Coral reefs worldwide are disappearing at an alarming rate, along with the ecosystem services they provide. Reefs are subjected to significant environmental stressors such as fisheries pressure, pollution, divers and tourism leading to habitat destruction, and biological invasions. The capacity of these reefs to resist and recover from environmental stressors – i.e. their resilience – is dependent, in part, on the fishes that associate with them. A prominent example are herbivorous fish, which act in preventing reefs from shifting to algal dominance. Parrotfish (Scaridae) have been long identified as key-functional species which perform significant functions on coral reefs, and are vital for maintaining a healthy ecosystem. However, these fish are too, under considerable pressure and must contend with many similar stressors which impact the reefs they inhabit. Apart from direct mortality, such stressors have shown to induce prolonged non-lethal stress which may result in decreasing fitness, yet it is unknown if individual stress scales-up to the population, community, and ecosystem levels. In this project, I intend to induce fear of predation using realistic predator models, and chronic sub-lethal stress using gluccortidoid manipulations, in order to examine the behavioral response by parrotfish. Movement and behavior of fish on the reef will be recorded using underwater acoustic transmitters, equipped with depth sensors and tri-axial accelerometers. Evaluating the extent of fishes’ spatio-temporal response to fear and stress will provide information needed to understand species’ vulnerability to environmental stressors, and how the impact of parrotfish on the coral reef might change due to natural and anthropogenic disturbances.

​

Online video of tagged parrotfish in recovery, prior to release back onto the reef.

​

This project is part of my PhD studies, and is conducted under the supervision of Dr. Jonathan Belmaker, Dr. Moshe Kiflawi, and Dr. Glenn Crossin.