Spectrographic Analyses of Marine Plankton1

The results of spectrographic analyses of ten species of zooplankton arc presented. The methods used are described in detail. The elements determined quantitatively were boron, molybdenum, vanadium, nickel, cobalt, titanium, chromium, lead, tin, and copper. Manganese, ccsium, rubidium, barium, strontium, and silver were detected in some or all of the specimens. Antimony, germanium, gallium, gold, and arsenic were sought for but not found. Cadmium was just detectable in only one species, the squid Ommastrephes (Illex) illecebrosa. The analytical results support the view that boron is actively concentrated or excluded by some marine animals. There is evidence that sedimentation of ptcropod shells could be a major pathway for the removal of vanadium and lead from sea water. Lead was greatly enriched in Centropages. Nickel and cobalt showed random variations with respect to one another. The clemcntal composition of marine organisms has interested chemists and biologists for a variety of reasons since before the nineteenth century, and an imposing amount of data has been accumulated. Most of the analyses obtained up to 1944, and some more recent, have been summarized and discussed by Vinogradov (1953). TJnEortunately for those engaged in study of ecological or geochemical relationships in the oceans, or for those who wish to use such information to supplement’ physical oceanographic investigations, it appears that very few appropriate data exist. Not merely have few analyses been performed on species found in the marine plankton which represents, in spite of small individual dimensions, by far the major part of the biomass in the sea, but those few analyses 1 Contribution No. 980 from the Woods Hole Oceanographic Institution, Woods Hole, Massachusetts. The work was supported partly by the Atomic ICncrgy Commission (AlX contract AT (30-l)-1918) and the National Science Foundation. 2 The analytical program was carried out in the Cabot Spectrographic Laboratory of the Department of Geology and Geophysics, M.I.T., during the tenure of a Robert Illair Fellowship of the London Cormty Council and a Fellowship of the School for Advanced Study, M.I.T. Present address: Dept. of Geology. University of Manchester, Manchester, .England. which arc available have often been made on specimens of uncertain provenance, and with methods of uncertain accuracy. We need a large number of analyses on simultaneously collected members of food chains, such collections being made often enough and from suficiently varied localities, to permit comparative interpretat,ion. Modern quantitative spectrographic techniques arc capable of the required accuracy and precision when carefully controlled. They are the only techniques readily available that yield data, for large numbers of elements, on the small samples usually convenient for the marine biologist to collect in species purity high enough to permit the most complete intcrprctation. The advent of atomic weapons testing has led to increased interest in the inorganic composition of marine organisms. Many marine plankters accumulate a variety of elements which may or may not have obvious biological significance. Some of these elements have radioactive isotopes which could eventually find their way into marine products of commerce, either directly or via food chains. Along these pathways the elements can bc cithcr concentrated or diluted depending upon the organisms involved. In the most general sense, the presence or