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Ace Aquatec unveils first in-water portable prawn stunner

May 8, 2023  By Hatchery International staff

Ace Aquatec has launched the portable Humane Stunner Universal (A-HSU) for prawns, following on from trials of Pacific white shrimp (Litopenaeus vannamei) with Neomar, Förde Garnelen and Crusta Nova in Germany. 

With over 400 billion prawns farmed each year, the global shrimp industry is one of the most prominent sectors in aquaculture. But until recently there has been no requirement to stun farmed prawns prior to slaughter – as is required of other farmed animals – until the scope of the Animal Welfare (Sentience) Bill in the U.K. was extended to recognise lobsters, octopus and crabs and all other decapod crustaceans (e.g. prawns) and cephalopod molluscs as sentient beings. 

The European Food Safety Authority (EFSA) also considers decapod crustaceans (e.g. prawns) to have the capability to experience pain, suffering, and distress. This means greater focus has been placed on the development of humane methods of slaughter for these animals.

The new Prawn A-HSU, developed in collaboration with scientists from the Silsoe Research Institute, uses Ace Aquatec’s Humane Stunner Universal technology to stun the prawns unconscious in less than one second, minimising their sensitivity to pain. This enables an immediate, humane and stress-free stunning process for prawns of all sizes and guarantees insensibility without compromising quality or shelf-life. 


The process begins with prawns being pumped or brailed into the entrance chute, where they flow directly into the water of the stun tube. The electric field in the stun tube ensures that they lose consciousness immediately and are maintained in the fields in order to maintain long insensibility after removal from the water. The whole process takes 40 seconds from start to finish and means prawns are not removed from the water, which research has shown causes them to react badly and become stressed.

“We know that current slaughter practices, including boiling alive, chilling, dismembering, Co2, high pressure processing, asphyxiation or immersion in ice slurry, are all harmful for shrimp welfare,” said Nathan Pyne-Carter, CEO of Ace Aquatec. “Thanks to the inclusion of decapod crustaceans in the Animal Welfare (Sentience) Act 2022, we’re now seeing retailers and producers approaching us to facilitate a humane electrical stunning process for these animals. The launch of our A-HSU for crustaceans will allow us to expand on our mission to elevate harvesting standards for all marine life, including invertebrate species.”

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