing levels of CO₂ in the atmosphere. This process has resulted in a drop of oceanic pH by 0.1 pH units since pre-industrial times and a further decrease of 0.3-0.4 pH units is predicted by 2100 if maintain current CO₂ emissions trajectories. Ocean acidification affects its carbonate chemistry, which will threaten many marine organisms and even the whole ecosystem that depend on the stability of chemical environment. Previous studies have focused mainly on calcifying organisms, and marine fish drew less attention because of being have better acid-base regulation system. However, over the past 5 years, this assumption has been challenged by quite a few experiment results on fish larval sensory system and behavioral studies. These studies documented that ocean acidification affected the early life of fish, and the slight changes in early life stage could increase mortality rates of fish in large. That probably will affect recruitment rates to natural population and species diversity, further impact on global fishery catches. This review focused on the impact of ocean acidification on sensory system and behavior in marine fish, including olfactory, hearing, visual systems with their related behavior, and the advanced consciousness studies. It provides perspectives from sensory biology of fish to prediction of ecological, economic and social effect of ocean acidification.