A colossal iceberg has detached from the Antarctic coastline, exposing an enormous and unexpected natural formation beneath its frozen base — a sprawling mega-nest believed to have been constructed by an immense colony of fish. The iceberg’s separation, while part of a recurring natural cycle, has drawn global attention for the remarkable ecological discovery that followed. Scientists studying satellite imagery and on-site data have described the find as one of the largest known breeding grounds beneath the Southern Ocean’s ice shelves.