Meeting Abstract
Schooling in marine fishes is a strategy that can facilitate migration, enhance prey detection, provide safety benefits, or hydrodynamic advantages. Many schooling species make acute and rapid structural and behavioral adjustments in a highly coordinated manner, supporting the idea that schools can display a high degree of plasticity. Studying collective dynamics of free-ranging marine organisms remains challenging since it requires the development of non-intrusive observation methods to monitor and quantify social patterns. Despite recent studies of blacktip shark (Carcharhinus limbatus) migration patterns, little is known about the behavioral mechanisms that underlie their massive aggregations and their functions. We hypothesized that shoal-level modifications and context-dependent collective responses reflect changes in the way individuals balance their fitness tradeoffs. We developed a semi-automatized tracking algorithm to quantify C. limbatus abundance and shoaling dynamics (inter-individual distances and alignment level). We analyzed images collected during aerial surveys over six years, to link the behavioral measurements with biotic and abiotic factors. Ultimately, adaptive behavioral changes at the collective level have the potential to inform us about the effects of global environmental patterns on population dynamics and migratory patterns of gregarious shark species; information of prime importance for the development of sound conservation and management.
