A-HSU® at Sanford, New Zealand
A-HSU® at Sanford, New Zealand
Courtesy of Scottish Sea Farms
Courtesy of Scottish Sea Farms

What it is and how it works

Powerful salmonids thrash about when removed from the water, often resulting in stress and bruising. The award-winning A-HSU® stuns the fish while they are still in water, providing a more efficient and humane way of harvesting compared to other methods.

Salmon from well boats, pens or tanks are gently pumped into the A-HSU®, travel through a de-watering tube, and then into the stunner water, where they lose consciousness immediately. If salmon leaving the stunner are bled promptly, they stay unconscious until death.

The A-HSU® is suitable to install on boats or rafts for dead haul harvesting and land-based processing plants. 

Key features

The A-HSU® stuns the fish with accurately calibrated voltage levels that prevents the need to remove them from the water, unlike percussive and dry-electric stunning methods.


Suitable for salt and freshwater fish


100% stun rate


Can accommodate various fish delivery systems


Automated system with touch screen controls & remote monitoring

Welfare benefits

  • Effective and humane, without pre-stun shocks 
  • Stuns fish fully unconscious in less than one second
  • Reduced handling and low stress
  • Less bruising and skin damage

Sustainability factors

  • Reduced harvesting pressure
  • Safer and calmer production line for processing workers 
  • Low environmental footprint
  • Robust and durable construction for a long lifespan 
Donald Buchanan, Scottish Sea Farms

“The A-HSU® makes it easier to handle fish when they exit the stunner, which has led to an increase in harvest rate for some customers and allowed others to operate with fewer processing workers.”

Donald Buchanan, Scottish Sea Farms

Get more information

Read our case study to learn how in-water electric stunning can increase fish welfare and processing speed. The A-HSU® fact sheet provides additional details about the system.

Let’s talk

Get in touch to discuss how the A-HSU® can benefit your harvest process.

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