Swimming Parameters for Pacific Herring Using Intermittent Respirometry

Bioenergetics models usually include an arbitrary multiplier to account for metabolic costs of activity due to lack of experimental data. This is especially true of schooling fish such as Pacific herring. We conducted swim trials using an intermittent respirometer with schools of 4 – 6 herring at two ambient mean temperatures (5.5 and 8.5 C^o) to determine oxygen consumption (mg O₂^. kg ^{-1 .} h^-1) with increasing swimming speed measured in body lengths per second (B^.s^-1). Results indicate that fish were apparently stressed at low velocities (less than 3 B^.s^-1). A positive linear correlation existed between oxygen consumption and velocity exists until critical swimming speed (Ucrit) was reached near 5 B^.s^-1. Levels of oxygen consumption seemed to be influenced by the length of time held in the laboratory before the swim trials occurred. These data will be applied to individual based bioenergetic models used to investigate the cost of predator avoidance.