Topp Banner Blogg Stunner Tesco 6

The most effective and humane way to stun fish and crustaceans. Optimar takes the lead with our electric stunner.

oktober 24, 2022

All animals killed for food should be slaughtered humanely. This means that they must be effectively stunned, rendered instantaneously insensible, and remain unconsciousness until death supervenes.


When moving an industry forward, large companies must take a stand. Optimar is proud to be the selected partner of Tesco when they focus on animal welfare in fish and crustaceans production among their suppliers.

During the last years Tesco and Hilton / Amanda Seafood have collaborated with farmers in Turkey and Vietnam on a few studies. These studies: “Electric stunning trials in commercial setting” were performed with our well-known Optimar Electrical Stunner.



See video from the trials


tesco-driving-innovation-in-humane-fish-slaughter (1)


Key benefits of electrical stunning system compared to immersion in ice slurry, by Tesco:

  • Less handling of animals 

  • Reduction in crowding times (in ponds) 

  • Easier access to measure effectiveness 

  • Consistency on stun delivery 

  • Faster method to render animals unconscious and insensible to pain

  • Greater efficiency and reduction in labour in harvest process, although initial investments required to implement the technology are high. 


- Ben Weis, Head of Aquaculture Tesco 



Electrical stunning instead of ice stunning

European sea bass, gilthead sea bream together with rainbow trout are becoming popular choices in European markets, and the consumers want high quality seafood products. Nevertheless, today only 20% of the Turkish industry is using electric stunning! 70% is using ice stunning (thermal shock) remaining 10% is sold as live fish.

GLOBALG.A.P. states that “stunning prior to killing is mandatory”, and in the EU markets there is a clear trend towards a 100% stunning preference.


The report concerning shrimps was summarized in a presentation by Ben Weis, Aquaculture Manager at Tesco, and the results are obvious:

Complete report can be read below the presentation.



tesco-and-hilton-seafood-case-study-improving-the-welfare-of-whiteleg-shrimp-at-harvest (1)



Optimar Electric Stunner. A well-known and established product. 

Since 2009 we have sold more than 600 stunners to fish farming, shore factories and onboard vessels / wild fish catching. The Optimar stunners are well known and tested approved for different fish species and crustaceans (wildcath and farmed), such as:


Wild fish

Cod, Haddock, Saithe, Whiting, Catfish, Halibut and Mackerel



Different Crabs, Lobster, Shrimps etc, and our latest development for Nephrops.


 Advantages with using the Optimar El-Stunner

  • Well tested over 13 years and recommended by Norwegian authorities

  • Consuming very little electric power (3kW), tested with EEG on several species.

  • Less corrosion

  • Software adjustable for different current dependent on specie

  • Flexible Capacity (from several 100 tons/day to laboratory tests)

  • Flexible pricing


Want to know more about our stunner?

Follow this link:  Optimar Electrical Stunner product information






Optimar Stun and Bleed Solution

Our stunner can be used as a single unit or in a factory line such as our stun and bleed solution. The animation under shows how the fish moves through water until it reaches the stunner and are sedated before gutted. With high focus on minimizing the number of times the animal is handled, we are able to maintain animal welfare through the whole process until slaughtering. 


 Feel free to download our product sheets here:



Are you interested in knowing more about all the benefits of electric stunning? Or how to stun in the most effective and humane way?

Sales Managers Mårten Jørgensen and Håvard Worren are ready to help you and answer all your questions!


Optimar Sales Managers Aqua


Or fill out our contact form with your details and we will contact you as soon as possible. 
- we encourage you to sign up for our newsletter, get the latest news first.