Variability of Harengula spp. school reactions to boats or predators in shallow water

Abstract

experiments, to investi- gate whether the large number of fish and the probably higher number of influences generate the same kind of reactions, with the same level of variability, as are observed in aquaria etc. We focused our attention on changes in structure and behaviour of tropical pelagic schools subjected to two sources of external stimuli: predator and vessel. This information is of interest in the case of acoustic surveys, as recent research programmes intend to use school characteristics for species identifi-