Complex sentence: Most entrapment events occur in narwhal wintering areas such as Disko Bay and the largest entrapment event occurred in 1915 in West Greenland where over 1,000 narwhals were trapped under the ice.
Split into simpler sentences: Most entrapment events occur in narwhal wintering areas such as Disko Bay. In the largest entrapment event in 1915 in West Greenland, over 1,000 narwhals were trapped under the ice.