They're not gutted or salted first — just hung whole on outdoor racks and left to the Arctic wind for days, which does the preserving that salt or a smokehouse would do everywhere else.
Ammassat are small capelin, caught by the netful when they swarm the coast each summer, then hung whole on wooden racks to wind-dry in the open air. Eaten by hand, bones and all, they're a grab-and-go snack sold at Nuuk's open-air market and kept stockpiled through the winter.