Acoustic observation of diel vertical migration and shoaling behaviour in Atlantic redfishes

• Published in: Journal of Fish Biology
• Main Authors: Gauthier, S., Rose, G. A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2002
• Subjects: Newfoundland
• Online Access: http://dx.doi.org/10.1111/j.1095-8649.2002.tb02461.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1095-8649.2002.tb02461.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1095-8649.2002.tb02461.x

Acoustic methods were used to study Atlantic redfishes Sebastes spp. vertical migration and shoaling behaviour in Newfoundland waters. Redfishes exhibited consistent patterns of vertical migration in winter, spring and summer, but pelagic shoals were not observed in winter. Pelagic daytime aggregations were generally in close proximity to dense patches of redfishes along the sea floor. Pelagic shoals exhibited high degrees of variability in size, shape and density. Attempts to explain variations in shoal density and area with features of shoal position and structure were unsuccessful. Nearest neighbour distance between fish in shoals had a lower limit near one body length. During the night, fishes were dispersed in the water column and distributions were more homogenous. Diel vertical migration appeared to be a foraging strategy, in which redfishes followed the migration of their euphausiid prey.