| Autor: |
Cherry, M., Cherry, R., Heyraud, M. |
| Předmět: |
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| Zdroj: |
Marine Biology; 1987, Vol. 96 Issue 3, p441-449, 9p |
| Abstrakt: |
Concentrations of the naturally-ocurring radionuclides Po and Pb were measured in krill ( Euphausia superba), mesozooplankton, phytoplankton and sea water collected during the South African SIBEX cruise to the Antarctic in autumn 1984. The data reported constitute the first substantial measurements on Po and Pb in such samples in the Antarctic Ocean. The concentrations of Po in mesozooplankton and phytoplankton are unexceptional in comparison with those from other oceans. The SIBEX E. superba, however, have higher levels of Po than usually found in euphausiids. The Po data, combined with reasonable estimates of biological quantitites such as the fractional assimilation, are used to obtain information about the diet of E. superba. It is suggested that the higher Po in the SIBEX E. superba reflects a change from an almost entirely phytoplanktonic diet in summer to a more omnivorous diet as winter approaches. The data show that there are allometric relationships between the Po content of euphausiids and animal size; these are discussed briefly. The limited sea-water data presented are characterized by unusually high Po:Pb activity ratios and need further investigation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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