Dr. John N, wolfe 4 April 19, Marshall Islande between May and July, 1954. 1963 When a similar United States survey was conducted early in 1955 aboard the U. &. Coast Guard cutter, Roger8. Laney, the Laboratory participated in the organization of the cruise and was represented on the scientific team. 1956 1957 OperationRedwing: At the request of the Commission, the Laboratory organized and conducted surveys of the ocean during and after the nuclear test series of 1956. These surveys, made aboard the U.8.8. Walton and the U.S. S. Marsh, were activities beyond the Laboratory's normal studies and represented the first occasion in which the United States attempted to document the levels of radioactivity placed in the Ocean by nuclear tests. ela a ¢ After 1954, the Laboratory had been continuingly involved in the assesament of the Rongelap contamination. The Laboratory conducted the assesaments on which it was determined that Rongelap was safe for a resumption of human habita- tion, and members of the staff were among the consultants involved in the preparation of Rongelap for the return of the native population. 1958 OperationHardtack: The depth of the Laboratory's emergency experience at Rongelap suggested that studicse of the atoll be continued as a formal program providing, for the first time in hiatory, a complete documentation of the biological developments at a place subjected only one time to a heavy, but sublethal, dose of radioactivity. Such a program was organized early in 1958, but meantime the Laboratory was asked by the Commission to conduct new ocean surveys in connection with the 1958 nuclear test series, Operation Hardtack. It was on certification by the Laboratory,in August, 1958, that contamination was at minimum levels that Joint Task Force Seven ordered the disestablishment of the proving ground danger area and brought to a close the nuclear tests in the Marehalle.