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  WMIC Publications

No. 2, September 1995


Table of Contents

What is NAWQA?

In 1991, the U.S. Geological Survey (USGS) began to implement a National Water-Quality Assessment (NAWQA) program. The long-term goals of the NAWQA program are to describe the status and trends in the quality of a large, representative part of the Nation's surface- and ground-water resources and to provide a sound, scientific understanding of the primary natural and anthropogenic factors affecting the quality of these resources.

To achieve these goals, the USGS is employing a multi-disciplinary approach which includes the collection of physical, chemical, biological, and ancillary anthropogenic data. These data will provide multiple lines of evidence to assess water quality.

The study-unit investigations comprise the principal building blocks of the national assessment. The 60 study-unit boundaries are based on one or more of the following: surface-water drainage basins, the extent of ground-water aquifers, and political boundaries (fig. 1).

WMIC Study Units

Fig. 1. National Water-Quality Assessment study units. (40K image)

The Western Lake Michigan Drainage Basin (fig. 2) was among the first 20 NAWQA study units selected to begin study activities in 1991.

WMIC Study Area

Fig. 2. Location of Western Lake Michigan Drainages (WMIC) study area. (16K image)

Why Use Biology in a Water-Quality Study?

Biological assessments of streams can provide important information on stream water quality, especially when conducted in conjunction with the collection of physical and chemical information. Additionally, the public is interested and concerned about the biology of our streams.

The ecology of streams are affected by a wide variety of human and natural factors. Some types of biota, such as algae, exist for only a few weeks at a specific place, and thus integrate water-quality influences over limited time and space. Others, such as some fish species, may live for years and range widely over a stream system, and thus possibly integrate long-term water-quality factors. The mobility of fish may also allow them to move away from short-term changes which might otherwise be deleterious to their health.

Each type of organism provides a unique assessment of the overall health of the stream. By sampling three communities of organisms (fish, benthic invertebrates, and algae) and physical stream habitat, as well as bed sediment and biotic tissue contamination, different biological pathways for contaminants, as well as secondary ecological effects that may not be observable in an individual species or population are accounted for.

Samples of bed sediment and biological tissues are used to assess contaminants in stream systems. Since contaminants are often concentrated in biological tissue due to bioaccumulation or bio-concentration, their use in assessments increases the probability of detecting low-level concentrations of contaminants, such as trace metals. Tissues also provide an assessment of contaminant levels over time and are a direct measure of the availability of contaminants to organisms. When used together, tissue, sediment, and water samples provide a better understanding of the distribution and fate of contaminants than any one measure can provide on its own.

Ecological Assessment Approach

For three consecutive years (1993-95), ecological sampling has been conducted in single-reaches at eight wadeable basic-fixed sites (BFS). Single-reach ecological sampling was completed at three non-wadeable BFS in 1995 so that all 11 BFS now have ecological data available. Information on species abundance and diversity of biota will be used together with other chemical and physical data collected to assess water quality at these sites. Temporal sampling is important to develop a baseline picture of biological communities and habitat for short- (3 years) and long-term (10-30 years) comparisons.

In 1994, ecological sampling was conducted at multiple-reaches at three of the BFS (Popple, Tomorrow, and North Branch Milwaukee Rivers). Multiple-reach sampling will provide information on variability among reaches.

Algae and invertebrate community samples and habitat data were collected in mid-May to early-June in 1993-95 in order to take advantage of the period of maximum diversity of invertebrates. In an effort to sample the streams at a similar season, sampling began at the southernmost sites and ended at the northern sites. Fish communities were sampled in late-July to early-August to take advantage of low-flow conditions and to avoid interference with spawning.

Assessment of aquatic communities was accomplished by a series of qualitative and semi-quantitative sampling methods. Reach lengths for sampling were determined by including repetitive geomorphic channel units (for example, 2 riffles and 2 pools) for a minimum of 150 m in wadeable streams, or a distance equal to at least 20 channel widths if the above channel units were not present.


Habitat data are collected at four spatial scales: (1) basin or catchment; (2) stream segment; (3) reach; and (4) microhabitat. Information from each scale is necessary for an overall understanding of the water quality of the stream and the composition of its biological communities. Methods are described in Meador and others (1993). A Geographical Information System (GIS) is used to determine habitat characteristics on a basin scale, including land use, ecoregion, soil characteristics, bedrock geology, and wetlands. Maps and aerial photos are used in collecting habitat information at the segment scale. A stream segment is a distinct stream unit bounded by tributaries or discontinuities (geomorphology or water-quality related). It includes the study reach at the BFS.

At the reach and microhabitat segment scales, features are measured that may more directly affect the water quality and biological communities. Information is collected on a wide variety of characteristics, including in-stream geomorphology, bank characteristics, and vegetation. This information is used to describe the site, and in conjunction with other biological and water-quality data to assess which habitat features are most important to the overall health of the stream. Multivariate statistical analyses will be used to correlate habitat features and biotic community information.


The objectives of the fish sampling are to determine community structure, relative abundance, and health. Sampling is done using either backpack or towed barge electrofishing units. Two passes are made through the sampling reach, each beginning at the downstream end of the reach and proceeding upstream. All electrofishing units are pulsed-DC power.

Fish are identified to species, measured (total and standard length), weighed, and released. Fish that cannot be identified to species in the field are preserved and later identified in a laboratory. All fish collected are checked for presence of external anomalies (deformities, eroded fins, lesions, tumors, diseases, and parasites). Methods are described in detail in Meador and others (1993).


Benthic invertebrate sampling consists of the collection of semi-quantitative and qualitative samples from each stream reach. Semi quantitative samples include riffle and pool sampling to provide relative abundance information. Qualitative Multihabitat samples provide taxa presence information. Sampling methods are described in detail in Cuffney and others (1993).

Riffle samples are collected in the habitat type that is believed to support the faunistically richest assemblage of invertebrates in the sampling reach. Riffle samples consist of a composite of 6 kick samples from two riffles using a modified surber net (425-micron mesh).

Pool samples are collected from fine-grained, organic-rich depositional habitats. Pool samples are composites of 6 grabs with a ponar dredge (425-micron mesh screen).

Multihabitat samples are qualitative composite samples collected from as many habitat types as possible in the sampling reach. The sampling effort in each reach is limited to one hour or less. All multihabitat samples are collected using a D-frame kick net (210-micron mesh) and supplemented by visual inspections and hand picking from woody snags, plants, rocks, and debris.

At each field location, samples are processed, preserved, and stored until they can be shipped to the contract laboratory for identification.


Benthic algal community sampling also consists of the collection of qualitative and semi-quantitative samples from each reach. Methods are described in detail in Porter and others (1993).

Semi-quantitative samples are collected from the predominant benthic algal microhabitat within the richest targeted habitat selected for invertebrate sampling. In most cases, the faunistically richest community of benthic algae is that attached to rocks in riffle areas. Samples consist of a composite sample from 5 cobble-sized rocks from each of 5 different locations at a site and from a defined surface area sampled from each rock. The NAWQA periphyton sampling device (SG-92) for flat surfaces is a modified syringe barrel and a small brush. Shallow depositional areas on the margins of streams are sampled using a petri dish and spatula.

Qualitative samples consist of 3 separate sample types: microalgae, macroalgae, and aquatic mosses. The microalgae sample is a composite from all available microhabitats within the sampling reach such that equal volumes of algal biomass from each microhabitat were composited into a single sample container. Samples are collected by scraping, brushing, suctioning, and hand-picking. The sampling effort in each reach is limited to one hour or less at each site.

At each field location, samples were processed, preserved, and stored until they could be shipped to the contract laboratory for identification.

Contaminants in Sediment and Tissue

Concentrations of contaminants in the aquatic environment are of concern when and where organisms, including humans, may be at risk. One way to assess this risk is by measuring the amount of contaminants available to organisms, known as bioavailability. Contaminants may be bioavailable through a variety of routes including (1) absorption, (2) assimilation through food, sediment, and detritus, and (3) adsorption onto the outside of the body. The bioavailability of contaminants vary depending not only on concentration but on various chemical, physical, and biological interactions. Measuring concentrations in sediment and biotic tissue can give information on the transfer of contaminants in sediment to particular organisms.

The NAWQA team sampled aquatic biota and fine streambed sediments from 18 sites in 1992, 8 in 1994 and 6 in 1995 for determination of inorganic contaminant concentrations, specifically trace elements. Biota sampled consisted primarily of whole caddisfly larvae. Samples also were collected and analyzed for a suite of organic contaminants in 1992 at 18 sites, and in 1995 at 6 sites. The biota collected for organic contaminants were fish, specifically Catastomus commersoni (white sucker).

The results of the sampling conducted in 1992 for inorganic contaminants indicate that concentrations of chromium and nickel in caddisfly larvae and fine streambed sediments were elevated in most streams relative to minimally affected or ÒreferenceÓ streams in the basin and other areas of the United States. Chromium and nickel have both been identified as potential respiratory-tract carcinogens. Compared to reference streams, concentrations of lead were elevated in sediment samples collected at river mouths, including the Fox, Menominee, Milwaukee, and Sheboygan Rivers and from two urban streams in the Milwaukee River basin. Positive correlations (SpearmanÕs rho > 0.6) were observed between trace-element concentrations in caddisfly larvae and sediments for chromium, cobalt, lead, selenium, and strontium. Sampling for inorganics was conducted in 1995 at selected sites for tissues and streambed sediments. Temporal sampling will provide information on short- and long-term variability in contaminant concentrations at these sites.

The organic contaminants detected in fish tissue samples collected in 1992 reflect historical contamination from the use of the insecticide DDT. The continued presence of this compound and its breakdown products in some samples indicates the longevity of DDT in the environment. However, concentrations at sites in the WMIC study unit were low compared to the national average from U.S. Fish and Wildlife Service monitoring programs. Many more compounds and higher concentrations were detected in sediment samples collected at river mouths and urban streams than in samples collected at upstream sites. Fish were not collected at these sites in 1992; however, fish were collected in 1995 and are being analyzed for organic contaminants to determine if similarly higher contamination is reflected in fish at these sites.

Benchmark Streams in Agricultural Areas of Eastern Wisconsin

Water-quality studies are often focused on "problem" streams or streams that are considered polluted as a result of anthropogenic effects. These studies may answer such questions as: What kind of anthropogenic effects impact water quality of streams? What kinds of biota and/or habitat are associated with these streams? How can practices be changed to improve water quality of streams?

Although these studies provide a great deal of information defining poor water quality and identifying methods to improve water quality, they often do not define what the potential water quality could be for these streams. Very few studies have focused on defining what constitutes a "healthy" stream community. Information on benchmark or "reference" sites are needed by scientists and managers as a standard to measure either improvements in currently impacted streams or degradation of streams due to anthropogenic effects.

The USGS WMIC staff is in the process of providing detailed information on the environmental setting and biological communities of 20 benchmark streams in the agricultural areas of eastern Wisconsin. Sites were selected in 4 subareas in the primarily agricultural areas of the study unit based on historical information and field reconnaissance.

The purpose of the study is to define a "healthy" stream in agricultural areas by describing the environmental setting, stream habitat, fish, invertebrate, and algal communities that exist in the study streams; determine if there are differences in communities among these sites; and relate these differences (if present) to variations in ecoregions, geology, land use/land cover, riparian and in-stream habitat characteristics; and water quality. Comparisons will also be made between algal, fish, and invertebrate indices of "health."

Data for the 20 benchmark streams were collected in May, June, and July of 1993, and April, June, and July of 1995; reports are scheduled for completion in 1996. The watersheds under study are Camp Creek, Casco Creek, Chaffee Creek, East Branch Milwaukee River, Hibbards Creek, Krok Creek, Lawrence Creek, Little Scarboro Creek, Mecan River, Mullet River, Neenah Creek, Nichols Creek, Pine River, Silver Creek, Smith Creek, Tisch Mills Creek, Watercress Creek, West Branch Red River, Whitcomb Creek, and Willow Creek.

Do Pesticides Disrupt Fishes' Reproductive Systems?

Biologists from the NAWQA Program and the National Biological Service have completed a reconnaissance study to determine whether fish in U.S. streams are being affected by endocrine-disrupting contaminants. Concerns are increasing about the effects that some organic contaminants and trace elements which have been introduced into the environment have on the reproductive systems of fish and wildlife (Colborn and Clement, 1992). Potential problems include reproductive failure, birth deformities, immune-system disorders, defeminization, and demasculization. About 50 specific compounds and elements have been identified as endocrine disrupters (Colborn and others, 1993), but others may have effects as well, and little is known about the effects of co-occurrence of these contaminants in real-world settings.

Aquatic ecosystems are a focus of current research on the topic of endocrine disrupters because they receive both point and non-point discharges of these contaminants and they support susceptible organisms, including fish and fish-eating predators. In this study, carp and largemouth bass were collected from streams throughout the U.S. and were evaluated for effects using three biomarker analyses, including vitellogenin, estrogen/11 keto testosterone ratio, and histopathology of reproductive organs. Whole fish will also be analyzed for a suite of endocrine-disrupting contaminants.

In the Western Lake Michigan Drainages, carp were collected at the North Branch Milwaukee River (agricultural land use site) and the Mullet River (reference site) in July 1994. Results from this study should provide valuable information linking contaminant exposure with measured biological effects.


Colborn, T., and Clement, C., 1992, Chemically-induced alterations in sexual and functional development: The Wildlife/Human Connection, v. XXI, Advances in modern environmental toxicology, Princeton Scientific Publishing Co., Inc., Princeton, N.J., 403 p.

Colborn, T., Vom Saal, F.S., and Sota, A.M., 1993, Developmental effects of endocrine-disrupting chemicals in wildlife and humans: Environmental Health Perspectives, 101: pp. 378-384.

Coordinating Environmental Monitoring Efforts in Wisconsin

A large data base containing information on benthic macroinvertebrate populations in streams has been compiled by Dr. Stanley Szczytko and his students at the University of Wisconsin-Stevens Point. Data are primarily from collection by the WDNR and are available from 1984 through the present. WMIC NAWQA team members have utilized a portion of the database to examine relations between insect abundance and diversity, and habitat characteristics of the basin. Preliminary findings suggest that the composition of invertebrate communities are affected by seasonality, sampling location in the stream, substrate, and one or more of the following: land use, bedrock geology, and surficial deposits in the watershed.

The invertebrate data is being matched with quantitative water-quality values from the USGS data base where sampling sites overlap. Additional USGS sampling of water quality has occurred in 1995 to obtain a statistically significant number of matched sites. These sites will be used to determine how the invertebrate data predicts water quality. The information obtained from these matched sites will provide a means of using this vast database as an additional tool to assess the water quality at the rest of the invertebrate sites in the Western Lake Michigan drainage basin.

Biology Reports: Plans and Progress

The biological component of NAWQA will be reported at the national, regional, and study unit level. The national reports focus on the study design and methods protocols. The regional reports will summarize findings from a number of study units on specific regional issues and the WMIC study unit will release results associated with the basin-wide biological effort.

Below is a list of some of the reports published at the national level, followed by a list of published, in preparation, and planned reports for the WMIC study unit.

National NAWQA Biology Reports


Crawford, J. Kent, and Luoma, Samuel N., Guidelines for Studies of Contaminants in Biological Tissues for the National Water-Quality Assessment Program, Open-File Report 92-494, 69 p.

Cuffney, Thomas F., Gurtz, M., and Meador, M., Methods for collecting benthic invertebrate samples as a part of the National Water-Quality Assessment Program, Open-File Report 93-406, 66 p.

Cuffney, Thomas F., Gurtz, M., and Meador, M., Guidelines for the processing and quality assurance of benthic invertebrate samples collected as part of the National Water-Quality Assessment Program, Open-File Report 93-407, 80 p.

Gilliom, Robert J., Alley, W., and Gurtz, M., Design of the National Water-Quality Assessment Program: occurrence and distribution of water-quality conditions, Circular 1112, 33 p.

Gurtz, Martin E., and Muir, Thomas A., editors, Report of the Interagency Biological Methods Workshop, Open-File Report 94-490, 85 p.

Meador, M.R., Methods for sampling fish communities as a part of the National Water-Quality Assessment Program, Open-File Report 93-104, 40 p.

Meador, Michael R., Hupp, C., Cuffney, T., and Gurtz, M., Methods for characterizing stream habitat as part of the National Water-Quality Assessment Program, Open-File Report 93-408, 48 p.

Porter, Stephen D., Cuffney, T., Gurtz, M., and Meador, M., Methods for collecting algal samples as part of the National Water-Quality Assessment Program, Open-File Report 93-409, 39 p.

Western Lake Michigan Study Unit NAWQA Biology Reports


Scudder, B.C., 1993, Biological assessments in the National Water-Quality Assessment Program-Western Lake Michigan Drainages study unit, abstract, Society of Environmental Toxicology and Contamination, abstracts with program, p. 239.

Scudder, B.C., 1995, Trace elements in caddisflies and streambed sediments from streams in the Western Lake Michigan Drainages, abstract: Bulletin of the North American Benthological Society, v. 12, no. 1, p. 159.

In Preparation

Benchmark streams in agricultural settings in Wisconsin: Environmental Setting. Summary of biological investigations that relate to water quality in a water-quality assessment of the Western Lake Michigan Drainages, Wisconsin and the Upper Peninsula of Michigan.

National Water-Quality Assessment Program: Fixed Monitoring Sites in the Western Lake Michigan Drainages-Environmental Setting.


Reports on algae, fish, benthic invertebrates, and habitat are planned for both the Relatively Pristine Streams and the Fixed Monitoring Sites. Additionally, reports are planned on: (1) occurrence of trace elements and organic compounds in tissue and streambed sediment; (2) variations in geomorphic characteristics of agricultural streams in southeastern Wisconsin and the effect on aquatic habitat; and (3) PCB uptake rate and capacity for individual phytoplankton species.

Where to find NAWQA reports

National NAWQA biology reports can be obtained from:

U.S. Geological Survey
Earth Science Information Center
Open-File Reports Section
Box 25286, MS 517
Denver Federal Center
Denver, CO 80225
(303) 236-7476
or can be found on the National NAWQA home page on the internet at: http://wwwrvares.er.usgs.gov/nawqa

Western Lake Michigan Drainages biology reports can be obtained from:

District Chief
U.S. Geological Survey
6417 Normandy Lane
Madison, WI 53719
(608) 276-3815
or can be found on the WMIC NAWQA home page on the internet at: http://wi.water.usgs.gov/widocs/madison/nawqa/nawqa.html

Next NAWQA News Due in March 1996

The next issue of NAWQA News is planned for March 1996. If there is something in particular you would like to see in the next issue of NAWQA News, please feel free to let us know.

This newsletter was prepared by the Western Lake Michigan Drainages study unit team. The purpose of the newsletter is to help keep the state and local water-resources community informed of our activities. The newsletter represents the views of the WMIC NAWQA team and is intended for informational purposes. It is not intended for redistribution or republication. If you would like your name added to or removed from the mailing list for this newsletter, or if you have any comments regarding this newsletter or our workplans, call Charlie Peters at (608) 276-3810, or write to:

U.S. Geological Survey
6417 Normandy Lane
Madison, Wisconsin 53719

or send e-mail to: capeters@usgs.gov

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