peve its tbe radioustivicty of plankton at Rongelap Atoll, ( 1954-1986, abscract THiS paper brings tojether aviilable cata on the betu-activity o§ RhanKTom a> Rengetap Siois ror the period 1954-15958 tneluding the values of radioaetivity reported in UWFL-+2 and 42. Values ure piven omtne asn as well aus tne welt weignt basis, und arc shown to fe more consistent on tie ash weight basis. suite frommnets of Gifiverent mesh sive, In a comparison of re- no signiricant difference appearai Im Jevels oi activity between fine and coarse mesh} plankTom Wels. Cc ye Rates of deray ever a 2-5 yeux period are given for atout 3u gem.ies. Tae Cebllaus in at ls eunsiderod to nave contributed Lé@ss Therm \Jlooth as muck ranioactivity as that of 154, and the Wd ISSEZ NOKT. Less Thenl/aoth thetor 1956. The 195"-55 fallout \ aFeclted Privmant ky the mortherr:, amd tne 1956 ani IGF fallouts, the gouFherm, Pex] of theafin. ee e e an a: croducsion Poaaius.. la Ronjrlup Logocn ftrse took up laise amounts of Mel urttvivy from the fallout following Srivo detonation at Bikint ALILL on ase 4, 1954. sSinee tnen, tne radioactivity nas declined Wot ody recautively 3giigny acaitions trom tie two succeeding series er tesmin lobo (Peawing) ana 1068 (Hardtaexk}. of Ll “heii, Levi, Since the writing clankton ‘11s Leen collected four times, July 1956 and ant Maren snd August 1953. 96.