For years, prawn welfare sat low on the list of supermarket priorities. Even as retailers sharpened animal welfare standards on chicken, eggs and beef, one of the UK’s most widely eaten farmed animals remained largely overlooked.
But, thanks to campaign groups such as the International Council for Animal Welfare (ICAW), that is now beginning to change. With Aldi Süd’s decision to phase in electrical stunning or similarly effective methods for all farmed prawns worldwide by 2035, and to end eyestalk ablation by 2030, all 11 major UK supermarkets have now made time-bound commitments on prawn welfare.
But for campaigners, this announcement is more than a late concession from a reluctant retailer. It is a sign that a niche issue once dismissed as fringe has become a mainstream supply chain question.
Why were supermarkets slow to act?
ICAW head of invertebrate welfare policy Jonas Becker says the shift has been years in the making.
“Animal welfare topics around aquatic animals, and then even most invertebrates, have traditionally been neglected in animal welfare policy of supermarkets,” he says.
That neglect is striking given the scale of the issue. UK supermarkets sell more than 1.2 billion farmed prawns each year, according to ICAW estimates based on Seafish data, making prawns the most consumed farmed animal in the country. Research from the London School of Economics and University of Stirling has also helped establish that crustaceans are sentient and capable of feeling pain, a position recognised in law under the Animal Welfare (Sentience) Act 2022.
Yet despite growing scientific evidence, progress among supermarket’s supply chains was slow.
Becker says retailers were initially cautious about entering what many viewed as an entirely new area of welfare reform.
The sentiment was cautious from supermarkets to open up an entire new field of animal welfare problems,” he says.
In the early years, he says, many retailers were unsure whether electrical stunning could be implemented at scale, and whether the science behind it was sufficiently robust. There was also a broader lack of awareness about what conditions on prawn farms actually looked like.
“I think that the awareness of the problem, both with the general population, but also with buyers, simply was not that big,” he says.
That changed as evidence mounted and pilot projects began to show that alternatives were commercially viable.
Electrical stunning, which causes prawns to become unconscious before slaughter, has increasingly been seen as a more humane alternative to ice slurry slaughter, where prawns can remain conscious while suffocating. Another controversial practice, eyestalk ablation, involves removing one eyestalk from breeding females to stimulate egg production.
According to Becker, years of trials and industry collaboration helped turn welfare concerns into something retailers could no longer dismiss as impractical.
“The prawn supply chain is very complex and very long compared to domestically sourced animal products,” he says. “To apply consistent welfare standards in contexts such as Southeast Asia and Latin America is naturally more challenging than domestically in the UK.”
That complexity helps explain why discounters were slower to move than premium grocers.
Waitrose and Marks & Spencer were said to be among the first to pilot reforms in 2023, followed by actual commitments by Tesco and other major chains in 2024. Asda, Iceland, Lidl and Aldi came later, prompting criticism from campaigners who argued that value-led retailers were dragging their feet.
Last year, ICAW led a high-profile protest outside Iceland’s Greenwich store, drawing more than 70 people in what organisers described as the world’s largest protest for prawn welfare.
The campaign, in which protesters held banners featuring Iceland chairman Richard Walker and the message ‘Does Iceland cut animals’ eyes off?’, was designed to force lagging supermarkets to catch up with their rivals.
However, Becker believes some retailers were put off not only by the cost of new equipment, but by the sheer quantities of shrimp sold, and therefore the operational burden of tracing welfare standards through fragmented global supply chains.
“Discounters tend to have a higher sales volume of shrimp,” he says. “I think they shied away from the work of assessing their supply chain, and putting robust systems in place to ensure animal welfare standards can be enforced in the complexity of that supply chain.”
Why Aldi’s move matters beyond the UK
Becker is careful not to frame Aldi’s move simply as a story of a retailer arriving late.
Aldi was the last major UK supermarket to put a timeline on ending the worst practices in prawn farming, but Becker argues its latest commitment goes further than any rival’s because it covers all Aldi Süd markets, including Europe, the US and Australia.
“However, they have gone beyond what other retailers are doing and put out a global commitment,” he says. “We consider them a first mover in those markets.”
Becker explains that this distinction matters. While UK supermarket pledges have helped create momentum domestically, most have only applied to British operations. Lidl can be looked towards as a useful comparison. Lidl recently committed to electrical stunning for prawns sold in Great Britain, but has yet to set equivalent timelines across its wider European business.
By contrast, Aldi Süd’s decision has the potential to influence suppliers far beyond the UK market because of the volume it buys globally.
“We believe this, by the sheer volume of shrimp that Aldi sells in its global markets, will indeed be a turning point,” Becker says.
Still, he is keen to stress that commitments are only the start.
“The important thing here is, these are pledges, these are promises that have been made to customers and to the general public,” he says.
ICAW’s focus in the UK will now shift from securing commitments to monitoring delivery. Becker says the organisation will remain open to working with retailers on practical challenges, but expects them to meet the deadlines they have publicly set.
“The important thing that differentiates the Aldi commitment is that they commit to annually report on their progress,” he says. “Frankly, I would love to see that from Iceland and Lidl as well.”
What comes next for prawn welfare
Becker is keen to stress that the issue is far from solved.
“I wouldn’t want to be quoted with the fact that prawn welfare is solved,” he says. “I would say we have now addressed two of the worst practices.”
Future reform could focus on farmed fish, where stunning standards remain inconsistent, and on wider parts of the seafood sector that have so far escaped meaningful scrutiny.
“There are potential changes that can affect and reduce the suffering of literally billions of animals every year,” he says.
Perhaps most striking, Becker points out, is how far the public conversation has shifted. What once seemed too obscure or too uncomfortable to gain traction is now forcing some of the world’s biggest retailers to rethink their supply chains.
“When we started this work three years ago, people, even animal welfare activists, thought we were kind of crazy,” Becker says.
“People would just not care about tiny animals living underwater, having the eyes cut off or suffocating to death. Frankly, I think they’ve been proven wrong.
“We realise that people do care about the welfare of the animals that they eat, and that doesn’t stop at whether these animals have a spine, or live in air or under water.
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