Environmental Engineering Reference
In-Depth Information
100
Toxic
Non-toxic
80
60
r
2
= 0.75
P
< 0.001
40
y = a/(1+exp(-(x-x
0
)/b))
20
0
10
-1
10
0
10
1
10
2
30
25
r
2
= 0.43
P
= 0.03
y = y
0
+ ax
b
20
15
10
5
0
10
-1
10
0
10
1
10
2
Mean PEC quotient
Fig. 7.4
Relation between the mean PEC quotient and the response of
Hyalella azteca
in the 10-day tests (as percentage survival)
or the response in the Microtox® solid-phase sediment toxicity test (as the EC
50
expressed as a toxicity reference index). Sediment
samples were collected from the Grand Calumet River and Indiana Harbor Canal located in northwestern Indiana.
From Ingersoll
et al
. (2002).
benthic macroinvertebrates are relatively sedentary
and are closely associated with the sedimentary envi-
ronment, they tend to be sensitive to both short-term
and long-term changes in habitat, sediment, and
water quality conditions (Davis & Lathrop 1992).
Therefore, data on the distribution and abundance of
these species can provide important information on
the health of the aquatic ecosystem. As such, benthic
invertebrate community structure (BICS) represents a
candidate indicator of sediment quality conditions.
Assessments of BICS have been used to describe
reference conditions, to establish baseline conditions,
and to evaluate the effects of natural and anthropo-
genic disturbances (Striplin
et al.
1992). In terms of
evaluating sediment quality, such assessments are
focused on establishing relations between various
community structure metrics (for example species
richness, total abundance, relative abundance of
various taxonomic groups, macroinvertebrate index
of biotic integrity (mIBI)) and measures of sediment
quality (for example chemical concentrations and
organic content). Data from benthic community
assessments have the potential to provide relevant
information for identifying impacted sites and, with
