Environmental Engineering Reference
In-Depth Information
Assemble data on community
structure
DQOs
not met
Evaluate data using data
quality objectives in quality
assurance project plan
Repeat necessary
components of sampling
program
DQOs
Met
Not
different
Compare data to reference
station(s)
a
Community unlikely to
be degraded
Different
Degraded community evident in
sediments from test station
Consider community structure
data with data on other
indicators
a
Comparison with reference sites is only appropriate if reference sites have been well characterized and satisfy criteria for
negative controls (that is, response in reference sediments should not be significantly different from that in negative
controls).
Fig. 7.5
Recommended procedure for assessing benthic invertebrate or fi sh community structure.
in such assessments include metals, methyl mercury,
PAHs, PCBs, OC pesticides, chlorophenols, and/or
PCDDs/PCDFs. However, this list should be refi ned
based on the land and water use activities that have
been documented near the site.
The selection of species for inclusion in assess-
ments of bioaccumulation requires an understanding
of the predator-prey relations in the ecosystem under
investigation. For example, the levels of COPCs in
benthic macroinvertebrates are likely to be relevant
when evaluating risks associated with dietary uptake
of COPCs by bottom-feeding fi sh or sediment-prob-
ing birds. Conversely, emergent insects may be the
primary focus of an investigation if swallows or bats
represent the primary receptor of concern. In cases
where fi sh-eating birds and mammals represent the
wildlife species of special concern, fi sh would be the
primary species targeted in sampling and analytical
programs. In this way, sampling programs can be
tailored to answer the key risk questions that are
being posed by the investigators. Bioaccumulation is
not an appropriate assessment approach for COPCs
that are rapidly metabolized or otherwise not accu-
mulated in the tissues of the organism(s) being
evaluated.
Ingersoll
et al.
(1997) identifi ed four general
approaches for conducting bioaccumulation assess-
ments, including the following:
