Ice pancakes, anyone?
Video shared by the Ness District Salmon Fishery Board (NDSFB) shows the phenomenon called "ice pancakes" as they floated on the upper Ness catchment which is near Inverness, NDFSB said.
The phenomenon is relatively rare and occurs in very cold lakes and oceans, most frequently in the Baltic Sea and Antarctica, according to the Met Office official website.
Ice pancakes can form in two different ways, first by waves causing pieces of ice to knock against each other, which rounds their edges.
They are also believed to form when a river's foam starts to freeze as they are sucked into a swirling water current and form into a circular shape, Met Office said.
