Accumulation of 109Cd by second-generation chironominae propagated from wild populations sampled from low-, mid-, and high-saline environments.
Our objective was to determine if second-generation (F2) chironomids propagated from adults of larvae sampled from low-, mid-, and high-saline environments differed in their ability to accumulate cadmium from their environment. Second-generation chironomids cultured from wild populations were exposed to 109Cd at 0, 0.7, and 4.3 ppt salinity for 10 days, at which time survival and amounts of 109Cd accumulated were determined. Cultures included two of Chironomus tentans from a freshwater lake (lake 78; 0 ppt), and the euryhaline C. athalassicus from a mid- (lake 71; 0.7 ppt) and high (lake 56; 4.3 ppt)-saline environment. A laboratory-reared culture of C. tentans was included as a positive control. Species-dependent accumulation of 109Cd occurred; second-generation C. athalassicus cultured from the high-salinity lake survived in the three salinities and accumulated significantly greater amounts of the radiotracer at 0 and 0.7 ppt compared to the second-generation freshwater species, C. tentans. Second-generation C. athalassicus cultured from lake 71 also survived all salinities with 109Cd accumulation tending to be greater than the freshwater species at the mid-salinity range. In contrast, the freshwater species cultured from lake 78 as well as the laboratory-reared culture did not survive the highest salinity of 4.3 ppt and accumulated less 109Cd compared to the species from the high-saline environments. Species-dependent differences in metal accumulation need to be considered in studies that assess metal concentrations in aquatic organisms across an environmental gradient, such as salinity.
Barjaktarovic
L
L
Department of Biological Sciences, Simon Fraser University, 8888 University Ave., Burnaby, British Columbia V5A 1S6, Canada.
Bendell-Young
L I
LI
D000818:Animals; D001682:Biological Availability; D002106:Cadmium Radioisotopes / Q000493:pharmacokinetics*; D002683:Chironomidae / Q000502:physiology*; D004781:Environmental Exposure; D007814:Larva; D011157:Population Dynamics; D012641:Selection, Genetic; D012965:Sodium Chloride; D016019:Survival Analysis; D014018:Tissue Distribution; D014867:Water / Q000737:chemistry
D002106:Cadmium Radioisotopes; D014867:Water; D012965:Sodium Chloride