Fish Behaviour in Turbulent Flows

In 1997, 1998 and 1999, we used underwater videography to monitor fish behaviour in several Denil fishways.  Miniature digital CCD cameras were placed at fishway entrances, exits and near areas that were identified as potentially problematic within primary fishway flows.  We have learned much about the behavioural effects of turbulence on fish passage using these techniques.  In 1999 and 2000, Biotactic used underwater videography to monitor fish passage and debris deflection at several fishways in Ontario, as well as overwintering congregations of fish under the ice in rivers and lakes.  Check out the following video clip that shows smallmouth bass (approx. 300 mm TL) negotiating turbulent flows in Denil fishways on the Grand River, Ontario.