Michael A. Rutzke | Geology Reports

USGS2017

Anomalous bioaccumulation of lead in the earthworm Eisenoides lonnbergi (Michaelsen)

Lead concentrations in soil organisms are usually well below those in the associated soil and tend to decrease with each higher trophic level in a food chain. Earthworms of the species Eisenoides lonnbergi provide an exception to this observation, accumulating very high concentrations of lead from acidic soils. Earthworms belonging to this species were collected from strongly to extremely acidic soils at 16 sites on a wildlife refuge in Maryland, USA. A lead concentration as high as 766 mg/kg, dry weight, was detected in depurated E. lonnbergi collected from soil containing only 17 mg/kg of lead. Concentration factors (ratio of lead concentration in earthworms to lead concentration in soil, dry wt) were highly variable at the sites, from 1.0 to 83. As suggested previously, lead absorption by earthworms is enhanced in low-calcium soils. The anomalously high concentrations of lead found in E. lonnbergi are more closely correlated with the uptake of calcium from acidic soils than with bioaccessibility of soil lead.

Environmental Toxicology and Chemistry↗

USGS2001

Relationships between thiamine content of eggs and concentrations of lead and other heavy metals in water and survival of Atlantic salmon fry

Atlantic salmon (Salmo salar) were extirpated in much of New York state by the late 1800s. Currently, Atlantic salmon from Little Clear Pond (Saranac Lake, NY) are stocked in Cayuga Lake (Ithaca, NY) and Lake Ontario to support a fishery, but reproduction is severely impaired by thiamine deficiency in Cayuga Lake and probably in Lake Ontario--apparently caused by adults feeding on prey fish high in thiaminase. One study suggested that survival of these fry may be reduced by phosphorus, calcium, magnesium, copper, or lead in water. Thiamine deficiency is known to increase lead toxicity. Bringing gravid Atlantic salmon from Little Clear Pond and Cayuga Inlet into the laboratory, we examined the effect of exposing their fertilized eggs during water-hardening to water with and without added lead (0.1 to 100 mg lead·liter-1) and to other contaminated waters (from New York State) on the survival of their eggs and fry. Our results showed no significant influence of our water-hardening treatments on survival of eggs or fry; therefore, it appears that exposure of eggs (during water-hardening) to lead in water (concentrations up to 100 mg lead·liter-1) or to several contaminated waters was not detrimental to the survival of eggs or fry of Atlantic salmon. We also determined the mineral and heavy metal content of dried eggs and found that eggs from Cayuga Lake salmon had significantly higher concentrations of copper (1.9 vs. 0.5 mg·g-1) than did eggs from salmon from Little Clear Pond. All concentrations of copper appeared to be within the range observed in other normal salmon. There were no other significant differences in concentrations of other minerals tested. Concentrations of copper in Cayuga Lake water (mean, 1.16 mg·liter-1) were significantly higher than in Little Clear Pond water (mean, 0.17 mg·liter-1). The effect of copper in eggs of thiamine-deficient salmon is not known.

Conference Paper↗