11 to The total correction factors to convert counts per minute aisintegrations per minute were 3.5 for plankton, 4.0 for water, and 3.3 for filter papers. Negative values are given wherever tne count was less than background. No correction was made for decay since the counting was done essentially immediately after collection tion. and the values given are as of the time of collec- Decay curves are shown in Figure 2. Gamma Rey Spectra. Gamma ray spectra were run at the Uni- versity of Washington laboratories in Seattle on a single channel, automatic advance, gamma spectrometer. The spectrometer consists of a Nuclear-Chicago Model 1810 radiation analyzer, a Nuclear-Chicago Model DS-3 scintillation well counter, a Tracer- lab Superscaler, 4 Nuclear-Chicago Model C-111 printing timer, and an automatic baseline advance device bullt at Seattle. Spectrum ranges of 0.5, 2.0, and 4.0 MEV were used. RESULTS OF SURVEY Plankton @ Th highest value of radioactivity in plankton, 21,000 d/m/g wet, was found at station 55 about 80 miles north of Eni- wetok and the lowest value, 27 d/m/g, was found immediately south of Guam. This lowest value was slightly lower than the value ob- tained near the same station during Operation Troll (39-61 d/m/g), indicéting that Guam was near the westernmost extremity of the radioactive contamination which resulted from Operation Redwing. A slight degree of contamination is indicated by comparison with Plankton samples from Puget Sound and off the Queen Charlotte