Locality: Bikini Atoll--Namu Is. Personnel: Same 14. Date: August 20, Weather: Pt. cloudy--some rain. Water conditions: Radiation level(s): 1964--Thurs. Calm. McClin-~Maximum average radiation level was 0.28 mr/hr at ground level for B-y radiation. Jackson: Rats were not found on Namu Island. The trap line of 30 traps was run through representative vegetation--Messerschmidia, morning glory, grass, etc. By evening, the traps were untouched--~so were picked up. Based on previous observation, they become active by 1700, are present. that if rats are not diurnal the conclusion follows that no rats The habitat seems sufficient to support a rat popu- lation both in terms of cover and food. Hermit crab population was very small so was of little consequence in trap disturbance. Gessel: "Namu Island, which has suffered much damage, bably total destruction of vegetation, provement. pro- is now on a cycle of im- Messerschmidia is the dominant vegetation except in the center areas where Ipomoea and sedge is dominant. Soil is beginning to improve through addition of organic matter and essential elements. I personally believe the sea birds are a very important factor. Distinct differences in vigor and color of Messerschmidia on Namu are associated with presence or absence of nesting terns. I hope to substantiate this by analysis of foliage and soil samples."