Vertical-slot fishways are one of the most common fishway designs used in Victoria, Australia. Fisheries researchers use several different active and passive sampling techniques to assess the effectiveness of fishways, however fishway traps are typically used for vertical-slot fishways. Fishway traps are customised mesh traps that are positioned in a vertical-slot fishway over a set time-period to collect fish moving upstream. Fishway trapping provides information about fish species, their abundances and size-classes that are attracted and or can successfully pass through the fishway. Fishway trapping can also be used as a biological control.
The focus of the presentation is about the design and operation of a fishway trap. Trap design is essential and influences their functionality. Several factors to consider include:
The operation of fishway traps can have many impacts, including to water movement and velocity, and fish behaviour. Such impacts must be minimised to obtain a true assessment of the fishway’s effectiveness.
Most importantly, the design and operation of the fishway trap must be completed in a safe and managed way.
By sharing our experiences in building and using fishway traps, we hope to foster continuous learning and improvement about trap design and operation for fishway assessments.