· Reef Fish Population Processes and Underlying Mechanisms
· Fish/Habitat Interactions and the Influence of Habitat Degradation on Fish Communities
· Larval Biology
· Fish Behaviour
· Behaviour and Chemical Ecology of Predator-Prey Interactions
· Parental effects
· Climate change effects on fish community dynamics - CO2 and thermal effects
· Effects of anthropogenically produced sound on fish population dynamics
Recent and Current Projects
I have a very broad range of interests within the field of reef fish population dynamics. My major research field explores the links between life history stages of coral reef fishes, and how events in earlier phases influence subsequent population dynamics. To this end, I have active research programs in the field of parental effects, larval development and growth, and how individual performance measures of larvae and juveniles influence survival within the confines of their social and physical environment.
I use field collections, observation and experiments in conjunction with laboratory experiments to address such questions as: the importance of starvation of larvae in tropical waters; the role of maternal condition in influencing fish population processes; whether mortality in the larval and juvenile phases are selective with respect to growth, size or body condition; the role of predator characteristics in influencing prey selection.
I have shown for a common damselfish that behavioural interactions that the mother experiences before laying a clutch of benthic eggs strongly influences the rates of development of the larvae and their subsequent growth, larval duration and mortality schedules. This was shown to be hormonally mediated, through a stress related mechanism. Field and laboratory manipulations have shown the relative importance of female feeding regimes, behavioural interactions and size in influencing the size of the larvae they produce. Paternal contributions have also been shown to be important in the laboratory.
I have used otolith microstructure to reconstruct growth histories and demonstrate the importance of size and growth selective processes in influencing larval survival. We are currently exploring the utility of otolith shape as a proxy for fish condition. In this way, growth and otolith shape have been found to be useful predictors of cohort success and be strongly influenced by feeding history and maternal stress.
I have an active research program exploring predator-prey interactions, and how these influence which prey survive. We have shown that chemical alarm signals are an important mechanism whereby newly settled fish can learn the identity of predators. We have recently shown that some reef fishes have an innate ability to detect predators. Elevated CO2 has an impact on the sophisticated learning mechanisms through an alternation in the GABA neuroreceptor activity; sadly despite doing transgenerational experiments we have not found evidence of acclimation (through parental effects or developmental acclimation) of the adverse behavioural effects to elevated CO2. The thermal environment also impacts predator-prey interactions by altering the energetic cost of activity, with species differing in their ability to tolerate altered temperature regimes.
Recently we have been examining the impact of vessel noise on fish population dynamics and been finding some rather startling things. Small recruit fish get stressed 250m from a 30hp engine, and it significantly affects predator-prey dynamics at closer distances!