squid were also radioactive the day after this underwater test. Data of radioactivity in plankton and water were also taken following the At about the end of the Unbrella test underwater in the Eniwetok lagoon. Ilardtack test series, two other ships, the Collett and Silverstein started a local-area survey and a cruise to Guam, respectively (Hines, 1962, p. 285). Plankton radioactivity was as high as 39,000 d/min+g as found 110 miles northeast of Guam on 7 September. Land-Based Earlier Surveys As seen by the above summary, expeditions wére made to one or both of the Eniwetok and Bikini Atolls in 1947, 1948, 1949, 1951, 1952, 1954, 1955, 1956, and 1958 to study biological effects of the detonations. However, these were primarily to study marine effects. Thus relatively less was done in these sea-based studies in following the residual radioactivity on land and in plants and animals, although some of these expeditions did make land observations. Of course, during each test operation extensive measurements of fallout radioactivity and instantaneous radioactivity were made at the time of each test and generally for the months involved in the duration of the test series. Studies were made on Bell (Bogombogo) Island in 1954 following the 13 March 1954 Nectar test during Operation Castle. This was a barge test located over the Mike crater 2.3 miles to the northeast of this island. The external radiation was found to decrease from 1000 mR/hr on 15 May 1954 two days after the test to 1 mR/hr on 21 March 1955 almost one year after the test. Essentially all the damage to land plants could be attributed to heat and blast, although possibly some could be attributed to radiation s effects (Palumbo, 1962). Observations were made of land hermit crabs, 21