The Phantom of the High Arctic Deep within the fractured, shifting labyrinths of the Arctic sea ice, the narwhal ( Monodon monoceros ) remains one of the ocean's most enigmatic residents. Often referred to as the 'unicorn of the sea,' this medium-sized toothed whale has long been defined by its iconic spiral tusk. However, recent acoustic monitoring studies conducted in the remote fjords of East Greenland have unveiled a far more sophisticated reality: the narwhal is a master of acoustic navigation in one of the planet's most inhospitable environments. Researchers utilizing advanced hydrophone arrays have discovered that narwhals do not merely use sound to locate prey; they employ a highly refined, multi-stage echolocation system to map the underside of moving ice floes. This behavioral adaptation...