Stunning Technology

Stunning Technology

Focus on Fish Welfare

Fish welfare is also under the spotlight in aquaculture. Scotland-based technology supplier Ace Aquatec noticed an increasing push for animal welfare and developed the Humane Stunner Universal, an in-water electric stunner.

Ace Aquatec’s system works on all sizes and species of fish and can be used in factories or on boats or barges.

‘The Humane Stunner Universal came from seeing problems with animal welfare and operational inefficiency that we thought could be solved by bringing new thinking to an old challenge,’ said Mike Forbes, head of sales and marketing at Ace Aquatec.

‘When harvesting fish, there’s potential for the slaughter process to be highly stressful for the fish. With our stunner, fish are unconscious before they even leave the water to be processed.’

Optimar technicians with one of the company's stunner systems. Image: Optimar

The Humane Stunner Universal is a system in which fish pass through a pipe containing a section of electrified water.

‘The pipe has several electrodes coating its inside,’ he explained.

‘Through the electrodes, we pass electricity into the water. When the fish enter that electrified section of water they become unconscious in less than one second. This speed of stunning is crucial to maintaining the highest level of animal welfare standards.’

There are also some secondary benefits such as better product quality, increased harvest speed, and improved egg production at hatcheries. Ace Aquatec introduced in-water electric stunning to Alaskan hatchery Southern Southeast Regional Aquaculture Association (SSRAA) to help improve their egg production process.

The Humane Stunner Universal stuns fish as they pass through a pipe containing a section of electrified water. Image: Ace Aquatec

Mike Forbes says that reducing fish stress leads to better results all round.

‘Happy animals taste better. If an animal has gone through considerable stress at the end of its life, that affects flesh quality and shelf life,’ he said. ‘Increased cortisol levels in fish can result from stress and affect flesh quality, and the meat of an animal that’s had a stressful end of life won’t last as long. Anything you can do to reduce stress at the end of an animal’s life has a huge impact on end product quality.’

With big retailers committed to the highest possible welfare standards in their supply chain, the adoption of stunning technology shows no sign of slowing down.

‘There’s growing pressure from consumers and retailers when it comes to fish welfare,’ he said. ‘Fish farmers are very aware of this and are always on the look out for new technologies that can improve their welfare credentials.’

Following the welfare trends seen in the aquaculture industry, wild-caught fisheries are also turning to Ace Aquatec for support. Seine netters and trawlers have expressed an interest, while talks are underway with companies that are looking to improve their fish welfare standards.

Stress affects taste, quality and shelf life, according to Mike Forbes at Ace Aquatec. Image: Ace Aquatec

Michael Burns at Blue North agrees that for wild-caught fish, market pressures are likely to spur more considerate killings. Blue North currently sells its Humane Harvest cod in restaurants and markets in Seattle and receives a premium. Director of Business Development Amelia Burns says there is growing consumer awareness in Seattle of how food has been processed.

‘Consumers are more likely to buy humanely-treated fish,’ she said. ‘They’re also keen to know how their food was handled and how it ended up on their plate. It’s not just where the food comes from. We know it comes from Alaska but what else happened to it is also important. That’s something that we try to educate our customers about.’

‘More supermarkets want their fish suppliers to guarantee that their fish have been humanely stunned,’ Optimar’s Frode Kjølås added.

‘This has allowed us to help suppliers prove their sustainability credentials. Meanwhile, Norwegian law states that all farmed fish must be stunned humanely, and such a law will undoubtedly be implemented for wild caught fisheries.’

How can stunning become more humane?

‘It must be a consistent ethos through the whole harvest process,’ Mike Forbes said. ‘You can bring in Ace Aquatec to improve the stunning process but we’d also ask what you’re doing before and after that part of the harvest process. How are you pumping your fish? How are you handling fish after stunning? It might sound very simple but you must make sure you’re treating your fish with care at all times.’

‘You really need the right attitude,’ said Mike Burns. ‘If people don’t believe in it, it’s not going to happen. We obviously do and we’re the only ones in the whole of Alaska fisheries that’s doing this. The biggest hurdle is having people agree that humane slaughter is worth pursuing.’

‘It’s important to remember that one problem with everyone adopting a stunning method is that different harvesting techniques will determine whether stunning could be done more easily or not,’ said Amelia Burns. ‘We’re longliners that catch fish one at a time on a hook. We can handle fish one at a time and stun fish as they come on board but other harvesting techniques may not allow this. That’s a constraint against trying to ensure that all wild fish are stunned and harvested humanely. Some harvesting methods may have to adapt and change in future.’

‘Stunning must be evaluated and proven that it works, because you can seemingly have a stunned fish that’s just immobilised,’ Frode Kjølås said. ‘A proper evaluation of the system is a must. Logging so you can trace back if something happens or see that you’re running at the proper currents may also be good.’