Micro-organisms as indicators of hydrological phenomena in seas and oceans—II

Abstract

• 1.

  (1) The microbiological investigations of the Indian Ocean water masses at 61 stations along the sections between Africa and the Antarctic, the Antarctic and Asia, showed that Antarctic waters are characterized by low concentrations of heterotrophs (which assimilate only easily accessible forms of organic substance), whereas the equatorial-tropical waters are characterized by high concentrations of these micro-organisms.

• 2.

  (2) The distribution of heterotrophs densities and individual bacterial species clearly indicate southerly currents carrying water from the tropical Indian Ocean south to the Antarctic coast and current flowing northward as far as the equator and the northern tropical zone.

• 3.

  (3) The microbiological data indicates a more complicated deep circulation in the Indian Ocean and in the adjacent parts of the Antartic Ocean than that suggested by Sverdrup, et al., (1956). The water masses flowing from the tropical zone to the Antartic coast were observed in the eastern half at depths of 25–75 m, 350–600 m, 1500–2500 m, and 2500–4000 m. In the tropical zone Antarctic water was found at 30–70 m, 100–300 m, 2500–3000 m, 3000–3500 m and in the equatorial zone at 1100–1500 m, 2000–2500 m, 2500–3000 m, 3000–3500 m.