Phytoremediation of Pb by Avicennia marina (Forsk.) Vierh and Spatial Variation of Pb in the Batticaloa Lagoon, Sri Lanka During Driest Periods: A Field Study

Abstract

Batticaloa Lagoon (Sri Lanka) is subjected to significant pollution as a result of anticipated unplanned development works since the cessation of a civil war in May, 2009. This paper presents the effectiveness of Avicennia marina(Forsk.) Vierh in the phytoremediation of Pb and the variation of Pb in sediments and water in the intertidal zone under drier weather conditions. Four pristine areas and 4 mangroves cut areas within the Manmunai North Divisional Secretariat Division / Batticaloa Municipal Council areas were investigated. Pb levels in the sediments and plants were negligible at all locations (i.e., below the method detection limit of the AAS for sediments and plants which is 0.25 mg/kg dry weight and 0.5 mg/kg dry weight, respectively). However, the water environment showed significant contamination (0.17–0.29 mg/L and 0.26–0.34 mg/L in pristine areas and cleared areas, respectively), hence Pb bioaccumulation is likely in fish and other biota. Avicennia marina is not effective to phytoremediate Pb under significant saline conditions.

KEY WORDS:

• Avicennia marina (Forsk.) Vierh
• Batticaloa Lagoon
• Pb
• Sediments
• water

ACKNOWLEDGMENTS

The results presented in this paper is a part and parcel of a consultancy assignment (Project tilted “An assessment of Pb contamination in mangrove sediments and Avicennia marina plants from Batticaloa Lagoon and community awareness on mangrove restoration and simultaneous sustainable harvesting”) undertaken for the International Union for the Conservation of Nature (IUCN) under the Mangroves for the Future (MFF) Investing in Coastal Ecosystems Small Grants Facility (Phase II). This project was supervised by the MFF Sri Lanka National Steering Committee (NSC) of the Ministry of Environment, Sri Lanka.

I would like to thank Prof. Y.N.A. Jayatunga (Department of Zoology, University of Colombo) for her useful comments and suggestions, Mr. Manoj Kanakarthna for performing the statistical analysis and other assistance, Mr. Ranjith Mudalige (Sociologist) for providing data on population size in the Batticaloa area, Mr. Isuru Biyanwila (GIS Specialist) and Dr. (Mrs.) Vinobaba, Prof. P. Vinobaba and Mr. J.M. Harris (Department of Zoology, Eastern University, Sri Lanka) for providing some useful information about the Batticaloa Lagoon including some literature. Special thanks are given to Mr. Gamini Ratnasuriya (Environmental Laboratory & Consultancy Services) who undertook the sampling and analysis as per the instructions given by the author, Ecologist Nalinda Peiris (for enabling the author to identify the plants), Mr. Gemunu Wimaladasa (Project Assistant from EML Consultants PVT LTD) and Mr. A. Rajaratnam and Mr. M.Y.M. Jiffry (Senior Project Managers from EML Consultants PVT LTD) for their tireless support. Useful comments and suggestions given by the anonymous reviewers, Dr. Jing Song (Chief Editor of this journal), Dr. Jagath Manatunge (University of Moratuwa, Sri Lanka), Prof. Rohan Weerasooriya (Uva Wellassa University, Sri Lanka) and Mr. Namal Dissanayake (SGS Lanka PVT Limited) further improved this manuscript.