Wild-caught fishing uses huge nets, longlines with thousands of hooks or trawlers—industrial boats that drag heavy nets across the ocean. This is where most fish come from globally.
But nets and longlines don’t just catch fish. Turtles, dolphins, sharks, rays and seabirds are all killed as ‘bycatch’. Discarded ‘ghost nets’ drift for decades, silently trapping animals. In 2024, a humpback whale was found off Victoria’s coast tangled in 800 kg of fishing gear.
Fish farming isn’t the ‘ocean-friendly’ alternative it’s marketed as. Salmon and tuna are the main farmed species in Australia. These farms rely heavily on wild-caught fish for feed: sardines and anchovies are scooped from the sea to feed animals in cages. And just like land-based factory farming, they consume more than they produce. Tassal, Australia’s largest salmon farmer, uses 100 kg of feed to produce only 48 kg of salmon. For tuna, it can take up to 20 kg of wild fish for just 1 kg of tuna.
Farms also damage ecosystems. Hungry seals, dolphins and seabirds are shot at or injured when they come too close. Waste and faeces pollute the ocean floor, while diseases spread to wild populations.
Fish are intelligent, social and capable of feeling pain. They can even recognise themselves in mirrors—a test of self-awareness that humans don’t pass until age two.
On farms, they’re treated like underwater factory-farmed animals: crammed into tanks, swimming in circles and plagued by disease. Studies suggest up to 1 in 4 farmed fish suffer from severe depression, floating lifelessly before dying. Amoebic gill disease, common in Australian farms, destroys their ability to breathe, causing slow, painful deaths.
For wild-caught fish, the suffering is just as grim. Many die from suffocation, crushing or injuries after being dragged from the depths.
Fish are often marketed as a health food, but the reality is murkier. Pollutants like mercury and microplastics build up in their bodies—and then in ours. One study found that 84% of the world’s fish contain unsafe levels of mercury. These toxins accumulate in our bodies, damaging the brain, liver and immune function.
Like land-based factory farms, fish farms rely on antibiotics to control disease in overcrowded conditions. In Tasmania, Tassal used 600 kg of antibiotics at just one farm in a single month. This overuse contributes to the growing threat of antibiotic resistance.
