Black cod are a deep-sea fish that range from southern California to northern Alaska, although the majority of the harvest comes from up north. They are caught by means of trawls and longlines in depths of 300 to 1,200 ft and can grow to as much as 30 lbs or more, although dressed fish typically weigh between 5 and 10 lbs. They have an extremely high fat content, up to 20%, and are one of the seafoods highest in omega-3 fatty acids. Black cod are considered a delicacy in many countries for its sweet, rich, buttery taste and its flaky texture.
The US Food and Drug Administration puts sablefish in the "Good Choices" category in their guide for pregnant women and parents, and recommends one 4-ounce serving a week for an adult, less for children. On the other hand, the Alaska epidemiology section considers Alaska sablefish to be "low in mercury" and advises "unrestricted consumption" of sablefish for all populations.