r/EPA
United States Environmental
Protection Agency
Office of Water
Washington, DC 20460
EPA822-R-02-014
March 2002
    METHODS FOR EVALUATING WETLAND CONDITION
                       #l  Introduction to
         Wetland Biological Assessment

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     United States Environmental   Office of Water        EPA 822-R-02-014
     Protection Agency         Washington, DC 20460    March 2002
METHODS FOR EVALUATING WETLAND CONDITION
                        #l  Introduction to
      Wetland Biological Assessment
                Principal Contributor
         Maine Department of Environmental Protection
                 Thomas J. Danielson
                 Prepared jointly by:
          The U.S. Environmental Protection Agency
 Health and Ecological Criteria Division (Office of Science and Technology)
                      and
    Wetlands Division (Office of Wetlands, Oceans, and Watersheds)

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NOTICE

The material in this document has been subj ected to U. S. Environmental Protection Agency (EPA)
technical review and has been approved for publication as an EPA document. The information
contained herein is offered to the reader as a review of the "state of the science" concerning wetland
bioassessment and nutrient enrichment and is not intended to be prescriptive guidance or firm advice.
Mention of trade names, products or services does not convey, and should not be interpreted as
conveying official EPA approval, endorsement, or recommendation.


APPROPRIATE  CITATION

U.S. EPA. 2002. Methods for Evaluating Wetland Condition: Introduction to Wetland Biologi-
   cal Assessment. Office of Water, U.S. Environmental Protection Agency, Washington, DC.
   EPA-822-R-02-014.


ACKNOWLEDGMENTS

EPA acknowledges the contributions of the following people in the writing of this module: Candy
Bartoldus (Environmental Concern, Inc.), Robert Brooks (Penn State University), Thomas J. Danielson
(Maine Department of Environmental Protection), Jeanne Difranco (Maine Department of Environmen-
tal Protection), Mark Gernes (Minnesota Pollution Control Agency), Judy Helgen (Minnesota Pollution
Control Agency), James Karr (University of Washington), Ken Kettenring (New Hampshire Depart-
ment of Environmental Services), Richard Lillie (Wisconsin Department of Natural Resources), and Billy
Teels (Natural Resources Conservation Service, Wetland Science Institute).

This entire document can be downloaded from the following U. S. EPA websites:

                           http://www.epa.gov/ost/standards

                           http://www.epa.gov/owow/wetlands/bawwg
                                           11

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                         CONTENTS
FOREWORD	v

LIST OF "METHODS FOR EVALUATING WETLAND
CONDITION" MODULES	vi

SUMMARY	1

PURPOSE	1

INTRODUCTION	2

EVALUATING WETLAND HEALTH	4

BlOASSESSMENT METHODS	8

USING BIOLOGICAL INFORMATION To IMPROVE
MANAGEMENT DECISIONS	19

ACKNOWLEDGMENTS	26

REFERENCES	27

GLOSSARY	3O

APPENDIX	33

                         LIST OF TABLES

TABLE 1:   REPORTS RELATED TO WETLAND
         BlOASSESSMENTS IN THE MONITORING
         WETLAND CONDITION SERIES	 1O

TABLE 2:   STRENGTHS AND LIMITATIONS OF ASSEMBLAGES
         FOR USE IN WETLAND BIOASSESSMENTS	11

TABLE 3:    TYPES OF WATER QUALITY CRITERIA	22
                              111

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                         LIST OF FIGURES

FIGURE 1:   ANNUAL AVERAGE RATE OF WETLANDS LOSS	4

FIGURE 2:   CONTINUUM OF HUMAN DISTURBANCE ON BIOLOGICAL
          CONDITION OF WETLANDS 	5

FIGURE 3:   ECOSYSTEM INFLUENCES ON BIOLOGICAL INTEGRITY	7

FIGURE 4:   NUMBER OF BEETLE GENERA PLOTTED AGAINST A HUMAN
          DISTURBANCE GRADIENT	  1 8

FIGURE 5:   FLORISTIC QUALITY ASSESSMENT INDEX PLOTTED AGAINST
          A HUMAN DISTURBANCE GRADIENT	  1 8

FIGURE 6:   NUMBER OF DIPTERA TAXA PLOTTED AGAINST RAPID
          ASSESSMENT METHOD (RAM) SCORES, A RAPID
          FUNCTIONAL ASSESSMENT 	  1 8

FIGURE?:   A TO-METRIC MACROINVERTEBRATE IB! PLOTTED
          AGAINST TURBIDITY 	  1 8

FIGURES:   FRAMEWORK FOR IMPROVING WETLAND MANAGEMENT	2O

FIGURE 9:   THE MANAGEMENT CONTEXT OF THE STRESSOR
          IDENTIFICATION (SI) PROCESS	25

FIGURE 1O: WATERSHED MANAGEMENT CYCLE	26
                               IV

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                                   FOREWORD

In 1999, the U.S. Environmental Protection Agency (EPA) began work on this series of reports entitled
Methods for Evaluating Wetland Condition. The purpose of these reports is to help States and
Tribes develop methods to evaluate (1) the overall ecological condition of wetlands using biological
assessments and (2) nutrient enrichment of wetlands, which is one of the primary stressors damaging
wetlands in many parts of the country. This information is intended to serve as a starting point for States
and Tribes to eventually establish biological and nutrient water quality criteria specifically refined for
wetland waterbodies.

This purpose was to be accomplished by providing a series of "state of the science" modules concerning
wetland bioassessment as well as the nutrient enrichment of wetlands. The individual module format
was used instead of one large publication to facilitate the addition of other reports as wetland science
progresses and wetlands are further incorporated into water quality programs. Also, this modular
approach allows EPA to revise reports without having to reprint them all. Alist of the inaugural set of
20 modules can be found at the end of this section.

This series of reports is the product of a collaborative effort between EPAs Health and Ecological
Criteria Division of the Office of Science and Technology (OST) and the Wetlands Division of the
Office of Wetlands, Oceans and Watersheds (OWOW). The reports were initiated with the support
and oversight of Thomas J. Danielson (OWOW), Amanda K. Parker and Susan K. Jackson (OST),
and seen to completion by Douglas G Hoskins (OWOW) and Ifeyinwa F. Davis (OST). EPArelied
heavily on the input, recommendations, and energy of three panels of experts, which unfortunately have
too many members to list individually:

•     Biological Assessment of Wetlands Workgroup

•     New England Biological Assessment of Wetlands Workgroup

•     Wetlands Nutrient Criteria Workgroup
More information about biological and nutrient criteria is available at the following EPA website:

                              http ://www. epa. gov/ost/standards


More information about wetland biological assessments is available at the following EPA website:

                          http://www.epa.gov/owow/wetlands/bawwg
                                            V

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  LIST OF "METHODS FOR EVALUATING WETLAND
                CONDITION" MODULES

MODULE #             MODULE TITLE
   1 	INTRODUCTION TO WETLAND BIOLOGICAL ASSESSMENT
   2	INTRODUCTION TO WETLAND NUTRIENT ASSESSMENT
   3	THE STATE OF WETLAND SCIENCE
   4	STUDY DESIGN FOR MONITORING WETLANDS
   5	ADMINISTRATIVE FRAMEWORK FOR THE IMPLEMENTATION OF A
            WETLAND BIOASSESSMENT PROGRAM
   6	DEVELOPING METRICS AND INDEXES OF BIOLOGICAL INTEGRITY
   7	WETLANDS CLASSIFICATION
   8	VOLUNTEERS AND WETLAND BIOMONITORING
   9	DEVELOPING AN INVERTEBRATE INDEX OF BIOLOGICAL
            INTEGRITY FOR WETLANDS
   10	USING VEGETATION TO ASSESS ENVIRONMENTAL CONDITIONS
            IN WETLANDS
   11 	USING ALGAE TO ASSESS ENVIRONMENTAL CONDITIONS IN
            WETLANDS
   12	 USING AMPHIBIANS IN BlOASSESSMENTS OF WETLANDS
   13	BIOLOGICAL ASSESSMENT METHODS FOR BIRDS
   14	WETLAND BIOASSESSMENT CASE STUDIES
   15	BIOASSESSMENT METHODS FOR FISH
   16	VEGETATION-BASED INDICATORS OF WETLAND NUTRIENT
            ENRICHMENT
   17	LAND-USE CHARACTERIZATION FOR NUTRIENT AND SEDIMENT
            RISK ASSESSMENT
   1 8	 BlOGEOCHEMICAL INDICATORS
   19	NUTRIENT LOAD ESTIMATION
   2O	SUSTAINABLE NUTRIENT LOADING
                            VI

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             SUMMARY

 7)i°l°gical assessments (bioassessments)
J-J evaluate the health of a waterbody by di-
rectly measuring the condition of one or more
of  its  taxonomic   assemblages   (e.g.,
macroinvertebrates, plants)  and supporting
chemical and physical attributes.  A major
premise of bioassessments is that the commu-
nity of plants and animals will reflect the under-
lying health of the waterbody in which they live.
When a waterbody  is  damaged by  human ac-
tivities, biological attributes such  as taxonomic
richness, community structure, trophic structure,
and health of individual organisms will change.
For example, in disturbed systems the number
of intolerant taxa typically decreases and the pro-
portion of tolerant individuals  typically in-
creases.  The biological community will reflect
the cumulative effect of multiple  stressors,
whether they be chemical (e.g., toxic chemical),
physical (e.g., sedimentation), or biological (e.g.,
non-native species).


 In recent years, a growing number of State and
Federal organizations  have started to develop
bioassessment methods and Indexes of Biologi-
cal  Integrity (IBI) for  wetlands.  An IBI is an
index that integrates several biological metrics
to indicate a site's condition.  A common ap-
proach among these organizations is  to first
sample attributes of a taxonomic assemblage in
wetlands ranging from good condition to poor
condition.  The data are reviewed to identify
metrics, which are attributes of the assemblage
that show a predictable and empirical response
to increasing human  disturbance.   After the
metrics are tested and validated, they are com-
bined into  an IBI, which provides a summary
score that is easily communicated to managers
and the public.
 Once wetland bioassessment methods are de-
veloped, wetland managers can use them for a
variety of applications.  Wetland managers can
use bioassessments to evaluate the performance
of wetland restoration activities or best manage-
ment practices, such as buffer strips, in restor-
ing and protecting wetland health. Wetland
managers can also use bioassessments to more
effectively target resources for restoring, protect-
ing, and acquiring wetlands.  Many States are
developing bioassessments to better incorporate
wetlands into  water quality  programs.
Bioassessments can help States refine their wa-
ter quality standards to reflect typical conditions
found in wetlands. Using bioassessment infor-
mation, States can refine the components of
water quality standards by designating ecologi-
cally  based  beneficial uses of wetlands and
adopting numeric and narrative biological cri-
teria (biocriteria). After improving water qual-
ity standards, States can use bioassessments to
determine if wetlands are meeting the identified
beneficial uses, track wetland quality, and in-
corporate wetlands into Clean Water Act Sec-
tion 305(b) water quality reports. Rigorous stan-
dards  will also help States improve water qual-
ity certification decisions for activities that re-
quire  Federal permits, such as dredge-and-fill
permits. Under Section 401 of the Clean Water
Act, States can certify, grant, or deny State per-
mits if a proposed activity will  harm the chemi-
cal, physical, or biological integrity of a wet-
land as defined in their water quality standards.


              PURPOSE

 r I This module provides an overview of wet-
 J. land bioassessments and refers the reader to
other modules for details on particular topics.

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         INTRODUCTION

 TT/etlands are important components of wa-
 r r  tersheds and provide many valuable func-
tions to the environment and to  society
(Richardson 1994, NRC  1995, Mitsch and
Gosselink 2000). Wetland ecosystem functions
include the transfer and storage of water, bio-
chemical transformation and storage,  the pro-
duction of living plants and animals, the decom-
position of organic materials, and the  commu-
nities and habitats for living  creatures
(Richardson 1994).  Based on these and other
ecological functions, wetlands provide "values"
to humans and naturally functioning ecosystems.
Important values include, but are not limited to,
flood control, filtering and cleansing water, ero-
sion control, food production (shrimp, ducks,
fish, etc.), timber production, recreation (boat-
ing,  fishing, bird watching, etc.), winter deer
yards, and habitat for plants and animals, includ-
ing many rare or endangered species (Box 1).


  Wetlands have not always been appreciated for
their many benefits. Historically, wetlands were
perceived as potentially valuable agricultural
land, impediments to development and progress,
and harbors of vermin and disease (Fischer 1989,
NRC 1995, Dahl and Alford 1996, Mitsch and
Gosselink 2000). Prior to the mid-1970s, drain-
age and destruction of wetlands were accepted
practices and even encouraged by public poli-
cies, such as the Federal Swamp Land Act of
1850, which deeded extensive wetland acreage
from the Federal Government to the States for
conversion  to agriculture (NRC 1995, Mitsch
and Gosselink 2000).  Some people today still
hold many  of these beliefs.  These public per-
ceptions of wetlands shaped wetland policy and
management during much of the past  century.
Consequently, wetland policy and management
have taken a very different path compared to the
policy and management of streams,  rivers, and
lakes.  These other aquatic systems have also
been damaged by human activities, but they have
not been subject to the same intense onslaught
of development and agricultural pressures as
wetlands. As a result, whereas most Federal and
State policies since the establishment of the
Clean Water Act have focused on maintaining
and restoring streams, rivers, and lakes, most
wetland policies have been focused on prevent-
ing wetlands from being converted to uplands.


 During the 1970s and 1980s, Federal and State
agencies did not focus many resources on wet-
land quality. They were attempting to slow the
rate of wetland loss and increase the rate of wet-
land restoration through various regulatory and
voluntary programs.  Today, wetlands are  still
being converted to uplands, but the national  rate
of wetland loss  has decreased over time
(Figure 1).


 Even though estimates of wetland acreage are
not exact, they can show general trends.  Ac-
cording to the U.S. Fish and Wildlife Service,
more than half of the original wetlands in the
continental United States have been lost. (Wilen
and Frayer  1990).  An estimated 105.5 million
acres of wetlands remained in the conterminous
United States in 1997 (Dahl 2000). Between
1986 and 1997, the net loss of wetlands was
644,000 acres. The loss rate during this period
was 58,500 acres/year, which represents an 80%
reduction in the average rate of annual loss com-
pared with  the period between the mid-1970s
and mid-1980s.  Various factors have contrib-
uted to the decline in the loss rate, including
implementation and enforcement of wetland pro-
tection measures, strengthened Federal and State
wetland regulatory programs, and elimination of
some incentives for wetland drainage.  Public
education and outreach about the value and func-
tion of wetlands, private land initiatives, coastal
monitoring  and protection programs, and wet-

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land restoration and creation actions have also   ity of wetlands.  The main goal of the Clean
helped reduce overall wetland losses.            Water Act is to "maintain and restore the chemi-
  .  ^  , T  .    ,      .         . .   .    «      cal, physical, and biological integrity of the
 As the Nation draws closer to achieving a no   -T .   ,        „.  ,  ,.      ,   ,  „
  it         ^   ,         .  .  ,      .   .      Nation s waters,  including wetlands. However,
net loss  in wetland acreage, it is becoming in-      ,          1-111      ,•    ^
    .  .         ^ ^  ^       ^   .     °       we know very little about the quality of our
creasmgly apparent that more attention and re-   -T .   ,      ,,     ,,,
           if  j    ,.,..    •   ,,     ,     Nation s  wetlands and whether or not we are
sources must be devoted to addressing the qual-
                      Box  1: EXAMPLES OF WETLAND VALUES


      80% of America's breeding bird population and more than 50% of protected migratory
      bird species rely on wetlands (Wharton et al. 1982).

      More than 95% of commercially harvested fish and shellfish in the United States are
      directly or indirectly dependent on wetlands (Feierabend and Zelazny 1987).

      Most of the United States' frogs, toads, and many salamanders require wetlands during
      their life cycle for reproduction or survival.

      A mosaic of small wetlands is important for maintaining local populations of turtles,
      small birds, and  small mammals (Gibbs 1993).

      Although wetlands account for only 3.5% of the United States' land area, about 50% of
      federally listed endangered animals depend on wetlands for survival (Mitsch and
      Gosselink 2000).

      Wetlands help prevent flood damage by storing storm runoff and slowly releasing water
      to streams and groundwater, thereby decreasing the severity of peak floods (Thibodeau
      andOstro 1981).

      Removal  of floodplain forested wetlands and confinement by levees has reduced the
      floodwater storage capacity of the Mississippi River by 80% (Gosselink et al. 1981).
      The severity of the 1993 Great Midwest Flood, which caused $20 billion of property
      damage, was partially increased by the historical loss of wetlands in the Missouri and
      upper Mississippi river basins (NOAA 1994, Tiner 1998).

      Wetlands help maintain the quality of streams and rivers by preventing erosion, filtering
      runoff, reducing peak floods, maintaining base flows, and providing food for stream
      animals.  Streams with drainage areas that contain higher percentages of naturally
      vegetated land, particularly wetlands, tend to have healthier fish communities, as shown
      by biological assessments (Roth et al.  1996, Wang et al. 1997).

      Wetlands enhance water quality  in streams and watersheds by trapping sediment and by
      accumulating and transforming a variety of nutrients and other chemical substances
      (Jones 1976, Mitsch et al. 1979, Lowrance et al. 1984, Whigham et al. 1988, Kuenzler
      1989, Faulkner and Richardson  1989, Johnston 1991).

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            -500,000
                         1950s-
                         1970s*
1970s-
1980s*
1980s-
1990s*
2005
Goal**
        * U.S. Fish and Wildlife Service National Wetland Inventory, 2000
        ** U.S. EPA goal (U.S. EPA 1998b)
             FIGURE  1: ANNUAL AVERAGE RATE OF WETLANDS LOSS.
meeting this goal.  This limited knowledge is
illustrated in the 1998 National Water Inventory
(U.S. EPA, 1999). The quality of only 4% of the
Nation's wetlands  was estimated,  and only a
fraction of these estimates were based on actual
monitoring data.  State and Federal agencies are
receiving increasing pressure to move away from
using the number of permits issued or number
of wetlands lost as primary data influencing man-
agement decisions.  Rather, they must  develop
and use more meaningful measurements to
evaluate the quality of the  environment and to
demonstrate the effectiveness of their programs
at improving the environment.


           EVALUATING
      WETLAND HEALTH

 TT/'etlands and other waterbodies are shaped
 r r  by the landscape and climate in which
they exist (Brinson 1993). Climatic conditions,
topography of the landscape, chemical and
     physical characteristics of underlying geology,
     and the amount and flow of water within a wa-
     tershed all contribute to determining what kind
     of plants and animals survive in a location.  The
     collective interaction of plants and animals with
     their physical and chemical environment form
     what we call wetlands and provide many of the
     functions that are both ecologically and eco-
     nomically important. Many wetlands have been
     shaped over thousands of years by complex in-
     teractions between biological communities and
     their chemical and physical environment.  The
     very presence of a wetland's natural biological
     community means that the wetland is resilient
     to the normal variation in that environment (Karr
     andChu 1999).


       Certain human activities can alter the interac-
     tions between wetland biota and their chemical
     and physical environment.  Figure 2 provides a
     simplified illustration of the relationship be-
     tween (a) the health of biological communities
     of wetlands and (b) human disturbances to wet-

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lands and their watersheds.  When human ac-
tivities within a wetland or its watershed are
minimal, the biological communities are resil-
ient and continue to resemble those that were
shaped by the interaction of biogeographic and
evolutionary processes. At this end of the con-
tinuum of biological condition, the community
is said to have biological integrity, which is the
ability to "support and maintain a balanced adap-
tive community of organisms having a species
composition, diversity, and functional organiza-
tion comparable to that of natural habitats within
a region" (Karr and Dudley  1981). At some
threshold (T), which is difficult to measure over
short time scales, is the point where degrada-
tion of the biological community creates an un-
healthy situation because a natural community
is no longer sustainable (Karr 2000).


 Some human activities are ecologically benign
whereas others can alter the environment to the
point where there are changes in the biological
communities. As the severity, frequency, or du-
ration of the disturbances increase, a wetland
may eventually reach a point where many of its
plants and animals can no longer survive. When
the interaction of wetland plants and animals
with their environment is disrupted, many of the
functions provided by wetlands will be dimin-
ished  or lost.  At a large scale, the subsequent
ecological and economic effects can be dramatic.
A wetland's biological community may recover
over time and move back up the continuum if
the pressures from the environmental distur-
bances are alleviated.  The amount of time re-
quired to move back up the continuum will de-
pend on the severity and nature of the distur-
bance. It may take some wetlands hundreds of
years to recover.


  The  challenge facing wetland biologists is to
develop practical ways to measure the biologi-
cal condition of wetlands in order to make in-
formed resource management decisions aimed
at minimizing loss of wetland acreage and func-
tion. It is neither scientifically nor economically
o Pristine
c
o
0
O
o T
o
m
•s
"c
0>
(0 Nothing
(5 Alive
Biological Integrity
healthy = "''-
sustainable ' .
T\
	 ^
-i-'
unhealthy = "•-,
unsustainable
,

No or minimal Severe
disturbance Disturbance
                                  Gradient of Human Disturbance

 FIGURE: 2: CONTINUUM oir HUMAN DISTURBANCE ON BIOI	OGICAI	CONDITION OF
                     WETI	ANDS (ADAPTED FROM KARR 2OOO).
                                          5

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practical to monitor every way that human ac-
tivities  can damage wetlands.  For instance,
wetlands can be dredged, filled, mowed, logged,
plowed, drained, inundated, invaded by non-
native or invasive  organisms, grazed by live-
stock, and contaminated by countless kinds of
pesticides, herbicides,  and other toxic sub-
stances. Therefore, wetland biologists must fo-
cus on measuring the attributes of wetlands that
will reflect biological condition without having
to measure each and every disturbance that con-
tributes to that condition.

  As mentioned earlier, wetlands are shaped by
the interaction of biological communities with
their physical and chemical environment.  The
plants and animals have evolved over time to
survive  within a given range of environmental
conditions. The interaction of wetland organ-
isms with each other and their environment can
be altered chemically, physically, or biologically
(Figure  3). For example, pesticides and herbi-
cides applied to a golf course can enter and
chemically alter a wetland after a rainstorm, re-
sulting in lethal and sublethal affects to aquatic
animals. Humans can physically damage wet-
land biological communities by plowing a wet-
land or discharging stormwater runoff into wet-
lands and altering wetland hydrology.  Wetland
biological communities can be biologically al-
tered by introducing  non-native or invasive
plants. Wetlands are rarely damaged by a single
stressor. Rather,  a  mixture of chemical, physi-
cal, and biological stressors typically impacts
them. Measuring all of the stressors that could
affect a wetland  in a way that is ecologically
meaningful is virtually impossible.  The only
way to evaluate the cumulative effect of all the
stressors is to directly measure the condition of
the biological community.

  The most direct  and cost-effective way to
evaluate the biological condition of wetlands is
to directly measure attributes of the community
of plants and animals that form a wetland. With
limited financial and staff resources, it is not
practical to focus the evaluation of wetland con-
dition on chemical endpoints because there are
too many to monitor.  Also, the interaction of
many chemicals in the environment is poorly
understood.   Stream bioassessment programs
have also found that bioassessments are less
expensive than many of the chemical measure-
ments (Yoder and Rankin 1995, Karr and Chu
1999).  A focus on physical parameters is im-
practical because our knowledge of interactions
of biological communities and many physical
parameters is incomplete. In addition, focusing
monitoring efforts on physical parameters would
overlook damage caused by chemical and bio-
logical stressors.

 In addition to reflecting the cumulative effects
of multiple stressors, biological communities in-
tegrate the effects of stressors overtime, includ-
ing short-term or intermittent stressors.  In con-
trast, it  is often difficult to detect changes in
chemical and physical stressors over time. The
biological effect of many chemicals is  often
much longer lasting than the pollution event it-
self. Some chemicals can enter a wetland, dam-
age the biological community, and be biochemi-
cally or photochemically altered rather quickly.
Even if researchers are  attempting to detect a
chemical,  they may completely miss it unless
they are sampling at the right time. The high
costs associated with processing water and sedi-
ment chemistry samples make it far too expen-
sive to sample with enough frequency to detect
many chemicals. Physical alterations can also
pose problems with respect to the ability to de-
tect changes in biological condition over time.
Some physical alterations  to wetlands  can
change the structure and composition of biologi-
cal  communities for years after the ability to
observe the physical alteration has been lost. For
example, more than 50 years after some farmed
wetlands in Montana were removed from pro-
                                            6

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Alkalinity
Orgnanics
Conductivity
Human-made
chemicals
Nutrients
Chemical
Variables
Transformation
Turbidity Depth
pH Duration
Land Use
Precipita

Runolf
Hydrology
Groundwater
tion
High/Low
Flow Extremes
         Reproduction   Life Stages

     Feeding

  Competition

       Parasitism     Keystone Species
Biotic
Factors
Disease

      Sunlight
     Organic
     Matter
     Inputs
                  Nutrients
                 Energy
                 Source
                Primary and
                Secondary
                Production
Seasonal
 Cycles
                     Water Depth
  Buffer

  Substrate
Composition
 Habitat
Structure
                       Water Flow
Topography


   Vegetation
                                  Canopy    Erosion
 FIGURE 3:  ECOSYSTEM INFI	UENCES ON BIOI	OGICAI	INTEGRITY (ADAPTED FROM
                         KARRETAI	 1986.YODER 1995).
duction, their biological communities are still
recovering and are noticeably different from
minimally  disturbed  wetlands   (Randy
Apfelbeck, MT DEQ, pers. comm.).
               In summary, the most direct and effective way
              of evaluating the biological condition of wet-
              lands is to directly monitor the biological com-
              ponent of  wetlands  through the  use  of


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bioassessments and to support that information
with chemical and physical data.  Relying on
surrogate measurements (e.g., water chemistry)
or using monitoring tools designed for other
purposes (e.g., rapid functional assessments)
may provide incomplete and misleading results.
Bioassessments can help prioritize where to fol-
low up with additional monitoring, help diag-
nose the causes of degradation, and provide data
to make informed management decisions about
protecting and restoring wetlands.
        BlOASSESSMENT
             METHODS

 T^Vuring the past decade, wetland biologists
-t-Xbegan to develop bioassessment methods
to evaluate the condition of wetlands and deter-
mine whether these wetlands are maintaining
biological integrity. Bioassessment methods fo-
cus on measuring attributes of a wetland's bio-
logical community that are reliable indicators
of wetland condition.  Many bioassessment
projects also include measures of physical and
chemical attributes that are used to help  diag-
nose potential sources of degradation.

  Bioassessments are based on the premise that
the community of plants and animals living in a
wetland will  reflect the health of  a wetland.
When  a wetland is  damaged, the diversity of
animals and plants often decreases and the com-
position of species changes. Typically, the pro-
portion of organisms that are intolerant to hu-
man disturbances will decrease while the pro-
portion of individuals or species that are  more
tolerant to the disturbance will increase. In com-
parison to a minimally disturbed site, a plowed
wetland located in a cornfield may have fewer
plant and animal species.  It also may be domi-
nated by organisms that can tolerate poor envi-
ronmental conditions. After examining an as-
semblage of plants or animals in wetlands  rang-
ing from high quality to poor quality, scientists
can use this known range to  estimate the rela-
tive health of other wetlands.


 Wetland biologists are fortunate to have sev-
eral decades of knowledge and experience re-
lated to evaluating the biological condition of
streams and rivers to help guide them. Although
wetlands and their biological communities are
different from streams and rivers, many of the
approaches and experiences  from stream
bioassessments can be applied to any biological
system. In fact, bioassessment methods  devel-
oped for streams and rivers have been adapted
to wetlands, lakes, estuaries, and terrestrial sys-
tems (U.S. EPA  1998a, 2000a, Karr and Chu
1999, Raderetal. 2001).


 The U.S.  Environmental Protection Agency
(EPA) formed the Biological Assessment of Wet-
lands Workgroup (B AWWQ pronounced "bog")
in  1997 to help State  agencies develop and ap-
ply wetland bioassessments (Box  2).   Many
B AWWG members are conducting pilot proj ects,
which are described in Wetland Bioassessment
Case Studies (U.S. EPA, in prep.).  BAWWG
has produced a series of reports to help other
State, Federal, and Tribal agencies develop and
implement bioassessment methods for wetlands
(Table  1).  The remainder of this report will in-
troduce the development and application of wet-
land bioassessments, provide recommendations
from B AWWQ and refer to the other reports in
the series for more detailed information.


 Wetland bioassessments involve the following
six general stages of development:

•  Selecting one or more biological assem-
   blages to monitor

•  Classifying wetlands

•  Selecting wetlands across a gradient of hu-
   man disturbance
                                           8

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Box 2: THE BIOLOGICAL ASSESSMENT OF WETLANDS WORKGROUP (BAWWG)

 The Biological Assessment of Wetlands Workgroup (BAWWG, pronounced "bog") was
 formed in 1997 to help advance the science and application of wetland bioassessments.
 Many people have participated in BAWWG meetings over the years, but the following list
 of people includes the core BAWWG members who have dedicated a considerable amount
 of time to advancing the goals of the workgroup.  The New England Biological Assessment
 of Wetlands Workgroup (NEBAWWG) was formed in 1998 and its members have also
 helped advance wetland bioassessments.

 Paul Adamus, Oregon State University
 Bill Ainslee, U.S. EPA, Region 4
 Randy Apfelbeck, Montana Department of Environmental Quality
 Rob Brooks, Penn State Cooperative Wetlands Center
 Mark Brown, University of Florida, Center for Wetlands
 Tom Danielson, Maine Department of Environmental Protection
 Jeanne DiFranco, Maine Department of Environmental Protection
 Naomi Detenbeck, U.S. EPA, Ecology Division
 Mike Ell, North Dakota Department of Health
 Sue Elston, U.S. EPA, Region 5
 Chris Faulkner, U.S. EPA, Office of Wetlands, Oceans, and Watersheds
 Russ Frydenborg, Florida Department of Environmental Protection
 Mark Gernes, Minnesota Pollution Control Agency
 Mike Gray, Ohio Environmental Protection Agency
 Judy Helgen, Minnesota Pollution Control Agency
 Denice Heller Wardrop, Penn State Cooperative Wetlands Center
 Doug Hoskins, Connecticut Department of Environmental Protection
 Susan Jackson, U.S. EPA, Office of Science and Technology
 James Karr, University of Washington
 Ryan King, Duke University Wetlands Center
 Don Kirby, North Dakota State University
 Peter Lowe, USGS Biological Resources Division
 John Mack, Ohio Environmental Protection Agency
 Ellen McCarron, Florida Department of Environmental Protection
 Mick Micacchion, Ohio Environmental Protection Agency
 Steve Pugh, U.S. Army Corps of Engineers, Baltimore District
 Klaus Richter, King County Department of Natural Resources, Washington
 Matt Schweisberg, U.S. EPA, Region 1
 Don Sparling, USGS Biological  Resources Division
 Art Spingarn, U.S. EPA Region 3
 Jan Stevenson, Michigan State University
 Linda Storm, U.S. EPA, Region  10
 Rich Sumner, U.S. EPA, Environmental Research Laboratory
 Billy Teels, NRCS Wetlands Science Institute
 Doreen Vetter, U.S. EPA, Office of Wetlands, Oceans, and Watersheds


                                       9

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              Title
        Description










Introduces several wetland classification systems and describes
how they can be used in wetland monitoring programs.
Introduces different study designs available for monitoring
wetlands.
Introduces the process of testing metrics and creating an Index of
Biological Integrity (ffll)
Introduces field sampling and analytical methods available for
using algae in wetland bioassessments.
Introduces field sampling and analytical methods available for
using amphibians in wetland bioassessments.
Introduces field sampling and analytical methods available for
using birds in wetland bioassessments.
Introduces field sampling and analytical methods available for
using macroinvertebrates in wetland bioassessments.
Introduces field sampling and analytical methods available for
using plants in wetland bioassessments.
Describes use of volunteers in wetland bioassessment projects.
Provides case studies of current wetland bioassessment projects
across the country.
   Sampling chemical and physical character-
   istics of wetlands
   Analyzing data

   Reporting results
 As discussed in Wetland Bioassessment Case
Studies (U.S. EPA, in prep.), BAWWG mem-
bers have used a variety of biological  assem-
blages in wetland bioassessments, including al-
gae, amphibians, birds, fish, macroinvertebrates,
and vascular plants.  Each assemblage has its
own strengths and limitations for developing
wetland bioassessment methods.  Convenience,
money, and time are often key factors in select-
ing a biological assemblage (Karr and Chu
1999). The selected assemblage must be cost-
effective to sample and identify.  However, a
number of other factors affect an assemblage's
practical usefulness  and  ability to reflect real
changes in wetland condition (Table 2). Plants
and macroinvertebrates are the most commonly
used assemblages in wetland bioassessments.
Vegetation is a convenient assemblage because
it occurs in most wetland types and there are
well-established sampling protocols; however,
identifying metrics can be challenging (U. S. EPA
2002a). Macroinvertebrates have been widely
used in stream bioassessments and show a lot
of promise for wetlands, but current sampling
methods focus on wetlands with standing water
(U.S. EPA 2002b).  Algae have been used to a

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           TABI.
:.;NGTHS AND LIN
      IN WETLANL _..
  DNS OF ASSEMBLAGES FOR
,,",SSESSMENTS
Attribute of Assemblage
An IBI has been developed in one or more
States
Prior research in wetland bioassessments
Present and able to be sampled in multiple
wetland types
Social recognition of importance
Difficulty of sampling protocols
(time, effort, etc.)
Ease of identification (number of species,
relative skill required to identify to genus or
species)
Laboratory analysis (time, cost)
Taxonomic richness (effects ability to
identify metrics)
Relative knowledge of taxa life history
requirements, tolerances, habits
Short time lag of response to stressor
Integrate effects over time
Integrate effects over broad landscape
Reflection of individual wetland condition
Reflection of connectivity to other wetlands
and natural habitats
Sensitivity to nutrient enrichment
Sensitivity to metals and contaminants
Sensitivity to herbicides
Sensitivity to pesticides
Sensitivity to hydroperiod alteration
Sensitivity to habitat alteration of individual
wetland
Ability to discern individual health
(malformations, deformities, lesions) from
exposure to wetland conditions
Ability to diagnose potential stressor
Algae
2
2
1
3
1°
3
29
1
1
1
2
3
1
3
1
3K
1
3
2
3
3
1
Amph
3
3
2
1
3C
1°
2
3'
2
2
1
1
2
1
3
2
2
2
1
2
1
3
Birds
2
2
1
1
3C
2e
1
2
1
3
1
1
3
2
3
2
3
2
3
2
2m
3
Fish
2
2
3a
1
2
2
1
3'
1
2
1
2
2
2
2
2
3
2
3
2
r\\\\
3
Invert
1
1
1
3
2
3T
3n
1
2
1
1
2
1
1
1
1'
2
1
2
2
1
2
Plants
1
1
1
2
2
2
1
1
3
3
1
2
2"
3
1
2'
1
3
1
1
2
2
Numerical Scores: 1 = best, 2 = intermediate, 3 = worst.

a  Fish are restricted to small number of wetland types.
b  Sampling methods are easy, but may require multiple site visits.
c  Analysis will likely require multiple site visits during season.
d  Adults are easy to identify, but some larvae are difficult to identify and may require rearing for positive identification.
e  Many amateurs are sufficiently trained to identify birds.
f  Identification of diatoms is aided by pictorial keys, but relatively few people are trained.
g  Wisconsin DNR is attempting to develop family-level assessment methods instead of identifying macroinvertebrates to genus and species.
h  Dip net and especially stovepipe samples can involve a lot of time-consuming picking; however, Minnesota PCA uses method to reduce
   time. Activity traps generally require less picking because they do not pick up as much detritus.
i  Amphibians  and fish may have insufficient taxonomic diversity to be effectively used in bioassessment in some wetland types or parts of the
   country.
j  Historical land use practices and immediate  landscape have significant influence on community.
k  Algae are sensitive to copper sulfate.
1  Many of these chemicals  have very high affinities to charged particles and end up in higher concentration in the sediments than in the water
   column. Minnesota PCA has found strong responses in the plant community to sediment concentrations of Cu, Zn, Cd, and other metals.
m Deformities, lesions, etc.  have been found in the field, but typically appear only in highly contaminated situations.
                                                            1   1

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limited degree but offer an inexpensive and ef-
fective alternative for some wetland types (U.S.
EPA2002c). Amphibians offer many advantages
but have insufficient taxonomic diversity in
some regions for traditional bioassessment meth-
ods (U.S. EPA 2002d).  The mobility of birds
makes them well suited for landscape-level as-
sessments (U.S. EPA 2002e). Fish have many
advantages that have been demonstrated in other
waterbodies, but the fish assemblage is limited
to a few wetland types, such as emergent wet-
lands on the fringes of lakes and estuaries.  In
summary, different assemblages have different
advantages depending  on the purpose of the
project, region of the country, and wetland types
being evaluated.   BAWWG members recom-
mend sampling two or more assemblages be-
cause it provides more  confidence in manage-
ment decisions and substantially improves the
ability to diagnose the causes of degradation.
with a variety of factors, including its landscape
position, hydrologic characteristics, water chem-
istry, underlying  geology, and climatic condi-
tions.  Each type of wetland consists of plants
and animals with adaptations to survive and re-
produce in a certain range of environmental con-
ditions. For example, organisms that inhabit salt
marshes must have physical, chemical, or be-
havioral adaptations to withstand variable salin-
ity and alternating wet and dry periods.  In con-
trast, organisms that inhabit oligotrophic bogs
must have adaptations to tolerate acidic condi-
tions and obtain and retain scarce nutrients. An
organism adapted for life in  a bog would not
likely survive in a salt marsh, and vice versa. As
a result, the biological community of a bog will
be much different from  the biological commu-
nity of a salt marsh. No one would disagree that
it is inappropriate to directly  compare the bio-
logical communities of a salt marsh to a bog.
        CLASSIFYING WETLANDS

 The goal of bioassessments is to evaluate the
condition of wetlands as compared to reference
conditions and determine if wetlands are being
damaged by human activities. An obvious chal-
lenge facing wetland scientists is to distinguish
changes in biological communities caused by
human disturbances from natural variations.
This challenge is complicated by the natural
variation found among the variety of U.S. wet-
land types (Cowardin et al. 1979, Mitsch and
Gosselink 2000,  Brinson  1993).  One way to
simplify the evaluation is to classify the wet-
lands and  only compare wetlands with others
within the same class. BAWWG members have
found that some type of classification method is
necessary when developing bioassessment meth-
ods for wetlands  (U.S. EPA 2002f).


 Consider an easy example of comparing a salt
marsh to an oligotrophic bog.  Each wetland is
shaped by the interaction of plants and animals
 The validity of making other comparisons is
often debated. For example, is it appropriate to
compare the biological communities of an emer-
gent marsh on the edge of a pond to an emer-
gent marsh on the edge of a slow-moving river?
Are the biological communities similar enough
to lump into one class or do they need to be split
into two classes? There are no easy answers to
these questions. They must be answered, how-
ever, to  ensure  scientific validity  of the
bioassessment results and management deci-
sions. The use  of a classification system pro-
vides a framework for making these decisions.


 For purposes  of developing bioassessment
methods, the goal is to establish classes of wet-
lands that have similar biological  communities
that respond similarly to human disturbances.
As discussed in Wetland Classification (U.S.
EPA2002f), a variety of wetland classification
systems have already been developed for a vari-
ety of purposes. BAWWG members have used
many of these classification systems (U.S. EPA
                                          12

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2002f; in prep.) to avoid "comparing apples to
oranges" and have come up with the following
list of observations and recommendations:
•  Do not reinvent the wheel. B AWWG mem-
   bers suggest starting with one or more ex-
   isting methods and, if necessary, modifying
   the classification to establish classes of bio-
   logically similar wetlands. Developing an
   entirely new system should not be necessary.
•  Classification is often an iterative process.
   Researchers often start with one or more sys-
   tems and then lump or split classes as needed
   to end up with an appropriate number of
   groups of biologically distinct wetlands. For
   example, when the Montana Department of
   Environmental Quality  (MT DEQ) devel-
   oped its IB I, it used ecoregions as a first tier
   and then further separated wetlands by land-
   scape position and other characteristics (e.g.,
   acidity and salinity). MT DEQ later deter-
   mined that it could lump the wetlands of two
   ecoregions because their macroinvertebrate
   communities were  similar and responded
   similarly to anthropogenic stressors. While
   establishing classes, examine other natural
   factors that  may  affect wetland communi-
   ties (e.g., size, successional stage, age of the
   wetland, salinity) to determine if they should
   be included in the classification system.
•  Do not become preoccupied with classifica-
   tion.  Even though proper classification is
   necessary to minimize natural differences
   among wetlands, the goal of this exercise is
   not to develop a new classification method.
   Rather, the goal is to improve the ability of
   wetland scientists to detect signals from the
   biology about the condition of wetlands.
•  Classify wetlands to a suitable level.  Ecolo-
   gists need to develop wetland classes that
   are broad enough to allow comparisons of
   several wetlands,  yet narrow enough to pro-
   vide biologically meaningful comparison.
   All ecologists are faced with a dilemma: the
   more ecologists learn about natural systems,
   the more they realize how little they actu-
   ally know. As a result, it is tempting to delve
   ever deeper into biology to help identify dif-
   ferences between wetlands  and develop
   more subclasses. However, ecologists are
   faced with another dilemma: limited finan-
   cial and staff resources.  For  each wetland
   class that is identified, a new set of wetlands
   must be sampled to calibrate analytical meth-
   ods. The endpoint therefore represents a bal-
   ance of (1) a need to have broad inclusive
   classes that will facilitate the comparisons
   of many wetland types, (2) a desire to have
   a narrow classification that includes detailed
   bioassessment data, and  (3) constraints on
   financial and staff resources.  Another lim-
   iting factor when classifying wetlands is
   having enough wetlands of each class to cali-
   brate analytical methods.
•  Recognize that the wetland classification
   and classes used for  one assemblage may
   not be  suitable for another assemblage. For
   example, wetland classes developed to ob-
   tain biologically similar macroinvertebrate
   communities may not work when applied to
   another assemblage, such as plants. Always
   test existing wetland classes to ensure that
   they are biologically meaningful in identi-
   fying the effects of human disturbances on
   the selected assemblage(s).

   SELECTING WETLANDS ACROSS A
        DISTURBANCE GRADIENT

 After classifying wetlands, researchers select
sampling sites across a disturbance gradient for
each wetland class.  These sites are used to docu-
ment how a biological assemblage responds to
increasing levels of anthropogenic stressors
(U. S. EPA 2002g).  A common way of portray-
ing bioassessment  results is to create a graph
with a measure of human disturbance along the
X-axis and a biological endpoint along the Y-
                                           13

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axis (Figure 2).  As discussed in Developing
Metrics and Indexes of Biological Integrity (U.S.
EPA 2002g), no standard method for establish-
ing gradients of human disturbance exists. Some
BAWWG members have tried to quantify dis-
turbance by using surrogates such as the  per-
centage of impervious surfaces or agriculture in
a watershed. Other projects have used qualita-
tive indices of human disturbance that incorpo-
rate a combination of watershed and wetland in-
formation. Regardless of the gradient used, it is
crucial to select wetlands that range from mini-
mally disturbed reference sites to severely de-
graded wetlands, with some sites in between.
BAWWG members have the following obser-
vations and recommendations about gradients
of human disturbance:
• Do not become preoccupied with disturbance
   gradient. It is impossible to develop a distur-
   bance gradient that incorporates every  way
   that humans can damage wetlands. The dis-
   turbance gradient should provide a gross es-
   timate that can be used in the site selection
   process and the calibration of metrics.  The
   biological  information will  ultimately be
   much more reliable and trustworthy in evalu-
   ating wetland condition than the disturbance
   gradient (Karr and Chu 1999).
• Define and describe the expected distur-
   bance gradient before sampling sites. If the
   disturbance gradient is established after the
   sites  are sampled, then there is the risk of
   sampling too few wetlands at either end of
   the gradient.
•  Use targeted sampling while developing
   bioassessment methods.  As discussed in
   Study Design for Monitoring Wetlands
   (U.S. EPA2002h), statistical sampling de-
   signs provide many  advantages when at-
   tempting to estimate  the percentage of
   waterbodies that are meeting their designated
   uses. However, BAWWG members have
   found that the targeted selection of sampling
   sites is preferable when  developing
   bioassessment methods. It is important to
   get sufficient numbers of minimally disturbed
   sites and severely degraded sites to (1) docu-
   ment  the condition  of a  biological
   assemblage at the two extremes and (2) cali-
   brate analytical methods. Statistical sampling
   methods often fail to select enough wetlands
   at either end of the disturbance gradient.

   SELECTING SAMPLING METHODS

  Sampling methods used in a wetland bioassess-
ment project will depend on the taxonomic as-
semblage and wetland class being sampled. Spe-
cific sampling methods for each assemblage, ex-
cept fish, are described in the reports listed in
Table 3. Regardless of the assemblage selected,
BAWWG members  have the following obser-
vations and recommendations:
• Use standardized sampling methods.  It is
   very important  to  standardize  sampling
   methods and establish quality assurance pro-
   tocols to ensure  the comparability of data.
   In addition,  equal sample effort must be
   given to each wetland.  EPA recommends
   developing Quality Assurance Project Plans
   (QAPP) to help maintain consistency at ev-
   ery stage of sampling from collection to
   transportation of samples and laboratory pro-
   cedures (U.S. EPA 1995b).
• Ensure that sampling methods are repeat-
   able. BAWWG members recommend test-
   ing all sampling  methods to make sure that
   they provide repeatable and consistent re-
   sults in different wetlands and with differ-
   ent field technicians.
• Standardize the sampling period.  The com-
   position and abundance of taxa in a biologi-
   cal assemblage will change during the course
   of a year.  Individual taxa within a biologi-
   cal assemblage breed at different times of
   the year, mature at different rates, and have
                                           14

-------
a variety of behavioral and physical adapta-
tions for life in wetlands. Depending on the
assemblage, sampling the same wetland at
different times of the year can yield strik-
ingly different communities. It is necessary
to establish a standard period of time within
the year to collect samples that (1) minimizes
variation caused by natural, seasonal changes
in community composition;  (2) provides
sufficient differentiation of communities
across a disturbance gradient;  and  (3) is lo-
gistically practical.
Retain some flexibility in sampling period.
Although it is important to maintain a stan-
dard sampling period, it helps to retain some
flexibility in scheduling sampling. Annual
climatic variations can delay  or accelerate
biological processes.  For example,  a  par-
ticularly warm winter can cause adult  am-
phibians to breed much earlier than they
normally would. It is important to pay at-
tention  to these  variations  and adjust the
sampling scheme accordingly to secure
samples that are not biased toward certain
taxa and do not misrepresent relative abun-
dance.
Consider time and resource constraints. Bi-
ologists are often tempted to  create  elabo-
rate sampling  designs using several  meth-
ods to ensure that all species are  captured
and represented in a sample. However, the
complexity of sampling methods  must be
balanced with the time and resources avail-
able. Remember that the goal  of the assess-
ments is to evaluate the condition of a wet-
land relative to a known range of condition
from wetlands across a disturbance  gradi-
ent.  It  is not necessary to monitor every-
thing within a wetland to detect differences
in biological communities across this gradi-
ent. Rather, the  sampling effort should be
focused on identifying characteristics of bio-
logical communities that show measurable
   and consistent relationships. For example,
   the Maine Department of Environmental
   Protection is focusing macroinvertebrate
   monitoring in emergent wetlands at the tran-
   sition zone between open water and emer-
   gent vegetation rather than attempting to
   sample every microhabitat within a wetland
   (Jeanne Difranco, Maine DEP, pers. comm.).
   Recognizing that wetlands are often mosa-
   ics of different vegetative communities and
   microhabitats, the Minnesota Pollution Con-
   trol Agency targets an area of the wetland
   that is representative of the wetland as a
   whole and uses a releve sampling method to
   evaluate the plant assemblage (U.S. EPA
   2002a).

      COLLECTING CHEMICAL AND
             PHYSICAL DATA

 Used independently,  measurements of a
wetland's physical characteristics or chemicals
in a wetland's water or sediment are not appro-
priate for estimating wetland health because they
do not adequately reflect the condition of bio-
logical communities. The ability to infer bio-
logical condition from physical and chemical
data is often limited to severely altered or pol-
luted  conditions. Water chemistry,  in particu-
lar, is very expensive to analyze, can vary widely
over time, and can be difficult to  interpret.
Methods that focus primarily  on a wetland's
physical structure, such as functional assessment
methods, fail to detect damage from subtle stres-
sors such as the effects of pesticides. Physical
and chemical information can be very useful
while classifying wetlands, interpreting biologi-
cal  data, and identifying potential  stressors.
BAWWG members use a variety of physical and
chemical data in their projects, including:
•  Water chemistry (e.g., nutrients, pH, DO,
   conductivity, dissolved metals, turbidity)

-------
    Substrate  (e.g.,  type of soil, sediment
    chemistry)
    Wetland topography and water depth (e.g.,
    functional assessment data)

    Characteristic vegetative structure

    Characteristics of immediate surrounding
    land use

    Watershed characteristics (e.g., land use, per-
    cent natural vegetation, nearest wetland)
 These chemical/physical data provide valuable
information for interpreting biological data, veri-
fying wetland class, and diagnosing potential
stressors.  However, these data should not be
used alone to infer biological condition.  Sev-
eral States have found that using chemical data
to  infer the biological condition of streams is
dangerously misleading.  States that have  in-
vested in strong stream bioassessment capabili-
ties have discovered that chemical assessments
vastly overestimated the quality of their streams.
Using the traditional chemical assessments, Ohio
EPA estimated that approximately  30% of
streams were not meeting the minimum stan-
dards for maintaining chemical, physical,  and
biological  integrity. Using their bioassessment
methods, Ohio EPA now estimates that about
70% of the same streams are not meeting their
designated uses (Chris Yoder, Ohio EPA, pers.
comm.). Other States, such as Delaware, have
come to a similar conclusion  (John Maxted,
Delaware Department of Natural Resources and
Environmental Control, pers. comm.).  Using
chemistry  data or physical data to infer biologi-
cal condition of wetlands would likely produce
similar misleading and  inaccurate results.  Ex-
periences like these show that one of the most
meaningful ways to evaluate the health of
streams, and arguably any habitat, is to directly
evaluate the plant and animal communities that
live in them.
            ANALYZING DATA

 After biologists sample and identify the taxa
in an assemblage, they can prepare a list of taxa
names and the abundance or percent cover for
each.  The challenge facing the biologists is to
identify ways to analyze these data to provide
meaningful measures  of biological condition.
Remember that the goal is to evaluate the data
and determine to what degree the wetlands are
being  damaged by human activities.  Both
multimetric indexes, such as Indexes of Biologi-
cal Integrity (IBI), and statistical approaches
have been used in stream, lake, and estuary
bioassessments (Davis and Simon 1995, Barbour
et al. 1999, U.S. EPA  1996a,b,  1998a, 2000a).
The virtues of the two  analytical methods have
been debated in the scientific literature (Norris
and Georges 1993, Suter 1993, Gerritsen 1995,
Norris 1995, Wright 1995, Diamond et al. 1996,
Fore et al. 1996, Reynoldson et al. 1997, Karr
andChu!999).


 As described in Wetland Bioassessment Case
Studies (U.S.  EPA, in prep.), most wetland
bioassessment projects use IBIs to analyze data.
Some States are exploring the use of advanced
statistics to analyze data. Maine Department of
Environmental Protection is exploring the use
of a combination of metrics and statistics to
evaluate macroinvertebrate data. Montana De-
partment of Environmental Quality uses canoni-
cal correspondence analysis and TWINSPANto
evaluate wetland algal data. Magee and others
used canonical correspondence  analysis  and
TWINSPAN to illustrate the extent to which wet-
lands in urbanizing landscapes are floristically
degraded in comparison to relatively undisturbed
systems (Magee et al. 1999).


 IBIs and related multimetric indexes identify
attributes of an assemblage that show empirical
and predictable responses to increasing human
                                           16

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disturbance (Karr 1981). Each metric is scored
individually. These scores are then combined
into an overall index.  The process of identify-
ing metrics and developing IBIs is discussed in
detail in Developing Metrics and Indexes of
Biological Integrity (U.S. EPA 2002g).  Data
from most attributes can be used to generate scat-
ter plots, i.e., plot each measure for an attribute
(Y variable) against a measure for human dis-
turbance (X variable).   Some attributes (e.g.,
abundance, density, production) typically form
shotgun patterns because they are naturally vari-
able.  Figure 4 provides an example of an at-
tribute that shows no dose-response relationship
when compared to a disturbance  gradient; this
attribute would not be used as a metric. Other
attributes will show clear dose-response patterns
and thus would  be considered as potential
metrics. Figures 5 and 6 illustrate attributes with
dose-response relationships when compared to
disturbance gradients; these attributes could be
used as metrics.
 After graphically and statistically analyzing po-
tential metrics, researchers select the best per-
forming metrics to include in an IBI. Ideally, an
IBI should consist of approximately 8-12 metrics
(Karr and Chu 1999). One way of combining
metrics into an IBI is to assign values of 5, 3, or
1 to  the measures for each metric, where a 5
corresponds with the least disturbed condition,
a 3 corresponds to intermediate disturbance, and
a 1 corresponds to the most disturbed condition
(U. S. EPA2002g). For a metric such as the num-
ber of intolerant taxa, a wetland with a lot of
intolerant taxa may receive a 5 and a wetland
with no intolerant taxa may receive a 1.  The
metric scores associated with a wetland are usu-
ally  added together to calculate the IBI score.
Figure 7 provides an example of IBI scores of
individual wetlands plotted across a gradient of
human disturbance.  The IBI consists of 10
metrics, which were scored using the 5/3/1 sys-
tem and then added together.  Thus the highest
possible IBI score in this example is 50 and the
lowest possible IBI score is 10.  Some States
use different scoring values (e.g., 6/4/2/0 or 107
7/3/0) to make the lowest possible  IBI  score
equal 0.
 On the basis of their experience, BAWWG
members have the following recommendations
related to developing metrics and IBIs:
•   Develop a separate IBI for each assemblage.
    BAWWG members recommend developing
    separate IBIs for each assemblage because
    it makes it easier for other organizations to
    use or adapt the IBI.  Advantages of having
    two or more IBIs include (1) having addi-
    tional  data  that   may  reinforce  the
    bioassessment findings, and (2) a second IBI
    may reveal different findings because some
    assemblages may respond more  to certain
    stressors.
•   Never use an attribute as a metric without
    testing it first.  BAWWG members recom-
    mend that all sampling and analytical meth-
    ods, including metrics, should be tested, veri-
    fied, and calibrated to regional conditions
    before they are used in a new area of the
    country (U.S. EPA2002g).
•   Investigate outliers.  Scatterplots of the met-
    ric or IBI values of individual wetlands plot-
    ted against a disturbance gradient often have
    outliers, or values that are inconsistent with
    the maj ority. BAWWG members have found
    that  outliers  are  often  the result  of
    misclassifying the wetland or damage to the
    wetland from a stressor that is not accounted
    for in the human disturbance gradient.  In-
    vestigation of outliers can identify important
    stressors and land use characteristics.
•   Avoid directly comparing the IBI scores of
    wetlands in different classes. IBI scores
    should be calibrated for each wetland class
    as defined by the classification system used.
    Consider an IBI  consisting of 10 metrics,
                                           17

-------
z

                                    8  30
                                    w
                                    <  25

                                    °  20

                                       15

                                       10
                                        0123456789 10 11

                                               Relative Disturbance Rank
                                                  10=least disturbed
               FIGURE 5: FLORISTIC QUALITY
           ASSESSMENT INDEX PLOTTED AGAINST
             A HUMAN DISTURBANCE GRADIENT
                  (SOURCE: OHIO EPA).
f
b
   16
   14
   12
   10
   8
   6


   0
    0      10
    poor quality
                  20
                RAM Score
30      40
 good quality
 FIGURE 6: NUMBER OF DIPTERA TAXA
PLOTTED AGAINST RAPID ASSESSMENT
   METHOD (RAM) SCORES, A RAPID
      FUNCTIONAL ASSESSMENT
        (SOURCE: OHIO EPA).
-0.5
0  0.5   1    1.5

 Log Turbidity in Water
Invertebrate IBI 10 Metrics
RO
50
40
30
20
10
n -

« Reference
o * D Agriculture
jt * A Urban
sl*^ D
D *E& D6 D AA
^'b AD D
A A A
A D
2   2.5
                                           FIGURE 7: A TO-METRIC
                                          MACROINVERTEBRATE IB!
                                         PLOTTED AGAINST TURBIDITY
                                         (SOURCE: MINNESOTA PCA).
                                  18

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   each scored with a 5, 3, or 1 where 5 repre-
   sents good condition and 1 represents poor
   condition. The best potential IBI score for a
   bog, when  compared with similar bogs,
   should be 50 (i.e., 10 metrics * 5 = 50). Simi-
   larly,  the best potential marsh IBI score
   should be a 50 when compared with other
   marshes (i.e.,  10 metrics x 5 = 50).  When
   the same metrics are used, avoid establish-
   ing a scoring system where a minimally dis-
   turbed bog  would receive a significantly
   lower score (IBI = 25) than a minimally dis-
   turbed marsh (IBI = 50).


         REPORTING RESULTS

 Perhaps the greatest benefit of an IBI is that it
summarizes and presents complex biological in-
formation in a format that is easily communi-
cated to managers and the public. Most people
can more easily understand plant and animal IBIs
than complex statistical calculations or abstract
chemical  and physical data. Although an IBI
score is helpful for quickly communicating the
overall condition of a wetland, most of the valu-
able information lies in the individual metrics.
When reporting bioassessment results, the IBI
score should be accompanied by the following
information:

•  Narrative description of overall biotic con-
   dition in comparison to reference wetlands
   of the same region and wetland type

•  Number values (e.g., number of taxa) and
   scores (e.g., 5, 3, or 1) for each metric

•  Narrative descriptions of each metric in com-
   parison to reference conditions of the same
   region and wetland type
      USING BIOLOGICAL
       INFORMATION To
  IMPROVE  MANAGEMENT
            DECISIONS
 7)i°l°gical monitoring provides a framework
J-J for improving wetland management, pro-
tection, and restoration. Bioassessments provide
information about a wetland's present biologi-
cal condition compared to expected reference
conditions.  By studying biology, wetland sci-
entists can better understand how a wetland's
biological community is influenced by the
wetland's present  geophysical  condition and
human activities within a watershed (Figure 8).
Managers, policymakers, and society at large can
use this information to  decide if measured
changes in biological condition are acceptable
and set policies accordingly (Courtemanch et al.
1989, Courtemanch 1995, Yoder 1995, Karr and
Chu  1999). As shown by many of the projects
in Wetland Bioassessment Case Studies (U.S.
EPA, in prep.), States can use information from
wetland bioassessments to improve many man-
agement decisions, including:
• Strengthening water quality standards

• Strengthening State wetland regulatory pro-
   grams

• Improving wetland tracking

• Improving water quality decisions

• Improving plans to monitor, protect, and re-
   store biological condition

• Evaluating the  performance of regulatory,
   protection, and restoration activities

• Incorporating wetlands into watershed man-
   agement

• Improving risk-based management decisions
                                        19

-------
  Physical, chemical, evolutionary, and biogeographic processes interact to produce


         Landscape position                                    Taxa richness
       Geological substrate                                  Species composition
        Climate, elevation                                   Tolerance/intolerance
          Wetland type                                   Adaptive strategies (ecology,
                                                           behavior, morphology)

              The baseline without human disturbance is influenced by
                   Land use (building, farming, logging, grazing, etc.)
                                Changes in hydrology
                 Introduction of pesticides, herbicides, and other chemicals
                      Introduction of non-native plants and animals

        which alter the biogeochemical processes to influence one or more of
                                 Wetland hydrology
                               Physical habitat structure
                                    Water quality
                                    Energy source
                                Biological interactions
                          Connectivity to other natural systems

                                  thereby altering
        Storage and flow of water                                Taxa richness
        Biogeochemical processes                            Taxonomic composition
        Groundwater interaction                                Individual health
Accumulation of sediment and organic matter                    Ecological processes
                                                           Evolutionary processes

                            Unacceptable divergence of
                                     stimulates
                                Regulations, incentives
                         Management, conservation, restoration

                                     to protect

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        STRENGTHENING WATER
          QUALITY STANDARDS

 The most common application of wetland
bioassessments is to improve the way wetlands
are incorporated into State water quality stan-
dards.   States can use the information from
bioassessments to develop ecologically based
designated uses and biocriteria to determine if
those uses are being met.  Under CWA Section
303, States and eligible Tribes develop water
quality standards to ensure that their waters sup-
port beneficial uses such as aquatic life support,
drinking water supply, fish consumption, swim-
ming, and boating.  As envisioned by Section
303(c) of the Clean Water Act, developing wa-
ter quality standards is a joint effort between
States and the EPA.  The States have primary
responsibility for setting, reviewing, revising,
and enforcing water quality standards.

 EPA develops regulations, policies, and guid-
ance to help States implement the program and
oversees States' activities to ensure that their
adopted standards are consistent with the re-
quirements of the CWA and relevant water qual-
ity standards guidelines (40 CFR Part 131). EPA
has authority to review and approve or disap-
prove State standards and, where necessary, to
promulgate Federal water quality standards. A
water quality standard defines the environmen-
tal goal for a waterbody, or a portion thereof, by
designating the use or uses to be made of the
water, setting criteria necessary to protect those
uses, and preventing degradation of water qual-
ity through antidegradation provisions (U.S. EPA
1991) (Appendix). Criteria are the narrative or
numeric descriptions of the chemical, physical,
or biological conditions found in minimally im-
pacted reference areas (Table 3). By comparing
the condition of a wetland to appropriate crite-
ria, States can  determine if the wetland is sup-
porting its designated uses. For examples of how
States have incorporated wetlands into water
quality standard programs, please refer to  the
Wetland  Bioassessment Case Studies module
(U.S. EPA, in prep.).

 Most States do not have wetland-specific des-
ignated uses or criteria to adequately protect wet-
land biological integrity. In their absence, States
must rely on designated uses and criteria devel-
oped for lakes, streams, or other waterbodies that
often have different ecological conditions.  In
addition,  States historically focused on devel-
oping chemical and physical criteria based on
sampling ambient water column conditions  and
conducting laboratory toxicity tests.  The infor-
mation on ambient water column conditions  and
toxicity tests was then used to infer biological
condition of aquatic habitats.  The development
and widespread use of formal biocriteria  has
lagged behind chemical-specific and  toxicity
based water quality criteria (U.S. EPA 1996a,b).
However,  EPA requires that States adopt
biocriteria as part of their water quality criteria
for wetlands (U.S. EPA 1990).

 States can use bioassessment methods to es-
tablish standards and criteria that are ecologi-
cally appropriate for conditions found in wet-
lands. Biocriteria for aquatic systems describe
(in narrative or numeric criteria) the expected
biological condition of a minimally impaired
aquatic community (U.S. EPA 1992, 1996a).
These criteria can be used to define ecosystem
rehabilitation goals and assessment endpoints.
Bioassessments are especially useful for assess-
ing damage from hard-to-detect chemical prob-
lems  and  nonchemical  stressors.   Thus,
biocriteria fulfill a function missing from EPA's
traditionally chemical-oriented approach to pol-
lution control and abatement (U.S. EPA 1994d).
                                          21

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                    Important backstop to numeric
                    chemical criteria, especially when
                    one considers that there are
                    thousands of chemicals with no
                    established criteria
                    Often expressed with general
                    Statements, such as "waters shall
                    be free from concentrations of
                    pollutants injurious to aquatic life"
          Most of the criteria fall in this
          category
          Usually expressed as a maximum
          or minimum allowed concentration
          of a chemical, such as X mg/L of
          copper
                    Important backstop to numeric
                    physical criteria, especially
                    because few physical criteria have
                    been developed	
          Not as well developed as chemical
          criteria
          Can include criteria for
          temperature, habitat condition, etc.
                    Possibly more important than
                    narrative chemical and physical
                    criteria because it is often difficult
                    to describe conditions of a healthy
                    biological community in numeric
                    terms alone
                    Very general narrative criteria
                    have been on the books in some
                    States for years
                    More need to be developed, and
                    many of those already on books
                    need to be made clearer, more
                    specific, and more applicable to
                    wetlands
          Describe the condition of
          biological communities (e.g.,
          macro invertebrates) of healthy
          waterbodies
          Often provide comparisons
          between actual condition in a
          waterbody to reference conditions
   ST R E N GT H E NIN G STAT E W ET LA N13
        R EG U L. ATO F?Y PROG R AM S

 Wetland bioassessments can  help  strengthen
State wetland regulatory programs and improve
confidence in management decisions. Ohio En-
vironmental Protection Agency's (Ohio EPA)
work  with an IBI and rapid functional  assess-
ment provides a good example.  The Ohio Rapid
Assessment Method (ORAM)  is a rapid func-
tional assessment, which was developed by the
State for use in reviewing numerous wetland
permit applications.  Recognizing that it could
not perform bioassessments with all wetland
permit applications, Ohio EPA calibrated its
detailed bioassessments with ORAM. Ohio EPA
now has more confidence in ORAM results
when the scores are within given ranges. When
ORAM scores are inconclusive, Ohio EPA can
justify delaying a decision on the application to
perform a detailed bioassessment to provide a
more reliable assessment of wetland condition.


-------
    IMPROVING WETLAND TRACKING

 Under Section 305(b) of the Clean Water Act
(CWA), States submit reports  to EPA every 2
years that summarize the quality of their aquatic
resources. In the 305(b) reports, States summa-
rize the amount of streams, rivers, lakes, estuar-
ies, and wetlands that are (1) meeting their des-
ignated uses, (2) partially supporting their des-
ignated uses, and (3) not supporting their desig-
nated uses. In the 1998 National Water Quality
Inventory, a summary of the State 305(b) reports
provided by EPA to the U.S. Congress, States
determined designated use support for only 4%
of the Nation's wetlands.  Of the 4% that  were
included in the report, only a small fraction of
the decisions were based on actual monitoring
data.  Wetland bioassessments provide badly
needed information to track wetland condition
and determine if wetlands are  supporting  their
designated uses. In addition, a number of Fed-
eral funding sources are tied to the information
provided in  305(b) reports.  By not including
wetlands in the report, States are potentially
missing out on resources for their programs.


       IMPROVING WATER QUALITY
               DECISIONS

 Water quality standards provide a program-
matic foundation for  a number of other water
quality programs. By using bioassessment data
to improve water quality standards, States can
also improve these other water quality programs.
For example, bioassessments can help assess the
impacts from nonpoint-source pollution (CWA
Section 319) or from point-source  discharges
(CWA  Section  402).    States  can  use
bioassessments to evaluate the effects  of
stormwater discharges on the biological condi-
tion of wetlands. Another potentially powerful
tool is  the water quality certification  process.
Under  CWA Section  401, States have the au-
thority to grant or deny "certification" of feder-
ally permitted or licensed activities that may re-
sult in  a discharge to wetlands or other
waterbodies. The certification decision is based
on whether the  proposed activity will comply
with State water quality standards. Under this
process, a State can use  information from
bioassessments  to determine if a proposed ac-
tivity would degrade water quality of a wetland
or other waterbodies in a watershed. If a State
grants certification, it is essentially saying that
the  proposed activity will  comply with State
water quality standards. Likewise, a State can
deny certification if the project would harm the
chemical, physical, or biological integrity of a
wetland as defined by water quality standards.
AState's Section 401 certification process is only
as good as its underlying water quality standards.
States can use bioassessments to refine narra-
tive and numeric criteria to make them more
suitable for conditions found in wetlands and
subsequently improve the Section 401 certifi-
cation process.


    IMPROVING PLANS To MONITOR,
        PROTECT, AND RESTORE
        BIOLOGICAL CONDITION

 Wetlands are often damaged by a complex mix
of chemical, physical, and biological stressors.
It can be difficult to pinpoint specific stressors
using biological information or any single source
of information alone.  However, properly
planned,  designed,   and  implemented
bioassessments  are not performed in a vacuum
(Yoder 1995). Proximity to known sources of
pollution, knowledge of the surrounding land-
scape, and supporting chemical and habitat data
are all important sources of information to help
identify how and why a wetland is being dam-
aged. Recent advances in stressor identification
and evaluation provide a framework for system-
atically  examining all available data, identify-
ing probable stressors,  and documenting the
decisionmaking  process (U.S. EPA2000b). The
                                         23

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Stressor Identification framework offers three
approaches to identify probable causes:  (1)
eliminate, (2) diagnose, and (3) assess strength
of evidence (Figure 9). The strength-of-evidence
approach will often be the most helpful approach
when the biota exhibits impairment and there is
no clear stressor.  In some cases, the stressor
identification process will indicate that addi-
tional monitoring of the biological community
is required or will provide a shortened list of
potential chemical or habitat stressors to be in-
vestigated. Thus, bioassessments and the stres-
sor identification process can help States iden-
tify problem areas and then target the use of more
expensive chemical and physical measurements
on these sites.  When the stressor identification
process identifies a probable stressor, appropri-
ate actions can be taken to restore wetland con-
dition. Under Section 303(d) of the Clean Wa-
ter Act, States are required to submit lists to EPA
of waterbodies that do not attain their designated
uses and criteria,  such as biocriteria.  Subse-
quently, States can use bioassessment data and
the stressor identification process to apply a va-
riety of management tools (e.g., total maximum
daily loads, Section 319 nonpoint source pollu-
tion reduction, NRCS wetland conservation pro-
grams) to  improve  wetland condition.
Bioassessment data will also be useful for States
and municipalities when they target resources
to protect or purchase easements on high-qual-
ity wetlands.

  EVALUATING THE PERFORMANCE OF
    REGULATORY, PROTECTION, AND
       RESTORATION ACTIVITIES

 States can evaluate the success of restoration
activities and best management practices, such
as buffer strips, by requiring followup assess-
ments in management plans.  By periodically
conducting bioassessments, States can track the
condition of wetlands and learn which manage-
ment activities work best.  States can use this
information to improve future management
plans and save time and money by targeting the
most effective restoration proj ects and best man-
agement practices that achieve greater environ-
mental benefits. Wetland biologists can also use
bioassessment data to track wetland biota recov-
ery time and to identify which features of wet-
land restoration projects, such as diverse
microtopography, are most important in improv-
ing biological condition. The USGS  Biological
Resources Division, NRCS Wetland Science In-
stitute, and EPA Wetlands Division coopera-
tively worked on  a project to develop
bioassessment methods to evaluate  the condi-
tion of restored wetlands on the Delmarva Pen-
insula in Maryland.

   INCORPORATING WETLANDS INTO
      WATERSHED MANAGEMENT

 The watershed management cycle is based on
sound monitoring data (U.S. EPA 1995a, 1996c).
Collectively,  watershed stakeholders  employ
sound scientific data, tools,  and techniques in
an iterative decisionmaking process (Figure 10).
This process includes:
•  Strategic monitoring. Target monitoring to
   inform management decisions
•  Assessment.  Evaluate data to determine con-
   dition of waterbodies, identify stressors, or
   evaluate effectiveness of prior management
   plans
•  Assigning priorities and targeting resources.
   Rank water quality concerns and decide how
   to allocate resources to address priority con-
   cerns
•  Developing management strategies.  De-
   velop clear goals and objectives to address
   priority concerns, identify a range of man-
   agement strategies, and evaluate their effec-
   tiveness
                                          24

-------
                Detect or Suspect Biological Impairment
D

-------
H  Management plans. Specify how goal swill
   be achieved, who is responsible for imple-
   mentation, on what schedule, and how the
   effectiveness of the plan will be assessed

   Implementation.  Implement activities de-
   scribed in management plans

 Information from wetland bioassessments is
necessary to evaluate the condition of wetlands,
set environmental objectives, and evaluate the
success of management actions. Without infor-
mation from bioassessments, watershed manage-
ment plans will not adequately address or will
completely overlook the biological condition of
wetlands. Wetlands will continue to be included
in watershed  management plans as buffers to
maintain streams and lakes, but not as impor-
tant components of the environment that should
be maintained and protected based on their own
intrinsic functions and values. Failure to pro-
tect wetland condition in watershed plans will
likely diminish the health of other aquatic sys-
tems in a watershed.
                Management
                   Cycle
                             Assigning
                            Priorities and
                             Targeting
                             Resources
                  Developing
                  Management
                  Strategies
         IMPROVING RISK-BASED
       MANAGEMENT DECISIONS


 By identifying the biological and ecological
consequences of human actions,  biological
monitoring provides an essential foundation for
assessing ecological risks (Karr and Chu 1999).
To date, most ecological risk assessments focus
on using  laboratory analysis of chemical end-
points and extrapolate the results to the natural
environment because of perceived shortcomings
in ecosystem-level risk assessment (Suter et al.
1993).   The combined information from
bioassessments  and stressor identification may
fulfill many of  the perceived shortcomings of
ecosystem-level risk assessments. Through the
process of developing wetland bioassessments,
wetland biologists identify a biological endpoint
(i.e, a biological assemblage), group wetlands
into classes that respond similarly to stressors,
establish standard sampling methods, determine
what time of year to sample, establish known
reference conditions, and provide a way to mea-
sure divergence from biological integrity.  Re-
sults from bioassessments are  combined with
other available data in the stressor identification
process to determine the most probable stressor
causing damage.  The combined information
from wetland bioassessments and the stressor
identification process provide a foundation for
improving whole-ecosystem  studies.  In many
cases, bioassessments may provide more realis-
tic predictions than chemical laboratory tests of
the impacts that stressors have on the natural
environment (Perry and Troelstrup 1988). These
types of analyses also will be useful for projects
involving the  cleanup of  contaminated
Superfund and RCRA sites.
          MANAGEMENT CYCLE,

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  109-144.
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                                   GLOSSARY
Aquatic life use A type of designated use per-
taining to the support and maintenance of healthy
biological communities.
Assemblage An association of interacting popu-
lations of organisms that belong to the  same
major taxonomic groups.  Examples of assem-
blages used for bioassessments include:  algae,
amphibians,   birds,   fish,   amphibians,
macroinvertebrates (insects, crayfish, clams,
snails, etc.), and vascular plants.

Attribute A measurable  component of a bio-
logical system. In the context of bioassessments,
attributes  include the ecological processes or
characteristics of an individual or assemblage
of species that are expected, but not empirically
shown, to respond to a  gradient of human dis-
turbance.

Benthos The bottom fauna of waterbodies.

Biological assessment (bioassessment)  Using
biomonitoring data of samples of living organ-
isms to evaluate the condition or health of a place
(e.g., a stream, wetland, or woodlot).

Biological integrity  "the ability of an aquatic
ecosystem to support and  maintain a balanced,
adaptive community of organisms having a spe-
cies composition,  diversity, and functional or-
ganization comparable  to that of natural  habi-
tats within a region" (Karr and Dudley 1981).

Biological monitoring  Sampling the biota of a
place (e.g., a stream, a woodlot, or a wetland).

Biota All the plants and animals inhabiting an
area.

Composition (structure) The composition of
the taxonomic grouping such as fish, algae, or
macroinvertebrates relating primarily to the
kinds  and  number of organisms in the group.

Community  All the groups of organisms liv-
ing together in the same area, usually interact-
ing or depending on each other for existence.

Competition  Utilization by different species
of limited resources of food or nutrients, refu-
gia, space, ovipositioning sites, or other re-
sources necessary for reproduction, growth, and
survival.

Criteria A part of water quality standards.  Cri-
teria are the narrative  and numeric definitions
conditions that must be protected and maintained
to support a designated use.

Continuum A gradient of change.

Designated use  A part  of water quality stan-
dards.  A designated use is the ecological goal
that policymakers set for a waterbody, such as
aquatic life use support, fishing,  swimming, or
drinking water.

Disturbance "Any discrete event in time that
disrupts ecosystems, communities, or popula-
tion structure and changes resources, substrate
availability or the physical environment" (Picket
and White 1985). Examples of natural distur-
bances are fire, drought, and  floods.  Human-
caused disturbances are referred to as "human
disturbance" and tend to be more persistent over
time, e.g., plowing, clearcutting of forests, con-
ducting urban stormwater into wetlands.

Diversity A combination of the number of taxa
(see taxa richness) and the relative abundance
of those taxa. A variety of diversity indexes have
been developed to calculate diversity.

Dominance The relative increase in the abun-
dance of one or more species in  relation to the
abundance of other species in samples from a
habitat.

Ecological risk assessment An evaluation of
the potential adverse effects that human activi-
ties have on the plants and animals that make
up ecosystems.
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Ecosystem  Any unit that includes all the or-
ganisms that function together in a given area
interacting with the physical environment so that
a flow of energy leads to clearly defined biotic
structure and cycling of materials between liv-
ing and nonliving parts (Odum 1983).

Ecoregion Aregion defined by similarity of cli-
mate, landform,  soil, potential natural vegeta-
tion, hydrology, and other ecologically relevant
variables.

Gradient of human disturbance  The relative
ranking of sample sites within a regional  wet-
land class based on degrees of human distur-
bance (e.g., pollution, physical alteration of habi-
tats, etc.)

Habitat The sum of the physical, chemical, and
biological environment occupied by individu-
als of a particular species, population, or com-
munity.

Hydrology  The science  of dealing with the
properties, distribution, and circulation of wa-
ter both on the surface and under the earth.

Impact A change in the chemical, physical (in-
cluding habitat), or biological quality or condi-
tion of a waterbody caused by external forces.

Impairment Adverse changes occurring to an
ecosystem or habitat. An impaired wetland has
some degree of human disturbance affecting it.

Index of biologic integrity (IBI)  An integra-
tive expression of the biological condition that
is composed of multiple metrics. Similar to eco-
nomic indexes used for expressing the condi-
tion of the economy.

Intolerant taxa Taxa  that tend to decrease in
wetlands or other habitats that have higher lev-
els of human disturbances, such as chemical pol-
lution or siltation.

Macroinvertebrates   Animals without back-
bones (insects, crayfish, clams, snails, etc.) that
are caught with a 500-800 micron mesh net.
Macroinvertebrates do not include zooplankton
or ostracods, which are generally smaller than
200 microns in size.

Metric  An attribute with empirical change in
value along a gradient of human disturbance.

Minimally impaired site  Sample sites within
a regional wetland class that exhibit the least
degree of detrimental effect.  Such sites help
anchor gradients of human disturbance and are
commonly referred to as reference sites.

Most-impaired site  Sample sites within a re-
gional wetland class that exhibit the greatest
degree of detrimental effect. Such sites help
anchor gradients of human disturbance and serve
as important references, although they are not
typically referred to as reference sites.

Population A set of organisms belonging to the
same species and occupying a particular area at
the same time.

Reference site (as used with an index of bio-
logical integrity) A minimally impaired site that
is representative of the expected ecological con-
ditions and integrity of other sites of the same
type and region.

Stressor Any physical, chemical, or biological
entity that can  induce an adverse response.

Taxa A grouping of organisms given a formal
taxonomic name such as species, genus, family,
etc.  The singular form is taxon.

Taxa richness The number of distinct species
or taxa that are found in an assemblage, com-
munity, or sample.

Tolerance The  biological ability of different
species  or populations to survive successfully
within a certain range of environmental condi-
tions.

Trophic  Feeding, thus pertaining to energy
transfers.
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Wetland(s)  (1) Those areas that are inundated
or saturated by surface or groundwater at a fre-
quency and duration sufficient to support, and
that under normal circumstances do support, a
prevalence of vegetation typically adapted for
life in saturated soil conditions [EPA, 40 C.RR.§
230.3 (t)/USAGE, 33 C.RR. § 328.3 (b)]. (2)
Wetlands are lands transitional between terres-
trial and aquatic systems where the water table
is usually at or near the surface or the land is
covered by shallow water.  For the purposes of
this classification,  wetlands must have  one or
more of the following three attributes: (a) at least
periodically, the land supports predominantly
hydrophytes, (b) the substrate is predominantly
undrained hydric soil, and (c) the substrate is
nonsoil and is saturated with water or covered
by shallow water at some time during the grow-
ing season of each year (Cowardin et al. 1979).
(3) The term "wetland" except when such term
is part of the term "converted wetland," means
land that (a) has a predominance of hydric soils,
(b) is inundated or saturated by surface or ground
water at a frequency and duration sufficient to
support a prevalence of hydrophytic vegetation
typically adapted for life in saturated soil condi-
tions, and (c) under normal circumstances does
support a prevalence of such vegetation. For
purposes of this Act and any other Act, this term
shall not include lands in Alaska identified as
having a high potential for agricultural devel-
opment which have a predominance of perma-
frost  soils [Food  Security Act,  16  U.S.C.
                                          32

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           APPENDIX: WATER QUALITY STANDARDS
                                AND CRITERIA
 The main objective of the Clean Water Act
(CWA) is to "restore and maintain the chemi-
cal, physical, and biological integrity of the
Nation's water." To help meet these objectives,
States must adopt water quality standards (WQS)
for all "waters of the U.S." within their bound-
aries, including wetlands.  Water quality  stan-
dards, at a minimum, consist of three maj or com-
ponents:  (1) designated uses, (2) narrative and
numeric water quality criteria for supporting
each use, and (3) an antidegradation Statement.

           DESIGNATED USES

 Designated uses establish the environmental
goals for water resources.  States and Tribes as-
sign designated uses for each waterbody, or seg-
ment of a body of water, within their boundaries.
Typical uses include public water supply, pri-
mary contact recreation (such as swimming), and
aquatic life support (including the propagation
offish and wildlife). States and Tribes develop
their own classification system and can desig-
nate other beneficial  uses including  fish con-
sumption, shellfish harvesting, agriculture, wild-
life habitat, and groundwater recharge.

 Since designated uses can vary, States and
Tribes may develop unique water quality require-
ments or criteria for their designated uses. States
and Tribes can  also designate uses to protect
sensitive or valuable aquatic life or habitat, such
as wetlands.  When designating uses for wet-
lands, States may establish an entirely different
format to reflect the unique functions and val-
ues of wetlands. At a minimum, designated uses
must be attainable uses that can be  achieved
using best management  practices and other
methods  to prevent degradation.  States and
Tribes can also designate uses that have not yet
been achieved or attained. Protecting and main-
taining such uses may require the imposition of
more stringent control programs.

       WATER QUALITY CRITERIA

 Federal water quality regulation requires States
to adopt criteria sufficient to protect and main-
tain designated uses. Water quality criteria may
include narrative Statements or numeric limits.
States and Tribes can establish physical, chemi-
cal, and biological water quality criteria. Wet-
land biological monitoring and assessment pro-
grams  can help States and Tribes refine their
narrative and numeric criteria to better reflect
conditions found in wetlands.

 Narrative water quality criteria define condi-
tions that must be protected and maintained to
support a designated use.  States  should write
narrative criteria to protect designated uses and
to   support  existing  uses  under  State
antidegradation policies. For example, a State
or Tribe may describe desired conditions in a
waterbody as "waters must be free of substances
that are toxic to  humans, aquatic life,  and wild-
life."  In addition, States and Tribes  can write
narrative biological criteria to describe the char-
acteristics of the aquatic plants and animals.  For
example, a State may specify that "ambient wa-
ter quality  shall be sufficient to support  life
stages of all native aquatic species."

 Narrative criteria should be specific  enough
that States and  Tribes can translate them into
numeric criteria, permit limits,  and other con-
trol mechanisms including  best management
practices. Narrative criteria are particularly im-
portant for wetlands, since States and Tribes
                                         33

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cannot numerically describe many physical and
biological impacts in wetlands by using current
assessment methods.

 Numeric  water quality criteria are specific
numeric limits for chemicals, physical param-
eters, or biological conditions that  States and
Tribes use  to protect and maintain  designated
uses.  Numeric criteria establish minimum and
maximum physical, chemical,  and biological
parameters for each designated use. Physical
and chemical numeric criteria can include maxi-
mum concentrations of pollutants,  acceptable
ranges of physical parameters, minimum thresh-
olds of biological condition, and minimum con-
centrations of desirable parameters, such as dis-
solved oxygen.

 States and Tribes can adopt numeric criteria to
protect both human health and aquatic life use
support.  For example, numeric human health
criteria include maximum levels of pollutants
in water that are not expected to pose signifi-
cant risk to human health. The  risk to human
health is based on the toxicity of and level of
exposure to a contaminant. States  and Tribes
can apply numeric human health criteria (such
as for drinking water) to all types of waterbodies,
including wetlands.

 Numeric  chemical  or  physical criteria for
aquatic life, however, depend on the character-
istics within a waterbody.  Since characteristics
of wetlands (such as hydrology, pH,  and dis-
solved oxygen) can be substantially different
from other water bodies, States and Tribes may
need to develop  some physical  and chemical
criteria specifically for wetlands.

 Numeric biological criteria can describe the ex-
pected attributes and establish values based on
measures of taxa richness, presence  or absence
of indicator taxa, and distribution of classes of
organisms.  Many States have developed bio-
logical assessment methods for streams, lakes,
and rivers, but few States and Tribes have de-
veloped methods for wetlands.  Several States,
including Florida, Maine, Massachusetts, Min-
nesota, Montana, North Dakota, Ohio, and Ver-
mont are currently developing biological assess-
ment methods for monitoring the "health" of
wetland plant and animal communities. Wet-
land biological assessment methods are essen-
tial to establish criteria that accurately reflect
conditions found in wetlands.

       ANTIDEGRADATION POLICY

 All  State  standards  must  contain  an
antidegradationpolicy, which declares that the
existing uses of a waterbody must be maintained
and protected.  Through an antidegradation
policy, States must protect existing uses and pre-
vent waterbodies from deteriorating, even if
water quality is better than the minimum level
established by the State or tribal water quality
standards.    States and Tribes  can  use
antidegradation Statements to  protect waters
from impacts that water quality criteria cannot
fully address, such  as physical and hydrologic
changes.

 States and Tribes can protect exceptionally sig-
nificant waters as outstanding national resource
waters (ONRWs). ONRWs can include waters
with special environmental, recreational, or eco-
logical attributes, such as some wetlands.  No
degradation is allowed in waters designated as
ONRW. States can designate waters that need
special protection as ONRWs regardless of how
they ecologically compare to other waters.  For
example, although the water of a swamp may
not support as much aquatic life as a marsh, the
swamp is still ecologically important. A State
or Tribe could still  designate the swamp as an
ONRW because of its ecological importance.
                                          34

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        APPLICATIONS OF WQS            •  Determine if federally permitted or licensed
                                                activities maintain WQS under CWA §401
 Water quality standards provide the foundation       water quality certification
for a broad range of management activities and    _  _   ,    ,    ^-r-.uj-           ^
            ,  ,   .                           •  Track and report it waterbodies are support-
can serve as the basis to:                               ^  .   ,  .    ^  ,          ,   fZ^Ti
                                                mg their designated uses  under CWA
•  Assess the impacts of nonpoint source dis-       §305(b)
   charges on waterbodies under CWA §319,
•  Assess the impacts  of point source dis-
   charges on waterbodies under CWA §402,
                                         35

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