Salmon farming, specifically in open-net ocean pens, has significant environmental and health impacts. These floating feedlots contribute to pollution by discharging waste, excess feed, chemicals, and parasites directly into the surrounding waters. This pollution can damage marine ecosystems and spread diseases to wild fish populations.

One study found that a single salmon farm with 200,000 fish produced fecal matter equivalent to a city of 65,000 people. This waste, along with excess feed and chemicals, contaminates the seabed and nearby marine life, turning the ocean floor toxic and depleting oxygen needed by other organisms. Another study in Scotland discovered a reduction in biodiversity up to 200 yards away from salmon cages, with other research indicating even wider impacts on marine life and wild salmon populations.

Escaped farmed salmon pose another threat to native fish populations. These non-native fish compete with wild salmon for habitat and food, and can interbreed to produce hybrid offspring too weak to survive. Millions of farmed fish escape each year, exacerbating this issue.

In addition to environmental concerns, farmed salmon can also pose health risks to consumers. Studies have shown that farmed salmon contains residues of pesticides and other chemicals, which can be harmful to humans, particularly fetuses and young children. The use of antibiotics in salmon farming is another concern, as it can contribute to antibiotic resistance in humans.

Despite these issues, salmon farming continues to grow as a global industry. To mitigate the negative impacts, it is crucial for governments, regulators, and consumers to demand more responsible practices and transparency in the production and labeling of farmed salmon.