Frequency distribution of Foraminifera in the Chilka lake
MetadataShow full item record
A total of sixtynine foraminiferal species have been identified from the sediment samples collected from the Chilka Lake during November 1997 and March, May 1998. These species have been quantitatively studied in regard to their relative abundance and distribution. Frequency distribution study of Foraminifera shows that Miliammina fusca, Ammobaculites exiguus, Trochammina hadai, Jadammina macrescens, Gaudryina exilis, Ammonia beccarii (Linne), A. tepida and Asterorotalia dentata are the dominant species of the fauna. Mean values of number of species (S), Shannon-Wiener index, H (S) and evenness index ( ) are highest in summer (May) for the outer channel suggesting very high species diversity of the area as compared with other parts of the lake due to strong marine influence. In contrast, Pielou's index of species dominance (D) decreases towards the sea. Variations in the mean diversity indices for the areas covered in the lake are related to the water characteristics prevailing there during different seasons. The sites dominated by M. fusca and A. exiguus are mostly inside the lagoon, while those dominated by A. beccarii (Linne) besides T. hadai, G. exilis, Hanzawaia asterizans, H. nitidula, A. tepida, A. dentata, Elphidium crispum and E.galvestonense are in the outer channel of the lake. Application of two similarity indices - Bray-Curtis coefficient and Community coefficient - for the data shows very high faunal affinity existing between stations in the northern sector. Furthermore, the degree of faunal variation has been discussed with the data in terms of percent number of species occurring in all the samples of sites (Sc) and of per cent population composed of species occurring in all the samples of sites (Pc) at each of the three areas of the lake.
- Scholarly literature