In a very large sense, this is no laughing matter. It turns out that there are unsafe levels of mercury in tuna. [1] Again. This was a problem in the 70s and sadly it is back. Mercury is a very bad thing to be poisened by.
Okay, now for the old joke. Did you hear that Ford is recalling the Mercury line of cars? Yea, it turns that they have unsafe levels of tuna in them.