title: A combined chemical and biological assessment of industrial contamination in an estuarine system in Kerala, India.
abstract: The Cochin Backwaters in India are part of the Vembanad-Kol system, which is a protected wetland and one of the largest estuarine ecosystems in South Asia. The backwaters are a major supplier of fisheries resources and are developed as tourist destination. Periyar River discharges into the northern arm of the system and receives effluents from chemical, petrochemical and metal processing industries which release huge amounts of wastewaters after little treatment. We investigated water and sediment contamination in the industrial vicinity and at one station further away including organic and inorganic contaminants. In total 83 organic contaminants were found, e.g. well known priority pollutants such as endosulfan, hexachlorobenzene, DDT, hexachlorocyclohexane and their metabolites, which likely stem from the industrial manufacturing of organochlorine pesticides. Furthermore, several benzothiazole, dibenzylamine and dicyclohexylamine derivatives were detected, which indicated inputs from rubber producing facilities. Several of these compounds have not been reported as environmental contaminants so far. A comparison of organic contaminant and trace hazardous element concentrations in sediments with reported sediment quality guidelines revealed that adverse effects on benthic species are likely at all stations. The chemical assessment was combined with an investigation of macrobenthic diversity and community composition. Benthic organisms were completely lacking at the site with the highest trace hazardous element concentrations. Highest species numbers, diversity indices and abundances were recorded at the station with the greatest distance to the industrial area. Filter feeders were nearly completely lacking, probably leading to an impairment of the filter function in this area. This study shows that a combination of chemical and biological methods is an innovative approach to achieve a comprehensive characterization of industrial contamination, to evaluate associated risks for bottom dwelling consumers regarding sediment quality guidelines, and to observe related adverse effects on the benthic community directly in the field.
authors.affiliation: Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstraße 4-20, 52056 Aachen, Germany. Electronic address: loga-pub@emr.rwth-aachen.de.
authors.forename: Larissa
authors.initials: L
authors.lastname: Dsikowitzky
authors.affiliation: Leibniz Center for Tropical Marine Ecology (ZMT), Fahrenheitstraße. 6, 28359 Bremen, Germany.
authors.forename: Inga
authors.initials: I
authors.lastname: Nordhaus
authors.affiliation: Department of Chemical Oceanography, School of Marine Sciences, Cochin University of Science and Technology, Cochin 682016, Kerala, India.
authors.forename: C H
authors.initials: CH
authors.lastname: Sujatha
authors.affiliation: Department of Chemical Oceanography, School of Marine Sciences, Cochin University of Science and Technology, Cochin 682016, Kerala, India.
authors.forename: P S
authors.initials: PS
authors.lastname: Akhil
authors.affiliation: Vakkom Moulavi Foundation Trust, Vakkom Moulavi Road, Thekkummoodu Jn., Thiruvananthapuram 695 035, Kerala, India.
authors.forename: Kunjupilai
authors.initials: K
authors.lastname: Soman
authors.affiliation: Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstraße 4-20, 52056 Aachen, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Schwarzbauer
mesh_terms: D017753:Ecosystem; D004726:Endosulfan / Q000032:analysis; D004784:Environmental Monitoring; D063366:Estuaries; D015386:Hazardous Substances / Q000032:analysis; D006581:Hexachlorobenzene / Q000032:analysis; D006843:Hydrocarbons, Chlorinated / Q000032:analysis; D007194:India; D008670:Metals / Q000032:analysis; D010575:Pesticides / Q000032:analysis; D011078:Polychlorinated Biphenyls / Q000032:analysis; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D015386:Hazardous Substances; D006843:Hydrocarbons, Chlorinated; D008670:Metals; D010575:Pesticides; D014874:Water Pollutants, Chemical; D006581:Hexachlorobenzene; D011078:Polychlorinated Biphenyls; D004726:Endosulfan
keywords: DDT-metabolites; Diversity; Emerging contaminants; Industrial wastewaters; Macrobenthic invertebrates; Organochlorine pesticides