on Jaly 16, 1957, a collecting was made in the channel off the northwest end of Kabelle ‘s1anag. Rungelap Ai‘: 15 feet or iess in depth most identical to All fie& were obtained in water 93 the -olle: iione were made in iocslities al- wee of me 354, 1955 and 1956 surveys. Locality, date of collection, commoa nares, genera, species and number of specimens for the 1956 and 1957 collections are listed in the appendiz. The fish were placed on ice in insulated containers within two hours of capture and transported to the Eniwetok Marine Biological Laboratory where they were frozen. There the fish were identified and dissected, except in the case of fish collected in 1956 when the frozen fish were shipped to the base Laboratory at the University of Washington for dissection and subsequent radiological analysis. Tissues used for analysis were muscle, bone, liver and stomach contents or viscera. Specimens which were too small to dissect were processed as whole fish. Partly because of the omnivorous food habits of the Marshallese natives and partly because of variations in the samples, it is advisable to analyze many specimens of a variety of species to obtain reliable es- tumates of levels of radioactivity (Welander, 1957). Consequently, two- gram samples of muscle tissue were taxen from each fish and aggregate was homogenized in a Waring Blendor. the Plates were made of aliquots of this homogenate and the remainder dried for radiochemical anaiysis. Aili sampies were dried at i007 C and tne piated samples ashed at temperatures up to 540° C, cooled, slurried, dried and counted in i ;