Estimating activity-specific energy expenditure in a teleost fish, using accelerometer loggers

Abstract

The ability to define and quantify the behaviour and energetic costs of different activities is fundamental to a full understanding of fish ecology and movement, but monitoring activity and measuring energy expenditure in fish in the field is problematic. New telemetry methods using data loggers that incorporate tri-axial accelerometers promise to provide a method for simultaneously recording the behaviour and activity-specific energy use in both the laboratory and field. Using electronic data loggers equipped with tri-axial accelerometers we have measured dynamic body acceleration (DBA) during aerobic exercise in European sea bass Dicentrarchus labrax whilst swimming in a swim-tunnel respirometer at ambient water temperatures of between 5.5 and 17.5C. For all individuals, dynamic body acceleration (both vectorial dynamic body acceleration [VeDBA] and overall dynamic body acceleration [ODBA]) scaled linearly with oxygen consumption and as a function of ambient temperature. When the 2 DBA metrics were compared, VeDBA was not significantly different from ODBA, though the value for Akaike's information criterion was lower for VeDBA (indicating a better fit for the VeDBA model). In this paper, we provide further evidence to support the use of acceleration as a means to quantify the activity-specific energetic costs of swimming in teleosts and highlight some of the problems associated with monitoring the activity and metabolic rate of fish in restricted laboratory conditions.