Independent of consensus on the threshold concentration for Mercury poisoning, What I explicitly stated is that sardines contain lower levels than tuna, which IS correct. By definition of them being a smaller fish with a shorter lifespan, less heavy metals and pollutants of ANY variety will have accumulated within them.
Also for environmental sustainability if we examine the Seafood Watch's website, we notice both farmed Oysters and Pacific Sardines on the Super Green List in the Best of the Best category http://www.montereybayaquarium.org/cr/cr_seafoodwatch/sfw_he... [ Further examination: On sardine page, only choice is "best choice". For tuna, everything is generally "avoid" unless it is "trole or pole" caught. ]
Also for environmental sustainability if we examine the Seafood Watch's website, we notice both farmed Oysters and Pacific Sardines on the Super Green List in the Best of the Best category http://www.montereybayaquarium.org/cr/cr_seafoodwatch/sfw_he... [ Further examination: On sardine page, only choice is "best choice". For tuna, everything is generally "avoid" unless it is "trole or pole" caught. ]
I object to the notions sardines taste fundamentally bad, I think Alton Brown's Avocado-Sardine sandwich was one of his few works of genius: http://www.seriouseats.com/2010/01/alton-browns-sardine-avoc...