First, the title is ambiguous. Most readers will think it means that all fish *located* in the US are laced with mercury. They will understand after they read the article, but it will make the site look bad.

Second, the cartoon was in very poor taste. It wasn’t a funny attempt at humor to begin with, and this is a serious topic. Feeding poisoned fish to our family’s isn’t funny, and you’re making light of it. I still can’t figure it out. The reader is likely going to be confused why a salt water fish will poison fresh water fish to get people to eat his kind.

And lastly, you seriously need to do some better editing: “It attacks especially the nervous systems of fetuses and children, but it’s effects are considerable on humans too.” It’s a rather offensive mistake to imply that children aren’t humans, and our fetuses aren’t exactly a different species either.