Transplant of benthic organisms between lentic systems: Reflect the trace metals bioavailability in the environment?

Freshwater bivalves Diplodon chilensis (Gray, 1828) were transplanted from a non antropized lentic system (Laguna Chica de San Pedro 36 degrees 50'S; 73 degrees 05'W), to a very antropized system that receives high inputs of Cu (Rapel Dam 34 degrees 10'S, 71 degrees 29'W). The objective of this stud y was to evaluate the bioconcentration of total Cu in soft tissues of the b ivalves by time and space. Cages of PVC of 0.01 m(3) volume and 5 mm of mes h size, with 35 individuals of D. chilensis of 35-40 mm of valve size, were installed in the two lentic systems. The organisms were obtained from the non antropized system in Nov. 17, 1994 at 3 m of depth. The cages were susp ended at 1 m from the bottom in Nov. 18, 1994 for 168 days. Five individual s were sampled from each cage on days 0, 32, 74, 125 and 168. The results a llowed to conclude that the concentrations of trace metals as total Cu, rec orded in the tissues of D. chilensis, reflects the exposition degree and bi oavailability of this element in the aquatic environment, and allows to qua ntify at a relative level, the degree of enrichment of the system by natura l or antropogenic sources, with respect to a non distributed reference area .