How dangerous are Beluga whales?
Beluga whales are at the top of the food chain. A nice distinction, however, it also means they acquire the sum total of toxins in the organisms in that chain. Since PCBs and heavy metals don’t break down in any organism they accumulate instead. So when a Beluga eats a salmon that ate a crustacean that grubbed on some plant, all the PCBs and heavy metals that these organisms absorbed end up in the beluga. Belugas, in fact, are so full of contaminants, when they are found beached they qualify as a toxic biohazard.
