The Effects of Ocean Acidification on Predator-Prey Interactions: A Kinematic Approach

Studies suggest that exposure to elevated CO₂ affects how fish perceive their environment, affecting behaviourial and cognitive processes leading to increased prey mortality. However, it is unclear what is driving this increase in mortality. We demonstrate that the kinematic interactions between a common predator and its prey (the damselfish Pomacentrus amboinensis and the dottyback Pseudochromis fuscus) are sensitive to elevated CO₂. Specifically, we observed differential changes in both the predator and the preys’ responses to each other, leading to changes in the survival of the prey. This suggests that the dynamics of predator-prey interactions under future CO₂ environments will depend on the extent to which the interacting species are affected. We also asked whether the acute effects of elevated CO₂ on the escape performance of juvenile reef fish could be ameliorated if the parents had been exposed similarly. Elevated CO₂ negatively affected the escape performance of juvenile fish, but parental exposure to high CO₂ reduced the effects in some traits, indicating the potential for acclimation of behavioural impairment across generations. However, acclimation was not complete in some traits, and absent in others, suggesting that transgenerational acclimation does not completely compensate the effects of elevated CO₂ on escape responses.