CHAPTER 4 INTERNAL CONTAMINATION OF FISH, MARINE SPECIMENS, AND BIRDS Fish and birds were collected from the following islands of the Rongelap Atoll: Rongelap, Gejen, Kabelle, and Labaredj. In addition, other animals were collected from Bikar, Likiep and Utirik Atolls and Eniwetek Island of the Rongerik Atoll. The majority of the marine specimens were collected in the lagoons off the shores of the islands. The larger fish were caught inthe middle of the lagoon. Most of the fish were collected after they were poisoned by a Rotenone solution dispersed in the shallow water. The birds (terns) were shot with a rifle. Each specimen was placed in a plastic bag and frozen. The frozen samples were transported to this laboratory. 4.1 LABORATORY PROCEDURES A number of the large fish were completely separated into skeleton, invertebrates were analyzed whole. The remaining fish and marine ae pony muscle, gills, liver, and viscera. All samples were dried at 100°C for 48 hr and ashed for 48 hr at 550°C. The ash was dissolved in 2N HCl and made upto volume. The gamma activity was counted ina deep-well, sodium iodide crystal, gamma scintillation counter; the beta activity was counted under a thin end-window, beta counter. The beta activity in each case was corrected for counter efficiency and mass absorption. The gamma and beta activ- ity is recorded in Mpc (Coe equivalent)". This unit was derived from comparison with a Co°® standard counted under identical conditions as the samples, Radiochemical analysis were performed to determine the concentration of several radionuclides in a number of the specimens. The radiochemical techniques employed will be described in a forthcoming report. at utait -15-