today we have the top six list of fish to avoid, due to contaminants and depleted supply:
Bluefin tuna is on the threatened species list, and they also have high levels of mercury and an Environmental Defense Fund (EDF) health alert.
Chilean sea bass has almost entirely vanished from the Antarctic waters, and the trawler and long lines used to catch them have damaged the ocean floor and other wildlife.
Groupers are vulnerable to overfishing and also contain high mercury levels and carry an EDF health advisory.
Monkfish habitats have been threatened by poor catching methods and are quite depleted.
Orange roughy is also vulnerable to overfishing due to its long life. Fish that live for a long time pose a higher mercury threat as well.
Farmed salmon is raised in an area with parasites and diseases, fed fishmeal, and given antibiotics to help with the diseases the farms create. They also contain high levels of PCB and have a health advisory from EDF.
Source: Eating Well