Concordia University
Candidat M.Sc.
superviseur(e): Nicola Smith
Début: 2025-09-01
Fin: 2027-08-31

Projet

Multiple Factors Determine the Strength of Non-Consumptive Effects on Coral Reef Fish
Predators shape ecosystems not only by consuming prey but also by influencing how prey behave. When prey sense danger, they may hide more, reduce feeding, or stay closer to shelter. These “non-consumptive effects” (NCEs) can lower growth, reproduction, both affecting long-term survival. Although these behavioural changes are known to be widespread and natural in ecosystems, we still lack a clear understanding of what controls their relative strength in complex natural environments with multiple predators and prey. This research investigates the drivers of these effects on Caribbean coral reefs, a system facing both declines in native predators and rapid increases in invasive ones. I will study three common herbivorous fish species and measure how their behaviour shifts in response to native and non-native predators. I will focus on three key factors known to play a role in NCEs: (1) predator biomass, (2) whether the predator is native or invasive, and (3) whether the prey species is social or solitary. Using underwater observations and a field experiment with realistic 3D-printed predator models, I will record changes in feeding rates, fleeing distance, spacing within groups, and other anti-predator behaviours. By identifying which predators elicit the strongest responses and which prey are most affected, this work will improve our understanding of how predators influence ecosystems beyond direct predation. These insights are essential as invasive species expand and predator communities shift, helping scientists and resource managers better predict and respond to changes in reef health and biodiversity.

Mots-clés

biology, Behaviour , ecology, Marine Ecosystems, Predator-prey interactions, Anti-predator Behaviours, Non-consumptive Effects

Publications

1- Ingestion of polyethylene microplastics impacts cichlid behaviour despite having low retention time
Felismino, Miguel Eduardo L., Ségolène Chevallier Rufigny, Samuel Evan Gonzalez-Fleurant, Grant E. Brown
2025 Aquatic Toxicology