Mercury Bioaccumulation in Pacific Lamprey Ammocoetes: the Role of Life History
Citation
James E. Haas and Gary Ichikawa. 2007. Mercury Bioaccumulation in Pacific Lamprey Ammocoetes: the Role of Life History. Poster at American Fisheries Society.
Summary
Abstract Stream sediments in several subwatersheds of the Guadalupe River drainage are contaminated with mercury (Hg) at concentrations exceeding hazardous waste criteria due to historic mining operations. From 1995-1998 we collected sediment, benthic macroinvertebrates, crayfish, and fish samples at sites with different mining histories and analyzed them for total mercury (T-Hg) and/or methylmercury (M-Hg). Fish and invertebrate Hg concentrations at each site were correlated with sediment T-Hg and to T- Hg in other species. We found Pacific lamprey (Lampetra tridentata) ammocoetes at the lowest elevation sites in three of the subwatersheds. Mercury concentrations in ammocoete tissues were positively correlated with sediment M-Hg concentrations. [...]
Summary
Abstract
Stream sediments in several subwatersheds of the Guadalupe River drainage are contaminated with mercury (Hg) at concentrations exceeding hazardous waste criteria due to historic mining operations. From 1995-1998 we collected sediment, benthic macroinvertebrates, crayfish, and fish samples at sites with different mining histories and analyzed them for total mercury (T-Hg) and/or methylmercury (M-Hg). Fish and invertebrate Hg concentrations at each site were correlated with sediment T-Hg and to T- Hg in other species. We found Pacific lamprey (Lampetra tridentata) ammocoetes at the lowest elevation sites in three of the subwatersheds. Mercury concentrations in ammocoete tissues were positively correlated with sediment M-Hg concentrations. At each location, mean ammocoete tissue Hg concentrations were 2-19X higher than those in other fish species. Ammocoete densities were inversely correlated with tissue Hg concentrations. Other habitat correlates with ammocoete density included water temperature and depth and number of pools; however, the small number of sites at which we found lampreys precluded multi-variate analyses. Trophic level is considered an important indicator of Hg bioaccumulation potential in fish, but other life history parameters seem to be more important in the lower trophic level lamprey ammocoetes. These include longevity, close contact with the substrate, and diet.
