Population genetic structure of earthworms (Lumbricus rubellus) in soils contaminated by heavy metals.

The genetic structure of earthworm (Lumbricus rubellus) populations from plots (N = 3) contaminated by sewage sludge (containing Cd, Cu, Pb, Zn) and reference plots (N = 3) was compared. Earthworms (N = 30-40 per plot) were collected during May 2000 and electrophoretic analyses were used to assess genetic variation at three polymorphic loci (GPI, LAP, PGM). Allele and genotype frequencies for GPI and PGM differed significantly between sludge and reference populations.

Ecological half-life of 137Cs in plants associated with a contaminated stream.

Ecological half-life (Te) is a useful measure for studying the long-term decline of contaminants, such as radionuclides, in natural systems. The current investigation determined levels of radiocesium (137Cs) in two aquatic (Polygonum punctatum, Sagittaria latifolia) and three terrestrial (Alnus serrulata, Myrica cerifera, Salix nigra) plant species from a contaminated stream and floodplain on the U.S.

Ecological half-life of 137Cs in fish from a stream contaminated by nuclear reactor effluents.

Radiocesium (137Cs) concentrations were determined during 1974, 1981 and 1998 for seven species of fish inhabiting a stream (Steel Creek) contaminated by effluents from a nuclear reactor to examine the decline of this radionuclide in a natural ecosystem. Median 137Cs concentrations were highest in Micropterus salmoides (largemouth bass) during each year of the investigation (1974 = 6.67 Bq g(-1) dry wt.