Ace Aquatec's second range of Humane Stunners (HS2) has been in development for 3 years. The first production model (a 12" design for Atlantic Salmon) was sold in May 2007.

Click on picture for more information of parts

The design is adaptable for both marine and fresh-water species. It is transportable, has a flexible configuration, small physical size and machines have been built in 6", 8" and 12" models to accommodate the size range of most species. Prototypes have been built and tested on commercial fish farms for: salmon, sea-bass, sea-bream, eel and tilapia.

Whereas the Pipeline Stunner relied on the farm's own water to stun the fish the HS2 conditions its own recycled water to optimise stunning performance. Control of the water conductivity is automatic with the machine adding fresh water or salt.

Operation of the system is simple. The operator ensures that the system has access to fresh water and fills the salt water tray with sea-water or a brine mixture. On instruction of the operator the machine fills itself with fresh water. The operator activates the water pump and instructs the machine to operate. The machine responds by flashing green and yellow beacons, adds salt if necessary and signals that all is well by a steady green light. 

Fish are then introduced into the machine where they are dropped into the stun tube, rendered unconscious and are then slowly carried through the system by the water. They then pass through a Maintenance section. 

They exit the machine after the required treatment time where they are de-watered. If additional water or salt is needed during the harvest the machine automatically adds it.

As with the Pipeline Stunner the fish have a superior appearance when they exit the machine and have less physical damage than traditional slaughter methods. Trials with the prototypes failed to detect any difference in carcass quality in those species studied.

click on parts of the stunner to see detail