Air Quality Criteria for Lead Volume II of II - (NEPIS)(EPA) - US ...

Poulton et al. (1995), the effects on richness and abundance of EPT taxa were compared to metal
concentrations in tissue (i.e., biofilm and macroinvertebrates). Lead levels in biofilm (32 to
1540 mg/kg dw) were significantly correlated with habitat scores and macroinvertebrate indices
(e.g., EPT taxa). However, macroinvertebrate tissue Pb levels were not significantly correlated
with macroinvertebrate community level metrics. As with most natural systems with potential
mine impacts, other metals also correlated with community level effects. However, the authors
indicated that Pb concentrations in biofilm appeared to have the most significant impact on
macroinvertebrate metrics.
A detailed investigation of sediment, macroinvertebrates, and fish was conducted for
tributaries in the Aquashicola Creek watershed near a former zinc smelter in Palmerton, PA
(Carline and Jobsis, 1993). The smelter deposited large amounts of Cd, Cu, Pb, and Zn on the
surrounding landscape during its operation from 1898 to 1980. The goal of the study was to
evaluate if there was a trend in the metal levels in sediment, macroinvertebrate and fish tissue,
and community indices going away from the smelter. Sites were chosen, from 7.8 to 24.6 km
from the smelter. There were no clear associations between proximity to the smelter and Pb
levels in sediment, macroinvertebrate tissue, and fish tissue. Furthermore, there were no
associations between proximity to the smelter and macroinvertebrate and fish diversity and
richness. The authors suggested that the transport of metals in the watershed has decreased since
the smelter ceased operation, and thereby no effects were observed.
Ecosystems and Communities, Community Dynamics, and Trophic Structure
As described in the SAB framework, community dynamics include interspecies
interactions such as competition, predation, and succession (Young and Sanzone, 2002).
Measures of biotic interactions (e.g., levels of seed dispersal, prevalence of disease in
populations of focal species) provide important information about community condition. If the
community dynamics are disrupted, then the trophic structure may also be disrupted. According
to the SAB framework, trophic structure refers to the distribution of species/taxa and functional
groups across trophic levels. Measures of trophic structure include food web complexity and the
presence/absence of top predators or dominant herbivores. Therefore, this section discusses how
aquatic species interactions can be affected by Pb. Examples of species interactions can include:
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