PiggyB: My gynae warned me against tuna, exceptionally canned tuna.
Looking at hq's list, it looks like some canned tuna are very high in mercury, some are just high while some may not be high (last one guess one)? I guess as laypeople, it may be confusing to differentiate which are high and which are less high, so he had simply banned me from tuna, especially canned tuna.
He did tell me to just eat a variety of fish (except tuna) don't just focus on eating one category.