A foraminiferal testimony for the reduced adverse effects of mining in Zuari Estuary, Goa

Abstract

This paper demonstrates the potentiality of foraminifera in detecting mining pollution. Goa’s Mandovi–Zuari estuarine complex is most vulnerable to deterioration caused by the mining industry. The objective of the present study is to estimate the health of the Zuari through foraminiferal distribution in its surface sediments. The foraminiferal data generated was compared with the three‐decade‐old foraminiferal data collected in 1972 and total suspended matter (TSM) data over the years. There has been a substantial increase in the maximum total foraminiferal number (TFN), from 1143 specimens in 1972 to 3057 specimens per gram sand in 2003. Even the Total Species Number (TSN) has increased from 24 in 1972 to 50 in 2003. This is in compliance with the TSM data collected over the years, which has considerably decreased. The foraminiferal data, TSM data and reduction in mining activities in the catchment area of the Zuari Estuary suggest an improvement in the environmental health of the estuary. This study also strengthens the view that foraminifera can be used as a tool to monitor marine pollution.

Keywords:

• Foraminifera
• Pollution‐indicator
• Zuari Estuary
• Mining
• Total suspended matter
• Reworked foraminifera

Acknowledgements

The authors wish to thank to Dr Satish R. Shetye, Director of National Institute of Oceanography for his encouragement and kind permission to publish this report. They are also grateful to all the cruise members on board the two vessels, CRV Sagar Sukti and fish trawler Datta Ravalnath, as well as Mr Abhijit Mazumder and Mr Rajiv Saraswat for their help in sample collection. The authors thank Dr P.D. Naidu, Scientist, NIO, for reviewing this manuscript and his suggestions.