The Environmental and Social Impacts of Fish Farming and Industrial Aquaculture
Salmon aquaculture close to Klaksvík, Faroe Islands. Photo: Ekrem Canli. CC BY-SA 4.0
Fish farming, a form of aquaculture, is now the fastest-growing form of factory farming worldwide. This rapid expansion can be attributed to the industry’s emphasis on buzzwords such as “climate,” “conservation,” and “sustainability.” While discussions about land-based farmed animals, such as cattle, pigs, and poultry, are dominated by their impact on emissions and the environment, aquaculture has been positioned as a sustainable alternative, allowing it to quietly transform coastlines into industrial zones while affecting marine ecosystems and communities in ways that are often invisible to the public. Addressing the flaws of fish farming is crucial to preventing the entrenchment of a global industrial system in oceans and climate agendas.
Industrial fish farms, particularly open-net salmon pens, concentrate thousands of animals in confined spaces, producing waste and requiring significant inputs of feed, antibiotics, and chemicals to maintain productivity. While these systems are promoted as a solution to unsustainable industrial fishing, the reality is far more complex. The expansion of industrial aquaculture comes at ecological, social, and climate costs that are often overlooked when evaluating its benefits.
Why Fish Matter
Fish are essential to healthy ocean ecosystems, but almost 90 percent of the world’s fisheries are considered “fully exploited” or “overfished” by the United Nations, and many species are in rapid decline due to industrial fishing and aquaculture. Research increasingly shows that fish are sentient and capable of learning, problem-solving, and exhibiting complex behaviors. Cleaner wrasse, a small reef-dwelling species, have passed a version of the mirror test, a classic indicator of self-recognition. Tuskfish have been observed using rocks as tools to open clams. Salmon can respond to pharmaceuticals in water, demonstrating behavioral complexity and sentience.
Caring about fish means safeguarding ocean ecosystems, maintaining biodiversity, and protecting the planet’s climate and ecological stability for future generations.
The Myth of Relieving Pressure on Wild Fish
One of the most common misconceptions about aquaculture is that it reduces pressure on wild fish populations. In reality, fish farming often entrenches it. Many farmed species considered high-value in rich countries, such as Atlantic salmon, require large amounts of wild-caught fish for their feed. This includes small pelagic fish such as sardines, anchovies, and menhaden, which are critical sources of protein for local communities in regions like West Africa and South America.
Norway’s salmon industry is an example of how fish farms are exacerbating food insecurity in poor countries where people are already experiencing high rates of hunger. Research by Foodrise (previously known as Feedback Global) shows that “in 2020, nearly 2 million tonnes of wild fish were required to produce the fish oil supplied to the Norwegian farmed salmon industry, and that throughout this feeding process, one-quarter of the wild fish ground up is lost. Furthermore, the amount of fish sourced off the West African coast… to supply fish oil to the Norwegian salmon farming industry in 2020 could have provided between 2.5 million and 4 million people in the region with a year’s supply of fish.”
According to the Food and Agriculture Organization of the United Nations (FAO), while aquaculture production “surpassed” capture fisheries in 2022, this was because capture fisheries have reached their ecological limits, and not because aquaculture is displacing the extraction of wild fish. Instead, aquaculture creates additional demand for them. Research published in Science Advances in 2024 found that millions of tons of wild fish are caught each year to feed farmed species, showing their heavy dependence on wild fisheries. This undermines claims that fish farming conserves marine ecosystems.
Moreover, referring to the FAO report, a Mongabay article highlighted how, despite the surge in aquaculture production, overfishing remains a big issue, which is “worsening” over time. “[M]ore fish are being harvested at an unsustainable rate, which can reduce future productivity. For communities reliant on fishing, stock collapses can be devastating. Overfishing is also a concern for the wild marine environment as it is one of the major causes of the loss of ocean biodiversity,” stated the article.
Industrial aquaculture has long used greenwashing tactics to present itself as a conservation-friendly enterprise. Marketing and lobbying efforts falsely present fish farms as solutions to overfishing, yet the primary motive has always been profit. This gap between narrative and reality contributes to public misunderstanding about the environmental impacts of aquaculture.
Impacts on Global Food Security
Aquaculture is frequently framed as a means of feeding a growing global population. Yet producing fish for human consumption is highly inefficient. Many of the most widely farmed and consumed species in high-income countries, such as salmon, are carnivorous and require feed derived from other fish or plant-based inputs. This means that producing one kilogram of edible fish can require multiple kilograms of feed. The inefficiency mirrors criticisms of terrestrial factory farms, where energy is lost at each step up the food chain, reducing the overall yield available for human consumption. Research has found that across multiple farmed aquatic species, only about 19 percent of the protein and 10 percent of the calories in feed inputs are ultimately retained for human consumption. While these retention rates are comparable to those of farmed terrestrial animals, they remain far lower than those of plant-based food systems, underscoring the inefficiency of feed-intensive animal production.
The diversion of resources from food-insecure regions in West Africa, South America, and Southeast Asia, not to feed local populations but to serve as feed for high-value species exported to wealthier countries, has been described as a form of “food colonialism.”
By contrast, plant-based proteins offer a far more efficient, just, and sustainable way to feed the world. Reducing reliance on industrially farmed fish could lessen pressure on wild fish populations and make global food systems more equitable.
Fish Farming and Overconsumption
Rather than addressing hunger, industrial aquaculture has historically stimulated consumption in wealthy markets. Since the 1960s, global per-capita consumption of aquatic animal foods has more than doubled, rising from about 9 kilograms per person in 1961 to more than 20 kilograms in 2022, increasing at nearly twice the rate of population growth, according to the FAO. This surge has been driven by marketing campaigns more than necessity, and has led to sea animal products, such as salmon and shrimp, being rebranded from luxuries to everyday staples.
By flooding the market with inexpensive farmed seafood, the industry has entrenched overconsumption. This demand, in turn, perpetuates pressure on wild fish to supply feed, creating a cycle that undermines both ecological sustainability and global food equity.
Effects on Small-Scale and Indigenous Communities
Industrial aquaculture often imposes severe environmental and social costs on small-scale and Indigenous fishing communities. Open-net salmon farms release waste, chemicals, and disease into shared waters, compromising the health of wild species and traditional fishing grounds.
In British Columbia, Canada, the Union of British Columbia Indian Chiefs has called for a “zero tolerance” approach to fish farms, citing threats to wild salmon and marine ecosystems. Similarly, a coalition of First Nations leaders in the province has repeatedly demanded the end of open-net salmon farming.
In Chile, the 2016 “red tide” crisis—a harmful algal bloom that devastated coastal fish populations—was exacerbated by the dumping of thousands of tons of dead salmon by aquaculture operations, which added nutrient loads to the water and intensified the die-offs.
Chile is the second-largest salmon producer in the world, and as the industry grows, it has led to devastating environmental, social, and cultural impacts for the local and Indigenous communities whose lands have been polluted in the process. Dozens of divers have died working on salmoneras(salmon farming facilities), with a 2024 report by a United Nations special rapporteur stating that “salmoneras are ‘one of the main threats to the environment in Patagonia,’ warning that the large amounts of chemicals and pesticides they use are damaging the marine ecosystem, creating vast ‘dead zones’ in the Patagonian sea.”
The Indigenous communities have been fighting to protect their lands and have been facing an uphill battle to prevent further damage to their sacred spaces. “It is not just pollution: it is cultural interference, the destruction of memory that salmon companies are carrying out,” Leticia Caro, leader of a nomadic Kawésqar community, told Open Democracy.
Reducing demand for farmed fish can help protect coastal ecosystems while supporting the rights, livelihoods, and cultural traditions of these communities.
Climate and Environmental Impacts
Despite marketing as “climate-smart” proteins, many farmed fish emit greenhouse gases comparable to, or exceeding, those of pork and chicken. Life cycle assessments show that farmed salmon’s emissions profile is in a similar range as pork, depending on feed and production practices, while farmed shrimp ranks among the most greenhouse gas-intensive aquatic animal products due to energy use and inefficient feed conversion. The bulk of emissions comes from feed production, which for salmon accounts for around three-quarters of total emissions. Meanwhile, shrimp farming adds energy-intensive aeration and pumping, further increasing its carbon burden.
Animal aquaculture also contributes to the destruction of critical carbon sinks. Small pelagic fish harvested for feed play a vital role in sequestering carbon in deep oceans. Soy production for fish feeddrives deforestation of carbon-rich rainforests, and shrimp farming has been a leading cause of mangrove destruction, which can capture four times as much carbon per capita as the Amazon. These impacts reduce the planet’s capacity to store carbon and exacerbate climate change.
Structural Limitations and Design Flaws in Seafood Certification Systems
Eco-certifications and sustainability labels are widely used to market aquacultural products to consumers, but their governance structures raise fundamental questions about independence and accountability. Leading schemes have been developed in close partnership with industry trade associations, and standard-setting bodies generate revenue from certification activities. This arrangement creates financial incentives to maintain standards that are acceptable to major producers. For example, major certification schemes allow the use of medically important antibiotics, place no limits on mortality, and permit open-net pens to discharge hazardous waste into the environment.
Enforcement is often limited, with many farms not being audited by a third party annually. Even audited farms fall short: a 2018 SeaChoice.org report found that only a small percentage of farms met the required standards, yet those that did not remained certified by the leading aquaculture certification body, the Aquaculture Stewardship Council. Meanwhile, the Outlaw Ocean Project foundevidence that shrimp certified under Best Aquaculture Practices (BAP) are associated with human rights abuses and the use of banned antibiotics. The Corporate Accountability Lab further documentedforced labor, child labor, and unsafe working conditions at BAP-certified Indian shrimp processing facilities.
Certifications garner consumer trust while concealing the realities of industrial farming, effectively functioning as a reputational buffer for an industry facing significant environmental and social criticism.
Health and Welfare Concerns
Crowded conditions in industrial fish pens foster parasites, disease, and frequent mass die-offs. Antibiotics and chemical treatments are widely used to maintain production, with antimicrobial use in aquaculture projected to increase significantly and, in some analyses, expected to exceed other food-animal sectors in intensity per kilogram of output by 2030. Many of these drugs are banned in marine animal products in the United States, yet regulators test only a small fraction of imports, allowing contaminated products to reach consumers. According to Food and Water Watch, “The FDA inspects only 2 percent of imported seafood; more than 5.3 billion pounds of seafood entered the U.S. food supply without even a cursory examination in 2015.”
Moreover, studies have found residues of prohibited antibiotics, such as nitrofurantoin, in shrimp sold in grocery stores. This widespread use—and limited oversight—contributes to the growing global threat of antimicrobial resistance.
Farmed marine animal products also pose direct risks to consumers. Shrimp has been linked to salmonella outbreaks, while listeria in smoked salmon has caused serious illness and deaths. Parasites such as sea lice can escape into wild populations, further threatening ecosystem health. While welfare reforms may improve conditions for farmed fish, they cannot address systemic problems like overconsumption, reliance on wild-caught feed, and environmental degradation.
Reducing Demand for Fish: An Upstream Approach
Sustainable alternatives in plant-based aquaculture include seaweed and kelp farming. These systems require no feed, freshwater, or antibiotics and can improve water quality, sequester carbon, and enhance biodiversity. By producing nutritious food without depleting wild fish stocks, plant-based aquaculture offers a scalable, ocean-friendly solution to aquatic animal products.
The most effective way to curb industrial aquaculture’s harms is to reduce overall sea animal consumption. Universities, corporations, and NGOs can play a pivotal role by adopting plant-forward menus, refusing to endorse weak certifications, and reducing the sale of fish and shrimp. These measures demonstrate leadership in climate and ocean protection, while also supporting global food equity.
Upstream interventions complement welfare improvements, helping to prevent billions of fish from being subjected to crowded, chemically intensive conditions in the first place.
Industrial fish farming is often marketed as a sustainable solution to overfishing and global hunger, yet it perpetuates ecological destruction, social inequities, and climate impacts. By addressing unsustainable fish consumption, supporting ecologically beneficial alternatives, holding the aquaculture industry and its certification systems accountable, and helping institutions shift toward more sustainable procurement, it is possible to chart a path toward a more resilient and equitable food system. Protecting oceans, supporting local and Indigenous communities, and reducing reliance on aquatic animal products are essential steps to ensure a healthy planet for both humans and the diverse marine life that sustains it.
This article was produced by Earth • Food • Life, a project of the Independent Media Institute. It is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License (CC BY-NC-SA 4.0).
