Freshwater Ecosystems Revitalizing Educational Programs in Limnology (1996) / Chapter Skim
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Bringing Biology Back into Water Quality Assessments
Bringing Biology Back into Water Quality Assessments
Pages 289-324
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From page 289... ...
Biological integrity is a concept central to successful bioassessment because it identifies the essential factors to be measured and provides a reference against which the degree of environmental disturbance or stress, either natural or anthropogenic, can be evaluated. Major anthropogenic stresses on the integrity of inland aquatic ecosystems include livestock grazing; forestry; agriculture; mining and smelting; urban usage; manufacturing; impoundment and diversion; and lake-, marsh-, and stream-bottom alteration.
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From page 290... ...
At the same time, many exciting developments, in fields ranging from molecular biology to landscape ecology, have potential application to the study and management of inland aquatic resources. This paper reviews the historical basis for the application of biological methods to water quality assessment and discusses factors that need to be considered in evaluating the biological integrity of inland aquatic ecosystems.
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From page 291... ...
Ecosystem management and sustainability are likely to have a major influence on research and management of many inland aquatic ecosystems in the United States for years to come. These concepts are especially relevant to federal agencies with large land holdings and broad responsibilities for the terrestrial and aquatic resources occupying them, such as
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From page 292... ...
were enacted in response to widespread surface water degradation and a growing public environmental awareness and concern. The implications of this legislation for inland aquatic science range from classroom to courtroom, and its implementation provides substantial opportunities for involvement in all aspects of water science.
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From page 293... ...
The Endangered Species Act has served to emphasize the importance of identifying and preserving the diversity of inland aquatic organisms and their habitats, and of assessing long-term trends in their conditions. Several recent developments stemming from these legislative acts have brought the biological aspects of water quality to the forefront: (1)
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From page 294... ...
The general authority for biological criteria comes from Section 101, which establishes as the objective of the act the restoration and maintenance of the chemical, physical, and biological integrity of the nation's waters. This section also includes an interim water quality goal for the protection and propagation of fish, shellfish, and wildlife.
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From page 295... ...
Narrative biological criteria are general definable statements of conditions or attainable goals of biological integrity and water quality for a given use designation; numeric criteria establish specific values based on measures such as species richness, presence or absence of indicator taxa (taxonomically related groups) , and trophic composition.
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From page 296... ...
Interim and lor~ger-term management strategies are being examined in several geographically specific environmental impact statements as required under NEPA; also under development is a comprehensive ecosystem management plan for the interior Columbia River Basin (Science Integration Team, 1994~. STRESSES ON BIOLOGICAL HEALTH OF INLAND WATERS The biological integrity of inland aquatic ecosystems is being assaulted in many ways (Power et al., 1988; Resh et al., 1988; Covich, 1993~.
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From page 297... ...
This can result in large-scale fish kills and the elimination of desirable fish species, production of foul odors, uncontrolled growth of algae and toxic bacteria, and obnoxious accumulations of filamentous algae and vascular plants. Not only do these activities affect the ecological integrity of inland
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From page 298... ...
Challenges of Assessing Biological Integrity Although legislation calls for maintaining biological integrity, measuring the biological health of inland waters is extremely complex; this complexity results not only from the need to account for natural variations in time and space, but also from the need to consider individual species as well as interactions among organisms in a particular aquatic community. Importance of Scale (Space and Time)
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From page 299... ...
influence many ecological phenomena in inland aquatic ecosystems (Hughes et al., 1986; Karr, 1991~. For example, streamflow characteristics vary with the type of soils and underlying geology; the topographic relief; and the form, amount, and timing of precipitation.
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From page 300... ...
However, for events occurring at intervals of 102 to 104 years, such as wildfire, the focus becomes the entire forest, which itself may cover numerous catchments. Landscape-scale events may affect aquatic ecosystems at various lower levels of resolution because of the hierarchical nature of these systems (Harris, 1980; Frissell et al., 1986; Pringle et al., 1988~.
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From page 301... ...
Aquatic ecosystems require certain spatial and temporal bounds for the maintenance of their structure and function. For example, many stream ecosystems are dependent on terrestrial leaves and other forms of allochthonous detritus for food and habitat.
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From page 302... ...
The demise of salmonid populations in the Pacific Northwest, referred to earlier, is symptomatic of a regionor basinwide loss of ecological integrity within the present century. Importance of Seasonal Variations in Time Variations in activity, condition, distribution, and abundance (hence, recruitment and/or mortality)
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From page 303... ...
is implicit in the modern, nonequilibrium view of ecosystems, its consideration is important in developing and applying the concept of ecosystem integrity to inland waters. Also, since ecosystem integrity is a scale-dependent concept, measuring or observing integrity or its loss in inland aquatic ecosystems requires observations over sufficient temporal extent to identify and characterize their patterns (King, 1993~.
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From page 304... ...
The suitability of a particular group is determined by the specific environmental stressor, the generation time of the organisms, and their mobility and dispersal capabilities. For example, fish may be better indicators of physical habitat conditions in streams and benthic macroinvertebrates more indicative of water quality conditions (C.
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From page 305... ...
To be useful as an indicator organism, an individual species must have a narrow range of tolerance for suitable environmental conditions that are known and related to some attribute of interest to humans. Few species satisfy these requirements because tolerance of a narrow range of conditions means that the organism may not be found widely in space or time and therefore will be of limited general utility as an indicator of environmental stress (Warren, 1971~.
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From page 306... ...
Attached microscopic forms can be scraped or brushed to free them from the substratum and then removed by suction for placement in a sample container or collection onto a filter (Lied, 1985; Porter et al., 1993~. Benthic macroinvertebrates are collected by a variety of dredges, nets, corers, baskets, and other devices depending on water depth, substratum type, and current velocity (Lied, 1985; Wetzel and Likens, 1991; Cuffney et al., 1993a,b)
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From page 307... ...
However, the recent renewed interest in biological integrity and its assessment has resulted in a reevaluation of those metrics that seem most effective, in an attempt to come up with standardized protocols (e.g., Karr et al., 1986; Plafkin et al., 1989; Karr, 1991; Resh and Jackson, 1993; Kerans and Karr, 1994~. After representative samples of the biota are obtained, the organisms are identified and enumerated, their biomass and condition are determined, and relevant metrics are calculated.
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From page 308... ...
(= EPT index) Pinkham-Pearson index Quantitative similarity index for taxa Community balance Hilsenhoff biotic index Proportion of individuals in the dominant taxon Dominants-in-common at each site for five most abundant taxa Proportion of Hydropsychidae individuals of the total number of Trichoptera Functional feeding group components Proportion of scraper abundance to sum of scrapers plus filterers Proportion of shredder abundance to total individuals Quantitative similarity index for functional feeding groups Fishc Species composition Total number of fish species Species richness and composition of selected groups (e.g., darters, suckers, sunfish)
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From page 309... ...
Some metrics are more responsive (and consistent) than others to the effects of livestock grazing.
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From page 310... ...
·s" 60 en ._ so C) 70 50 40 _ 30 _ 20 SRP T T NBR PCA TOTAL PCA TOTAL 8 metrics 18 metrics 10 metrics 18 metrics FIGURE 1 Health of macroinvertebrate communities in streams affected and unaffected by livestock grazing in two Idaho ecoregions: the Snake River Plain (SRP)
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From page 311... ...
It often is assumed that ecosystems are functionally resilient to alteration of structure due to compensatory responses, but this assumption has not been tested adequately for aquatic ecosystems. A compensatory functional response occurs when rates and amounts of ecosystem processes remain unchanged in the face of changes in structural composition, such as alteration of species dominance or loss of species richness.
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From page 312... ...
. Although methods are now available to begin adding functional measures to the assessment of ecological integrity in inland waters, many are still crude and simplistic.
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In particular, increased levels of acid, chlorine, chlorine plus ammonia, and salt have been shown to lower litter decomposition (Reice and Wohlenberg, 1993~. Another important process in aquatic ecosystems is biogeochemical cycling.
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From page 314... ...
Failure to address evolutionary aspects adequately has led to major misconceptions regarding ecosystem properties and processes such as succession (Hager, 1992; Colinvaux, 1993~. The dilution, isolation, and extinction of genetic pools are bound to be major problems in inland waters both now and in the future (Noss and Cooperrider, 1994~.
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From page 315... ...
The complexity and magnitude of the questions facing researchers and resource managers will increasingly require an interdisciplinary approach and the ability to work cooperatively. The ecological integrity of inland waters is being assailed on many fronts.
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From page 316... ...
The effects of natural and human-caused factors on inland aquatic ecosystems require consideration at multiple spatiotemporal scales that include adequate heterogeneity across landscapes (Covich, 1993~. Hierarchy theory commonly is used to address these questions of scale (Allen and Hoekstra, 1992~.
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From page 317... ...
Rapid technological advances ~ these and other areas such as data logging and wireless transmission, radiotelemetry, geographical positioning systems, acoustical sounding, electronic surveying and distance measurers, and pressure transducers for remote water-level sensing will increasingly provide powerful tools for addressing important questions relating to inland aquatic resources.
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1977b. Quantification of biological integrity.
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1991. Comparative responses of aquatic ecosystems to toxic chemical stress.
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1993. Measuring biological integrity: Lessons from streams.
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Pp. 234-286 in Freshwater Biomonitoring and Benthic Macroinvertebrates, D
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1994. How people in the regulated community view biological integrity.
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1994. Scientific Framework for Ecosystem Management in the Interior Columbia River Basin.
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1994. Theoretical habitat templets, species traits, and species rimless: Aquatic insects in the Upper Rhone River and its floodplain.
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