You can have lingcod fish during pregnancy but moderation is the key. According to a report published by the Mercury Policy Project, lingcod is a fish with medium levels of mercury. It should, therefore, be eaten in a moderate amount. Having said that, it is fish rich in nutrients. It is an excellent source of protein, selenium, phosphorus, niacin, and Omega-3 fatty acids. These nutrients are essential for the growth and development of the unborn baby and the nourishment of the pregnant mother.