HR: 1330h
AN: B33B-01    [Abstracts]
TI: Trophic transfer of cadmium from a freshwater oligocheate Lumbriculus variegates to predatory stoneflies (Perlodidae and Perlidae).
AU: * Buchwalter, D B
EM: buchwalt@usgs.gov
AF: US Geological Survey, 345 Middlefield Road MS 465, Menlo Park, CA 94025 United States
AU: Cain, D J
EM: djcain@usgs.gov
AF: US Geological Survey, 345 Middlefield Road MS 465, Menlo Park, CA 94025 United States
AU: Luoma, S N
EM: snluoma@usgs.gov
AF: US Geological Survey, 345 Middlefield Road MS 465, Menlo Park, CA 94025 United States
AB: In trace metal-contaminated streams, insects accumulate metals from both aqueous and dietary sources. Previously, we demonstrated that aquatic insect species differ tremendously in their rates of dissolved metal accumulation in addition to metal efflux rates (after dissolved exposures). We have also observed large inter-specific differences in how dissolved metals are partitioned subcellularly, detoxified and stored. Our current work examines dietary metal exposures in predatory stonefly species. Specifically, we are exploring the extent to which stonefly species differ in their assimilation efficiencies of cadmium from their prey, and how widely their post-assimilation efflux rates vary. We also are comparing subcellular distributions of Cd from aqueous versus dietary sources, and are exploring these differences in a phylogenetic context, working with several species in both the Perlidae and Perlodidae. To date, consistencies have been observed among four perlid genera in terms of metal sub-cellular distributions. Cadmium is beter detoxified in the perlodids we have examined, than in the perlids. Ongoing work is being conducted to determine if Cd handling is consistent among different genera of these two families. We also ask whether generalizations about species' sensitivities at broad taxonomic levels are appropriate for heavy metal pollution.
DE: 0345 Pollution--urban and regional (0305)
DE: 0614 Biological effects
DE: 1803 Anthropogenic effects
DE: 1871 Surface water quality
SC: Biogeosciences [B]
MN: 2005 Joint Assembly