Octopuses Are Highly Intelligent. Should They Be Farmed for Food?

Animal rights activists from around the world disagree and are calling for an immediate halt to the approval process. “We must not condemn these highly sensitive animals to such misery,” they wrote in a petition to the Spanish government and the European Union parliament.

So far, final approval has not yet been granted for the project. But the controversy raises far larger questions: What kind of relationship do humans want to have with octopods, which show the highest levels of invertebrate intelligence in the world? How intensively should we exploit them, either for food, science, or display, and how well are we protecting them?

For centuries, humans have eaten octopods. But apart from their food value, the animals were considered so alien that they received only scant attention, even from science. In Europe, they were mainly regarded as monsters, rumored to sink ships. In the 19th century, Victor Hugo wrote, “If there are no limits to the imagination when it comes to creating something hideous, the octopus can be considered a masterpiece.” But the more people observed and learned about these creatures in aquariums, the more their disgust turned to sympathy, even affection.

When in 2016 an octopus called Inky climbed out of his tank one night at New Zealand’s National Aquarium, moved several meters across the floor, and vanished into the sea through a long and thin pipe, news of the escape travelled around the world. People were taken aback when Billye, a Pacific giant octopus, quickly learned how to remove screw caps from jars at the Seattle Aquarium. After an octopus in Germany, which had become famous by predicting the outcome of World Cup soccer matches, died, newspapers around the world eulogized him. And in 2020, the Netflix documentary My Octopus Teacher was watched by millions of viewers.

Recent research has revealed that octopods can plan ahead, identify and remember humans individually, and solve complex tasks. Last year, scientists from the Okinawa Institute of Science and Technology showed that, just like humans, octopods have two very different sleep phases, one deep and one with increased bodily activity. Researchers even posit that they can dream. All of that is quite remarkable for a creature that lacks a spine and is more closely related to ants, slugs, and worms than to vertebrates.

Biologists know of about 300 species of octopods, inhabiting many different parts of the ocean, from coastal lagoons to depths of 5,000 meters. Some have a huge range, like the common octopus, which can be found in the tropics, subtropics, and in temperate waters. Some are extremely rare, like the roughy umbrella octopus, which is known only from a few locations near New Zealand’s Chatham Islands.

Apart from their body architecture, almost all octopods share a predatory and solitary lifestyle (social octopods have been observed in just a few small colonies off Australia, Japan, and Nicaragua). All octopods live for between one and three years, and after hatching their eggs, females die. Despite these characteristics, octopods show signs of intelligence usually attributed only to millions of years of intensively social lifestyles in mammals. Scientists are still struggling to understand how something so short-lived as octopods — which have no chance to learn from parents and peers — can perform its cognitive feats.

When the scientist Nikolaus Rajewsky visited the Monterey Bay Aquarium a few years ago, his gaze fell on a dark, motionless lump with large eyes. The octopus and he looked each other in the eye for half an hour. The scientist felt strangely moved. “On the one hand, I had this animal without a spine in front of me, a relative of snails,” he recalls, “and on the other, there was a real individual communicating with me as a human being.”

The encounter left a deep impression. “I often think about that moment,” says Rajewsky, who heads the Berlin Institute for Medical Systems Biology, where he studies gene regulation and, more recently, octopus intelligence. In 2022, Rajewsky published a paper suggesting that the parallels between mammalian and octopod brains lie in their genetic programming — which is curious, because their last common ancestor, a primitive wormlike animal, lived more than 500 million years ago. But in their brain cells, cephalopods have mechanisms — called microRNAs — that are considered a prerequisite for intelligent behavior in mammals, too.

Such discoveries drive a fairly young movement to increase the protection of octopods, from research labs to the depths of the oceans. In 2022, the British government included octopods in the list of “sentient beings” of its Animal Welfare Act, according them a status like vertebrates. And in September 2023, the U.S. National Institutes of Health asked the public for input on new rules for how cephalopods — a group that includes nautiluses, squid, and cuttlefish — could be treated better in research labs.

This increased level of concern is in stark contrast to how octopods are dealt with in fisheries. Between 350,000 and 500,000 tons of between 20 and 100 different species of octopods are caught each year for human consumption, up from about 100,000 tons in the early 1970s, according to the Food and Agriculture Organization (FAO).

Octopods are often taken as bycatch in industrial-scale fishing operations, but they are not discarded, due to their monetary value. In more artisanal fisheries, especially along coastlines in Japan, South Korea, Spain, and Portugal, they are the main target. Hunters go after the animals with traps that simulate safe hiding spaces. Spears are sometimes used in East Africa. In coastal communities, octopods can be an important source of protein and “a crucial resource for the livelihoods of vulnerable people,” according to Sustainable Fisheries, a U.S.-based NGO.

But experts are deeply worried about the lack of an international management system and, in many parts of the world, coordinated catch restrictions. For whales and for some fish species, monitoring efforts lead to strict annual quotas, which are at least partly enforced. But for octopods, the global industry is in many circumstances running blind: they are harvested without knowledge of their species or reproductive capacity, according to a comprehensive assessment by a team of scientists led by Warwick Sauer, from Rhodes University in South Africa.

For example, a study revealed that in a large part of the Atlantic, annual catches of the common octopus might have been five times higher than official statistics indicate. “Global catch data for octopuses should be considered a very rough estimate of total harvest, and likely to be a considerable underestimate,” the FAO warns.

Along coastlines, national or regional rules may limit how often artisanal octopus fishers can go out to sea or set a minimum catch size to protect potential offspring. “But rules are only as good as controls, and in many areas these don’t exist,” says Daniel Oesterwind, a marine biologist with the Thünen Institute of Baltic Sea Fisheries in Rostock, Germany, and a member of the Cephalopod International Advisory Council. Even the E.U., which prides itself as a champion of nature protection, so far has no monitoring and governance system in place for octopods in its common fishery policy.

The FAO warned in late 2023 that “global octopus landings have been on a declining trend for several years.” The IUCN’s Red List records octopods, with only a few exceptions, as either “data deficient” or “of least concern,” but with the footnote that population trends are “unknown.”

Oesterwind points out that projections are hindered by the octopods’ short lifespan. “They reproduce only once, which leads to strong fluctuations, so populations trends are difficult to predict,” he says. This is a hazard for their survival, too: “If one generation of spawners is entirely removed, the stock will cease to exist.” In some parts of the world, efforts are underway to stabilize populations. Fishers in Asturias, in Spain, and in Western Australia have committed to following rules — regarding the number of traps used by fishermen, the minimum weight of catch, and the fishing period — for certification as a sustainable fishery by the Marine Stewardship Council.

In other countries, local communities are managing their own systems. In the shallow reefs around the Tanzanian island of Songosongo, for example, the common octopus and large blue octopus live in small caves. Villagers have long used spears to bring the animals ashore. However, as octopods have increasingly been traded and exported, overexploitation has become a big problem. To address this, communities have started to manage the fishery collaboratively.

“You sit together, discuss, and find a solution,” says Modesta Medard, the marine program coordinator at WWF Tanzania. To stop the downward trend in stocks, villages chose a way that was as simple as it was effective: they began to close the reefs for three months every year. “It was part of the traditional knowledge that octopods always live in a home for three months, grow up, and then move on,” says Medard. The periodic closures, which gives the animals time to reproduce and grow, proved worthwhile. The average octopus catch has increased measurably, and with it, local income. At the same time, the reefs and their other inhabitants are better protected.

While there is consensus among octopus scientists that such projects should get more support and be implemented in many more regions, opinions diverge on octopus farming.

Some scientists have joined the protest against the Nueva Pescanova project: “Octopods should never be kept in large numbers in confined spaces. It leads to stress, conflict, and high mortality,” says Jonathan Birch, who researches animal consciousness at the London School of Economics. “It is obvious that wild octopods lead a much better life than [octopods] fattened up in plastic containers to end up on our plates,” says environmental scientist Jennifer Jacquet, of New York University.

But octopus farms also have advocates in the scientific community. “Perhaps this will help to better protect wild octopus populations and create an additional source of protein for us humans,” says Australian marine ecologist Zoë Doubleday. “Octopus are prime candidates for aquaculture because of their high rates of growth and food conversion,” Warwick Sauer and colleagues conclude in their comprehensive assessment of the group. They see the biggest challenge in obtaining a sustainable artificial feed that’s formulated from vegetarian sources. Otherwise, octopus farming might simply increase overexploitation of fish stocks.

According to reports in Spanish media in late 2023, Nueva Pescanova has yet to raise sufficient funds for its farm and is continuing to pursue its necessary licenses, but it has no firm start date. The company did not respond to requests for comment.

One leading octopus researcher, zoologist Louise Allcock of the University of Galway, thinks that the debate about the Spanish plan calls for a broader interrogation. “Pigs are also special animals, they are among the most intelligent creatures, and yet we keep them in atrocious conditions,” she says. This is why, in her view, the entire food production system needs to be challenged. The aim, she says, should be to “switch to a plant-based diet as far as possible” — and leave sentient, wild animals like octopods alone to roam the ocean.