-17- RESULTS AND DISCUSSION Plankton Tables 3 and 4 give the plankton data from 1954 to 1958, including the values from which Table 12 of UWFL-43 (1955) dividual plate values was compiled. In- appear in order to show the degree of variability, and for 1954-1955, to permit comparison of coarse- and fine-meshed net samples. Radioactivity is expressed per unit weight of both wet plankton and planktonic ash in order to assess the relative suitability of these two bases of reporting results. Levels of radioactivity were equally high in coarse- and in finemeshed nets. The equality prevailed on either a wet weight or ash weight basis among the ten pairs of simultaneous tows with coarse- and fine-meshed nets listed in Table 3. The higher value of the pair was from a coarse-meshed net five times and from a fine-meshed net five times on the ash weight basis, and the same was true on the wet weight basis. In only half of the cases was the specific activity higher for a certain mesh size on both the ash and the wet basis. vation indicates a randomness, The above obser- or in other words, a lack of correlation between mesh size and specific activity. In the Laboratory's earlier reports (AECD-3446:103; WT-616:29; UWFL-42:31; UWFL-43:47; UWFL-46:9; UWFL-47:11), beta radioactivity