Tilt angles of schooling penned saithe

Abstract

Saithe (Pollachius virens) of nearly uniform 32 cm length have been photographically observed during the daytime in an apparently free-swimming and schooling state in a pen of dimensions 90 m length, 10 m width, and 7 m depth. The resulting tilt angle distribution is essentially normal, with mean -0.9 deg and standard deviation 5.4 deg.