Complex sentence: The Melbourne Cricket Ground was decorated with creatures to represent the participating countries; the Isle of Man's creature is a basking shark, owing to the high number of sightings of the species in Manx waters.
Split into simpler sentences: The Melbourne Cricket Ground has been decorated with creatures to represent the participating countries. The Isle of Man's creature is a basking shark, owing to the high number of sightings of the species in Manx waters.