The foraminifera and tintinnids are essential indicators of the health status of marine
and estuarine ecosystems, both past and present, and can be used for monitoring
purposes in the future. Tintinnids are known to group among ciliates possessing hard
loricate to be considered by hydrogeologists as one of the bio-indicator species, exhibiting a strong positive correlation with phytoplankton. Pulicat Lake is a marginal
marine environment present near the south coast of India. Intertidal sediment samples
were collected from September 2013 to August 2014 and were subjected to isolate
the foraminiferans and tintinnids by adopting standard methods. In all, twenty-one
genera and 24 species of foraminifera have been identified from the stream, where
Quinquelina seminulum was found to be abundant. Contrary to this, a minimum number of species was present in the freshwater inflow zone, mainly Amomalinula glabrata,
Haplophragmoides kirki, Natlandia secasensi and Valvulineria candeiana. Tintinnopsis
are recorded in the sampling sites, belonging to 5 families and 6 genera, and 12 species have been identified, and among these Favella campanula species was found to
be abundant in the study area. From our results, the recorded species in terms of numerical abundance of foraminiferans appeared predominant over the tintinnids. The
dominant role of foraminiferans may be a significant contribution to the carbon cycle
of marine/estuarine ecosystems proved elsewhere in turn responsible for the substantial uptake of phytodetritus deposition. Based on these findings, our preliminary
study may be useful to explore the carbon sequestration process in the Pulicat Lake
ecosystem.