AECD -2446 not always, more radioactive than hurd parts, F:ankton-feeders were on the average significantly more radioactive than non-plankto:-feeders with the notable exception of corals which were low. From the thirty-five species of algae that were identified and their habitats noted, 129 samples were ashed and counted. Average d/m/g ranged irom as low as 3 at control areas through 64, for Bikini Target Area, and up to 1700 from near the Shct Islands of Eriwetck. to be more radioactive than calcareous forms. Succulent forms tended Values for 1949 were approxi- mately one-half as great as they had been in 1948 at the same localities, Activity of plankton samples from areas other than tre Bikini Target Azea and the Eniwetok Shot Islands averaged no greater than the average of nd the Likiep plankton samples which was about 50 d/m/g. Since the Likiep samples were collected after those from Bikini and Eniwetok, speck contamination in nets or pump might possibly account for the relatively high count of the Likiep samples. Compared to Likiep, the radioactivity of plank- ton samples from the Bikini Target Area was three times greater and from the Eniwetok Shot Islands, eight times greater, from catches in fine-meshed nets. Samples of highest activity were From comparable active areas, the 1949 counts were about one-half those of 1948. Alpha activity of three-liter water samples was not significantiy greater than Santa Monica Bay water and was less than laboratory tap water. Areas adjacent to collecting stations were monitored with beta -gamma survey instruments. At Likiep counts of sand averaged 21 per minute and of vegetation 27 per minute. At Bikini the values were one to three times those at Likiep with the exception of drift items from the target fleet that counted up to 100,000 c/m. On the Eniwetok Shot Islands, activity was greater than 100,000 c/m in limited areas. Peaks of activity were found at the bombsite and in the three-hundred-yard area, and from there on decreased rapidly. Seven specimensof birds including three species of terns were dissected and the organs and tissues ashed. The d/m/g of bird tissue, in most cases, was zero, with only one gut sample giving a count as high as 5.1.