CONICET | Buscador de Institutos y Recursos Humanos

The foraminiferal fauna was studied qualitatively and quantitatively from 195 surface plankton samples gathered by the authors during the month of February, 1969, in Mar de la Flota (Bransfield Strait), Antarctic. This area belongs to the High Antarctic Zone and is covered by ice during eight months of the year. The method of collection was not a traditional one, and consisted of pumping by means of a fire pump and by putting a net below a fire-hose. This method has many advantages for the microplankton recollection in general and foraminifera in particular; it might be especially recommended with regard to the peculiar conditions encountered in high latitudes. The following five species-were determined: Globiqerina quinqueloba Natland (43,7%); G. pachyderma (Ehrenberg) (I. typica and f. superficiaria ) (40,7%); G. bullouies d'Orbigny (f. typica and f. trilocularis ) (7,3%); Globigerinita uvula (Ehrenberg) (4,5%) and G._glutinata (Egger) (1,0%). The remaining 2,8% corresponded to sp. indet. (specimens which were too young or damaged). It is believed that Globigerina quinqueloba was represented by micro and macrosphaerical individuals. Two anomalies were observed in the test of the foraminifera found: a) Two specimens of the same species firmly attached, and, b) formations similar to strong and sometimes almost shapeless spines which were distributed sparsely and irregularly. These formations were quite unlike the delicate and long "traditional" spines typical of many planktonic Foraminifera. They were also found in another area (NE from the Malvin Islands) on the tests of several species which did not even possess "traditional" spines (e. g. Globigerina pachyderma, Globigerinita uvula, G. glutinata). Twenty four planktonic samples had benthonic Foraminifera. Some of these samples were gathered over very great depths, up to 2.194 m. Qualitatively the foraminiferal planktonic fauna of Mar de la Flota is distributed rather uniformly. Its quantitative distribution is shown on map 3. It is very poor quantitatively and the number of foraminiferal specimens in one cubic meter of water is in average 0,4. The daily vertical migration was not observed.

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