A salmon underwater, looking at the camera, with fellow fish in the background.

Salmon farms take wild fish from the oceans to feed their fish.

Farming fish does not mean leaving the oceans untouched – in fact, fish farms rely on wild-caught fish for feed.

Animals Australia

Animals Australia team

Last updated April 13, 2023

Salmon is a carnivorous species, so each year, millions of wild fish are caught and killed to feed salmon trapped in underwater factory farms.

Like most animals bred to be killed for their meat, salmon in farms eat more food than they produce ‘for humans’. According to the 2022 report of fish farm giant Tassal, producing 48kg of farmed salmon requires 100kg of feed – feed that is made up of other fish (fishmeal and fish oil), and land-based foods fish wouldn’t naturally eat such as soy, wheat and canola.

Using wild fish to feed farmed fish contributes to the depletion of forage fish populations in the wild, which are critical food sources for other marine animals. In search of food, hungry animals naturally approach these fish farms – like protected seals who are ‘deterred’ by the industry with lead-filled projectiles (bean bags), explosive charges, and sedation darts which can result in injury or even death.

This image contains content which some may find confronting

Large number of tuna fishes caught in fishing nets
The fishing industry pulls fish from the oceans in incomprehensible numbers – taking vital food sources away from other marine animals like seals and dolphins in order to meet consumer demand for fish, including 'farmed fish'.
Image credit: Greenpeace

For farmed tuna, the amount of feed required is even more concerning. Research suggests that for the Southern Bluefin tuna, confined in “sea cages” off the coast of South Australia, it can take between 10 and 20 kgs of wild-caught fish to produce just 1 kg of tuna. What’s more, commercial tuna farms around the world rely on the capture of young tuna from the wild, which are then ‘fattened up’ in pens. Southern Bluefin Tuna have been classified as ‘critically endangered’, with populations down to an estimated 5% of their original numbers. Yet fishing continues.

Fish in farms live an unnatural life

The ecological impacts are not the only reason we should be concerned about fish farms. Just like animals in factory farms on land, fish in fish farms live a cramped and stressful life.  Research on salmon in farms found that 1 in 4 experience brain chemistry and behaviour identical to that of severely depressed people, and can be seen floating lifelessly at the surface.

On top of the psychological stress, the crowded environments are also a risk to the physical health of these fish, too. Disease is common and can spread rapidly in the overcrowded conditions. Instead of giving fish more space, many farms instead feed them antibiotics, which the World Health Organisation has warned is contributing to the threat of antibiotic resistance in humans (ie. ‘superbugs’).

Tassal recently made headlines trying to prevent the release of a report on its antibiotic use. Despite calls to shift away from antibiotics and instead use vaccination,  the report revealed that in January 2022 alone, Tassal used 600kgs of antibiotics at just one marine farm site. Concerningly, wild fish caught near these fish farms have been found with  ‘elevated antibiotic levels’.

What are the issues with wild-caught fish?

There are several animal welfare concerns and environmental issues with the wild-caught fishing industry too. Firstly, sea animals have the ability to feel pain and each individual suffers greatly when dragged from their ocean home – they can be crushed to death with the weight of their fellow animals in the net, or suffocate slowly once they are out of the water.

With the use of indiscriminate fishing trawlers and enormous nets, it’s not just these ‘targeted’ fish who are suffering. All kinds of marine life, including seals, sharks, rays and dolphins, are caught in fishing nets. If they survive being pulled onto the ship, they may be thrown back into the sea, injured or dying.

Globally, industrialised fishing is impacting wild fish populations, destroying food sources for marine predators and damaging the intricate ecosystems that we still know so little about.

This image contains content which some may find confronting

A school of sardine fish swimming closely together in very blue water.
Fish feel pain, yet we allow them to endure treatment we'd never permit for land-dwelling animals. When pulled from the ocean in giant nets, fish can be crushed by the weight or slowly suffocate to death.

What is the most sustainable option?

The good news is that there is a way to enjoy nutritious and delicious food while helping to spare marine animals and their natural environment! By filling our plates with more plants – and leaving sea animals in the sea – we can shift demand to alternatives that are kinder to animals and the planet.

A plant-rich diet can provide all the nutrients your body needs to thrive, including omega-3. If you are ready to get cooking, check out these 10 mouth-watering sea-inspired dishes that are kind to fish here.

Keen to find out more about eating kindly? Order your free Veg Starter Kit here, or head straight to VegKit.com to browse our collection of 100+ tasty plant-based recipes!


The most powerful thing we can do to protect fish, seals, whales and other sea animals, is to leave sea life off our plates. It’s also important to note that animals consuming more food than they produce isn’t just an issue with the farmed fish industry. Farmed land animals consume 2-20kg of feed for every 1kg of ‘meat’ they produce for human consumption.

Watch the video below to learn more about our current food system, and why it’s time to shape the kinder future for our planet that we all dream of: