Farmed Salmon Are Growing So Quickly They’re Going Deaf

Salmon bred and raised at fish factory farms are forced to grow at such an accelerated rate that more than half of them are going partially deaf, according to a study published in the Journal of Experimental Biology.

Led by the University of Melbourne, the study found that these intensively-farmed fish develop inner-ear deformities. Because the salmon grow unnaturally quickly, the otoliths, or tiny crystals, in their inner ears do not properly develop. Essential to detecting sound, normal otoliths are made of the mineral aragonite, but deformed otoliths are partly made of vaterite, which is lighter, larger, and less stable, according to the Daily Mail. These larger, more brittle otoliths result in impaired balance and hearing loss.

The deformity was first recorded in the 1960s, but this new study is the first to show that it affects more than 95 percent of fully-grown factory-farmed fish globally. The study included fish in Norway, Chile, Scotland, Canada, and Australia and found that the deformity was extremely common—but only in farmed fish. The study concluded that more than 50 percent of farmed salmon are at least partially deaf. The deformity is irreversible and only gets worse with age.

In an interview with, the study’s co-author, Dr. Tim Dempster, stated:
These results raise serious questions about the welfare of farmed fish. In many countries, farming practices must allow for the “Five Freedoms, which are freedom from hunger or thirst; freedom from discomfort; freedom from pain, injury, or disease; freedom to express (most) normal behaviour; and freedom from fear and distress. Producing animals with deformities violates two of these freedoms: the freedom from disease, and the freedom to express normal behaviour.
What’s worse is that going deaf is just one problem for factory-farmed salmon. A study by Royal Society Open Science found that many farmed salmon suffer from severe depression. Known as “drop outs, depressed salmon float lifelessly in filthy tanks.

In drop-out salmon, scientists measured significantly higher levels of the stress-response hormone cortisol and observed increased activity in the serotonergic system, a key regulator of sleep, respiration, and mood. Interestingly, studies of humans suffering from poverty and other socioeconomic hardships have revealed similar physiological changes.

Additionally, because factory farms are so filthy, they’re the perfect breeding grounds for parasites. Last year, an outbreak of sea lice occurred from Sweden to Norway to Chile. Now nearly half of Scotland’s salmon farms are infested with the parasite that feeds on the blood, skin, and slime of salmon.

To combat the parasites, farmers are decimating wild wrasse populations. 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.

Luckily, vegan seafood options are abundant and don’t contribute to the cruel commercial fishing industry that decimates wild fish populations; keeps fish in filthy, lice-infested conditions; and raises fish to suffer deformities.

Click here for some of our favorite vegan seafood recipes!