Grantee Research Project Results
2002 Progress Report: Protocols for Selection of Classification System and Reference Conditions: A Comparison of Methods
EPA Grant Number: R828777Title: Protocols for Selection of Classification System and Reference Conditions: A Comparison of Methods
Investigators: Johnson, Lucinda , Richards, Carl , Schuldt, Jeffrey A. , Host, George E. , Ciborowski, Jan
Current Investigators: Johnson, Lucinda , Richards, Carl , Schuldt, Jeffrey A. , Host, George E. , Brady, Valerie J , Holland, Jeffrey L. , Hollenhorst, Thomas P. , Breneman, Dan , Ciborowski, Jan , Gathman, Joseph
Institution: University of Minnesota - Duluth
EPA Project Officer: Packard, Benjamin H
Project Period: March 26, 2001 through March 25, 2004 (Extended to March 25, 2005)
Project Period Covered by this Report: March 26, 2002 through March 25, 2003
Project Amount: $707,404
RFA: Development of National Aquatic Ecosystem Classifications and Reference Conditions (2000) RFA Text | Recipients Lists
Research Category: Water , Aquatic Ecosystems
Objective:
The objectives of this research project are to: (1) apply an a priori classification system to Great Lakes coastal ecosystems; (2) quantitatively identify least impacted sites within classification units using widely available spatial databases; (3) define biological conditions that best characterize reference classification units; (4) use biological data to test the efficacy of reference classifications; and (5) determine whether biological conditions in degraded classification units differ from conditions in reference areas at a subset of classification units.
Progress Summary:
In conjunction with the Estuarine and Great Lakes Program-Great Lakes Environmental Indicators (EaGLe-GLEI) project, we compiled spatial data layers to summarize stressors for coastal areas of the U.S. side of the Great Lakes Basin. Last year, we developed an inventory of wetlands, embayments, and high-energy shoreline areas of the U.S. side of the Great Lakes using low altitude aerial photographs, digital orthophoto quadrangles, digital raster data, and several wetland inventories (e.g., National Wetland Inventory, Herdendorf, et al., 1981, Wisconsin Wetland Inventory). Maps/images of the shoreline were visually inspected and classified. Three hydrogeomorphic classes of wetlands were identified based on a classification by Keough, et al. (1999), accounting for the degree of exposure to open waters of the Great Lakes.
We have defined the reference condition as the relative absence of anthropogenic stresses. To identify the least disturbed riverine wetlands within an ecoregion, we first delineated unique topographic receiving areas for 84 riverine wetlands in the Basin. Measures of residential/commercial land use, agricultural land use, human population density, and distance to point sources were summarized for each wetland and its receiving area (see Table 1).
Table 1. Stressor Data Summarized for Shoreline Segments as a First Step in the Selection of Reference Sites. Candidate high energy shorelines also were evaluated with respect to the extent of shoreline hardening, based on shoreline vector files from the U.S. Army Corps of Engineers.
Type |
Source |
Description |
Population Density | U.S. Census Bureau | average density in a 1-km window |
Agricultural Land Use | USGS- NLCD | number of pixels in a 1-km window |
Residential/Commercial Land Use | USGS- NLCD | number of pixels in a 1-km window |
Point Sources of Stress | EPA | mean distance to point sources (NPDES, TRI, and AOC's, see below) |
NPDES Permits | EPA | discharge permits (metals, solvents, nutrients, particulates, salt, chlorinated compounds, PAHs, hydrocarbons, physical disturbance, pharmaceuticals, pathogens, sewerage), summed 5 different ways (total number, active, inactive, major, and minor permitted facilities) |
Toxic Release Inventory (TRI) points | EPA | number of TRI facilities discharging into air, water, land, underground or POTW systems per area |
Distance to Nearest Areas Of Concern (AOC) | EPA | distance to the nearest AOC |
Shoreline Modification | U.S. Army Corps of Engineers | shoreline vector file |
Because of the linear nature of high-energy shorelines and embayments, we conducted a moving window analysis to summarize the stressors listed in Table 1. We used the ArcInfo Focalsum command to summarize stressor variables in an area extending 1 km in each direction (except into the lake) around each shoreline pixel. This command evaluated a 1-km area around each 33 m x33 m shoreline pixel, and assigned a summary value (e.g., a count or average) to that pixel.
Potential reference shoreline pixels were identified by examining the cumulative distributions of each of the stressor variables based on minimal levels of disturbance. The absolute pixel scores were scaled to make rankings equivalent across each of the types of disturbance. Each pixel was then assigned a "relative maximum" summary score; the single largest value for any disturbance class (RelMax), based on the assumption that the single most severe stressor likely exerts the greatest effect on the biological community. A site was a candidate to be a reference area if its RelMax score fell below a predetermined "reference area threshold value," typically taken to be equivalent to the 20th percentile. Adjacent reference area candidate pixels were agglomerated into polygons. To appear in a final list of candidate reference areas, a polygon had to encompass a shoreline segment greater than 2 km in length.
A similar scoring approach was used for coastal and protected wetland polygons for which unique topographic basins were delineated during Year 2 of the project. An inventory of the geomorphic types in each of the Great Lakes Ecological Sections is shown in Table 2.
A significant portion of this year was spent inventorying coastal and protected wetlands and delineating unique receiving areas for those systems. We used the same approach described above for riverine wetlands to identify candidate reference areas for these two wetland types. Our reference condition approach currently is being tested in those ecoregions for which there are a minimum of 30 wetlands or shoreline segments in the sampling population, and where at least 6 candidate reference areas meet criteria for boat access within 5 km of the site.
Evaluating Reference Conditions Using Fish and Invertebrates. We have elected to evaluate our reference condition approach by characterizing fish, macroinvertebrates, and physical habitat attributes. This information will allow us to establish a benchmark (both a value and some measure of variability) that reflects the best attainable abiotic and biotic conditions, and evaluate the appropriate spatial scale for developing reference areas for coastal regions.
Field Methods. One of the primary effects of anthropogenic stress on an ecosystem is habitat degradation. In 2001, we developed a habitat assessment methodology for wetlands that involves three scales of observations. Throughout 2002, we refined these habitat assessment methods in the field to improve their utility, reproducibility, and efficiency of collection.
During 2002, we spent the majority of our efforts developing the framework for site selection, and collected habitat and biological data from 11 sites, mainly high-energy and riverine wetlands. The balance of the sites will be sampled in 2003, to produce a total of approximately 60 sampling locations allocated across the 6 ecological sections that adjoin the U.S. Great Lakes coastline (see Table 2). Fish and habitat data from all locations have been compiled into an integrated database. We have identified and enumerated the organisms in benthic samples collected in 2001 and 2002, and data are being entered into the database.
Table 2. Distribution of Wetland Types, Embayments, and High Energy Shorelines Across Dominant Ecoregions of the Great Lakes. Six sites within each of the units shown in bold will be sampled during the project.
Ecosection |
High Energy Shoreline |
Embayment |
River Influenced Wetland |
Protected Wetland |
Coastal Marsh |
Erie Ontario Lake Plain | 1613 km |
18 |
84 |
45 |
31 |
Northern Great Lakes | 2687 km |
34 |
54 |
51 |
152 |
Northern Superior Uplands | 389 km |
0 |
16 |
3 |
0 |
South Central Great Lakes | 592 km |
2 |
12 |
6 |
32 |
Southwestern Great Lake Morainal | 520 km |
0 |
2 |
10 |
0 |
South Superior Uplands | 920 km |
10 |
39 |
29 |
27 |
References:
Herdendorf CE, Hartley SM, Barnes MD, eds. Fish and Wildlife Resources of the Great Lakes Coastal Wetlands within the United States. U.S. Fish and Wildlife Service, Volume 1: Overview, 1981a. FWS/OBS-81/02-v1.
Herdendorf CE, Hartley SM, Barnes MD, eds. Fish and Wildlife Resources of the Great Lakes Coastal Wetlands within the United States. U.S. Fish and Wildlife Service, Volume 2: Lake Ontario, 1981b. FWS/OBS-81/02-v2.
Herdendorf CE, Hartley SM, Barnes MD, eds. Fish and Wildlife Resources of the Great Lakes Coastal Wetlands within the United States. U.S. Fish and Wildlife Service, Volume 3: Lake Erie, 1981c. FWS/OBS-81/02-v3.
Herdendorf CE, Hartley SM, Barnes MD, eds. Fish and Wildlife Resources of the Great Lakes Coastal Wetlands within the United States. U.S. Fish and Wildlife Service, Volume 4: Lake Huron, 1981d. FWS/OBS-81/02-v4.
Herdendorf CE, Hartley SM, Barnes MD, eds. Fish and Wildlife Resources of the Great Lakes Coastal Wetlands within the United States. U.S. Fish and Wildlife Service, Volume 5: Lake Michigan, 1981e. FWS/OBS-81/02-v5.
Herdendorf CE, Hartley SM, Barnes MD, eds. Fish and Wildlife Resources of the Great Lakes Coastal Wetlands within the United States. U.S. Fish and Wildlife Service, Volume 6: Lake Superior, 1981f. FWS/OBS-81/02-v6.
Keough JR, Thompson TA, Guntenspergen GR, Wilcox DA. Hydrogeomorphic factors and ecosystem responses in coastal wetlands of the Great Lakes. Wetlands 1999;19(4):821-834.
Future Activities:
Future activities include work that is ongoing to sample the candidate list of "least impacted" sites identified last year and this year. Field sampling will continue until mid- September 2003. Sample processing and data analysis will continue throughout the year.
Journal Articles:
No journal articles submitted with this report: View all 10 publications for this projectSupplemental Keywords:
watersheds, water, ecological effects, aquatic, habitat, integrated assessment, biology, ecology, modeling, surveys, measurement methods, satellite, landsat, remote sensing, Great Lakes, Midwest, EPA Regions 5, 3, 2., RFA, Scientific Discipline, Geographic Area, Ecosystem Protection/Environmental Exposure & Risk, Aquatic Ecosystems & Estuarine Research, Hydrology, Aquatic Ecosystem, Ecology and Ecosystems, Great Lakes, reference condition, coastal environments, anthropogenic impact, comparison of methods, environmental indicators, biological indicators, ecological classification, remotely sensed dataProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.