EPA
                            United States
                            Environmental
                            Protection
                            Agency
                     Office of
                     Solid Waste and
                     Emergency Response
Publication 9345.0-051
March  1994
ECO   Update
Office of Emergency and Remedial Response
Hazardous Site Evaluation Division (5204G)
                                                             Intermittent Bulletin
                                                            Volume 2, Numbers
Field  Studies for Ecological  Risk Assessment
   Ecological risk assessments of Superfund sites evaluate
the  actual  or potential  effects of site contaminants  on
plants and  animals and  assess the need for remediation,
including considering remedial alternatives and evaluating
ecological  effects of remediation.   Such ecological risk
assessments make use of a variety of desktop, laboratory,
and  field  approaches,  which  may  include chemical
analyses of media,  toxicity testing, literature searches,
evaluation  of the condition of organisms,  and ecological
field studies.   As the  name implies, ecological field
studies are investigations that take place in the actual area
under scrutiny, focusing on the site's habitats and biota1
(resident organisms) and comparing them with unimpacted
conditions.  The ecological risk assessment of a Superfund
site nearly  always requires some type of field study. At a
minimum,  some field study  is  necessary  in order to
identify organisms and habitats2 that may  be at risk. By
themselves, hazard indices based on literature values rarely
prove adequate for characterizing ecological effects.

   Rather  than studying  individual  organisms,  field
studies generally focus  on populations or communities.
Populations are groups of organisms belonging to the
same   species   and  inhabiting  a  contiguous  area.
Communities consist of populations of different species
living together.  For example, a forest community  consists
of the plants,  animals,  and microorganisms found in a
forest.  A community also can be a more restricted group
of organisms.   Within  the forest,  the soil community
consists  of only those organisms living in, or in close
association with, the soil.  Less  frequently,  a field study
evaluates an ecosystem,  which consists   of both the
organisms  and the nonliving components of a specific,
   1 The first time that a technical term appears, it is bolded and either
defined in the text or in a footnote.

   2 A habitat is the place that a species naturally inhabits.
                                limited area.    In the case  of a forest,  the ecosystem
                                includes the soils, rocks, streams, and springs as well as
                                the resident organisms that make up the forest community.

                                   Which sites warrant a detailed field study?  At many
                                sites  the  existing  information  indicates  a  significant
                                likelihood of present or future adverse  impact but is
                                insufficient to support remedial decision making. At such
                                sites, field studies can identify actually  or  potentially
                                exposed organisms,  exposure routes, ecological effects,
                                and also the potential of the site to support biota.  In the
                                initial phase of an ecological risk assessment, a field study
                                can take the form of a site's habitats and many of its
                                species and also note any  obvious adverse ecological
                                effects. If a site warrants further study, a  more intensive
                                effort  during the analysis  phase can help to provide
                                evidence of a link between a site's  contaminants and an
                                adverse effect.   As Table  1 shows, field studies  can
                                contribute information at different stages of the ecological
                                risk assessment and  can  assist  with  each  of  the
                                assessment's components:
                                             IN THIS BULLETIN

                                The Organisms in a Field Study	2
                                Elements in the Design of a Field Study	5
                                Catalogue of Field Methods	9
                                Field Studies: Their Contribution	12
                                   3 Although ecologists often use this term to include much larger
                                resources, this definition gives the word dimensions usable at a Superfund
                                site.
   ECO Update is a Bulletin series on ecological risk assessment of Superfund sites. These Bulletins serve as supplements to Risk Assessment Guidance for
Superfund, Volume II: Environmental Evaluation Manual (EPA/540-1-89/001). The information presented is intended to provide technical information to EPA and
other government employees. It does not constitute rulemaking by the Agency, and may not be relied on to create a substantive or procedural right enforceable by any
other person. The Government may take action that is at variance with these Bulletins

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problem formulation, analysis, and risk characterization.

    The  specific role of field study in an ecological risk
assessment varies  with the site.   Site managers5 should
consult with  the Biological  Technical Assistance Group
(BTAG) in their Region to determine the best approach to
each site.6  This consultation should occur at the earliest
possible stage  of site  investigation.   The BTAG  may
suggest  other methods—in  addition to, or  instead of,
techniques discussed in this document—that are especially
appropriate for a particular site.

    This Bulletin provides site managers with an overview
of  field study options.  Four main sections  follow this
Introduction.  The first considers the organisms, which are
the  major focus of most field studies,  and  the second
describes the  remaining elements in the design of a field
study.  The third section presents a catalogue of common
field study  methods, while the fourth section summarizes
the contributions that field study can make to an ecological
risk assessment.

    This Bulletin is intended only  as  quick reference for
site managers,  not as a  comprehensive review of field
methods or of the ecological attributes evaluated using
these methods.  Those who want to examine the subject in
greater depth should consult the list of references at the
end of the Bulletin and also the list of additional resources
available from the federal government.


The Organisms  in a Field  Study

    Although  a large number of species can inhabit a site,
an ecological  risk assessment of a Superfund site concerns
itself  only  with  those that are  actually  or potentially
adversely affected by site contamination or that can serve
as surrogates for such species.  Such organisms are among
a site's ecological components.  Ecological components
are  populations,  communities, habitats,  or  ecosystems
actually or potentially  affected by  site contamination.  A
field survey conducted as part of a reconnaissance visit can
help to identify the potentially affected organisms at a site.
Some factors to  consider in  making this  identification
    4 In preparing this Bulletin every effort was made to use terminology
found in the Framework for  Ecological Risk Assessment (U.S.  EPA.
1992.  Office of Research and Development, Risk Assessment Forum.
EPA/630/R-92/001. Washington, D.C.). The three phases listed in the text
are equivalent to the four components of an ecological risk assessment
described in "Ecological Assessment of Superfund Sites: An Overview"
(ECO Update  Vol.  1,  No.  2).  The  Framework's analysis phase
corresponds to the "Overview's" exposure assessment and the ecological
effects assessment phases.

    5 Site managers include both remedial project managers and on-scene
coordinators.

    6 These groups are sometimes known by different names, depending
on the Region. Readers should check with the appropriate  Superfund
manager for the name of the BTAG coordinator or  other sources of
technical assistance in their Region. A more complete  description of
BTAG structure and function  is available in "The  Role of BTAGs in
Ecological Assessment" (ECO Update Vol. 1, No. 1).
include which  media  (e.g.,  soil, surface water,  ground
water) have become contaminated, the site's contaminants,
their    environmental    concentrations,     and    their
bioavailability.7
Table 1. Field Study Contributions to Ecological
Risk Assessments
Task

Problem
Formulation




Analysis










Risk
Characteri-
zation





Site Reconnaissance
Visit
Identify ecological
components potentially
exposed to contaminants.



Identify ecological
components likely to be
exposed to contaminants.
Identify readily apparent
effects.







Develop hypothesis of
relationship between
exposure and effects.





Intensive Field
Study
Identify specific
ecological
components and the
exposure pathways
for populations and
communities.
Describe
populations and
community
attributes with
respect to exposure.
Quantify exposure
of specific
ecological
components.
Quantify effects on
specific ecological
components
Characterize and
document links
between exposure
and effects.
Quantify relation-
ship between
exposure and
effects.
General    Considerations   in    Selecting
Organisms for Study
   Most sites  have a large  number of species, making it
necessary  for  the  investigator8  to focus  on a  limited
number of  these  for  detailed study.   A variety of site-
   7 Bioavailability is the occurrence of a contaminant in a form that
organisms can take up.

   8 The term "investigator"  refers to the individual  charged with
responsibility for designing and/or carrying out any part of an ecological
risk  assessment.  Investigators  can  include government  scientists,
contractors, or university scientists. However, the site manager (remedial
project manager or on-scene coordinator) retains ultimate responsibility
for the quality of the ecological risk assessment.
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                                          ECO Update

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specific factors—including the size of the site and the
types  of habitats  that have  become  contaminated—
contribute to  making this selection.   In their  role  as
protectors of natural resources, trustees also can influence
the selection of organisms for study.

    Species-specific factors also enter  into the selection.
These include:

    •    Intensity of  exposure.    Species vary  in  the
        intensity of their contact with contaminated media.
        For  example,  earthworms and  other invertebrates
        inhabiting a contaminated medium receive longer
        and  more intense exposures than wider-ranging
        invertebrates such as butterflies.   Some animals
        have limited mobility early in their life cycle—as
        eggs, larvae, or nestlings,  for  example—so have
        greater exposure than older animals.

    •    Relative  sensitivity to contaminants.   Evaluation
        of a highly sensitive species can bring about de
       facto consideration and protection of other species
        inhabiting the site.   However, at a  site with  a
        complex mixture of contaminants, the investigator
        may be  unable to identify  one sensitive species
        that  is most appropriate for study.

    •    Ecological function, along with significance of a
        species'   contribution   to   this  function.   An
        investigator may select  a species for  study based
        on its ecological function.  For example, at a site
        with contaminated surface water, the  investigator
        may choose   to  study  algae  as the  aquatic
        community's   primary   producers.9      The
        investigator may specifically focus on those algal
        species that make a large  contribution to this
        function.

    •    Time spent on-site. To qualify  for further study, a
        species should inhabit  the site  during  either  a
        considerable portion or a critical stage of its life
        cycle.

    •    Ease of difficulty of conducting field  studies with
        the  organisms.   A field  study that  requires
        capturing birds is resource-intensive, and unlikely
        to occur at a typical Superfund assessment. Where
        fish-eating    birds   are    at    risk   because
        bioaccumulating substances have contaminated the
        surface   water  or   aquatic   organisms,   the
        investigator  might   choose  instead  to   focus
        primarily on the fish that the birds eat or to study a
        mammal  or reptile with feeding habits similar to
        birds.

    •    Appropriateness of surrogate species.  In the case
        of a site with an endangered or  threatened species,
        the  investigator may elect  to  study  a surrogate
   9 A primary producer is an organism, such as an alga or a terrestrial
plant, that converts the energy from sunlight to chemical energy.
        species with similar exposure.   Surrogate species
        offer the  advantage of  sampling  and analysis
        options that cannot be  employed with threatened
        or endangered species.   However,  in selecting a
        surrogate species, the investigator should identify
        one that resembles the site  species  in behavior,
        feeding,  and   physiological  response  to  the
        contaminants of concern.  The best choice for a
        surrogate is not necessarily the one most closely
        related to the site species.

    •    Other  recognized values.   At some  sites  the
        investigator may want  to  consider  a species
        because of other values associated with it, such as
        economic or recreational value.

Based on the above considerations, the investigator
generally selects no more than a few species as subjects of
the field study.  However, an investigator can choose to
        Although a large number of species
can  inhabit  a  site,   an  ecological  risk
assessment  of a Superfund  site concerns
itself only with  those  that are  actually or
potentially  adversely  affected   by  site
contamination  or   that  can   serve   as
surrogates for such species.
study  a  community.    For example,  at  a lake  with
contaminated  water and sediment the investigator  can
study the benthic community that lives in association with
the lake's bottom.   When selecting a community  as an
ecological component, the investigator needs to ascertain
that the  study includes populations representing multiple
trophic levels.10

    At some Superfund sites, investigators have selected a
wetland  habitat  as  the ecological component for further
study.   Such choice can  prove  more protective  of the
environment since the investigator can document a variety
of  adverse effects  on the habitat rather  than having to
demonstrate significant impact to only selected  species.
Studying a habitat becomes especially important when one
or  more of  the remedies  under  consideration  could
adversely affect the habitat.  However,  designating  a
habitat as the ecological  component can  prove  costly,
depending upon how the  ecological risk  assessment
delineates the habitat.
    10 A trophic level is a stage in the flow of food from one population
to another.  For example, as primary producers, plants occupy the first
trophic level, and grazing organisms occupy the second trophic level.
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   To  extend  these  general  guidelines  for selecting
ecological components,  the  following sections  consider
different kinds of organisms  that inhabit either aquatic or
terrestrial environments and detail how each can increase
an investigator's knowledge of the ecological conditions at
the site.

Aquatic Organisms

   At a  site  where  contaminated  surface  water is  a
medium of concern, field studies can focus on periphyton,
plankton,    benthic    macroinvertebrates,    or   fish.
Periphytons are microscopic algae that grow on sediment,
stems  and leaves of rooted  water vegetation, and other
surfaces that project above the bottom of a body of water.
Studying  periphyton provides information about primary
producers in an  aquatic environment.  These organisms
also  include many  species useful  in assessing the cause,
extent, and magnitude of contaminant problems.

   Plankton are microscopic organisms that float or swim
weakly in the water column.   Plankton includes algae,
protozoa,  and  small  crustaceans.    Planktonic  algae  are
called phytoplankton, and the  protozoa  and crustaceans
are referred to as zooplankton.  Because plankton include
primary producers, which supply food for larger animals
and also increase the amount of oxygen dissolved in water,
these organisms  make  an important contribution  to  the
aquatic community.  Like periphyton, plankton includes
species that are  sensitive indicators of ecological injury
resulting  from  contamination  or enrichment  of  water
bodies.

   As defined by EPA,  benthic macroinvertebrates  are
invertebrate animals that live in or  near the bottom of a
body of  water and that will not  pass  through a U.S.
Standard  No.  30 sieve,  which  has  0.595 mm openings.
Such organisms occur in gravel, sediments,  on submerged
logs and debris, on pilings, and even on filamentous algae.
Freshwater  benthic macroinvertebrates  include  insects,
worms, freshwater clams,  snails,  and crustaceans.   The
benthic macroinvertebrate communities  of marine and
estuarine  environments  include worms,  clams,  mussels,
scallops,  oysters,  snails,   crustaceans,  sea  anemones,
sponges,  starfish,  sea urchins, sand dollars,  and  sea
cucumbers.  When water becomes contaminated, some of
the contaminants migrate to the sediment and accumulate
there.   Field  studies of benthic  macroinvertebrates can
indicate the degree to which sediment contamination can
adversely affect biota.  In addition, the composition and
diversity  of benthic macroinvertebrate communities can
indicate the  overall  well-being of the  aquatic ecosystem.

   Because fish occupy a range  of trophic levels, they
serve as useful indicators of community-level effects. The
relative ease of identifying most juvenile  and adult forms
makes fish particularly convenient subjects for field study.
In addition, field study methods for fish are relatively
simple  and inexpensive.    In  selecting  a  species  for
sampling,  the investigator  will  want  to  consider   its
characteristic home range.  For a species that spends little
time on-site, a field study may not be  able to establish
whether any adverse effects result from  exposure  to site-
associated contaminants.

Semi-aquatic and Terrestrial Animals

   Semi-aquatic   and   terrestrial    animals—including
insects,  other  invertebrates,   and vertebrates—can  all
provide  useful  information   about   ecological  effects
associated with the site.  Soil fauna,  the organisms most
intimately  associated  with this  medium, include many
species that perform  important functions in  terrestrial
ecosystems.  For example, earthworms  aerate the soil.
Other  soil-dwellers—such as  some   small  insects,  soil
mites,  and  certain nematodes  (a kind of worm), break
down organic wastes and dead organisms—releasing the
elements and compounds they  contain and making these
available to living organisms.   Both soil aeration  and
organic decomposition support the growth of terrestrial
plants. Consequently, plants can suffer impact if soil fauna
are affected.

   Insects'  small size and their large numbers make them
convenient subjects of study.  Further,  a site generally has
a large number of species. Because these species occupy a
variety of microhabitats and also differ in their behaviors,
the investigator  can  measure  a range  of effects.   For
example,  because  insects include  species  at different
trophic levels,  a  field study  can assess  the potential for
biomagnification11 of a site's contaminants.

   Field  studies  focusing   on  such   vertebrates   as
amphibians, reptiles,  and mammals can contribute to a
site's ecological assessment.  Depending on their trophic
level, these vertebrates may ingest contaminants as a result
of  consuming  contaminated   plants,  other   terrestrial
animals,  or fish.  Burrowing animals,  such as voles, can
show greater  ecological effects  from contaminated  soil
than animals that have less intimate contact with the soil.
Where investigators at Superfund sites  decide to study
terrestrial vertebrates, they generally choose small species,
which are likely  to range over a smaller area than larger
species.  As a result,  the  smaller species tend to spend
more of their time on the site, making  it easier to estimate
exposure.

   Field studies  of birds present  certain difficulties at a
Superfund  site.   These organisms can range far off-site,
making it difficult for a field study to establish whether an
adverse ecological  effect results from exposure to site-
associated  contaminants.   In addition,  bird studies  can
prove especially resource-intensive.  However, at a large
   11  Biomagnification is  the  increasing  of concentration  of  a
bioaccumulating contaminant as it passes up a food chain or a food web.
A food chain is a series of organisms that sequentially feed on one
another. For example, mice eat seeds and are in turn eaten by owls. A
food web, which is a group of interrelated food chains, takes into account
a species'  participation in multiple food  chains.  For example, birds,
insects, and other mammals also eat seeds, and cats, as well as owls, prey
on mice.
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site or a site with a complicated contaminant picture, the
investigator and the BTAG  may decide that avian field
studies are worth the effort.  For example, many sites have
large populations of waterfowl that can potentially suffer
adverse effects from site contaminants.

Terrestrial Vegetation

   When a site has contaminants associated with soil, field
study can focus on terrestrial  vegetation.   In particular,
investigators  may want to  conduct  field  studies  of
vegetation at Superfund  sites where plants show signs of
stress, such  as  stunted  growth or yellowing,  or  where
pollution-tolerant species are abundant.  Since plants are
the  primary producers  in  terrestrial environments,  an
ecological impact to vegetation can affect other terrestrial
biota.
Elements  in  the  Design  of a  Field
Study

   As with any study, an ecological field study has several
elements.  In addition to selection of the  organisms, the
elements of a field study encompass the study's objectives,
a reference site, endpoints, methods, level of effort, sample
design, quality assurance/quality control standards, and the
statistical analysis of  the  data.   When the investigator
carefully crafts each of these elements, the  resulting study
should achieve its objectives and should further the overall
ecological risk assessment of the Superfund site.  Under-
developing any of these elements can weaken the study's
results and adversely  affect the  results  of the  overall
assessment.

Objectives

   To ensure that the  study will have clear direction, the
investigator needs to establish study objectives that address
ecological concerns  for that site.  The objectives should
ensure that the field  study supports the over-all objectives
of an ecological risk  assessment for a Superfund site.
These objectives  are  (1)  to  determine  whether  site
contamination poses  a current or potential threat of adverse
ecological  effects; (2) if a  threat does exist,  to decide
whether remediation is required; and (3) if remediation is
required, to set cleanup levels.
   Investigators will find that  study  objectives  help  to
indicate the appropriate level of effort.  In an initial field
study to  identify ecological components, for instance, an
investigator might find that  a qualitative  survey  method
would achieve the study's objective.   The later  study  of
adverse  effects  to  a  population  might require  a more
resource-intensive  approach,  such  as semi-quantitative  or
quantitative  sampling  to  estimate  population sizes   or
capture of organisms  and transport to  a  laboratory for
biochemical analysis.
   Although the specific objectives for a field study will
vary both with the site and its stage in the ecological risk
assessment process, investigators should keep in mind that
a field study performed  as part  of a  Superfund  site's
ecological  risk  assessment  is  not  a  research  project.
Generally, a snapshot of site characteristics can provide the
needed information.

   In addition to stating the purpose of a field study, the
objectives also should indicate whether the field study  is
occurring in conjunction with another type of study, such
as a toxicity  assessment.  In such  a case, the two studies
have  a  shared  goal:  to  determine  whether  adverse
ecological  effects  correlate  with toxicity.   To meet this
goal, the studies' objectives should emphasize the  need for
integrating sampling plans and coordinating the collection
of data.  When sampling for coordinated studies occurs  at
the same time and location, and with similar data quality
objectives  and levels  of  precision,  the  investigator can
more convincingly compare results.

Reference Site

   A reference site is a location that closely resembles the
Superfund site in  terrain, hydrologic regime, soil  types,
vegetation, and wildlife.   A well-chosen reference site
provides background conditions, allowing the investigator
to  draw  conclusions  about  the  ecological effects  of
contaminants on the  Superfund site. The more closely the
reference site resembles the  Superfund site, the more valid
will be the conclusions based on comparisons of the two.
In  some   cases,   no  single  reference   site  adequately
approximates  the  Superfund  site.   In  such a case, the
investigator may need to identify multiple reference sites.

   The investigator should try to locate a reference  site as
close as possible  to the  Superfund site so that it  will
accurately  reflect   the  conditions   prevailing  at  the
Superfund site. Yet  the reference site should lie at a great
enough distance from the Suprerfund site to be outside its
sphere of influence  and relatively  contaminant-free.  For
example,   an  upstream  location  often  can  provide
appropriate  reference  site  conditions  for  a  site  with
contaminated  surface water.   A woodland site used as a
reference site needs to lie at a great enough distance from
the Superfund site  that ranges  of organisms will not
include both sites.  Failure to choose appropriate reference
sites can result in inaccurate conclusions.  For example, if
the surface water at  the Superfund site consists largely of
soft-bottomed pools, then  an area  having fast-running
streams  with  gravel  bottoms  will   not  provide  an
appropriate   comparison.      Differences   in  species
composition and other features at the two  sites will, at least
in part, reflect their  very different aquatic habitats  rather
than contamination at the Superfund site.

   In  the  absence  of  suitable  reference  sites,  an
investigator may need to turn to historical information
about the site and/or a large database in order to make a
comparison between site conditions and conditions in an
uncontaminated area. If this approach becomes necessary,
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the investigator needs to choose a data source that reflects
the site's  geologic, hydrologic, and ecological  traits as
closely  as possible.   In  making this  selection,  the
investigator can obtain advice  and suggestions from the
BTAG.
A field study performed as  part  of a
Superfund     site's     ecological     risk
assessment is not a research project.
Endpoints

   The identification of endpoints, which are ecological
characteristics that  may  be adversely  affected by  site
contaminants, is essential to a successful ecological  risk
assessment as a whole and also to each of the studies  that
make up this assessment. Ecological risk assessors have
found  it useful to  recognize  two levels as  endpoints,
assessment and measurement endpoints.  An assessment
endpoint is an explicit  expression of the environmental
characteristic that is to  be protected (24, 29).12  At a
Superfund site an assessment endpoint is an endpoint  that
may  drive  remedial  decision-making.    Determining
potential contaminants of concern and potential ecological
components and developing  a conceptual model of a site's
contaminant situation generally indicates which ecological
traits are assessment endpoints at a particular site.

   A measurement endpoint is an ecological trait that is
closely related to an assessment endpoint and that is, in
addition, readily measurable.   A measurement  endpoint,
then, is a response that  can approximate or represent an
assessment  endpoint which is not amenable  to  direct
measurement.    A  site's  ecological   components  and
assessment  endpoints  drive   the  selection   of  the
measurement endpoint(s). (See Figure 1.) For example, at
a site where lead is a contaminant of concern and which
has resident species  sensitive to lead, the investigator may
identify lead poisoning as an assessment endpoint and one
or more lead-sensitive species  as ecological  components.
The  investigator's choices of measurement endpoints are
then limited to accepted ways of measuring the presence of
lead in organisms or its effects on them.

   Table 2  summarizes  measurement endpoints for field
studies.   Although  a field  study can  focus  on  one
population,  an  entire community, or even two or three
communities, as both Table 2 and the following discussion
indicate, measurement endpoints for field studies are much
more than simply "head counts."
   12 Numbers in parentheses refer to references listed at the end of this
Bulletin.
   Biomass,  the  total  weight of individuals, can be  a
measurement   endpoint  for  both   populations   and
communities.   An investigation  may measure  biomass
directly by weighing collections of some organisms or, for
larger organisms,  by  weighing individuals and summing
their weights.  Alternatively, he or she may use an indirect
method, such as applying length-to-weight regressions to
data detailing the  number and length of individuals in a
population, an especially common approach for fishes.
     Figure 1. The Relationship Between
              Ecological Components,
              Assessment Endpoints, and
              Measurement Endpoints
     In designing a field study, the ecological
     components and assessment endpoints
     generally drive the selection of measurement
     endpoints.
      Ecological
      Component
                     \,
                      \
                        Measurement
                        Endpoint
      Assessment
      Endpoint
   Productivity,   the  rate   of  increase,   is  another
measurement endpoint that can apply to both populations
and  communities.   For plants, the rate  of increase in
biomass  indicates productivity.    For  many animals,
investigators take the rate of increase in numbers as the
measure of productivity.  Because productivity is a rate,
measurements  or estimates  must occur  at  least  twice
during growing season. However, investigators can infer
productivity by  conducting  seed  or  egg counts or by
studying the age structure of a population.  At Superfund
sites, investigators  can infer  relative  productivity by
comparing data from the Superfund site and the reference
site(s).

   A common measurement endpoint for terrestrial  plant
population  is cover, which is the percentage of ground
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area that lies beneath the canopy (uppermost branches) of
a tree or shrub species. In evaluating a stand of trees, an
investigator can instead measure basal area, which is the
sum of the cross-sectional area of the trees' trunks.

    Some measurement  endpoints relate  specifically  to
community parameters. Species richness is the number of
species  in a community.   Species  density refers to the
number of individuals of a  given species  per unit area,
while relative abundance is the number of individuals in
a  particular  species  compared to  the  total  number  of
individuals. Dominance,  in the sense of commonness at a
site, describes a species that  occurs in high abundance, as
indicated largely by species density. Diversity relates the
abundance  of  individuals  in  one  taxon  (level  of
classification) to the total abundance of individuals in all
other taxa.   Evenness measures  how evenly  distributed
individuals  are  among the  community's  taxa.   Guild
structure, which refers to the different types  of feeding
groups  in  a community,  also  can be used to  evaluate
community  structure.13    A  number  of similarity  and
different indices14  can compare community structure at
Superfund and reference sites.

    Another  community-level   measurement   endpoint
concerns  indicator species, which  are  species  whose
presence, absence, or population density helps to indicate
whether the environment  is contaminated.  Some species
are  associated  with  thriving  communities,  so  either
absence  or  a  reduced  population  can  indicate   an
ecologically  disturbed environment.   For example,  the
larval  stage of insects  in the  orders  Ephemeroptera
(mayflies),   Plecoptera   (stoneflies),   and Trichoptera
(caddisflies), referred to collectively as the "EPTs,"  show
sensitivity  to metals  and other inorganic  contaminants.
Reduced populations  of  EPTs, then, can  indicate toxic
levels   of  metals  or other  inorganics   in  a  stream.
Conversely,  some  species  occur in  association with  a
disturbed habitat,   where  they  dominate or kill  native
species  weakened  by exposure  to  contaminants.   For
example,  such plant  species as Phragmites and cattails
(Typha)  characteristically  grow abundantly in disturbed
wetlands.  Consequently,  dense growth of Phragmites or
cattails   indicates  that a wetland may  have  suffered
ecological stress.

Methods

    Field  studies gather  information  about the  site by
observing organisms,  noting signs of an animal species'
presence, or collecting organisms  for further study.  With
respect to methods, the work plan for a site should include
    13 Guilds, also called functional feeding groups, are groups of
animals occupying the same trophic level and feeding either in the same
way or in the same location.  For example, among terrestrial plant-eaters
there are five guilds: stem-eaters, root-eaters, leaf-eaters, bud-eaters, and
nectar-sippers.

    14 An index is a single number that incorporates information from a
class of data.
    detailed instructions for sampling organisms and collecting
    the relevant data.  This  data may  include such  physical
    measurements  as  the temperature  at  a  sampling  site.
    Proper methodology ensures that the data collected can be
    analyzed and results interpreted.

       Observation indicates whether a species occurs at the
    site.  For vegetation and for animals with limited mobility,
    the observer also can  note the condition of the  organisms.
    Investigators need to  keep in mind that for more mobile
    animals,  observation  indicates only whether the species
    occurs at the site,  not what percentage of time it spends
    there.  Observing organisms  can be as straightforward as
    walking  the site  or can involve the use  of  specialized
    equipment, as in remote sensing of terrestrial  vegetation.
    Remote sensing by such means as infrared or multispectral
    photography  can prove  an  effective way of detecting
    stressed vegetation at a large site.

       The signs of an animal's presence include scat (feces);
    burrows, nests, or dens; cast-off larval cases or cocoons;
    tracks; and carcasses.   Characteristic sounds, such as bird
    song, also can reveal an animal's presence  and  sometimes
    provide  limited information about  relative  abundance.
    Like direct observation of resident organisms, observation
    of animal sign indicates only whether a species occurs at
    the site, not the percentage of time it spends there.
      Table 2. Measurement Endpoints in Field Studies
         Type
Measurement Endpoints
for Populations
Measurement  Endpoints
for Communities
      Measurement Endpoint
Biomass

Productivity

  -Cover (terrestrial vegetation)

  -Basal area (terrestrial vegetation)
Biomass

  -Productivity and Respiration
(aquatic communities)

  -Species richness

  -Species density

  -Relative abundance

  -Dominance

  -Diversity

  -Evenness

  -Similarity/difference between
Superfund site and reference site

  -Similarity/difference in guild
structure between Superfund site and
reference site.

  -Presence, absence, or population
density of indicator species.
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   Methods of collecting samples for further study vary
with the kind of organism being studied.  A field worker
can catch a fish in a net, capture a mouse in a trap, or sieve
organisms from a soil or sediment sample.  Depending on
the species and  objectives,  once  the  investigator has
collected the  organisms, he or  she  may  make  direct
observations  and then  release them.  Alternatively, the
investigator may  retain the organisms for further study,
such as analyzing tissues for their contaminant content or
examining  them   microscopically  for  indications  of
contaminant-related abnormalities.

   From among  the  wide  variety of  available  field
methods, those used at a Superfund site should provide
data  at a  reasonable  cost  and  within  a reasonable
timeframe  for  that  site.    They   should  be  readily
reproducible, reliable, and relevant to the site.  The BTAG
can assist investigators in selecting methods appropriate to
a site.  In choosing a method, investigators also need to be
aware that they should obtain permission from federal and
state  fish  and   wildlife  agencies  before  collecting
vertebrates.  Some states also require  permits for collecting
certain other organisms.

   At sites in the nation's  temperate areas,  investigators
need to  coordinate site studies  with seasons.   Floristics
surveys  and   photosynthetic  measurements  must  be
conducted  during  the  growing season.   Surveying  a
migratory population,  such as  most  bird species,  will
require  coordination with season.   In addition, natality
studies should occur during the warm months, when most
animal species produce young.

   The final section of this Bulletin provides additional
information about techniques available for field studies of
different types of populations and communities.

Level of Effort

   A site's characteristics, its contaminant picture, and a
proposed field study's objectives  together  indicate the
level of effort appropriate to carrying out the study.  For
example, an objective to  identify  potentially  affected
animal species at a small site with few habitats will require
a  lower level  of effort  than one  that  specific to the
evaluation of community structure  at a large  site with
several  habitats.   The number  and  nature of ecological
components are endpoints specified by the  objectives also
may affect a study's level of effort.  As  the number of
ecological components and  assessment and measurement
endpoints increases, the  level  of  effort  generally  will
increase. Additionally, some organisms are more difficult
to observe or sample than others, and some measurements
are more difficult to make. For example, collecting insects
usually entails less effort than collecting fish.

   In conducting field  studies,  the  level of effort varies
with  the sampling method  chosen:  qualitative,  semi-
quantitative, or quantitative (17).   Qualitative  sampling
which has as its goal to observe or sample as many taxa as
possible in the available  time,  requires the least  effort.
                                                                     Qualitative sampling attempts to sample all habitats, using
                                                                     several collection methods at each sample station. Such an
                                                                     approach can prove useful for a site reconnaissance visit,
                                                                     with  the  objective  of  identifying potentially  exposed
                                                                     ecological components and readily apparent effects.

                                                                        Rapid Bioassessment Protocol II is an  example of a
                                                                     semi-quantitative, or intermediate-level, sampling method
                                                                     for benthic macroinvertebrates inhabiting flowing waters
                                                                     (21).  This approach offers a time-saving and cost-effective
                                                                     means   of   obtaining    information   about   benthic
                                                                     macroinvertebrates. In this approach, the field team uses a
                                                                     net to collect  organisms from two  approximately one-
                                                                     square-meter areas, one in a fast-flowing part of the stream
                                                                     and the other in a slow-flowing area.  The organisms  are
                                                                     then enumerated and classified only to family level, which
                                                                     requires less time than classification to genus or species.
                                                                     A sub-sample  of  100  organisms  is then  classified
                                                                     according to guild. An additional sample is collected from
                                                                     an area with coarse paniculate organic matter,  such as a
                                                                     leafpack or an area near the shore.  The organisms in this
                                                                     sample are classified simply as shredders or non-shredders.

                                                                        Quantitative sampling uses methods that sample a unit
                                                                     area or volume of habitat.  Generally, these methods  are
                                                                     applied to  randomly  selected  sampling units.   As with
                                                                     semi-quantitative sampling,  the organisms  collected  are
                                                                     counted and classified.

                                                                        In deciding on level of effort, investigators  should be
                                                                     aware that limited sampling efforts could provide enough
                                                                     data for an  adequate ecological risk assessment  of a
                                                                     Superfund site.   It is true  that differences in  life cycle
                                                                     characteristics  and diurnal  effects do  prevent limited
                                                                     sampling from providing a comprehensive  estimate of all
                                                                     species.   However,  if field studies at the site  sample
                                                                     enough biota, these kinds of variations will  have minimal
                                                                     effect on the overall assessment.

                                                                     Sampling Plan

                                                                        A sampling plan for field study indicates the number of
                                                                     sampling  points,  the number of  replicates  for  each
                                                                     sampling  point,  the  method for determining  sampling
                                                                     locations,  holding times  for samples, and any  sample
                                                                     preparation required for laboratory analysis.  In making
                                                                     these  decisions  for  an  ecological  field  study,   the
                                                                     investigator needs to  consider the study objectives,  the
                                                                     level of effort, the site's soil, the ecological component(s),
                                                                     the measurement  endpoints, the method,  the  statistical
                                                                     method of analyzing data, and the available resources. For
                                                                     example, the approach to statistical analysis will  affect
                                                                     sampling size.   If the field study  is one  of a group of
                                                                     coordinated  studies,  then the investigator also needs to
                                                                     consider whether a particular sampling method  can apply
                                                                     to all the studies in the group.

                                                                        In general,  sampling locations can be  selected either
                                                                     non-randomly  or randomly.   Qualitative  and  semi-
                                                                     quantitative  surveys  make use of non-random  sampling,
                                                                     taking into  account   the  habitat  and mobility  of  the
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organisms  and the  location of contaminant "hot spots."
For  quantitative  sampling, investigators  generally use
random sampling methods.

   When the  investigator has decided on the number  of
sampling locations and the method of selecting them, he or
she  must also decide how  many  replicate samples  to
collect per site. Both the study  objectives and the data
quality  objectives   (discussed  below)   influence  this
decision.    While  natural  variability  makes  replicate
sampling  desirable, for some field studies the sampling
population cannot  specify  a  fixed number of replicates.
For example, field biologists have no  control over trapping
success.
Quality      Assurance/Quality
(QA/QC) Standards
Control
   Quality assurance and quality control standards are an
essential element in the study plan.  Included among the
QA/QC considerations  are  the  data quality objectives
(DQOs).  These are statements that define the level of
uncertainty that the investigator is  willing to accept in
environmental data used to support  a remedial decision.
DQOs address  the  purpose and  use  of  the data, the
resource  constraints  on   data  collection,   and  any
calculations based on the data.   In particular, DQOs help
investigators to decide how many samples and replicates to
collect in order to limit uncertainty to  an acceptable level.

   DQOs also guide decisions  about the level of detail
necessary for the study.  For example, in field  studies
involving certain groups of organisms,  such as  insects,
DQOs establish the level to which the investigation should
take the identification of organisms.  Identification to the
level of family or genus requires less expertise and time
than identification to the level of species.  However, the
DQOs may require  identification to  the species level to
obtain  detailed  enough  information  about the  site's
ecological condition.

   In addition to defining acceptable uncertainty, QA/QC
standards address other concerns:

•   Reference sites.  As discussed earlier, the investigator
     should achieve a careful match between the Superfund
     site and one or more reference sites.

•   Accurate identification of organisms. The investigator
     must  identify  organisms accurately.    A common
     means of ensuring the  accuracy  of  identification
     involves   having the classification  of a  subset of
     organisms verified by independent experts.

•   Adherence to sampling plan.  Field biologists must
     adhere closely to the sampling  plan in order to collect
    valid data. Consequently, the study's design will need
    to incorporate  methods for checking how precisely
    personnel have followed the sampling plan.  For
     example,   QA/QC   standards   may   require  field
    biologists to  maintain  field notebooks  and  submit
     copies of these.  Chain of custody documents provide
    another means  of tracking small  collection, transfer,
    and analysis.

•   Contractor.    The  contractor  selected  must  have
    personnel with the  expertise needed to perform  the
    particular type of field study and interpret the data.  In
    addition, the  contractor  must have  the  necessary
    equipment  and personnel  skilled  in  its use  and
    maintenance.

Statistical Analysis of Field  Data

    In performing statistical analyses of field data from
Superfund sites,  two issues require  special  consideration:
lack of randomness and use of indices.
   Lack of Randomness.  Neither the Superfund site  nor
the reference site is selected randomly. As a result of this
lack of randomness, the investigator must use one of the
following approaches in statistically analyzing  differences
between the Superfund site and the reference site:

   •   The  investigator   selects    sampling  stations
       randomly at both  the  Superfund  site  and  the
       reference site(s), and then tests the hypothesis that
       observed differences between these  stations result
       from conditions at the  stations in the Superfund
       site.

   •   The  investigator tests  the  hypothesis that  the
       reference site(s) and the Superfund  site differ.  If
       such a difference  exists, the investigator then
       employs   nonstatistical   methods   to  evaluate
       whether  contamination  at  the  Superfund   site
       causes this difference.

    Use of Indices.  A field study can generate a volume of
data too  large to be analyzed efficiently.  In such a case,
reducing classes of data to a  single  number, called  an
index, simplifies the analysis.   Some of the community
traits  discussed earlier, including evenness  and diversity,
are examples of indices calculated from taxonomic data.
Indices also  include biotic  indices, which examine  the
environmental tolerances  or requirements of particular
species or groups of species.

   While indices can make  field data more manageable,
investigators need  to   appreciate  that   indices  have
properties that can preclude standard statistical comparison
of results among sampling locations (9).  If an ecological
risk assessment makes use of indices, the discussion of
uncertainty needs to address the limitations of the indices
and acknowledge the assumptions that they make.
                        Field Methods

                           The following list includes a brief description, by type
                        of organism, of field methods useful  in  ecological risk
                        assessments at Superfund sites.  Some methods  focus on
                        ways to collect organisms, while others concern ways to
                        examine them.
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   These methods represent  only  a selection  of those
available.  In  designing  a  field study,  the investigator
should consult the BTAG, which may suggest approaches
not described here.  Please  note also that this catalogue
includes only  methods  used  in  studying biota.   For
methodology relating to the study of physical and chemical
characteristics of a site,  investigators should consult the
following EPA documents:

   •    Sampler's Guide to  the  Contract Laboratory
        Program. EPA/540/P-90/006, December 1990.

   •    Compendium ofERT Surface Water and Sediment
        Sampling Procedures. EPA/540/P-91/005, January
        1991.

   •    Compendium of ERT Soil  Sampling and Surface
        Geophysics   Procedures.    EPA/540/P-91/006,
        January 1991.

   •    Compendium  of ERT  Groundwater  Sampling
        Procedures. EPA/540/P-91/007, January 1991.

   •    Compendium of ERT Waste Sampling Procedures.
        EPA/540/P-91/008, January 1991.

Periphyton

   Scraping,  coring,  or  suction.    Field studies  of
periphyton can involve collecting these  organisms from
their natural environment by means of devices that scrape,
core, or use suction (18,30).

   Artificial  substrate.   Materials such  as granite, tile,
plastic,  and glass can  serve as  an artificial substrate on
which periphyton communities can develop (18, 30).

   Data Analysis. Investigators can study the taxonomic
composition,  biomass,   species richness,  and  relative
abundance of periphyton communities from either natural
habitats or artificial substrates.  In addition, analysis  of
data can yield information about diversity, evenness, and
similarity (18, 30).

Plankton

   Trapping,  pumping,   netting,   and   using  closing
samplers.    Samples  can  be  collected  from natural
substrates by means of  traps,  pumps, nets,  and closing
samplers such as tubes and bottles (3,  18, 30).

   Data Analysis. After identifying  the organisms in the
sample  investigators  can  determine  species   richness,
relative abundance and diversity (18).

Benthic Macroinvertebrates

   Dredging and digging. Dredging and digging provide
qualitative samples from the natural environment (17, 18).

   Stream  netting,  coring,  or sampling  with  a  grab.
Stream  netting, coring and sampling with a grab collect
quantitative   samples  from  the  natural  environment.
Stream  netting  involves using specialized nets  to collect
        samples.   The  Surber and  the  Hesser are stream nets
        commonly used to  sample  macroinvertebrates  in or  on
        substrate.     Some   types   of   stream   nets  collect
        macroinvertebrates drifting in the water column ( a normal
        occurrence  with  benthic  macroinvertebrates  inhabiting
        flowing water).  A grab is a sampling device with jaws that
        penetrate and extract an area of the substrate (1,  4, 12,  17,
        18,21).

           Sweep netting.  Sweep nets collect qualitative samples
        associated with aquatic vegetation (17, 18).

           Sampling  with  other  devices.    More quantitative
        methods   of   sampling   benthic   macroinvertebrates
        associated with aquatic vegetation involve using  either  the
        Wilding  stovepipe  or  the  Maca the  Minto,  or   the
        McCauley samplers (17, 18, 21).

           Artificial substrate.  Communities of benthic macro-
        invertebrates   can  develop  on  artificial    substrates
        introduced in the site's water (17, 18, 21).

           Data Analysis.   Once the sample  has been  collected,
        the  investigator can  identify  the  species present and
        measure biomass.  Further analysis of data can disclose
        such parameters  as  species  richness,  species density,
        diversity, and relative abundance (17, 18, 21).

        Fish

           Seining.   Seines are  effective sampling devices  for
        shallow water such as stream, nearshore areas of lakes, and
        shallow  marine and  estuarine  locations.   The most
        commonly  used  seines  consists  of a  specialized   net
        attached to long vertical poles (4, 21, 30).

           Trawling.  In deeper waters that have no obstructions,
        investigators use tapered conical fishing net called a trawl.
        A boat pulls the trawl through the water at  a  specified
        depth (18, 21,30).

           Passive Netting.  For passive netting, the field biologist
        attaches a net to the bottom  of a river or lake.  Fish that
        swim into the net become entangled or unable to escape.
        Passive nets  include gear trammel, and hoop nets (20,  18,
        21,30).

           Electrofishing.   This  technique  which  applies  an
        electrical charge to a small  area in a  body  of water
        momentarily immobilizing fish.  Electrofishing is effective
        for sampling fish in streams, rivers, and lakes (18, 21, 30).

           Chemical collection.     This  specialized   technique
        involves  exposing the animals  to fish  toxicants (21).
        Investigators  should  familiarize  themselves  with  state
        regulations regarding the use of these substances. While
        use of such chemicals  is a standard procedure, this method
        is not preferred because of its negative effects.

           Fish tissue  collection.    Methods  for  collecting fish
        tissue are described in References 25, 27, and 28.
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   Data analysis.  Once the investigator has identified the
fish, he or she can determine such measurement endpoints
as relative abundance and species richness (18, 21, 30).

Terrestrial Vegetation

   The methods described for terrestrial vegetation work
equally well for upland and wetland areas.  This is true
even though in wetlands,  by definition,  the  prevailing
vegetation is typically adapted to saturated soil conditions.

   Remote sensing.   Remote sensing, which uses either
satellite  imagery or aerial  photography, is  useful when
contamination of a site has resulted in restricted access or
when initial site reconnaissance  requires surveys  of large
areas.  The  technique provides information about general
landscape patterns, gross  features of the vegetation,  and
photosynthetic  rates.   Infrared  and multispectral remote
sensing also can be used to identify and  map  areas of
stressed vegetation (13).  Usually,  some limited  ground-
level  survey  (ground-truthing)  is  required  to  verify
identification of species and condition.

   Quadrats and  transects.   Quadrats  and transects are
often used in vegetation survey  and sampling methods to
provide a more quantitative approach to collecting data.
Quadrats are closed sampling units or plots.  Transects
consist of belts, strips,  or lines  used as a  sampling unit.
Both methods define precise, isolated areas for sampling,
recording, mapping, or studying  organisms  within a larger
area.   Both  methods  allow  investigators to  estimate
characteristics  such as  cover,  species frequency,  and
density (2, 10).

   Point method.  The point method estimates cover using
sampling points (2, 10).

   Distance methods.  Distance  methods provide  a means
of estimating coverage and  species density in  forests,
which would require large  quadrants  to  sample trees
adequately.    There  are   several  different  versions  of
distance  methods but in general  the methods are based on
measuring distances between  random  points   and  the
sampled plants, or between individual plants (2, 10).

Soil Fauna

   Coring.   Field biologists collect samples  by  coring
devices (23).

   Driving organisms from soil sample. Heat, moisture,
or chemical stimuli drive the organisms from the  soil into
collection chambers (23).

   Sieving.  Sieving can be used to retrieve  the fauna from
the  soil.  Dry sieving separates soil fauna from fallen
leaves and  friable soil.   Wet  sieving, also called  soil
washing,  is used  to  extract  organisms  from fine mud,
sediments, and leaf litter (23).

   Density  separation.   Floatation, centrifugation,  and
sedimentation separate organisms from soil  on the basis of
density (23).
           Data analysis.  After the investigator has identified the
        organisms,  he  or  she  can  determine  parameters  that
        characterize the community.

        Terrestrial and Flying Insects

           Trapping.   Traps can be used to collect insects  of
        particular species, groups of species, insects at specific life
        stages, or  insects  with specific  behaviors.   Trapping
        methods include  the  use  of attractant chemicals,  light,
        hosts, host  substitutes, and insect sounds.  Traps include
        emergence, pitfall, and sticky traps, to name a few (23).
        The type of trap used affects both the range of species
        collected and the types of data collected.  When collecting
        several kinds of  insects, the investigator can  determine
        such measurement endpoints as species diversity (23).

           Sign.   Frass  (feces), nests,  cast-off larval  cases  or
        cocoons,  and auditory signals  indicate  the presence  of
        particular insects (23).

        Amphibians, Reptiles, and Mammals

           Auditory  and visual  study.    Visual  studies   can
        determine the presence of species on  a site.  In addition,
        sounds can indicate the presence of certain amphibians and
        mammals (19, 22).

           Sign.  Tracks, nests, burrows, dens, scat, or carcasses
        indicate which species occur on a site (19, 22).

           Trapping.     Traps  and   nets  can  provide  more
        quantitative  means of sampling, and depending on  the
        breadth of the  study, allow an investigator to  determine
        population  and/or community parameters relative to  the
        reference site.  Trapping methods include both live traps
        and kill traps.  Depending on the study objectives,  the
        investigator  either  makes  observations  on live-trapped
        animals and leases them or retains the animals for further
        study (5, 6, 7, 19).

           Tissue  collection.  Methods for collecting  tissues  are
        described in Reference 26.

        Birds

           Auditory and visual studies. Ornithologists identify the
        species at a site by walking  specified areas or distances
        (e.g.,  along  a  transect)  and  record birds  sighted  or
        identified through their songs (5).

           Nest success.   The evaluation of  nest success on the
        basis  of measures  such as clutch size  and  number  of
        fledglings is practical only for very large Superfund sites
        (7).
           Trapping.  Not practical for most Superfund sites,  a
        variety of traps and nets can be used to capture birds (6).
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Field Studies: Their Contribution

   As the previous sections of this Bulletin indicate, field
studies can contribute to all phases of the  ecological risk
assessment of a Superfund site and in a variety of ways.
Specifically,  a well  designed  field  study  can  allow
investigators to:
   •   Identify and describe the habitats  and species
       (including those of special concern)  actually  or
       potentially exposed to  waste site contaminants.
   •   Indicate detrimental  ecological effects that may
       have occurred on or near the site.
   •   Provide information  adding  to  the  weight  of
       evidence linking adverse  effects to  the  site's
       contaminants.
   •   Provide samples for biomarker studies, such as
       bioaccumulation  studies,  biochemical  analyses,
       and histopathological studies.15
   •   Aid  in identifying remedial alternatives  that  are
       protective of natural resources.
   •   Assist in monitoring remediation effectiveness.
   Investigators should consult with their Region's BTAG
to determine whether and when to conduct field studies
and to select the studies most appropriate to their sites.
References

1.  American Society for Testing and Materials (ASTM).
    1988. Annual Book of ASTM Standards: Water and
    Environmental  Technology,  Vol.  11.04.   American
    Society for Testing and Materials, Philadelphia, PA.
2.  Harbour,  M.G., J.H.  Burk  and W.D.  Pitts.  1980.
    Terrestrial Plant Ecology. The  Benjamin/Cummings
    Publishing company, Inc., Reading, MA.
3.  Bloesch,  J.  (Editor).  1988.   Mesocosm  Studies.
    Hydrobiologia  159:221-313. W. Junk,  Publishers,
    Dordrecht, The Netherlands.
4.  Coull,  B.C.  1980.  Shallow Water Marine  Biological
    Research. Pages  275-284  in  P.P.  Diemer,  FJ.
    Vernberg  and  D.Z.   Mirkes   (Editors).   Ocean
    Measurements for  Marine  Biology.  University  of
    South Carolina Press, Columbia, SC.
5.  Davis, D.E.  and R.L. Winstead. 1980. Estimating the
    Numbers  of Wildlife Populations. Pages 221-245 in
    S.D.   Schemnitz  (Editor).  Wildlife  Management
    Techniques  Manual.  Fourth Edition. The Wildlife
    Society, Washington, DC.
   15  A biomarker is  a  physiological,  biochemical,  or histological
response that is measured  in individual organisms and that indicates
either exposure or sub-lethal stress.
        6.  Day, G.I., S.D.  Schemnitz and R.D.  Taber.  1980.
           Capturing and Marking Wild Animals. Pages 61-88 in
           S.D.   Schemnitz  (Editor).  Wildlife  Management
           Techniques Manual.  Fourth Edition.  The Wildlife
           Society, Washington, DC.

        7.  Downing,  R.L.  1980.  Vital  Statistics  of Animal
           Populations.  Pages   247-267  in   S.D.   Schemnitz
           (Editor). Wildlife Management Techniques Manual.
           Fourth  Edition. The  Wildlife Society,  Washington,
           DC.

        8.  Escherich,  P. and D. Rosenburger. 1987. Guidance on
           Use of Habitat Evaluation Procedures and Habitat
           Suitability  Index Models for CERCLA Applications.
           U.S.  Department of  the  Interior,  CERCLA  301
           Project, Washington, DC.

        9.  Greig-Smith, P.  1983.  Quantitative Plant Ecology.
           Third   Edition.  University  of   California   Press,
           Berkeley, CA.

        10. Green,  R.H.  1979.  Sampling Design and Statistical
           Methods for  Environmental Biologists.  J.  Wiley and
           Sons, New York, NY.

        11. Hair, J.D. 1980. Measurement of Ecological Diversity.
           Pages  269-275 in S.D. Schemnitz (Editor). Wildlife
           Management Techniques Manual. Fourth Edition. The
           Wildlife Society, Washington, DC.

        12. Hess,  A.D.   1941.   New   Limnological   Sampling
           Equipment. Limnol Soc. Amer. Spec. Pub I. 6:1-5.

        13. Kapustka, L.A. 1989.  Vegetation Assessment. Section
           8.3  in Warren-Hicks, W.,  B.R.  Parkhurst, and  S.S.
           Baker  Jr.   (Editors).  Ecological  Assessment  of
           Hazardous  Waste Sites: A  Field and  Laboratory
           Reference.      EPA/600/3-89/013.     Environmental
           Research  Laboratory,  Office  of  Research  and
           Development, U.S. Environmental Protection Agency,
           Corvallis, OR.

        14. Karr, J.R. 1981. Assessment of Biotic Integrity Using
           Fish Communities. Fisheries 6:21-27.

        15. Karr, J.R.,  K.D. Fausch, P.L Angermeier,  P.R. Yant,
           and  I.J.   Schlosser.   1986.  Assessing   Biological
           Integrity  in  Running   Waters:  Method and Its
           Rationale.  Illinois Natural Historical Survey, Special
           publ. No. 5.

        16. Kirkpatrick,  R.L.  1980.  Physiological  Indices in
           Wildlife Mangement. Pages 99-112 in S.D. Schemnitz
           (Editor)   Wildlife Management Techniques Manual.
           Fourth  Edition. The  Wildlife Society,  Washington,
           DC.

        17. Klemm, D.J.,   P.A.   Lewis,  F.  Fulk,  and  J.M.
           Lazorchak.   1990.  Macroinvertebrate  Field  and
           Laboratory Methods  for Evaluating the  Biological
           Integrity  of  Surface  Waters.  EPA/600/4-90/030.
           Environmental   Monitoring  Systems  Laboratory—
           Cincinnati, Office of Modeling, Monitoring Systems,
March 1994 • Vol. 2, No. 3
12
ECO Update

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    and Quality Assurance, U.S. Environmental Protection
    Agency. Cincinnati, OH.

18. LaPoint,  T.W.  and  J.F.  Fairchild.  1989.  Aquatic
    Surveys  Section  8.2 in  Warren-Hicks,  W.,  B.R.
    Parkhurst, and  S.S. Baker Jr.  (Editors). Ecological
    Assessment of Hazardous  Waste  Sites: A  Field and
    Laboratory      Reference.      EPA/600/3-89/013.
    Environmental  Research  Laboratory,   Office  of
    Research  and  Development,  U.S.  Environmental
    Protection Agency, Corvallis, OR.

19. McBee, K. 1989. Field Surveys: Terrestrial Vertebrate
    Section 8.4 in Warren-Hicks, W.,  B.R. Parkhurst, and
    S.S.  Baker Jr.  (Editors). Ecological Assessment of
    Hazardous Waste Sites: A Field  and Laboratory
    Reference.    EPA/600/3-89/013.    Environmental
    Research  Laboratory,   Office   of  Research  and
    Development, U.S. Environmental Protection Agency,
    Washington, DC.

20. Nielsen,  L.A.  and  D.L.  Johnson (Editors).  1983.
    Fishing  Techniques.  American  Fisheries  Society,
    Bethesda, MD.

21. Plafkin, J.L., M.T. Barbour, K.D. Porter, S.K. Gross,
    and  R.M. Hughes.  1989.   Rapid  Bioassessment
    Protocols for Studies in Streams and Rivers: Benthic
    Macroinvertebrates  and  Fish.  EPA/600/4-89/001.
    Assessment  and  Watershed   Protection  Division,
    Office  of Water,  U.S.  Environmental  Protection
    Agency, Corvallis, OR.

22. Smith,  R.L. 1966. Ecology and Field Biology. Harper
    and Row, New York, NY.

23. Southwood, T.R.E.  1978. Ecological Methods:  With
    Particular  Reference   to  the   Study   of Insect
    Populations. Second Edition. John Wiley and Sons,
    New York, NY.

24. Suter,  G.  1989. Ecological Endpoints. Chapter 2 in
    Warren-Hicks, W., B.R. Parkhurst, and S.S. Baker Jr.
    (Editors).  Ecological Assessment of Hazardous Waste
    Sites: A Field and Laboratory Reference. EPA/600/3-
    89/013. Environmental Research Laboratory, Office
    of Research and  Development, U.S.  Environmental
    Protection Agency, Corvallis, OR.

25. U.S. Environmental Protection Agency, 1981. Interim
    Methods for the Sampling and Analysis of Priority
    Pollutants in Sediments and Fish Tissue. EPA/600/4-
    81/055.   Environmental   Monitoring    Systems
    Laboratory, Cincinnati, OH.

26. U.S. Environmental Protection Agency, 1982.  Test
    Methods    for    Evaluating    Solid     Waste:
    Physical/Chemical Methods.   SW-A46. 2nd edition.
    Office  of Solid  Waste and Emergency  Response,
    Washington, DC.

27. U.S.   Environmental   Protection  Agency.   1990.
    Analytical Procedures and Quality Assurance Plan for
    the  Determination  of  PCDD/PCDF  in  Fish.
           EPA/600/3-90/022.       Environmental
           Laboratory, Duluth, MN.
    Research
       28. U.S.  Environmental  Protection  Agency.    1990.
           Analytical Procedures and Quality Assurance Plan for
           the Determination  of Xenobiotic  Contaminants in
           Fish.  EPA/600/3-90/023.   Environmental Research
           Laboratory, Duluth, MN.

       29. U.S.   Environmental  Protection  Agency.   1992.
           Framework   for   Ecological   Risk  Assessment.
           EPA/630/R-92/001.      Risk   Assessment   Forum,
           Washington, DC.

       30. Weber, C.I. (Editor).  1973.   Biological Field and
           Laboratory Methods for Measuring  the  Quality of
           Surface Waters and  Effluents.   EPA/67/4-73-001.
           National  Environmental  Research   Center,  U.S.
           Environmental Protection Agency, Cincinnati, OH.
       Additional Print Resources Available
       from the Federal Government
       Adamus, P.R. etal. 1991. Wetland Evaluation Technique.
          Vol. I: Literature Review and Evaluation Rationale.
          Technical Report WRP-DE-2. U.S. Army Corps of
          Engineers.
       Baker, B. andM. Kravitz. 1992. Sediment Classification
          Methods Compendium. EPA/823/R-92/006. U.S. EPA
          Office of Water.
       Beyer, W.N. 1990. Evaluating Soil Contamination.
          Biological Report 90(2). U.S. Department of Interior.
       Fletcher, J. and H. Ratsch. 1990. Plant Tier Testing: A
          Workshop to Evaluate Nontarget Plant Testing in
          Subdivision J Pesticide Guidelines. EPA/600/9-91/041.
       Linder, G. et al. 1992. Evaluation of Terrestrial Indicators
         for Use in Ecological Assessments at Hazardous Waste
          Sites. EPA/600/R-92/183.  Office of Research and
          Development, ERL-Corvallis, OR.
       U.S. Environmental Protection Agency. 1988. Guidance
         for Conducting Remedial Investigations and Feasibility
          Studies under CERCLA.  EPA/540/G-89/004.
March 1994 • Vol. 2, No. 3
13
ECO Update

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U.S. EPA Regional BTAG  Coordinators/Contacts
EPA Headquarters
Ruth Bleyler
Toxics Integration Branch
(OS-230)
OERR/HSED
USEPA
Washington, DC 20460
(703) 603-8816
(703) 603-9104 FAX

David Charters
ERT
U.S EPA(MS-lOl)
2890 Woodbridge Ave.
Bldg. 18
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(908) 906-6826
(908) 906-6724 FAX

Steve Ellis
Elaine Suriano
OWPE
U.S. EPA(OS-510)
401 M Street, SW
Washington, DC 20460
(202) 260-9803
(202) 260-3106 FAX

Joseph Tieger
U.S. EPA(OS-510W)
401 M Street, SW
Washington, DC 20460
(202) 308-2668

REGION 1
Susan Svirsky
Waste Management Division
U.S. EPA Region 1
(HSS-CAN7)
JFK Federal Building
Boston, MA 02203
(617) 573-9649
(617) 573-9662 FAX

REGION 2
Sharri Stevens
Surveillance Monitoring
Branch
U.S. EPA Region 2
(MS-220)
Woodbridge Avenue
Raritan Depot Building 209
Edison, NJ 08837
(908) 906-6994
(908) 321-6616 FAX
REGION 3
Robert Davis
Technical Support Section
U.S. EPA Region 3 (3HW13)
841 Chestnut Street
Philadelphia, PA  19107
(215) 597-3155
(215) 597-9890 FAX

REGION 4
Lynn Wellman
WSMD/HERAS
U.S. EPA Region 4
345 Courtland Street, NE
Atlanta, GA  30365
(404) 347-1586
(404) 347-0076 FAX

REGION 5
Eileen Helmer
U.S. EPA Region 5
(5HSM-TUB7)
230 South Dearborn
Chicago, IL 60604-1602
(312) 886-4828
(312) 886-7160 FAX

REGION 6
Jon Rauscher
Susan Swenson Roddy
U.S. EPA Region 6 (6H-SR)
First Interstate Tower
1445  Ross Avenue
Dallas, TX 75202-2733
(214) 655-8513
(214) 655-6762 FAX

REGION 7
Bob Koke
SPFD-REML
U.S. EPA Region 7
726 Minnesoata Avenue
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(913) 551-7468
(913) 551-7063 FAX
REGION 8
Gerry Hennington
U.S. EPA Region 8
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999 18th Street
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(303) 294-7656
(303) 293-1230 FAX
REGION 9
Doug Steele
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(415) 744-2309
(415) 744-1916 FAX

REGION 10
Bruce Duncan
U.S. EPA Region 10
(ES-098)
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Seattle, WA 98101
(206) 553-8086
(206) 553-0119 FAX

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