In 1914, the Empire of Japan occupied the Marshall Islands, and transferred German government properties to their own, including Bikar. Like the Germans before them, the Japanese colonial administration (the South Seas Mandate) did not attempt to exploit the atoll, and the Northern Radak Marshallese continued to hunt and fish unmolested. Following the end of World War II, the island came under the control of the United States as part of the Trust Territory of the Pacific Islands. In 1951, the U.S. Geological Survey and the Army Corps of Engineers sponsored an expedition to Bikar and Taongi Atolls, to characterize their primeval environment.