How Octopuses Are Farmed and Killed

• ‘Cephalopod’ is Greek for ‘head-foot,’ which makes sense as octopuses’ arms are attached directly to their heads
• If a predator gets too close, octopuses can escape quickly, shooting themselves forward by expelling water from a muscular tube called a siphon
• They can squeeze through impossibly small openings, as long as the holes are not smaller than the only hard part of their body – their beak
• Octopuses do not have teeth, yet they bite
• These sea invertebrates have three hearts
• Surprisingly, they have blue blood
• Octopuses are experts at camouflage and can quickly change the colour, pattern and texture of their skin to blend in with their surroundings
• These extraordinary creatures are intelligent and inquisitive

Octopuses (or octopi) are cephalopods, invertebrates that also include squid and cuttlefish. There are around 300 species found in oceans across the world, from shallow coastal waters, tide pools, seagrass and algal beds to deep-sea habitats. They are often found in rocky crevices, coral reefs or soft sediments, where they can hide and find prey. They are generally solitary and territorial creatures – they prefer to live alone and not be bothered.

Octopuses have soft bodies, bulbous heads, large eyes and eight arms lined with hundreds of suckers. Most of their neurons (nerve cells) are in their arms – nearly twice as many as in the central brain. These complex bundles of neurons act as a ‘mini-brain’ in each arm, letting them touch, smell and manipulate objects quickly and effectively.

Octopuses have blue blood because the protein haemocyanin, which carries oxygen around their body, contains copper rather than iron – as we have in our haemoglobin. This copper-based protein is more efficient at transporting oxygen in cold conditions, so it is ideal for ocean life. An octopus has not one but three hearts: two branchial hearts pump blood to the gills, where it collects oxygen and a third, systemic heart, pumps oxygenated blood around the body.

Remarkable Cognitive Abilities

With 500 million neurons – a number more typically found in vertebrates such as dogs – octopuses have the largest nervous systems among invertebrates and are considered among the most intelligent of them.³Carls-Diamante S. 2022. Where is it like to be an octopus? Frontiers in Systems Neuroscience. 16, 840022. They can exhibit remarkable cognitive abilities, such as maze-solving and observational learning. Once octopuses have solved a new problem, they retain long-term memory of the solution. They have the reputation of being remarkable escapologists and are adept at getting themselves in and out of containers. They can construct a shelter, often using a makeshift ‘door’ to protect it.

Tool use is a good indicator of the ability to learn but is relatively rare among animals and is usually associated with apes, monkeys, dolphins and some birds, such as crows and parrots. However, among invertebrates, octopuses and a few insects are known to use tools. An impressive and convincing example of tool use by octopuses came in 2009 in Indonesia, when a few veined octopus (Amphioctopus marginatus) individuals were seen collecting discarded coconut shells and carrying them across the seafloor to use as a shelter when required.⁴Finn JK, Tregenza T and Norman MD. 2009. Defensive tool use in a coconut-carrying octopus. Current Biology. 19 (23) R1069-70. To carry the shells, they had to use some of their arms to walk along the seafloor as if on stilts, potentially making them vulnerable to predators, but they appeared willing to accept the short-term risk for future protection.

The incredible film My Octopus Teacher on Netflix documents the life of a female wild common octopus and the filmmaker’s close relationship with her as he follows her around for nearly a year. Her daring escape from a shark is mind-bogglingly creative and her camouflages, an impressive delight. One thing is certain: octopuses are bright creatures, poorly understood by humans.

Experts at Camouflage

Octopuses have thousands of specialised cells (chromatophores) under their skin that allow them to change colour instantaneously. They can change not only their colouring but also the texture of their skin to match rocks, corals, sand or plants – a clever tactic that can help them hide in plain sight and surprise prey. According to a study published in the journal Current Biology, octopuses may also darken their colour and increase their size by standing taller to signal aggression towards another animal, different species or not, to stand their ground, or even to initiate a fight.⁷Scheel D, Godfrey-Smith P and Lawrence M. 2016. Signal Use by Octopuses in Agonistic Interactions. Current Biology. 26 (3) 377-382.

Most cephalopods can expel a cloud of ink to confuse predators, allowing them to escape. The ink is produced, stored and evacuated from an ink sac via a muscular tube called a siphon. Each species produces slightly differently coloured inks; octopuses typically produce black ink, the colour is due to its main constituent – melanin. Stress-induced inking has been reported after shipping octopuses and at least one report has directly attributed the death of an aquarium-housed California two-spot octopus (Octopus bimaculoides) directly to ink clogging around their ctenidia (gills).⁸Bennett H and Toll RB. 2011. Intramantle inking: a stress behavior in Octopus bimaculoides (Mollusca: Cephalopoda). The Journal of the American Association for Laboratory Animal Science. 50 (6) 943-945.

Another useful strategy in their armoury includes being able to ‘jet propel’ themselves out of trouble. They do this by filling their mantle cavity (used to get oxygenated water to their gills) with water and then quickly expelling it out of the siphon (also used to expel ink). This type of locomotion is a great way for an octopus to accelerate away from danger quickly. Their ability to hide and use defensive strategies can help them evade predation from seals, whales and larger fish.

What Do Octopuses Eat?

Crabs, shrimp and lobsters rank among their favourite foods, though some can attack larger prey. Research shows that octopuses prefer to use certain arms when hunting and adjust their tactics according to prey.¹³Bidel F, Bennett NC and Wardill TJ. 2022. Octopus bimaculoides’ arm recruitment and use during visually evoked prey capture. Current Biology. 32 (21) 4727-4733. They pounce, like cats, onto crabs with a move the scientists call ‘parachuting’, whereas they are more likely to make a snatch for shrimp, which are more skittish and sensitive to large movements. They have very sharp beaks that are capable of breaking open clams and lobster shells and delivering a venomous bite to incapacitate their prey. Although all octopuses and some squid are venomous¹⁴Fry BG, Roelants K and Norman JA. 2009. Tentacles of venom: toxic protein convergence in the Kingdom Animalia. Journal of Molecular Evolution. 68 (4) 311-321., out of the 300 species of octopuses, only venom from the blue-ringed octopus species poses a serious threat to humans as it may be 1,000 times more toxic than cyanide.¹⁵Lago J, Rodríguez LP, Blanco L et al. 2015. Tetrodotoxin, an extremely potent marine neurotoxin: distribution, toxicity, origin and therapeutical uses. Marine Drugs. 13 (10) 6,384-6,406. The toxin in these surprisingly small creatures is not produced by the octopus itself though; symbiotic bacteria living in their salivary glands produce it.¹⁶Osterloff E. 2023. The blue-ringed octopus: small, vibrant and exceptionally deadly. Available at https://www.nhm.ac.uk/discover/blue-ringed-octopus-small-vibrant-deadly.html [Accessed 10 October 2023].

How Long Do Octopuses Live?

Octopuses typically live from one to five years, depending on the species. They are semelparous, which means they reproduce only once in their lifetime. After mating, females lay thousands of eggs, which they guard and care for until they hatch. The male dies soon after mating, while the female dies shortly after the eggs hatch.

Do Octopuses Feel Pain?

Cephalopod expert, Dr Jennifer Mather, told VICE in 2015: “It’s probable that the octopus’s reaction to pain is similar to a vertebrate. They can anticipate a painful, difficult, stressful situation – they can remember it. There is absolutely no doubt that they feel pain.”²⁰Pollack H. 2015. How an Octopus feels when it’s eaten alive. VICE. Available at https://www.vice.com/en/article/vvxzzx/how-an-octopus-feels-when-its-eaten-alive [Accessed 10 October 2023].

A report from the London School of Economics (LSE), investigating sentience in cephalopod molluscs and decapod crustaceans, found strong and diverse evidence of sentience in both and said that “invertebrates should be treated in the same way as vertebrates” and called for an end to the asphyxiating of octopuses, boiling of lobsters and dismembering of crabs. Their report, which reviewed over 300 scientific studies, led to the UK Government’s decision to legally recognise these animals as sentient beings.²¹Birch J, Burn C, Schnell A et al. 2021. Review of the evidence of sentience in cephalopod molluscs and decapod crustaceans. LSE Consulting. LSE Enterprise Ltd. The London School of Economics and Political Science. Available at: https://www.lse.ac.uk/News/News-Assets/PDFs/2021/Sentience-in-Cephalopod-Molluscs-and-Decapod-Crustaceans-Final-Report-November-2021.pdf [Accessed 10 October 2023].

The Animal Welfare (Sentience) Act 2022 recognised animal sentience in UK law for the first time.²²Animal Welfare (Sentience) Act 2022. Available at: https://www.legislation.gov.uk/ukpga/2022/22/enacted [Accessed 10 October 2023]. The legislation includes all vertebrates and cephalopods (such as octopuses, squid and cuttlefish) and some decapods (such as crabs, lobsters and crayfish). Campaigners hoped this may lead to greater protection for invertebrates – but the Government says the legislation is for future guidance only and will not impact industries such as fishing or restaurants.

Many applauded this law as if it was a new concept, but when the UK was part of the EU, animals were legally recognised as sentient and it made little if any difference to how farmed animals were confined and killed. The new law may sound like good news, but the reality is that when it comes to farmed animals, almost nothing is changing.

The appetite for octopus is growing and the annual global trade is now worth more than £2.25 billion.  

Octopus Factory Farms

Octopus aquaculture is the factory farming of octopuses and commercial sale of their meat. Aquaculture already causes huge environmental damage – commercial octopus farming will likely increase harm to local ecosystems. Furthermore, like farmed fish, octopuses have a food conversion ratio of at least three to one, meaning that they require as much as three times their weight in feed. Given the decline in global fisheries, farming a carnivorous species makes no sense and increases the threat to global food security.

To date, the majority of octopuses used for food are wild-caught but octopus fisheries are in decline, with many now overfished. Because of this, Compassion in World Farming says that “there are plans to confine these fascinating, inquisitive and sentient creatures in factory farms”.²⁹Compassion in World Farming. 2021. Octopus farming: a recipe for disaster. Available at https://www.ciwf.org.uk/media/press-releases-statements/2021/10/octopus-farming-a-recipe-for-disaster [Accessed 10 October 2023]. According to Sentient Media, there are a number of facilities in the works that could become commercial octopus farms.³⁰Mishler, J. 2023. Explainer: is octopus farming ethical? Available at https://sentientmedia.org/octopus-farming/ [Accessed 10 October 2023]. In 2019, it was reported that in several countries, including Spain, Italy and Australia, experimental production has begun in tanks on land, in open-ocean net pens and on ‘ranches’ where wild-caught octopuses are raised in captivity, and that attempts to farm octopuses are also underway in Latin America, China and Japan.³¹Jacquet J, Franks B, Godfrey-Smith P et al. 2019. The case against octopus farming. Available at https://issues.org/the-case-against-octopus-farming/ [Accessed 10 October 2023].

The farm that appears closest to production is based in the Canary Islands and could be the world’s first octopus factory farm. Grupo Nueva Pescanova’s plan came into public view in 2021 when it applied for permits to build a two-storey farm at the port of Las Palmas in Gran Canaria. They are planning a farm that could eventually provide up to 3,000 tonnes of octopus meat a year – requiring the slaughter of about one million common octopuses (Octopus vulgaris).³²Kassam A. 2023. ‘A symbol of what humans shouldn’t be doing’: the new world of octopus farming. The Guardian, 25 June. Available at https://www.theguardian.com/environment/2023/jun/25/a-symbol-of-what-humans-shouldnt-be-doing-the-new-world-of-octopus-farming [Accessed 10 October 2023]. Roberto Romero Pérez, a marine biologist who oversees aquaculture at Grupo Nueva Pescanova, suggests the first batch of product – which could be between 300 and 500 tonnes of octopus meat – will probably not hit the market before 2027.

The reason most octopuses currently used for food are wild-caught is probably due to the huge difficulties associated with farming them for food – they are not very sociable and show little tolerance for other individuals. Scientists say they are particularly ill-suited to life in captivity and mass production and that it would cause them to suffer greatly due to their intelligence as well as curious, solitary and territorial nature. Philosopher Stefan Linquist of the University of Guelph in Ontario, who studied octopus behaviour, says octopuses “know that they are inside this special place, and you are outside it. All their behaviours are affected by their awareness of captivity”.³³Godfrey-Smith P. 2017. The mind of an octopus. Scientific American, 1 January. Available at https://www.scientificamerican.com/article/the-mind-of-an-octopus/ [Accessed 10 October 2023]. This is probably why there are so many tales of daring escapes, like Inky, a common New Zealand octopus (Macroctopus maorum) who climbed out of his tank, crossed the aquarium floor and went down a 50-metre drainpipe to the sea and freedom.³⁴Ainge Roy E. 2016. The great escape: Inky the octopus legs it to freedom from aquarium. The Guardian, 13 April. Available at https://www.theguardian.com/world/2016/apr/13/the-great-escape-inky-the-octopus-legs-it-to-freedom-from-new-zealand-aquarium [Accessed 10 October 2023].

At least 420,000 tonnes, which could equate to around 91 million individuals, are caught each year – more than 10 times the amount caught in 1950.³⁸Carwardine M. 2022. The world’s first commercial octopus farm is a disaster waiting to happen. Available at https://www.discoverwildlife.com/people/opinion/mark-carwardine-the-worlds-first-commercial-octopus-farm-is-a-disaster-waiting-to-happen [Accessed 10 October 2023]. Just in the UK, approximately 1,300 tonnes – around 280,000 individuals – are consumed each year and that amount has increased 12-fold since 1990.¹²Compassion in World Farming. 2021. Octopus farming: a recipe for disaster. Available at https://www.ciwf.org.uk/media/press-releases-statements/2021/10/octopus-farming-a-recipe-for-disaster [Accessed 10 October 2023]. As global demand for octopuses grows, so have efforts to farm them.

More than 100 different species of octopuses are caught in the wild using nets, pots, lines and traps. For octopuses caught in the wild, a variety of methods are used to kill them, from clubbing to asphyxiation and slicing their brains. The proposed method of killing for the large octopus farm in the Canary Islands is to use ice slurry without pre-stunning,³⁹Eurogroup for Animals and Compassion in World Farming. 2023. Uncovering the horrific reality of octopus farming. Available at https://www.ciwf.org/media/7453342/octopus-factory-farming-report-english.pdf [Accessed 10 October 2023]. an inhumane method that causes pain, fear and suffering.⁴⁰Roth B, Imsland A and Foss A. 2009. Live chilling of turbot and subsequent effect on behaviour, muscle stiffness, muscle quality, blood gases and chemistry. Animal Welfare. 18 (1), 33-41. There is no humane slaughter method for octopuses and therefore octopus farming should not be allowed due to the suffering it would cause.¹⁹Eurogroup for Animals and Compassion in World Farming. 2023. Uncovering the horrific reality of octopus farming. Available at https://www.ciwf.org/media/7453342/octopus-factory-farming-report-english.pdf [Accessed 10 October 2023].

An international team of scientists writing in Issues in Science and Technology say that right now, the farming of octopus for food is limited by the technology but fear that with further investments, research and testing, the technology may well become available to farm octopuses on an industrial scale.¹⁴Jacquet J, Franks B, Godfrey-Smith P et al. 2019. The case against octopus farming. Available at https://issues.org/the-case-against-octopus-farming/ [Accessed 10 October 2023]. Because of the serious welfare and environmental problems associated, they hope octopus farming will be prohibited and that governments, companies and researchers will focus their efforts instead on achieving a sustainable and compassionate future for food production.

Alex Schnell, a comparative psychologist and co-author of the LSE report,¹⁰Birch J, Burn C, Schnell A et al. 2021. Review of the evidence of sentience in cephalopod molluscs and decapod crustaceans. LSE Consulting. LSE Enterprise Ltd. The London School of Economics and Political Science. Available at: https://www.lse.ac.uk/News/News-Assets/PDFs/2021/Sentience-in-Cephalopod-Molluscs-and-Decapod-Crustaceans-Final-Report-November-2021.pdf [Accessed 10 October 2023]. said: “In my 15 years of experience, I’ve never encountered a facility that groups octopuses together without incidents of aggression or escape. Cannibalism commonly occurs when octopuses are housed together. Stress from overcrowding or non-ideal living conditions can lead to self-cannibalism, where they eat their own arms.”¹⁵Kassam A. 2023. ‘A symbol of what humans shouldn’t be doing’: the new world of octopus farming. The Guardian, 25 June. Available at https://www.theguardian.com/environment/2023/jun/25/a-symbol-of-what-humans-shouldnt-be-doing-the-new-world-of-octopus-farming [Accessed 10 October 2023]. The report concludes: “We are convinced that high-welfare octopus farming is impossible,” and the authors suggest the Government consider banning imported farmed octopus.¹⁰Birch J, Burn C, Schnell A et al. 2021. Review of the evidence of sentience in cephalopod molluscs and decapod crustaceans. LSE Consulting. LSE Enterprise Ltd. The London School of Economics and Political Science. Available at: https://www.lse.ac.uk/News/News-Assets/PDFs/2021/Sentience-in-Cephalopod-Molluscs-and-Decapod-Crustaceans-Final-Report-November-2021.pdf [Accessed 10 October 2023]. Better still, just don’t eat them!