Worrying about shrimp may seem like a mild form of insanity—until one considers: what if there are powerful beings in the universe for whom we are like shrimp? )))
Thanks, Alex! I very much agree with treating others as we would want to be treated by them (Golden Rule). On the other hand, I would want to increase the welfare of shrimp and other less powerful beings even if I was sure humans and their descendents would forever remain the most powerful beings. I just think suffering is bad, and happiness is good no matter where the beings experiencing them fall in the universal distribution of power.
Executive summary: Shrimp welfare is an overlooked yet crucial issue, as billions of shrimp suffer annually due to industrial farming practices, and emerging evidence suggests they are sentient; cost-effective interventions like humane slaughter methods and improved farming conditions can significantly reduce their suffering.
Key points:
Shrimp are among the most numerous farmed animals, with 440 billion slaughtered annually and 27 trillion caught in the wild, yet they receive little attention in animal welfare discussions.
Scientific research increasingly supports the idea that shrimp are sentient, capable of learning, experiencing pain, and displaying behaviors indicative of suffering.
Industrial shrimp farming practices, including overcrowding, poor water quality, and cruel slaughter methods, cause significant and preventable suffering.
New welfare interventions, such as electrical stunning before slaughter and improved water quality management, have already begun reducing suffering for billions of shrimp.
Major food retailers, including UK supermarkets, are starting to implement higher welfare standards, but there is still vast potential for improvements in shrimp farming and wild capture practices.
Addressing shrimp welfare is a moral imperative and an opportunity for large-scale impact, requiring further advocacy, research, and industry cooperation.
This comment was auto-generated by the EA Forum Team. Feel free to point out issues with this summary by replying to the comment, and contact us if you have feedback.
All arguments based on behavioral similarity only proof we all come from evolution: "we are neural networks trained by natural selection. We avoid destruction and pursue reproduction, and we are both effective and desperate in both goals. The (Darwinian) reinforcement learning process that has led to our behavior imply strong rewards and penalties and being products of the same process (animal kingdom evolution), external similarity is inevitable. But to turn the penalty in the utility function of a neural network into pain you need the neural network to produce a conscious self. Pain is penalty to a conscious self. Philosophers know that philosophical zombies are conceivable, and external similarity is far from enough to guarantee noumenal equivalence."
Now, regarding how much information is integrated, supperativity implies that the ammount of resources devoted to the shrimp shall be propotional to their number, but (at most!) to their brain mass:
"As a rule, measures of information integration are supper additive (that is, complexity of two neural networks that connect among themselves is far bigger than the sum of the original networks), so neuron count ratios (Shrimp=0.01% of human) are likely to underestimate differences in consciousness. The ethical consequence of supper additivity is that ceteris paribus a given pool of resources shall be allocated in proportion not to the number of subjects but (at most!) to the number of neurons. "
All arguments based on behavioral similarity only proof we all come from evolution
Shrimps have a welfare range of 0.430 (= 0.426*1.01) under Rethink Priorities's (RP's) quantitative model, which does not rely on behavioral proxies.
This model aggregates several quantifiably characterizable physiological measurements related to activity in the pain processing system. Many lacked data for certain species, and our numbers reflect the averages of those measures that had data for different taxa. In some cases, we used surrogates when specific species data was not available. The advantage of this approach is that all of the results lend themselves to model construction and plausibly have some connection to welfare. However, many of these features are found in the peripheral nervous system, and as such aren’t necessarily related to conscious experiences which presumably take place in the central nervous system. This approach also could be thought to reflect the flaws of only focusing on those things that are easily measurable at the expense of looking at features which are likely to be more directly relevant.
The quantitative model relies on:
Nociceptive just noticeable differences (JNDs).
Maximum nociceptor response (spikes/s).
Nociceptor density (NF/mm or NF/mm2).
Substance P concentration (ng/g).
Change in stress hormone (% from control).
Change in heart rate (% from control).
Change in respiration rate (% from control).
Brain mass to body mass ratio.
Encephalization quotient.
Neuron packing density.
To arrive to a super low welfare of shrimp, one has to be not only super confident that behavioral proxies do not matter for welfare, but also that a very specific structural criteria (e.g. number of neurons, which have major flaws) is practically all that matters.
neuron count ratios (Shrimp=0.01% of human)
RP estimated shrimp have 1*10^-6 as many neurons as humans, not 0.01 % (10^-4).
All those proxies tell us they have the wires to feel the pain. But what abour the self? You need the side of penalty and the side of self to have real pain. Pain shall inflicted to a conscious mind.
With their ridiculously small brains, how likely is a self on the receiving side of penalty?
Claiming the "quantitative model" doesn't rely on behavioral proxies is technically true but misses the point I think.
The model looks mainly at physiological responses to stimuli. It seems similar to the behavioral model in that if some physiological thing like heart rate or respiration or stress level changes in A similar way to a human then they get a similar score to a human.
I can see the idea with behavioral proxies but I struggle to see what this model really adds. They then seem to bend over backwards somewhat to add other neurological measures that are not neuron count and that will bump up the moral weight as much as possible. "brain mass to body mass ratio" seems especially strange to me in this front
This is a crosspost for Yes, Shrimp Matter by Andrés Jiménez Zorrilla, which was originally published on Asterisk in January 2025. Thanks to Giles Thomas for bringing it to my attention.
[Subtitle.] What made a private equity analyst decide to devote his life to tiny aquatic crustaceans?
I left private equity to work on shrimp welfare. When I tell anyone this, they usually think I've lost my mind. I know the feeling — I’ve been there. When I first read Charity Entrepreneurship's proposal for a shrimp welfare charity, I thought: “Effective altruists have gone mad — who cares about shrimp?”
The transition from analyzing real estate deals to advocating for some of the smallest animals in our food system feels counterintuitive, to say the least. But it was the same muscle I used converting derelict office buildings into luxury hotels that allowed me to appreciate an enormous opportunity overlooked by almost everyone, including those in the animal welfare space. I still spend my days analyzing returns (though they’re now measured in suffering averted). I still work to identify mutual opportunities with industry partners. Perhaps most importantly, I still view it as paramount to build trust with people who — initially — sit on opposite sides of the table.
After years of practicing my response to the inevitable raised eyebrows, I now sum it up simply: ignoring shrimp welfare would have been both negligent and reckless.
This may seem like an extreme stance. Shrimp aren't high on the list of animals most people think about when they consider the harms of industrial agriculture. For a long time — up until the last few years — most researchers assumed shrimp couldn't even feel pain. Yet as philosopher Jonathan Birch explains in The Edge of Sentience, whenever a creature is a sentience candidate[1] and we cannot rule out its capacity for conscious experience, we have a responsibility to take its potential for suffering seriously.
We don’t know what it is like to be a shrimp. We do know that if shrimp can suffer, they are doing so in the hundreds of billions.
Counting billions
Why worry about shrimp in a world where so many mammals and birds live in torturous conditions due to industrial agriculture?[2] The answer is that shrimp farming dwarfs other forms of animal agriculture by sheer numbers. An estimated 230 billion shrimp of various species are alive in farms at any given moment[3] — compared to the 779 million pigs, 1.55 billion cattle,[4] 33 billion chickens,[5] and 125 billion farmed fish.
Shrimp are harvested at around 6 months of age, which puts the estimated number slaughtered annually for human consumption at 440 billion. For perspective: that’s more than four times the number of humans who have ever walked the earth. At sea, the numbers are even more staggeringly shrimpy. Globally, 27 trillion shrimp are caught in the wild[6] every year, compared to 1.5 trillion fish.[7]
Despite their size, shrimp are the proverbial “elephant in the room” when discussing animal welfare in food systems.
What the science says
These numbers wouldn’t matter if shrimp didn’t have the internal experience associated with suffering, but a growing body of evidence suggests that they do. A comprehensive review commissioned by the U.K. government found strong evidence of sentience in decapods, which includes shrimp, lobsters, prawns, and crabs. Evidence was particularly strong in true crabs.[8] Crabs can learn. They can make trade-offs and act to protect themselves in flexible, complex ways. Everything we know about the structure of their brains suggests that they feel pain. While shrimp have been studied less extensively, the evidence suggests that they have similar capabilities. The fundamental neural architecture have in common with other animals includes pain receptors, nerve centers capable of integrating information from different sensory sources, and molecular machinery for detecting noxious stimuli.
The Welfare Range Table, a comprehensive assessment of animal capacities, reveals that shrimp display numerous sophisticated behaviors: they can learn from experience and show anxiety-like states when threatened; when injured, they display targeted grooming behavior (basically, tending to the injury) that can be reduced by local anaesthetic, suggesting conscious pain response rather than mere reflex; and their nervous systems show a striking level of complexity, with clear evidence of integrative processing centers that could support conscious experience.
In Rethink Priorities’ Welfare Range Estimates, philosopher Bob Fischer effectively extends Jeremy Bentham's famous question about animals — “The question is not, Can they reason? nor Can they talk? but, Can they suffer?” — by asking, "If so, how much?" His findings suggest that shrimp's capacity for improved welfare is substantial when compared to octopuses, and even pigs.[9]
Shrimp’s nervous system, behavior, and estimated welfare capacity all point toward meaningful sentience. The fact that they haven't been studied as extensively as some other animals should not blind us to the evidence we do have, nor to their evident similarities with better-studied relatives.
Beyond the water
In modern shrimp farming, life begins in a hatchery born to a mother who has endured one of the industry's most severe practices: eyestalk ablation. This procedure involves physically cutting off the appendage from which her eyes protrude — imagine having your optic nerve severed and your entire eye removed, all without anaesthesia.[10][11] This mutilation, designed to induce spawning, sets the tone for a life marked by intensive farming practices.
At just a few days old, the young shrimp is transferred to a grow-out pond where it will spend the next three to six months of its life. In super-intensive systems, which represent a non-negligible portion of the industry in some regions, 500 to 1,000 shrimp are packed into each square meter. For a creature that grows to 13 centimeters in length, this density makes it impossible to perform natural behaviors like burrowing or resting on the bottom. Instead, the shrimp must swim continuously in the crowded space.[12]
Poor water quality poses a persistent threat, regardless of stocking density. Just as humans need clean air to breathe, shrimp require clean water to survive. Their environment is often impacted by fluctuating oxygen levels and the presence of toxic gases — ammonia and hydrogen sulfide from accumulated waste, to name two. In densely packed systems, these challenges become especially dangerous as a single water quality mishap can rapidly cascade into a mass mortality event. These conditions weaken their immune systems, leading to widespread disease. In what is considered a successful harvest, 20 to 30% of the population may die before reaching market size.
Those who survive face an ending that recent research suggests may be more cruel than previously thought. In the best-case scenario, they're immersed in ice slurry, a practice long considered humane. However, emerging evidence from EEG studies indicates this method merely paralyses the shrimp while still leaving them conscious and capable of feeling pain for an extended period. In many cases, the reality is even harsher — some are left on crates for several minutes to drain excess water weight, while others are forced to endure long-distance transport in severely under-oxygenated barrels for up to eight hours, journeys that can stretch hundreds of kilometers from farm to market.
To be clear, not all shrimp experience every welfare concern listed here, nor do most shrimp suffer from all of them simultaneously. However, these issues arise so frequently that nearly all shrimp will likely experience at least two or more of these welfare violations during their lives.[13]
During my work with the Shrimp Welfare Project, I visited farms across the globe and saw this mistreatment firsthand. In India, earthen ponds with 15 to 30 shrimp per square meter had mortality rates over 30%. In contrast, Vietnam’s super-intensive farms reduced mortality to 5% but caused constant stress from overcrowding. Even in organic mangrove farms with low densities (three to five shrimp per square meter), 95-97% of shrimp die before harvest. This type of “free-range farming” in shrimp, I learned, equates to almost certain death for all but the luckiest few.
Karol Banach
A roadmap to compassion
Despite these grim realities, there is hope. New interventions are emerging that are cost-effective, scalable, and already reducing the suffering of billions of shrimp every year.
One key advancement is the promotion of electrical stunning before slaughter. As of today, this method is the only one proven to render shrimp unconscious in under a second, making it far more humane than traditional methods. It’s also highly efficient. Despite only eight electrical stunning machines being used globally as of November 2024, these devices are predicted to have improved the slaughter conditions of over 2.5 billion animals per year. And four to five more are on the way.[14]
The Sustainable Shrimp Farmers of India (the Indian branch of Shrimp Welfare Project) has introduced another promising intervention: removing sediment from earthen ponds between shrimp farming cycles. This simple step reduces hydrogen sulfide and generally improves water quality, addressing welfare concerns over a much longer portion of the shrimp’s life than just the final moments before slaughter. The SSFI team believes this approach could be even more cost-effective in reducing suffering than electrical stunning.[15]
Leading UK supermarkets are transforming how shrimp are treated in their supply chains. Marks & Spencer, Tesco, Sainsbury's, Waitrose, and Ocado, along with the Dutch retail giant Albert Heijn, are spearheading this welfare revolution.[16] While collaborative organizations initially helped these retailers make gradual improvements, advocacy powerhouses Wakker Dier and Mercy for Animals have recently stepped in to accelerate change. Their campaigns demand immediate action on critical issues like eyestalk ablation and push for humane slaughter through electrical stunning. As these retailers represent major buying power in the global shrimp market, their commitment to higher welfare standards is already creating waves of change throughout the industry.[17]
Perhaps most excitingly, there are still numerous areas for improvement in shrimp welfare that have yet to be addressed. These include enhancing the capture and slaughter conditions for wild-caught shrimp, promoting lower-density farming models, and pushing for trade regulations that limit the import of shrimp produced under poor welfare conditions.[18] The potential for progress is vast and there is significant white space for new approaches and organizations.
The future of shrimp welfare is one of the most underexplored areas in modern animal rights, but its potential for impact is immense. We are only at the beginning of a movement that could fundamentally shift the way we treat aquatic animals — both on farms and for those caught in the ocean. While challenges remain, including entrenched industry practices and global trade complexities, the path forward is becoming clearer with each step taken by animal NGOs and progressive food companies.
For the first time ever, shrimp welfare is becoming a relevant topic within the broader animal welfare movement, one that has traditionally focused on larger animals and more familiar causes. But the staggering number of shrimp affected, their capacity to suffer, and the emerging solutions make this a moral issue we can no longer ignore. Addressing shrimp welfare isn’t just about reducing suffering for billions of animals — it’s about redefining our relationship with the natural world, expanding our circle of compassion, and challenging the limits of our ethical responsibilities.
We stand at a pivotal moment where meaningful changes can be made. The choices we make today will shape the future of animal welfare for generations to come. And while shrimp may be small, the moral imperative to protect them looms large. The time to act is now.
Andrés Jiménez Zorrilla is the Chairman of the Board and co-founder of Shrimp Welfare Project (SWP), an organisation dedicated to improving the welfare of farmed shrimp. Prior to SWP, he worked for more than 15 years in investment banking and private equity for firms such as Morgan Stanley and Aermont Capital in the UK, Spain, Portugal, Mexico and Qatar.
According to philosopher Jonathan Birch’s framework, a “sentience candidate” is any being for which there is sufficient evidence to suggest a realistic possibility of sentience. This means there is a credible chance that the being can have conscious experiences, including the capacity to suffer. Birch argues that, in such cases, ignoring evidence of possible sentience is negligent and recognising it without acting is reckless.
From this point on, I’m using “shrimp” as short-hand for Litopenaeus Vannamei (whiteleg shrimp) and Penaeus Monodon (tiger prawn), which account for more than 90% of all farmed shrimp worldwide.
The reason why these numbers are so astronomically high despite the fact that tonnage from aquaculture and wild-caught are relatively similar is because a large portion of the wild-caught shrimp are Acetes japonicus.
The LSE review identifies eight criteria for assessing sentience in cephalopod molluscs and decapod crustaceans. These are: possession of nociceptors, the presence of integrative brain regions, neural pathways connecting nociceptors to the brain, responses modulated by anaesthetics or analgesics, evidence of motivational trade-offs, flexible self-protective behaviors, associative learning, and the valuing of analgesics or anaesthetics when injured. Each criterion serves as a proxy for sentience, helping to determine the likelihood that these animals can experience pain or suffering. Crabs satisfy five with high confidence. In cases without high confidence, this is because we lack evidence, rather than positive evidence that any animals fail to meet this criteria. Testing this stuff is hard.
At the 50th percentile, shrimp show a welfare range of 0.031 (where 1 represents human capacity for pleasure and pain); pigs, for example, are 0.515 and octopuses 0.213.
Eyestalk ablation forces female shrimp to produce eggs more predictably by removing an organ that regulates reproduction based on environmental conditions.
Strikingly, recent research has now shown that shrimp can be equally productive in terms of number of eggs without ablation, and their offspring are more resistant to diseases. Despite some industry efforts to eliminate this practice, particularly in supermarkets and large producers, progress has been slow, especially in fragmented markets like Asia, where hatcheries rarely see the financial benefits of change.
Electrical stunning, by far the most humane practice, is extremely rare, and therefore inhumane slaughter is almost a given for all farmed shrimp in the system.
Shrimp Welfare Project has signed 13 Memoranda of Understanding to provide electrical stunning equipment to shrimp producers through their Humane Slaughter Initiative, but only five were operational as of October 10th, 2024. One additional stunner was purchased by a producer independently from SWP’s HSI.
The Dutch Parliament, instigated by the Party for the Animals, is considering proposing a European-wide ban on imports of shrimp produced using eyestalk ablation.
This is the third in a sequence of posts taken from my recent report: Why Did Environmentalism Become Partisan?
Summary
Rising partisanship did not make environmentalism more popular or politically effective. Instead, it saw flat or falling overall public opinion, fewer major legislative achievements, and fluctuating executive actions.
Public Opinion...
This post presents the executive summary from Giving What We Can’s impact evaluation for 2025. At the end of this post we share links to more information, including the full report and...
Worrying about shrimp may seem like a mild form of insanity—until one considers: what if there are powerful beings in the universe for whom we are like shrimp? )))
To shrimps and other sentient non-humans, we are a misaligned superintelligence
Great analogy Alistair
Thanks, Alex! I very much agree with treating others as we would want to be treated by them (Golden Rule). On the other hand, I would want to increase the welfare of shrimp and other less powerful beings even if I was sure humans and their descendents would forever remain the most powerful beings. I just think suffering is bad, and happiness is good no matter where the beings experiencing them fall in the universal distribution of power.
Vasco, I absolutely agree with you. My idea was just a small thought experiment to let those people who disagree to view this from another angle.