The exposé, by welfare organization Compassion in World Farming (CIWF), highlights how fish are often killed inhumanely and many suffer slow, painful deaths by asphyxiation, crushing or even being gutted alive.
CIWF says fish are sensitive, intelligent, emotional animals - who deserve to be treated humanely.
Suffering of fish
CIWF's footage shows what the charity describes as 'appalling welfare conditions' sea bass, sea bream and trout are being reared in. Live fish are often crammed into tanks alongside dead ones. The cramped conditions mean disease and parasites can thrive.
In addition, the investigation shows the 'shockingly inhumane' way fish are killed.
"Sea bass and sea bream are commonly dumped into large buckets of ice slurry, where they thrash about, fighting for their lives, as ice gets lodged in their gills and they struggle to breathe," says CIWF. They can remain conscious throughout this ordeal, and many are still alive when they are packaged up in Styrofoam boxes, ready to be sold."
This kind of suffering is illegal according to European law, which mandates animals should not suffer while being killed. These fish can be found on supermarket shelves across the continent.
The suffering of fish is often overlooked
"Currently, billions of fish are living lives of abject misery," Matt Mellen, Compassion's Fish Welfare Campaign Manager, said in a statement sent to Plant Based News.
"Fish farming does not have to be intensive, industrial, cruel and unsustainable. More humane fish farming can become a reality. If decisive action is taken now, we can once again have a thriving fishing industry.
"Consumers will be able to buy fish in confidence, knowing that reasonable levels of concern for animal welfare and environmental sustainability have been taken into account."
Vegan campaigners say the only way to eliminate suffering is to stop eating fish altogether. According to animal rights charity PETA: "Fish are smart, social animals with their own unique personalities, and just like dogs, cats, and humans, they feel pain.
"Scientists who study pain are in complete agreement that the fish pain response is basically identical to that of mammals and birds.
"No matter how they're raised or caught, eating fish supports cruelty to animals."
Compassion is now calling on the UK Government to ensure that we introduce laws in compliance with the EU Slaughter Directive. To support Compassion in World Farming’s campaign please visit rethink.fish