Description: The Biological Stream Ratings for Diversity map is one of two parts that comprise a replacement for the Biological Stream Characterization (BSC) process. The BSC was jointly developed by the Illinois Department of Natural Resources (IDNR) and the Illinois Environmental Protection Agency (IEPA) in 1989 (Hite and Bertrand 1989) and was updated in 1996 (Bertrand et al. 1996). In 2006, the IDNR initiated an effort to combine and update the previous stream rating efforts into a single rating. The purpose was not only to update outdated information, but to create a rating system that would help resource managers determine efficacy in implementing the aquatic goals of the Illinois Wildlife Action Plan (http://dnr.state.il.us/orc/wildliferesources/theplan/). For purposes of implementing Illinois' Wildlife Action Plan, IDNR developed a rating system that would include both diversity and integrity measures, although the ratings have not been directly combined into an overall rating. All the information that contributed to integrity and diversity ratings were considered in identifying Biologically Significant Streams (BSS). Available data from 1997-2006 that were collected as part of IDNR, IEPA, and INHS monitoring programs were considered in this version. Specifically, diversity ratings are based on fish species richness (from IDNR); macroinvertebrate taxa richness (from IEPA); Ephemeroptera (E), Plecoptera (P), and Tricoptera (T) species richness (Critical Trends Assessment Program - CTAP); sensitive EPT species richness (Illinois Natural History Survey - INHS); mussel species richness (IDNR and INHS); crayfish species richness (INHS); and threatened and endangered species richness (IDNR). All datasets were overlaid on the 1:100,000 National Hydrography Dataset (NHD; USGS 2000) that was refined for a previous project. Point locations associated with large rivers and undigitized streams were omitted from the analysis. If a single site had more than one sample from the past decade, then the sample with the highest richness was included in the final rating calculation.A main objective of this project was to give equal weight to all communities of organisms found in streams if adequate and comparable sampling had occurred. Therefore, classes were developed for each dataset used in the analysis in an attempt to interpret raw data from different sources and classify it similarly. All class scores range from 1 to a greater number with that greatest number always representing the highest class. Each class score was divided by the total number of classes available to obtain a proportional score (P score), which has a maximum of 1. When multiple datasets were available for macroinvertebrates, the average of the proportional scores was used to determine the macroinvertebrate taxonomic score (T score). The T score combined information from separate assessments into a combined signal for macroinvertebrates, while equally weighting fish, macroinvertebrates, and mussels in the final rating. Because data were used from programs that sampled in similar but not exact places, valley segments were used to determine which sites should be grouped. Valley segments are aggregations of linearly adjacent, physically similar stream reaches (Seelbach et al. 1997). Physical characteristics used to define valley segments were related to stream size (drainage area), surficial geology (bedrock, course substrates), discharge (flow yield), and gradient. Valley segments were independently derived prior to this project using a spatially-constrained clustering technique (Brenden et al. 2008). Valley segment numbers were assigned to datasets through a spatial join in ArcMap 9.2. Datasets were then associated with each other for calculation of the final rating according to valley segment number in a query performed in Microsoft Office Access 2003. When multiple sites were associated with a particular valley segment within a dataset, the average of P or T (for macroinvertebrates) scores was used to calculate the final diversity score.
Copyright Text: Illinois Department of Natural Resources - Office of Resource Conservation and the Illinois Natural History Survey
Description: The Biological Stream Ratings for Integrity map is one of two parts that comprise a replacement for the Biological Stream Characterization (BSC) process. The BSC was jointly developed by the Illinois Department of Natural Resources (IDNR) and the Illinois Environmental Protection Agency (IEPA) in 1989 (Hite and Bertrand 1989) and was updated in 1996 (Bertrand et al. 1996). In 2006, the IDNR initiated an effort to combine and update the previous stream rating efforts into a single rating. The purpose was not only to update outdated information, but to create a rating system that would help resource managers determine efficacy in implementing the aquatic goals of the Illinois Wildlife Action Plan (http://dnr.state.il.us/orc/wildliferesources/theplan/). For purposes of implementing Illinois' Wildlife Action Plan, IDNR developed a rating system that would include both diversity and integrity measures, although the ratings have not been directly combined into an overall rating. All the information that contributed to integrity and diversity ratings were considered in identifying Biologically Significant Streams (BSS). Available data from 1997-2006 that were collected as part of IDNR, IEPA, and Illinois Natural History Survey (INHS) monitoring programs were considered in this version. Specifically, integrity ratings are based on fish Index of Biotic Integrity (IBI) scores (from IDNR), macroinvertebrate IBI (from IEPA), Mussel Classification Index (IDNR), and two mussel intactness values (INHS and IDNR). All datasets were overlaid on the 1:100,000 National Hydrography Dataset (NHD; USGS 2000) that was refined for a previous project. Point locations associated with large rivers and undigitized streams were omitted from the analysis. If a single site had more than one sample from the past decade, then the sample with the highest value was included in the final rating calculation.A main objective of this project was to give equal weight to all communities of organisms found in streams if adequate and comparable sampling had occurred. Therefore, classes were developed for each dataset used in the analysis in an attempt to interpret raw data from different sources and classify it similarly. All class scores range from 1 to a greater number with that greatest number always representing the highest class. Each class score was divided by the total number of classes available to obtain a proportional score (P score), which has a maximum of 1. When multiple datasets were available for mussels, the average of the proportional scores was used to determine the mussel taxonomic score (T score). The T score combined information from separate assessments into a combined signal for mussels, while equally weighting fish, macroinvertebrates, and mussels in the final rating. Because data were used from programs that sampled in similar but not exact places, valley segments were used to determine which sites should be grouped. Valley segments are aggregations of linearly adjacent, physically similar stream reaches (Seelbach et al. 1997). Physical characteristics used to define valley segments were related to stream size (drainage area), surficial geology (bedrock, course substrates), discharge (flow yield), and gradient. Valley segments were independently derived prior to this project using a spatially-constrained clustering technique (Brenden et al. 2008). Valley segment numbers were assigned to datasets through a spatial join in ArcMap 9.2. Datasets were then associated with each other for calculation of the final rating according to valley segment number in a query performed in Microsoft Office Access 2003. When multiple sites were associated with a particular valley segment within a dataset, the average of P or T (for mussels) scores was used to calculate the final diversity score.
Copyright Text: Illinois Department of Natural Resources - Office of Resource Conservation and the Illinois Natural History Survey
Description: The Biologically Significant Streams (BSS) map replaces the map by Page et. al (1992). Following the publication of the first Biological Stream Characterization (BSC) ratings (Hite and Bertrand 1989), the Illinois Natural History Survey developed a list of BSS for the purpose of protection 100% of the stream-dependent biodiversity. In 2006, the IDNR initiated an effort to combine and update the previous stream rating efforts (BSC and BSS) into a single rating process. The purpose was not only to update outdated information, but to create a rating system that would help resource managers determine efficacy in implementing the aquatic goals of the Illinois Wildlife Action Plan (http://dnr.state.il.us/orc/wildliferesources/theplan/). All the information that contributed to integrity and diversity ratings were considered in identifying BSS. Specifically, BSS are defined as streams that have a high rating or score based on data from at least two taxonomic groups. This can be achieved by obtaining an A rating either for diversity or for integrity that is based on data from two or more taxonomic groups. A second way to achieve this status is for a stream segment to have class scores in the highest class for at least two different taxonomic groups when considering the combined data from the diversity and integrity ratings. Stream segments identified as biologically significant are unique resources in the state and the biological communities present must be protected at the stream reach, as well as upstream of the reach. Simple, practical constraints were used to extrapolate site-specific information to upstream stream segments to arrive at the final segments identified as biologically significant (see pages 23-24 in Illinois Department of Natural Resources. 2008. Integrating multiple taxa in a biological stream rating system. IDNR-Office of Resource Conservation, Springfield, Illinois, 34 pages).
Copyright Text: Illinois Department of Natural Resources - Office of Resource Conservation and the Illinois Natural History Survey