The mighty bluefin: Are rumors of its death at least slightly exaggerated? "Nations free to fish bluefin tuna to extinction," thundered Tom Laskawy's headline on Grist. On the Politics of the Plate blog, Barry Estabrook's title was more concise: "Bye-bye bluefin."  They were reacting to the decision by the Convention on International Trade in Endangered Species (CITES) not to ban trade in Atlantic bluefin tuna, a highly overfished species prized in Japan. Slow down, everyone: don't go into mourning for this iconic fish just yet. Even if the CITES ban had been approved, we can't be certain the situation was …