Fish raised on farms might get thyroid tumors over time if their food lacks important nutrients, and we've seen signs of this in jade perch that were fed a poor diet.

Farmed jade perch are getting tumors in their thyroid because their food is missing important nutrients like iodine and vitamin C — scientists found this by checking the fish tissues and their feed.

If jade perch on fish farms are fed homemade food that's really low in iodine and vitamin C, they might end up with thyroid problems — and this was seen in real farm conditions by checking the food and the fish's tissues.