Octopus farming unsustainable, unethical, and unnecessary, scientists warn

With efforts underway around the globe to develop commercial octopus farming operations, scientists from Australia, Spain, and the U.S. have penned an article, published in the journal Issues in Science and Technology this month, warning of the severe impacts octopus aquaculture would have on animal welfare and the environment.

Octopuses have “sophisticated nervous systems and large brains” and are known for their fascinating and complex behaviors, the authors of the article note. For instance, octopus are famous for their ability to rapidly change colors and camouflage themselves in the wild, as well as their problem-solving skills that have allowed many octopuses to repeatedly escape captivity, among many other incredible talents.

“Given their exceptional abilities, one might ask whether humans should be eating octopus at all, but here we want to raise a different ethical question,” the scientists write. “As global demand for octopus grows, especially in affluent markets, so have efforts to farm them. We believe that octopuses are particularly ill-suited to a life in captivity and mass-production, for reasons both ethical and ecological.”

Some 550 different aquatic animal species are currently raised in captivity in about 190 countries, accounting for as much as half of the seafood market in many industrialized countries. Spain is leading the charge to farm species like the common octopus, Octopus vulgaris, employing a variety of experimental aquaculture practices while the Spanish Institute of Oceanography carries out and publishes major research on octopus farming. Other farming and research projects are being pursued in Australia, Chile, Greece, Italy, Mexico, and Portugal. As many as eight different octopus species are now experimentally farmed in China, and the Japanese seafood company Nissui is reportedly expecting to bring a fully farmed octopus to market by 2020.

“We are all living during the rapid domestication of aquatic species and research is almost entirely around the question of which aquatic animals we can farm, rather than which animals we should farm,” Jennifer Jacquet, an assistant professor in the Department of Environmental Studies at New York University and the lead author of the article, said in a statement.

“Universities and companies are investing time and money into farming octopus, which we believe is a big mistake. Mass producing octopus would repeat many of the same mistakes we made on land in terms of high environmental and animal welfare impacts, and be in some ways worse because we have to feed octopus other animals.”

Aquaculture’s impacts on the environment are well known and include nitrogen and phosphorus pollution, released from feces and the decomposition of uneaten food, which contributes to oxygen depletion in ocean waters. Contamination from fertilizers, algaecides, herbicides, and disinfectants are also a concern, as are the excessive use of antibiotics and the loss of natural habitats, like mangrove swamps, that are used for farms.

But the biggest ecological impact of farming octopuses would derive from the fact that they are carnivorous animals who depend on fish protein and oil, according to Jacquet and her co-authors. Whereas most terrestrial animals we farm are herbivores, the majority of farmed aquatic species, such as salmon, trout, and shrimp, are carnivorous. That means that feeding aquatic animals raised in industrial farming operations puts additional pressure on wild fish and invertebrates for fishmeal.

“Around one-third of the global fish catch is turned into feed for other animals, roughly half of which goes to aquaculture,” the authors write. “Many fishmeal fisheries are subject to overfishing and are declining,” and octopus farming would greatly exacerbate that problem.

“Octopuses have a food conversion rate of at least 3:1, meaning that the weight of feed necessary to sustain them is about three times the weight of the animal. Given the depleted state of global fisheries and the challenges of providing adequate nutrition to a growing human population, increased farming of carnivorous species such as octopus will act counter to the goal of improving global food security.”

But even if a sustainable diet for captive octopus could be found, farming the cephalopods would still be unethical, Jacquet and colleagues argue. The 2012 Cambridge Declaration on Consciousness, the first formal documentation of the scientific consensus around the consciousness of non-mammal species, cited octopuses as the sole invertebrate capable of conscious experience. Experimental work has confirmed that octopuses are curious creatures who like to explore their surroundings. And octopuses are not only capable of problem-solving, but retain long-term memories of how to perform tasks: “One study found that octopuses retained knowledge of how to open a screw-top jar for at least five months. They are also capable of mastering complex aquascapes, conducting extensive foraging trips, and using visual landmarks to navigate.”

All of which means that octopus are poorly suited to being raised in captivity. Little research has been done on how octopuses fare in farmed settings, but “existing evidence suggests intensive farming systems are likely to be associated with high mortality rates and increased aggression, parasitic infection, and a host of digestive tract issues. Beyond their basic biological health and safety, octopuses are likely to want high levels of cognitive stimulation, as well as opportunities to explore, manipulate, and control their environment. Intensive farm systems are inevitably hostile to these attributes.”

Beyond the ecological and ethical challenges octopus farming poses, Jacquet and colleagues question whether it is even necessary to the future of humanity’s food needs. The main markets for farmed octopus are upscale outlets in Australia, China, Japan, northern Mediterranean countries, South Korea, and the U.S., all regions that are largely food secure, meaning that all people have sufficient access to safe and nutritious food.

“As consumers become increasingly concerned about animal welfare and sustainability, the case against octopus farming should only become stronger,” the researchers write. “If society decides we cannot farm octopus, it will mean relatively few people can continue to eat them. But it does not mean that food security will be undermined; it will mean only that affluent consumers will pay more for increasingly scarce, wild octopus.”

Octopus farming is currently constrained by the available technology, but we may eventually develop the ability to farm octopus at an industrial scale. “If such an opportunity comes, we hope that the serious welfare and environmental problems associated with such projects are recognized, and octopus farming is discouraged or prevented,” Jacquet and colleagues say. “There are better directions for the future of farming.”

CITATION

• Jacquet, J., Franks, B., Godfrey-Smith, P., & Sánchez-Suárez, W. (2019). The Case Against Octopus Farming. Issues in Science and Technology 35(2): 37–44.