The bluefin tuna, a giant of a saltwater fish that’s prized for its sushi-quality flesh, has been plummeting in numbers worldwide since the 1950s. So why is that bastion of all that is holy environmentally, The National Geographic Society, associating its name with a reality TV show that all but glamorizes the catching of bluefin? Is it to raise awareness about a critical conservation issue? Or is something else at play?