1. Distribution and environmental implications of planktonic foraminifera in the surface sediments of southwestern part of Bay of Bengal, India
- Author
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D. Senthil Nathan and N. Anbuselvan
- Subjects
geography ,education.field_of_study ,geography.geographical_feature_category ,biology ,Continental shelf ,Species distribution ,Population ,Temperature salinity diagrams ,Globigerina bulloides ,biology.organism_classification ,Foraminifera ,Oceanography ,education ,Bay ,Geology ,Globigerinoides - Abstract
Surface sediment samples were collected from the shelf and slope region of the southwestern part of Bay of Bengal to evaluate the distribution of planktonic foraminiferal assemblages and their relationship with environmental variables such as water depth, temperature and salinity. Statistical clusters (Q-mode and R-mode), principal component and correlation analyses were performed to identify the factors that control the foraminiferal assemblages. From the cluster analysis of abundant species at 46 stations, the study area was divided into two segments based on distinct planktonic foraminiferal assemblages. The spatial distribution of the species assemblage was found to be closely associated with water depth, temperature and salinity. The species population was observed increasing from 50 m water depth with the maximum value (39%) at 150 m and minimum value (4.3%) at 15 m water depths. Most of the identified species were tropical-to-subtropical forms. The abundance of Trilobatus sacculifer and Globigerinoides ruber in the shallowest region indicates their distribution was mainly influenced by temperature. The positive correlation between Globigerina bulloides and Neogloboquadrina dutertrei indicated their similar ecological behavioer and their abundance in the middle-to-outer shelf region which was possibly related to the occurrence of upwelling processes in the area during the summer monsoon. The principal component analysis revealed that the overall species distribution in the continental shelf region is mainly controlled by depth associated with distance of coastline, hydrodynamic and sedimentary dynamic processes, stability of physicochemical parameters, among others. The significant number of premodern species present in the surface sediment samples indicate a low rate of sedimentation. more...
- Published
- 2021
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