Organochlorine pesticides sequestered in the aquatic macrophyte Schoenoplectus californicus (C.A.!Meyer) Sojak from a shallow lake in Argentina

This study was conducted in Los Padres Lake from Argentina in order to assess the ability of Schoenoplectus californicus to bioconcentrate organochlorine pesticides (OCPs). Bulrush tissues, superficial and near root sediments were collected from the input and the output creek areas. OCP analyses were carried out by GC-ECD. Samples from the input creek area showed the higher OCP levels as a result of contaminants washed down from upstream agricultural fields. Bulrush roots accumulated the highest concentrations of pollutants (30.2-45.7 ng g(-1) dry weight). DDTs and chlordanes predominated in sediments and roots besides endosulfan sulfate. The sediments constitute the main source for these OCPs partitioning to bulrush. Stems mainly exposed to water column accumulated preferentially the less hydrophobic pesticides, such as HCHs and endosulfans. We have confirmed the important role of S. californicus in the contaminant removal from sediments. Therefore, this macrophyte can be used as a tool for field studies of OCP pollution monitoring and remediation. (C) 2004 Elsevier Ltd. All rights reserved.