Summary of Abstract Submission

Abstract Submission No. IO50-03-0038PresentationPoster

MULTI-PROXY RECORD OF SURFACE SOIL SAMPLES FROM THE MOUTH OF KRISHNA RIVER- SOUTH EAST COAST, INDIA

Ranjana*1, Anjum Farooqui1

1 Birbal Sahni Institute of Palaeobotany,53 University road Lucknow, India

ABSTRACT :

Krishna river merges into the Bay of Bengal at Hamsaladeevi (near Koduru)Andhra Pradesh.A large expanse of mangrove swamps surround the three distributaries at the mouth-the northern,central and the southern.Relative salinity changes and the palynological, thecamoebian and diatom study was carried out in the 34 grab samples from the sediment-water interface covering about 9 km of the river mouth on land.The deltaic ecosystem is largely governed by climate, rainfall, hydrology,topography and tidal flooding in the study area. The salinity in northern part ranged from 14.1 to 1.0 while in southern part it ranges from 0.4 to 4.0. Salinity in the northern part is highest and in the southern part it is low. Dominance of Avicennia and Suaeda pollen (back mangroves) along with the Coconies diatom is present in the northern part,while in the southern part pollen grains of Avicennia, Suaeda, Excoecaria, Acanthus ilicifolius, Foraminifera lining, thecamoebians such as Nebella, Cyclopyxis sp. Spiniferites,Operculodinium and diatom eg.,Neidium were recorded. Results show that high salinity in the northern part is vulnerable to mangroves whereas, the southern part has good evidences of mangroves due to low salinity.Visual observations reveal more growth of mangroves both qualitatively and quantitatively in the southern part as compared to the northern part.The northern part shows deteriorated mangroves and dominance of salinity tolerant mangroves.Both visual and palynological study reveal sea water ingression in the northern part which is increasing salinity in the ecosystem as compared to southern part.