Prawns set to benefit from new humane stunning tech

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 UK was extended to recognise lobsters, octopus and crabs and all other decapod crustaceans (eg prawns) and cephalopod molluscs as sentient beings. The European Food Safety Authority (EFSA) also considers decapod crustaceans 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, is using Ace Aquatec’s Humane Stunner Universal technology to stun the prawns unconscious in less than one second, minimising their sensitivity to pain. According to a news release from Ace Aquatec, this allows producers to use an immediate, humane and stress-free stunning process for prawns of all sizes and guarantees insensibility without compromising quality or shelf-life.

Speaking of his experience using the tech, Dr Bert Wecker, CEO of Neomar and Förde Garnelen, said: “The recent trials of the A-HSU stunner in Germany saw improved outcomes for prawns, both in terms of the time taken to complete the stunning procedure and reduced exposure to pain in the process. The implementation of this technology with an intermediate ice slurry exposition afterwards is a remarkable progression in fish welfare and quality.”

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.

Nathan Pyne-Carter, CEO of Ace Aquatec said: “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. 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”.

Dr Fabian Riedel, CEO and founder of Crusta Nova, added: “Effective, safe and rapid, in-water electric stunning is an essential component of responsible aquaculture. Crustaceans react strongly to being taken out of water which results in stress and can impact the quality of the product. This portable system not only challenges the status quo of outdated slaughter methods for invertebrates, but also heralds a new era of improved standards, both in terms of harvesting and in better-quality end products.”

Ace Aquatec has developed a range of humane stunning tech for salmon, trout, tilapia, cod, seabass and seabream. According to the firm, the stunner range meets the highest welfare standards expected by consumers, retailers and regulators. The company has received global recognition for its technology that stuns fish fully unconscious in less than one second.

*Ace Aquatec is part of Aqua-Spark's investment portfolio, but The Fish Site retains editorial independence