Fish Farming Is So Filthy Salmon Are Getting Lice

Last year, wholesale salmon prices rose by 50 percent due to an outbreak of sea lice from Sweden to Norway and Chile, according to The Guardian.

A sea louse, or common salmon louse, is a parasite that feeds on the blood, skin, and slime of salmon. Sea lice killed thousands of tons of farmed fish in 2016 and caused skin lesions and secondary infections in millions more fish. Now the parasites infest nearly half of Scotland’s salmon farms.

Sea lice are more prevalent in farmed salmon, and the confined spaces of factory farms are the perfect breeding grounds for the parasites. Warmer waters brought on by climate change also add to the spread of sea lice, a study suggests.

To combat the growing epidemic of sea lice, salmon factory farms are importing tons of wild-caught wrasse fish and introducing them to the farmed salmon. “Cleaner” fish, wrasse consume parasites and are used instead of chemicals to combat lice infestations. The importation of these fish for parasite control wreaks havoc on natural populations.

The Guardian reports:

“We are very worried that a large local fishery has developed rapidly over the past couple of years—with large numbers of wrasse being taken from local waters—without proper management or any indication of its sustainability,” said Samuel Stone, of the Marine Conservation Society. “It is a real concern.”

Annual wrasse catches from Norwegian fishing crews have risen from fewer than 2 million in 2008 to 22 million in less than a decade, according to New Scientist. These population depletions will have an unforeseeable effect on the marine ecosystem. Even worse, the fish are killed and discarded after their lice-eating duty is done.

While farming wrasse has been proposed, this solution would be inhumane for many other reasons. Factory-farmed fish endure crowded waste-filled pools and lives of misery. A study published in 2016 noted that factory-farmed salmon become “so depressed they give up on life.”

Watch this Mercy For Animals investigation at a fish slaughter facility.



Keeping fish off your plate is the best way to protect marine ecosystems and end support of a cruel industry.

To get started, try these vegan seafood recipes.