Table 2. STRONTIUM-90 IN SURFACE SEA-WATER (VALUES IN pe./l) Location and dates Ref, Artes “thal — 1 10 No. of samples analysed 250 miles off Oregon coast, January 1962 Christmas Island, January 1962 Atlantic Ocean and Carribbean Sea, 1956-60 Chukchi Sea, 1959-62 12 9 Range of values 1 0-04 6 0-03-0-2 60 0-031-0:30 7 0-095-0:27 Pacific and Indian Oceans, 1960-61 6°-40° N 25 0-1-0-9 0°-40° S 6 0-06-0-1 60° 5 (Antarctic) Western North Pacific Ocean, 1958-60 a 0-01--0-02 15 0-6-3-] samples collected at various times durimg the period indicated. The appearance of mixed fission products after September 1961 in the samples from the mouth of the Columbia River is the result of fall-out, presumably from the nuclear tests by the U.S.8.R. in October 1961. Chromium-51. produced in the Hanford reactors. was the most abundant radionuclide in the coastal waters near the mouth of the Columbia River, where it is of interest to the oceanographer as a tag of Columbia River water and sediments. Chromium-51 was neither expected nor detected by visual inspection of the y-spectra of the Christmas Island watcr samples. ‘The two values for strontium-90 from the single sample of sea-water from off the Oregon coast analysed by both the method of Miyako, Saruhashi and Katsuragi® and the modified Kawabata—-Held methed* deseribed here were 0-037 + 0-003 (95 per cent counting error) and 0-041 + 0-009 pe./l., respectively. The latter was the faster of the two methods and produced a sample of lesser mass. The reduction of mass was from several grams to a few milligrams. The values for strontium-90 in surface seawater from off the Oregon coast and from other areas round the world ranged from 0-01 to 3-1 pe./L and are presented m Table 2. This radionuclide seems to be ubiquitous in surface waters since no zcro values are given in these reports. Table 3. PHosyHorus-32 IX FILTERED SURFACE ShA-WATER FROM NEAR THE MOUTH OF THE COLUMBIA RIVER, JULY 1963 (VALUES IN pe./l. + S.D.) Salinity (parts per thousand} Stalion Miles fro ni mouth 63 3g 31-76 a9 2g 31-63 1 5-15 74 18 27-80 3 8-03 + 0-58 TD a 27-74 a 4-68 41-65 6 No. of, determinations 3 2p 3:57 + 0-60