Together with water chemistry and hydrologic data, ecological data is collected as a complementary means of assessing water quality in the Western Lake Michigan Drainages. Methods used are nationally consistent within the USGS to allow comparison with other areas of the U.S. Ecological data collected includes distribution and abundance of algae, invertebrates, and fish, as well as stream habitat at stream sites.
Cycle I ecological data at 11 fixed sites and an ecological
survey of 20 benchmark streams in agricultural areas was summarized in several
reports. In Cycle II, 4 of the original 11 Cycle I fixed sites were resampled
for water quality and ecology, during the period from 2002 through 2004. From
2005 through 2006, only one site was sampled.
Beginning in 2007, ecological assessments will be conducted at
3 sites on a rotational basis. An ecological assessment will be conducted at
Popple River every year, beginning in 2007, and at Lincoln and Duck Creeks, every
other year beginning in 2007 and 2008, respectively.
Ecological Studies at Fixed Sites
Ecological studies were conducted once per year at the Cycle I fixed sites from 1993 through 1995. Ecological sampling focused on 8 wadable sites out of the 11 fixed sites but sampling was done at the final 3 non-wadable sites in 1995. Reports summarizing these data are listed on the WMIC Publications page and include: Sullivan and others, 1995 (Environmental setting); Fitzpatrick and others, 1997 (Habitat); Sullivan, 1997 (Fish); Lenz and Rheaume, 2000 (Invertebrates); algae data is unpublished.
In Cycle II, ecological studies were done once per year from 2002 through 2004 during low flow in late summer/early fall. At a subset of sites, algae and invertebrate communities also were sampled in late spring. Upon review, ecological data are available from the NAWQA Data Warehouse.
Ecological Study of Agricultural Benchmark Streams in Eastern Wisconsin
Aquatic communities were studied at 20 sites in agricultural areas of eastern Wisconsin by the U.S. Geological Survey in May and June, 1993 as part of the National Water-Quality Assessment Program Western Lake Michigan Drainages study unit. These "benchmark" stream sites were selected for study to represent standards of reference for comparison to other streams in similar physical settings that appear to be more detrimentally affected by agriculture. The agricultural benchmark streams were selected from four physical settings, or relatively homogeneous units (RHU's), that differ in bedrock type and texture of surficial deposits. The results of this study were published in the following USGS Water-Resources Investigations Reports:
Rheaume, S.J., Stewart, J.S., and Lenz, B.N., 1996, Water-Quality Assessment of the Western Lake Michigan Drainages: Environmental Setting of Benchmark Streams in Agricultural Areas of Eastern Wisconsin : Water-Resources Investigations Report 96-4038-A
Fitzpatrick, F.A., Peterson, E.M., and Stewart, J.S., 1996, Habitat Characteristics of Benchmark Streams in Agricultural Areas of Eastern Wisconsin : Water-Resources Investigations Report 96-4038-B
Rheaume, S.J., Lenz, B.N., and Scudder, B.C., 1996, Benthic Invertebrates of Benchmark Streams in Agricultural Area of Eastern Wisconsin - Western Lake Michigan Drainages : Water-Resources Investigations Report 96-4038-C
Sullivan, D.J. and Peterson, E.M., 1997, Fish Communities of Benchmark Streams in Agricultural Areas of Eastern Wisconsin : Water-Resources Investigations Report 96-4038-D
Scudder, B.C., and Stewart, J.S. 2001, Benthic algae of benchmark streams in agricultural areas of eastern Wisconsin : Water-Resources Investigations Report 96-4038-E
NAWQA also examined the 20 benchmark agricultural streams and 5 fixed sites in eastern Wisconsin to determine relations among fish, invertebrate, and algalmetrics, and multiple spatial scales of land cover, geologic setting, hydrologic, aquatic habitat, and water-chemistry data (Fitzpatrick and others, 2001). Spearman correlation and redundancy analyses were used to examine relations among biotic metrics and environmental characteristics. Riparian vegetation, geologic, and hydrologic conditions affected the response of biotic metrics to watershed agricultural land cover but the relations were aquatic assemblage dependent. It was difficult to separate the interrelated effects of geologic setting, watershed and buffer land cover, and base flow. Watershed and buffer land cover, geologic setting, reach riparian vegetation width, and stream size affected the fish IBI, invertebrate diversity, diatom IBI, and number of algal taxa; however, the invertebrate FBI, percentage of EPT, and the diatom pollution index were more influenced by nutrient concentrations and flow variability. Fish IBI scores seemed most sensitive to land cover in the entire stream network buffer, more so than watershed-scale land cover and segment or reach riparian vegetation width (figures A, B, and C). All but only one stream with more than approximately 10 percent buffer agriculture had fish IBI scores of fair or poor. In general, the invertebrate and algal metrics used in this study were not as sensitive to land cover effects as fish metrics. Some of the reach-scale characteristics, such as width/depth ratios, velocity, and bank stability could be related to watershed influences of both land cover and geologic setting. The Wisconsin habitat index was related to watershed geologic setting, watershed and buffer land cover, riparian vegetation width, and base flow, and appeared to be a good indicator of stream quality. Results from this study emphasize the value of using more than one or two biotic metrics to assess water quality and the importance of environmental characteristics at multiple scales.
Further analysis of data from this study indicated that the Wisconsin habitat index was related to watershed geologic setting, watershed and buffer land cover, riparian vegetation width, and base flow (see figure D below), and appeared to be a good indicator of stream quality.
The results of this study were published in 2001 in the Journal of American Water Resources Association, vol. 37, no. 6, p. 1489-1507 "Effects of Multi-Scale Environmental Characteristics On Agricultural Stream Biota In Eastern Wisconsin" by Faith A. Fitzpatrick, Barbara C. Scudder, Bernard N. Lenz, and Daniel J. Sullivan.