The first of the two surveys was operating at sea, June 11-21, 1956, during the weapons testing program. of this survey are summarized itn UWFL-46 3 . The results The summary of this report states: A survey to determine the amount of radioactivity in the waters about Bikini and Eniwetok Atolls was made during the period June 1] to 21, 1956. A grid of stations about 45 miles apart covering 78,000 gquere miles of ocean between 10” and 159° 15' N to 14° n to 1667 E was ccvered by the survey. tance traveled was 3.399 miles. The dis- Radioective matertals were found in the plankton samples from every station. The highest plankton counts, 1,100,090 d/m/g (wet weight) were obtained near Bikini Atoll, and the lowest, 1,300 d/m/g, in the northwestern part of the survey area, The average value for plankton was 71,000 d/n/g which was 7,100 times the average surface water value. Water samples were collected at surface and at depths of 25, 50, 75 and 100 meters. The average radioactivity of water was 10,000 d/m/l at the surface and 3,900 d/m/l at 100 meters. The second survey of the 1956 series was conducted during September, about six weeks after the termination of the weapons teating program, during which time decay and dispersion of the radioactivity had taken place. As U. &. Navy assigned a naval vessel, in the first survey, the in this case the USS Marsh (Destroyer Escort 699), to be used as the survey ship. This