title: To fear or to feed: the effects of turbidity on perception of risk by a marine fish.
abstract: Coral reefs are currently experiencing a number of worsening anthropogenic stressors, with nearshore reefs suffering from increasing sedimentation because of growing human populations and development in coastal regions. In habitats where vision and olfaction serve as the primary sources of information, reduced visual input from suspended sediment may lead to significant alterations in prey fish behaviour. Here, we test whether prey compensate for reduced visual information by increasing their antipredator responses to chemically mediated risk cues in turbid conditions. Experiments with the spiny damselfish, Acanthochromis polyacanthus, found that baseline activity levels were reduced by 23 per cent in high turbidity conditions relative to low turbidity conditions. Furthermore, risk cues elicited strong antipredator responses at all turbidity levels; the strongest antipredator responses were observed in high turbidity conditions, with fish reducing their foraging by almost 40 per cent, as compared with 17 per cent for fish in clear conditions. This provides unambiguous evidence of sensory compensation in a predation context for a tropical marine fish, and suggests that prey fish may be able to behaviourally offset some of the fitness reductions resulting from anthropogenic sedimentation of their habitats.
authors.affiliation: ARC Centre of Excellence for Coral Reef Studies, and School of Marine and Tropical Biology, James Cook University, Townsville QLD, Australia. susannah.leahy@my.jcu.edu.au
authors.forename: Susannah M
authors.initials: SM
authors.lastname: Leahy
authors.forename: Mark I
authors.initials: MI
authors.lastname: McCormick
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Mitchell
authors.forename: Maud C O
authors.initials: MC
authors.lastname: Ferrari
mesh_terms: D000818:Animals; D003463:Cues; D003532:Cyprinodontiformes / Q000502:physiology; D005260:Female; D020387:Food Chain; D009043:Motor Activity; D055696:Olfactory Perception; D010473:Perciformes / Q000502:physiology*; D014796:Visual Perception; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D060753:Water Quality
chemical_list: D014874:Water Pollutants, Chemical