Can bathymetry be a discriminatory factor for the distribution of benthic foraminiferal morpho-groups in modern marine sediments?

Abstract

The foraminiferal content of one hundred eight modern marine sediment samples off Vengurla-Cochin sector (ranging in water depth from 30 to 1330 m). West Coast of India was studied. A total of two hundred four foraminiferal species (comprised of one hundred eighty benthic and twenty-four planktonic species) were recorded. Based on the external morphology, the benthic foraminiferal population was clubbed into two coarser morphogroups namely, angular-asymmetrical and rounded-symmetrical. The distribution profiles of these morpho-groups in the surface sediments apparently showed that angular-asymmetrical morpho-group is more or less abundant in deeper regions while, rounded-symmetrical morpho-group tends to flourish in relatively shallower regions. Such characteristic pattern indicates depth control over the external morphology of benthic foraminifera. Therefore, if these morpho-groups are studied in the subsurface, sediments may show great potential in generating proxy data for paleodepth.