using mbss data to identify stressors

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USING MBSS DATA TO IDENTIFY STRESSORS FOR STREAMS THAT FAIL BIOCRITERIA IN MARYLAND Prepared by: Mark Southerland Jon Vølstad Edward Weber Versar, Inc. Columbia, MD

Ray Morgan University of Maryland Frostburg, MD

Lee Currey John Holt Charles Poukish Matt Rowe Maryland Department of the Environment Baltimore, MD

DEPARTMENT OF THE ENVIRONMENT 1800 Washington Boulevard, Suite 540 Baltimore, Maryland 21230-1718 June 2007

Stream Disturbance Index Development Report Document Version: June 15, 2007

FINAL Table of Contents List of Tables ...................................................................................................................... i List of Figures.................................................................................................................... ii List of Abbreviations ....................................................................................................... iii 1.0 BACKGROUND ......................................................................................................... 1 2.0 OBJECTIVES ............................................................................................................. 2 3.0 STRESSOR IDENTIFICATION CONCEPTUAL FRAMEWORK..................... 3 4.0 STRESSOR IDENTIFICATION METHODOLOGY ............................................ 6 4.1 Review Data and Screen Variables........................................................................... 6 4.2 Test Variables for Significance Using Quantile Regression..................................... 9 4.3 Calculate Normalized Scoring For Stream Disturbance Index............................... 10 4.4 Ecological Rationale for Variables Included in the Method................................... 12 4.4.1 Flow and Sediment (AB) .................................................................................. 13 4.4.2 Energy (CD)..................................................................................................... 14 4.4.3 Inorganic Pollution (E).................................................................................... 15 4.5 Assigning Likely Causes to Impaired Watersheds ................................................. 16 5.0 DISCUSSION ............................................................................................................ 22 REFERENCES................................................................................................................ 24 Appendix A ..................................................................................................................... A1 Appendix B ......................................................................................................................B1 Appendix C ..................................................................................................................... C1 Appendix D ..................................................................................................................... D1 Appendix E ......................................................................................................................E1 Appendix F ......................................................................................................................F1


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List of Tables Table 1: Flow/Sediment Percentile Thresholds Used to Develop the Stream Disturbance Index Scores for Each Variable by Region............................................................... 11 Table 2: Energy Source Percentile Thresholds Used to Develop the Stream Disturbance Index Scores for Each Variable by Region............................................................... 11 Table 3: Inorganic Pollutants Percentile Thresholds Used to Develop the Stream Disturbance Index Scores for Each Variable by Region .......................................... 11 Table 4: Final Variable Selection for Each IBI per Geographic Region .......................... 13 Table 5: Likely Stressors in Each Maryland PSU (single or combined 8-digit watersheds) Based on Both Benthic IBI and Fish IBI Components of Final Stressor Identification Approach................................................................................................................... 17


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List of Figures Figure 1: Flow/Sediment Stressor (AB) Identification Conceptual Framework ................ 4 Figure 2: Energy Source (CD) Stressor Identification Conceptual Model ......................... 5 Figure 3: Inorganic Pollutants Stressor Identification Conceptual Framework.................. 5 Figure 4: Steps Used to Develop the Stressor Identification Method................................. 7 Figure 5: Emebeddedness Variable Values Exceeding (Red) and Not Exceeding (Black) the 75th Percentile of Reference watersheds ............................................................... 8 Figure 6: Quantile Regressions of Embeddedness Stressor Variables Against Benthic and Fish IBIs to Identify Significant Relationships......................................................... 10 Figure 7: Scoring Method Used to Normalize Variable Values as Stream Disturbance Index Scores.............................................................................................................. 12


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List of Abbreviations ANC BIBI CADDIS DNR DO DOC EPA EPT FIBI HBI IBI MBSS MDE PSU SAV TMDL TN TP

Acid Neutralizing Capacity Benthic Macroinvertebrate Index of Biotic Integrity Causal Analysis Diagnosis Decision Information System Maryland Department of Natural Resources Dissolved Oxygen Dissolved Organic Carbon U.S. Environmental Protection Agency Ephemeroptera, Plecoptera, and Trichoptera Fish Index of Biotic Integrity Hilsenhoff Biotic Index Index of Biotic Integrity Maryland Biological Stream Survey Maryland Department of the Environment Primary Sampling Unit Submerged Aquatic Vegetation Total Maximum Daily Load Total Nitrogen Total Phosphorus


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FINAL 1.0 BACKGROUND Over the coming years the Maryland Department of the Environment (MDE) is required to prepare a number of Total Maximum Daily Load (TMDL) analyses for Maryland 8digit watersheds listed as impaired under Category 5 of the State 303(d) list. MDE recognizes that the TMDLs will contain uncertainty, but at the same time, the Department plans to ensure that the TMDLs can be adapted to new information that may become available in the future. For all waterbodies listed as impaired under Category 5 of the Integrated 303(d) List, the State is required to either establish a TMDL of the specified substance that the waterbody can receive without violating water quality standards, or demonstrate that water quality standards are being met (CFR 2007). Examples of possible impairments include: pH, fecal coliform, nutrients, sediments, and metals. Additionally, a number of Maryland waterbodies are currently listed for impacts to biological communities, indicating that while the biology of a stream is impaired, the specific stressors to the waterbody are unknown (MDE 2007). MDE, with the support of the University of Maryland and Versar, Inc., has recently revised its approach to developing TMDLs for sediment-impaired waters. The new approach is based on the Maryland Biological Stream Survey (MBSS) data (DNR 2007). The study described within this report applied an MBSS-based analytical approach similar to that used in the sediment study to identify additional stressors that are likely to affect biologically impaired watersheds on the Category 5 List. This study was a cooperative effort between the University of Maryland, Versar, and MDE. It compliments MDE’s stressor identification framework by accumulating evidence for differentiating candidate causes of impairment.


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2.0 OBJECTIVES The primary goal of the cooperative study summarized in this document was to identify likely stressors affecting “biologically” impaired watersheds within Maryland by using a wide range of physical, chemical, and biological data made available by the statewide MBSS program (DNR 2007). In addition, to ensure valid ecological concepts and methodologies, Versar and the University of Maryland completed a peer review of the MDE framework. As a result, a systematic weight-of-evidence approach was developed that compares conditions for stressor surrogate variables in reference watersheds to values found at sites in other watersheds throughout Maryland. While the weight-ofevidence approach provides indicators of stressor likelihood that are based on the currently available information, it is also flexible enough to accommodate new information and an evolving MDE stressor identification framework.


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3.0 STRESSOR IDENTIFICATION CONCEPTUAL FRAMEWORK Versar and the University of Maryland reviewed MDE’s conceptual stressor identification framework described in the draft document entitled Development of a Decision Matrix for Biological Impairments (Holt 2006). MDE’s framework consists of candidate causes of degradation, conceptual cause and effect models, and specific predictions of variable response. The initial framework included 13 candidate causes (i.e., stressor categories), each with specific predictions. The framework was evaluated for: (1) the validity and comprehensiveness of the thirteen candidate causes (and causal scenarios) proposed, (2) the validity of the proposed stressors and mechanisms involved in each causal scenario (conceptual model), (3) the validity and practicality of specific predictions, and (4) the validity of a weight-of-evidence methodology. The consensus of the study team (Versar, University of Maryland, and MDE scientists) was that the framework was valid and useful for accomplishing MDE objectives. Development of the final conceptual framework was an iterative process. First, the number of candidate causes was reduced as many predictions did not have data to support them. Specifically, the 76 predictions with data (each with one or more variables) were combined into the following six general candidate causes (Appendix A): • • • • • •

Flow regime, Terrestrial sediment, Energy source, Oxygen consuming and thermal waste, Inorganic pollutants, Organic pollutants.

Next, the team evaluated the merits of each variable (see Appendix A) as a surrogate under each candidate cause (i.e., stressor category). Of concern was the ability to differentiate among different candidate causes when about one-third of the variables were duplicated among causes. If a variable was deemed a significantly better predictor of one stressor, it was retained in that category only, while equally applicable variables were retained in more than one stressor category. The team made additional revisions to the framework as analyses eliminated candidate variables and the ability to distinguish among candidate causes (stressor categories) diminished. In particular, the land use variables were eliminated so that they could be used for source identification in the future. The team also recognized that certain candidate causes could not be evaluated with the available data and that additional water chemistry sampling would be required. As a result, the final stressor identification Stream Disturbance Index Development Report Document Version: June 15, 2007

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FINAL conceptual framework (see Figures 1, 2, and 3) was simplified to include only the following three candidate causes: •

The Flow Regime (A) and Terrestrial Sediment (B) candidate causes were combined into one Flow/Sediment (AB) candidate cause.

•

The Energy Source (C) and Oxygen-Depleting Thermal Waste (D) candidate causes were combined into a single candidate cause, Energy Source (CD). This was done because both causes shared the Dissolved Organic Carbon (DOC) and Dissolved Oxygen (DO) variables and were therefore hard to differentiate.

•

The Hilsenhoff Biotic Index (HBI) variable was moved from the Organic Pollutants (F) candidate cause to the Energy (CD) candidate cause, leaving no variables in Organic Pollutants (F) and eliminating that category. Thus, the remaining third and final candidate cause was Inorganic Pollutants (E).

Figure 1: Flow/Sediment Stressor (AB) Identification Conceptual Framework


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Figure 2: Energy Source (CD) Stressor Identification Conceptual Model

Figure 3: Inorganic Pollutants (E) Stressor Identification Conceptual Framework Stream Disturbance Index Development Report Document Version: June 15, 2007

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FINAL 4.0 STRESSOR IDENTIFICATION METHODOLOGY Beginning in March 2005, the cooperators from MDE, Versar, and the University of Maryland, with advice from the Maryland Department of Natural Resources (DNR) and the U. S. Environmental Protection Agency (EPA) developed and evaluated several candidate stressor identification approaches (see Appendix B), which related stressor surrogate information (e.g., instream measures of embeddedness) to degraded biological condition. The study team considered several ways of relating degraded biological conditions to candidate stressor variables. In the end, the group decided to use both the fish and benthic macroinvertebrate Indices of Biotic Integrity (IBIs) to describe degraded biological conditions (Southerland et al. 2005), as this approach was already codified in the state’s biocriteria. The team chose quantile regression as the most suitable method for identifying the threshold values indicative of biological degradation in a stressor variableIBI relationship. The option of developing a multivariate approach was considered but was deemed statistically not tractable nor intuitive enough for implementation. The team decided to focus on analyzing individual MBSS variables to develop a metric for each variable based on a comparison with reference conditions in the appropriate geographic region: Coastal Plain, Eastern Piedmont, or Highlands. The goal of the analysis was to identify watersheds or Primary Sampling Units (PSUs) used in Round 2 of the Maryland Biological Stream Survey where the metric values of selected variables were outside of the normal range for unimpaired streams in the region. Finally, the team needed to decide how to combine the individual stressor variables into a weight of evidence at the scale of the biological impairments (i.e., Maryland 8-digit watersheds or combined watersheds within MBSS PSUs with at least 10 MBSS sites). Ultimately, the team recommended using a “stream disturbance index” method to score stressor values on a 1-3-5 scale and subsequently combine them in a manner analogous to the multi-metric IBIs. Figure 4 summarizes the steps used to develop the stressor identification method. 4.1 Review Data and Screen Variables Appendix A lists the MBSS stream site and upstream catchment variables associated with each of the predictions in the original stressor identification framework. This list includes one or more MBSS stream site and catchment variables for most of the 11 to 14 different predictions within each original candidate cause. The appendix also includes comments for variables that are limited in their utility or need further development. When deciding on an appropriate reference benchmark, the team decided to use the IBI of 3.0 plus a confidence limit (approximately 3.1-3.2). This approach is consistent with Maryland’s biocriteria. The stressor identification analyses used only the benthic macroinvertebrate IBI (BIBI) as it would be difficult to combine or reconcile the differing results of the BIBI and fish IBI (FIBI) values. While the team recognized that stressor-variable relationships may differ by environment, developing unique regions for Stream Disturbance Index Development Report Document Version: June 15, 2007

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FINAL each variable is intractable. Thus, the team decided to test all variables separately in each of the three geographic regions (consistent with IBI development) and use only those variables that performed well in each region. Finally, analysis of the biological variables (e.g., dominance of pioneer taxa) used the original MBSS reference sites (selected based on abiotic conditions) rather than the BIBI to avoid circularity.

Develop Conceptual Models

Calculate Normalized Scoring for Index

Review/Suggest Supporting Datasets and Parameters (Committee)

Compute Stressor Index (Site/PSU)

Determine Significant Variables (Quantile Regression)

Stressor Summary

Figure 4: Steps Used to Develop the Stressor Identification Method The team reviewed the complete list of candidate stressor variables by comparing the distribution of variable values within each watershed to the variable distribution at reference sites within the appropriate region: Highlands, Eastern Piedmont, and Coastal Plain. Only variables with a less than 0.2% chance of having the same distribution as the references sites (defined as having a BIBI score of 3.0 plus a confidence limit) were retained. In addition, for each of the MBSS variables, the 75th percentile of all values occurring at reference sites was also determined. The variable value for each site in the watershed was plotted and coded red if it exceeded the 75th reference percentile; sites not exceeding the 75th reference percentile were coded black (see Figure 5 for example). The team compared the relative number of red values vs. black values in each of the three watershed categories: watersheds passing biocriteria, watersheds indeterminate for biocriteria, and watersheds failing biocriteria. Only variables where at least 50% of the failing watersheds had relatively more red than black values were retained. Lastly, the Stream Disturbance Index Development Report Document Version: June 15, 2007

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FINAL team visually inspected the graphs to determine if the magnitude of the difference in red values between passing and failing watersheds was sufficient to retain the variable.

100

Embededdness

80

23

60

40

20

28

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Figure 5: Embeddedness Variable Values Exceeding (Red) and Not Exceeding (Black) the 75th Percentile of Reference watersheds Appendix C provides the graphs of all variable values for each watershed as described above. The box and whisker graph plot to the left of each bar graph shows the distribution of reference sites within the region. The bars at each PSU show the distribution of variable values within that PSU. The red and black numbers above and below the bar graphs indicate the total number of red or black sites, respectively. The dotted blue lines separate PSUs in each of three categories of watersheds: watersheds passing biocriteria, watersheds indeterminate for biocriteria, and watersheds failing biocriteria (appear in order from left to right in the graphs in Appendix C). If the variable is binary, the proportion of reference sites is marked with a symbol rather than a box plot, and PSUs are recorded using bar graphs that indicate the proportion of sites affected. Stream Disturbance Index Development Report Document Version: June 15, 2007

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FINAL Additionally, the Stranko et al. (2005) fish model data (e.g., percent of fish species excluded by low DO) was included and treated the same as the other variables. The variables meeting all three criteria were designated as the ultimate candidate variables for use in the subsequent analysis. Next, the team reviewed the results for additional candidate variables including a wide range of land use variables developed by Holt (2006) and a few additional biological variables. As a result of this analysis, a decision was made to replace any MBSS land use variables with comparable variables developed by Holt (2006). Appendix D provides the full list of candidate variables. 4.2 Test Variables for Significance Using Quantile Regression The variables based on land use data were removed from the candidate variable list so that they could be used to identify sources of degradation in the future. In addition, minimum buffer width, SO4, Submerged Aquatic Vegetation (SAV), and anomalies were removed after additional review of the data, while total nitrogen (TN) and total phosphorus (TP) were added to the list because of their importance to the TMDL process. The remaining 15 candidate variables were evaluated for inclusion in the final method using quantile regression, which is a robust technique for evaluating relationships to biological conditions where both natural variability and interacting stressors can influence the analysis (Cade and Noon 2003). Variables to be retained as significant stressor surrogates were selected based on the 90th (or 10th) percentile quantile regression of all values within each ecological region: Highlands, Eastern Piedmont, and Coastal Plain. Quantile regressions were done separately for BIBI values and FIBI values (see Figure 6 for an example). A variable was selected if the p value for the quantile regression slope was less than 0.05. This criterion was consistent with visual inspection of the quantile regression plots, (i.e. those graphs showing a clear relationship between the variable values and IBI values from 1 to 5). Appendix E shows the quantile regression graphs for each variable separately for BIBI and FIBI scores grouped by ecological region.


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Figure 6: Quantile Regressions of Embeddedness Stressor Variables Against Benthic and Fish IBIs to Identify Significant Relationships 4.3 Calculate Normalized Scoring For Stream Disturbance Index A stream disturbance index for normalizing variables with significant quantile regression slopes was developed by scoring them as 1-3-5 for each site. Variable vs. IBI relationships were developed separately for the BIBI and FIBI scores in each of the three IBI regions: Highlands, Eastern Piedmont, and Coastal Plain. For variables that increase with higher IBI scores, variable values less than the 10th percentile of sites with an IBI equal to or greater than 3 were scored a 1, values between the 10th and 50th percentiles were scored a 3, and values greater than the 50th percentile were scored a 5. For variables that decrease with higher IBI scores, the scoring was reversed (i.e., 1 greater than the 90th, 3 between the 90th and 50th, and 5 less than the 50th). The 10th percentile limit for pH was adjusted to 6.2 to match the established pH threshold. Also, The 10th percentile limit for DO was adjusted to 6 mg/l in the Highlands and Eastern Piedmont and 5 mg/l in the Coastal Plain to match the established threshold. The percentile thresholds used to score each variable value are shown in Tables 1, 2, and 3. This 1-3-5 scoring method is consistent with that used to develop the Maryland IBIs and is illustrated in Figure 7.


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FINAL Table 1: Flow/Sediment Percentile Thresholds Used to Develop the Stream Disturbance Index Scores for Each Variable by Region Highland Eastern Piedmont Coastal Percent Percent Percent n 10 50 90 n 10 50 90 n 10 50 90

Stressor Category - Flow/Sediment (AB)

Bank Stability Index Site F&B IBI >=3 122 12 19 Benthic Tolerant Species 4.2 5.3 139 4.7 5.6 172 5.6 6.5 Site F&B IBI >=3 122 Embeddedness 25 40 139 24 45 Site F&B IBI >=3 121 Epifaunal Substrate Condition 139 11 16 172 7 13 Site F&B IBI >=3 122 10 15 Instream Habitat Condition 139 11 16 172 8 14 Site F&B IBI >=3 122 10 16 * Sites with fish and benthic IBIs were used to determine percentiles.

Table 2: Energy Source Percentile Thresholds Used to Develop the Stream Disturbance Index Scores for Each Variable by Region Highland Eastern Piedmont Coastal Percent Percent n 10 50 90 n 10 50 90 n 10 50 90 Hilsenhoff Biotic Index Site F&B IBI >=3122 3.7 5.6139 4.6 6.6 172 5.4 7.0 Percent Shading Site F&B IBI >=3 122 40 83 139 55 85 172 30 87 Dissolved Oxygen Site F&B IBI >=3 122 7.3(a) 8.4 139 7.2(a) 8.3 171 4.8(b) 7.0 Dissolved Organic Carbon Site F&B IBI >=3 122 1.4 2.5139 1.5 2.9 171 3.6 10.7 Total Nitrogen Site F&B IBI >=3 122 0.8 2.8 Ammonia - NH3 Site F&B IBI >=3 122 0.004 0.018139 0.011 0.036 171 0.028 0.099 Total Phosphorus Site F&B IBI >=3 122 0.011 0.023139 0.016 0.045 171 0.03 0.094 Notes: (a) Dissolved oxygen 10th percentile adjusted to 6.0 mg/l based on daily cold water use per COMAR (b) Dissolved oxygen 10th percentile adjusted to 5.0 mg/l per COMAR * Sites with fish and benthic IBIs were used to determine percentiles Stressor Category - Energy Source (CD)

Table 3: Inorganic Pollutants Percentile Thresholds Used to Develop the Stream Disturbance Index Scores for Each Variable by Region Stressor Category - Inorganic Pollutants (E)

Highland Percent 10 50 90

Eastern Piedmont Percent n 10 50 90

n Site F&B IBI Conductivity >=3 122 0.11 0.30 139 0.17 Site F&B IBI Low pH >=3 122 6.9(a) 7.3 139 6.9* 7.3 Acid Neutralizing Site F&B IBI Capacity >=3 122 90(b) 271(c) 139 225(b) 439(c) (a) Notes: Value adjusted to 6.2 based on literature review (b) Value adjusted to 50 based on literature review (c) Value adjusted to 200 based on literature review * Sites with fish and benthic IBIs were used to determine percentiles * ANC = Acid Neutralizing Capacity


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Eastern Piedmont Percent n 10 50 90

0.27 172 172

0.14 6.1

6.7

172 66(b)

225(c)

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Figure 7: Scoring Method Used to Normalize Variable Values as Stream Disturbance Index Scores 4.4 Ecological Rationale for Variables Included in the Method The final variables listed in Tables 1-3 were determined to be the best surrogates for stressors available in the MBSS data set. Unlike the land use variables, the selected variables are direct measures of degradation in the stream itself rather than hypothesized causes of degradation. They are also closely tied to specific predictions in the stressor identification framework. This section summarizes the ecological rationale for including each variable in the method.


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Table 4: Final Variable Selection for Each IBI per Geographic Region Stressor Category AB AB AB AB AB CD CD CD CD CD CD CD CD E E E

Highland Eastern Piedmont BIBI FIBI BIBI FIBI

Stressor Bank Stability Index (10%) Benthic Tolerant Species (90%) Embeddedness (90%) Epifaunal Substrate Condition (10%) Instream Habitat Condition (10%) Hilsenhoff Biotic Index (90%) Percent Shading (10%) Dissolved Oxygen (10%) Dissolved Organic Carbon (90%) Temperature (b) (90%) Total Nitrogen (90%) Amonnia-NH3 (90%) Total Phosphorus (90%) Conductivity (90%) Low pH (10%) Acid Neutralizing Capacity (10%)

S S S S NS S NS NS S S S S S S S NS

NS NS S S S NS NS S NS NS S NS NS S S S

NS S S S S S NS S S S NS S S S NS NS

NS S S S S S NS S S NS NS S NS S S S

Coastal BIBI FIBI NS S NS S S S NS S S NS NS S S S S S

Notes: (a) Regression analysis results indicated parameter was not significant, but it was retained since it is a regulatory water quality criterion. (b) Temperature removed from future analysis. * Final variables for each IBI and geographic region were selected based on results from stepwise logistic regression. S denotes 10th or 90th percentile QR slope significantly different than zero at p < 0.05. NS denotes QR slope NOT significantly different than zero at p < 0.05. Stressor categories are Flow/Sediment (AB), Energy Source (CD), and Inorganic Pollutants (E).

4.4.1 Flow and Sediment (AB) Bank Stability Index The bank stability index is a composite score combining a visual rating based on the presence or absence of riparian vegetation and other stabilizing bank materials, such as boulders and rootwads, with quantitative measures of erosional extent and severity. Bank stability is a measure of channel erosion, which is a major source of downstream sediment transport. Low bank stability values indicate that a substantial amount of stream bank soil is being eroded and deposited in the stream. Such erosion is the result of high stream flows, frequently caused by stormwater runoff. More than half of the sediment loading in Maryland may result from bank erosion rather than from terrestrial sources. Benthic Tolerant Taxa Benthic tolerant taxa is the percentage of the benthic macroinvertebrates in a stream sample considered tolerant of disturbance (i.e., individuals with tolerance values between 7 and 10). Tolerant species are the last to disappear following disturbance and the first to return as systems begin to recover. The percentage of tolerant individuals within a stream increases with increased physical and chemical habitat degradation. The most frequent Stream Disturbance Index Development Report Document Version: June 15, 2007

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NS S NS S S NS NS S(a) NS NS NS NS NS S S S

FINAL causes of disturbance in many streams are high flows from increased stormwater runoff. High flows scour benthic habitats and increase sediment inputs to the system. Runoff and sediment particles can also carry pollutants into the stream, further increasing the percentage of tolerant taxa. Embeddedness Embeddedness is the percentage of gravel, cobble, and boulder particles in the streambed that are surrounded by fine sediment. High embeddedness is direct evidence of sediment deposition. Although embeddedness is confounded by natural variability (e.g., Coastal Plain streams will naturally have more embeddedness than Highlands streams), embeddedness values higher than reference streams are indicative of anthropogenic sediment inputs from overland flow or stream channel erosion. High embeddedness values indicate a reduction in the amount of habitat available to benthic macroinvertebrates, fish, and salamanders for shelter, foraging, and breeding. Instream Habitat Instream habitat is a visual rating based on the perceived value of habitat within the stream channel to the fish community. Multiple habitat types, varied particle sizes, and uneven stream bottoms provide valuable habitat for fish. High instream habitat scores are evidence of a lack of sediment deposition. Like embeddedness, instream habitat is confounded by natural variability. Low instream habitat values can be caused by both high flows that collapse undercut banks and sediment inputs that fill pools and other fish habitats. 4.4.2 Energy (CD) Hilsenhoff Biotic Index The Hilsenhoff Biotic Index is a numerical index originally developed to identify low dissolved oxygen conditions caused by organic loading. The HBI uses only arthropods that require dissolved oxygen for respiration to calculate a 0-10 tolerance value for each benthic macroinvertebrate sample. Organisms that are most sensitive to low concentrations of dissolved oxygen have low tolerance values and organisms that are least sensitive to low DO concentrations have high tolerance values. The HBI index is indicative of thermal pollution and nutrient enrichment that reduce dissolved oxygen, but it may also be sensitive to effects of impoundment, high sediment loads, and some types of chemical pollution. Dissolved Oxygen Dissolved Oxygen is the amount (usually measured in mg/L) of oxygen dissolved in the water as a function of physical parameters such as water temperature, atmospheric pressure, and flow. In unpolluted streams, DO levels are generally above 80% saturation; low DO levels may indicate organic pollution since heterotrophic organisms such as bacteria consume oxygen. DO levels within a stream typically exhibit diel and spatial variation, but unusually low DO levels may result from thermal inputs (via discharges or Stream Disturbance Index Development Report Document Version: June 15, 2007

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FINAL sunlight in unshaded streams) or nutrient enrichment (via bacterial consumption of organic matter). Dissolved Organic Carbon Dissolved Organic Carbon is the amount of organic carbon present in stream water, usually measured as mg/L. DOC is an important component of normally functioning stream ecosystems; however, elevated levels may indicate the presence of organic pollution sources (i.e., fertilizer, animal wastes, sewage, etc.). Naturally occurring elevated DOC concentrations are often associated with blackwater streams. In Maryland, blackwater streams occur in both the Coastal Plain and boreal bog ecosystems of western Maryland. Total Phosphorus Total Phosphorus is a measure of all phosphorus species (either as µg/L or mg/L) found in a stream, consisting of both inorganic and organic forms of phosphorus. The movement and cycling of phosphorus, a naturally occurring nutrient, within a stream system is vital to stream ecosystems. In freshwater ecosystems, phosphorus is often the limiting nutrient, and excess phosphorus may severely affect stream ecosystems. As with TN, excess TP may come from stormwater runoff carrying fertilizers and animal wastes. It may cause aesthetic impairment, interference with uses by the human population, severe effects on aquatic life, and excessive downstream nutrient loads, especially to coastal ecosystems. 4.4.3 Inorganic Pollution (E) Conductivity Conductivity, the ability of water to pass an electrical current, is one of the fundamental water quality parameters measured in streams (either as µS/cm or mS/cm). Stream conductivity is affected by inorganic dissolved solids such as chloride, nitrate, sulfate, and phosphate anions (all carrying a negative charge) or sodium, magnesium, calcium, iron, and aluminum cations (carrying a positive charge). Stream conductivity is determined primarily by the geology of the area through which the stream flows. Streams supporting fish assemblages usually have a range between 150 and 500 µS/cm; conductivity outside this range may indicate that the water is unsuitable for certain species of fish or macroinvertebrates. In urban systems, high conductivity may be an indicator of road salt usage. Low pH Low pH may affect stream chemical and biological processes. Most stream organisms are tolerant of a pH range of 6.5 to 8.0; however, there are stream systems in Maryland that drain freestone geological formations with only low levels of cations to provide buffering. Normal pH levels in these streams may be from 6.1 to 6.2, with low alkalinities. In addition, there are blackwater streams with viable biotic assemblages that have pH levels from 4.4 to 4.8, where weakly dissociated organic acids drive pH levels. Unnaturally low stream pH may be caused by acidic deposition, acid mine drainage, and Stream Disturbance Index Development Report Document Version: June 15, 2007

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FINAL wastewater discharges. Low pH may allow toxic elements, such as aluminum, to be mobilized for uptake by aquatic plants and animals, producing conditions toxic to aquatic life. Acid Neutralizing Capacity Acid neutralizing capacity (ANC) is a measure of the ability of dissolved constituents in the water column to react with and neutralize acids and can be used as an index to assess the sensitivity of surface waters to acidification. The higher the ANC, the more acid a system can assimilate before experiencing a decrease in pH. Repeated additions of acidic materials may cause a decrease in ANC. 4.5 Assigning Likely Causes to Impaired Watersheds The stream disturbance index scores were used to identify the candidate cause(s) of impairment within a particular watershed or PSU. Only watersheds or PSUs with 10 or more sites were evaluated. The stream indicator scores were averaged in two steps: (1) average of all variables within a stressor category (candidate cause) at each site and (2) average of these composite stream disturbance index site scores over the entire watershed (or PSU). The likelihood of a candidate cause affecting the watershed (or PSU) was described as high, medium, low, or none based on the following average watershed indicator scores: • • • •

High - upper confidence limit of score < 3, Medium - mean of score < 3 and upper confidence limit of score >3, Low - mean of score >3 and lower confidence limit of score < 3, None - lower confidence limit of score > 3.

The final evaluation of likely causes to impaired watersheds was based on the Round 2 MBSS data. This round is the first Maryland biocriteria assessment sampling conducted at the 8-digit watershed scale. All Round 2 MBSS sites were sampled between 2000 and 2004. The MBSS sites used in the final analysis were comprised of the core random sites (allocated to PSUs in a stratified random manner) and other randomly selected sites sampled within the Round 2 time period. These other random sites included those sampled within specific geographic areas for the National Park Service, US EPA Wadeable Stream Assessment, and other programs. Multiple sample results from the same site were not used; however, average IBIs were used for random sites that later became sentinel sites and were sampled annually. Any core or other random site sampled within a PSU during Round 2 was used regardless of which year it was sampled. Table 5 lists the likely cause ratings (high, moderate, or low) derived from the average stream disturbance index scores in each watershed or PSU (listed in alphabetical order within the three ecological regions) for each of the three candidate causes. The left-hand columns list the ratings for the BIBI, and the right-hand columns list the ratings for the Stream Disturbance Index Development Report Document Version: June 15, 2007

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FINAL FIBI. Appendix F provides the stream disturbance results for each watershed, and a summary graph shows the likelihood that the particular watershed is degraded (based on the IBI). Furthermore, separate graphs for each candidate cause (stressor category) show the average IBI and stream disturbance scores (and 90% confidence interval) for each constituent variable. Results for the benthic IBI and fish IBI are shown separately. Table 5: Likely Stressors in Each Maryland PSU (single or combined 8-digit watersheds) Based on Both Benthic IBI and Fish IBI Components of Final Stressor Identification Approach Region

PSU

Benthic

Flow/ Energy Sediment Source

Inorganic Pollutants

Fish

Flow/ Sediment

Energy Source


COASTAL

Aberdeen Proving fail Ground/Swan Creek

moderate

low

----

indeterminate

moderate

moderate

----

COASTAL

Assawoman/Isle fail of Wight/Sinepuxent/ Newport/Chincote ague Bays

high

----

moderate

indeterminate

high

Low

moderate

COASTAL

Bodkin Creek/Baltimore Harbor

fail

high

----

high

Fail

high

moderate

high

COASTAL

Breton/St. Clements Bays

pass

----

----

----

indeterminate

----

High

----

COASTAL

Corsica River/Southeast Creek

pass

low

moderate

----

Pass

low

moderate

----

COASTAL

Dividing indetermi ---Creek/Nassawang nate o Creek

----

low

Pass

----

moderate

low

COASTAL

Eastern Bay/Kent indetermi moderate Narrows/Lower nate Chester River/Langford/K ent Island

moderate

----

indeterminate

moderate

moderate

----

COASTAL

Fishing fail Bay/Transquaking River

high

moderate

low

indeterminate

high

moderate

low

COASTAL

Gilbert Swamp

pass

----

----

----

indeterminate

----

----

----

COASTAL

Honga River/Little Choptank/Lower Choptank

indetermi high nate

low

high

Fail

high

moderate

high


17

FINAL Region

PSU

Benthic



Fish

Flow/ Sediment

Energy Source


COASTAL

Lower Elk River/Bohemia River/Upper Elk River/Back Creek/Little Elk Cree

indetermi ---nate

low

----

indeterminate

----

----

----

COASTAL

Lower Pocomoke fail River

high

low

high

indeterminate

high

moderate

high

COASTAL

Lower fail Wicomico/Monie Bay/Wicomico Creek/Wicomico River Head

moderate

high

----

indeterminate

moderate

High

----

COASTAL

Magothy/Severn River

indetermi moderate nate

----

high

Fail

moderate

----

high

COASTAL

Marshyhope Creek


----

moderate

indeterminate

moderate

moderate

moderate

COASTAL

Mattawoman Creek

pass

----

low

indeterminate

----

----

low

COASTAL

Middle Chester River


----

----

Pass

moderate

----

----

COASTAL

Miles River/Wye River

pass

moderate

----

indeterminate

moderate

Low

----

COASTAL

Nanjemoy Creek

indetermi low nate

----

low

indeterminate

low

moderate

low

COASTAL

Nanticoke River

indetermi low nate

----

----

indeterminate

low

Low

----

COASTAL

Patuxent River (Lower)

pass

low

----

----

Fail

low

----

----

COASTAL

Patuxent River (Middle)

pass

----

----

low

indeterminate

----

----

low

COASTAL

Patuxent River (Upper)

fail

moderate

----

----

Fail

moderate

----

----

COASTAL

Piscataway Creek fail

low

----

low

indeterminate

low

----

low

COASTAL

Pocomoke fail Sound/Tangier Sound/Big Annemessex/Man okin River

high

high

high

indeterminate

high

High

high

COASTAL

Port Tobacco River

indetermi low nate

----

----

fail

low

High

----

COASTAL

Potomac Lower Tidal/Potomac Middle Tidal

pass

----

----

indeterminate

----

moderate

----

----

moderate

----


18

FINAL Region

PSU

Benthic



Fish

Flow/ Sediment

Energy Source


moderate

----

low

fail

moderate

----

low

moderate

----

indeterminate

moderate

moderate

----

COASTAL

Potomac Upper fail Tidal/Oxon Creek

COASTAL

Sassafras River/StillpondFairlee

COASTAL

South River/West fail River

high

----

moderate

fail

high

Low

moderate

COASTAL

St. Mary's River

pass

----

----

----

indeterminate

----

----

----

COASTAL

Tuckahoe Creek

pass

low

----

----

indeterminate

low

Low

----

COASTAL

Upper Chester River


----

----

pass

moderate

Low

----

COASTAL

Upper Choptank River


----

----

indeterminate

moderate

Low

----

COASTAL

Upper Pocomoke indetermi moderate River nate

moderate

low

indeterminate

moderate

moderate

low

COASTAL

West Chesapeake pass Bay

moderate

----

----

fail

moderate

High

----

COASTAL

Western Branch


----

----

pass

moderate

Low

----

COASTAL

Wicomico River

pass

low

----

----

indeterminate

low

----

----

COASTAL

Zekiah Swamp

pass

----

----

low

indeterminate

----

----

low

EPIEDMNT

Anacostia River

fail

high

moderate

high

indeterminate

high

moderate

high

EPIEDMNT

Back River

fail

high

moderate

high

fail

high

High

high

EPIEDMNT

Brighton Dam

pass

----

----

----

indeterminate

----

----

----

EPIEDMNT

Broad Creek

pass

----

----

----

indeterminate

----

----

----

EPIEDMNT

Bush fail River/Bynum Run

high

moderate

moderate

indeterminate

high

moderate

moderate

EPIEDMNT

Deer Creek

pass

----

----

----

indeterminate

----

----

----

EPIEDMNT

Gunpowder River/Lower Gunpowder Falls/Bird River/Middle River-Browns

fail

moderate

low

high

indeterminate

moderate

moderate

low

EPIEDMNT

Gwynns Falls

fail

----

low

high

fail

low

Low

low



19

FINAL Region

PSU

Benthic



Fish

Flow/ Sediment

Energy Source


EPIEDMNT

Jones Falls


----

high

indeterminate

moderate

Low

----

EPIEDMNT

Liberty Reservoir pass

----

----

----

pass

----

----

----

EPIEDMNT

Little Gunpowder pass Falls

----

----

----

indeterminate

----

----

----

EPIEDMNT

Little Patuxent River

fail

low

low

high

pass

low

low

low

EPIEDMNT

Loch Raven Reservoir


low

moderate

indeterminate

moderate

low

----

EPIEDMNT

Lower indetermi ---Susquehanna nate River/Octoraro Creek/Conowingo Dam Susquehanna River

----

low

indeterminate

low

----

----

EPIEDMNT

Lower Winters Run/Atkisson Reservoir

fail

low

high

pass

low

low

low

EPIEDMNT

Middle Patuxent River


moderate

moderate

indeterminate

moderate

high

----

EPIEDMNT

Northeast River/Furnace Bay

pass

high

low

----

pass

high

high

----

EPIEDMNT

Patapsco River Lower North Branch

fail

low

----

high

indeterminate

low

----

moderate

EPIEDMNT

Prettyboy Reservoir

pass

----

----

low

indeterminate

----

----

----

EPIEDMNT

Rock Creek/Cabin fail John Creek

low

low

low

indeterminate

moderate

low

----

EPIEDMNT

Rocky Gorge Dam pass

low

moderate

high

pass

----

high

----

EPIEDMNT

S Branch Patapsco pass

----

----

----

pass

----

----

----

HIGHLAND

Antietam Creek

fail

high

high

----

indeterminate

moderate

low

----

HIGHLAND

Casselman River

indetermi low nate

----

low

indeterminate

----

----

moderate

HIGHLAND

Catoctin Creek


high

high

fail

moderate

----

----

HIGHLAND

Conewago Creek/Double Pipe Creek

fail

high

high

----

indeterminate

moderate

moderate

----

HIGHLAND

Conococheague

fail

high

high

high

indeterminate

high

low

high

HIGHLAND

Evitts Creek

fail

moderate

moderate

----

indeterminate

moderate

low

----

low


20

FINAL Region

PSU

Benthic



Fish

Flow/ Sediment

Energy Source


HIGHLAND

Fifteen Mile Creek

pass

----

----

----

indeterminate

----

moderate

low

HIGHLAND

Georges Creek

indetermi ---nate

----

----

fail

----

----

low

HIGHLAND

Little pass Conococheague/Li cking Creek

----

----

indeterminate

low

----

low

HIGHLAND

Little indetermi high Youghiogheny/De nate ep Creek Lake

high

----

fail

high

high

----

HIGHLAND

Lower Monocacy fail River

low

moderate

----

indeterminate

low

----

----

HIGHLAND

Potomac R WA fail Co/Marsh Run/Tonoloway/L ittle Tonoloway

high

----

moderate

fail

high

----

----

HIGHLAND

Potomac River (Frederick County)

fail

high

high

----

indeterminate

high

low

----

HIGHLAND

Potomac River (Lower North Branch)

pass

----

----

----

fail

----

----

low

HIGHLAND

Potomac River AL indetermi ---Co/Sideling Hill nate Creek

----

high

indeterminate

----

----

low

HIGHLAND

Potomac River MO Co


high

----

pass

----

----

----

HIGHLAND

Potomac River Upper North Branch

indetermi ---nate

----

high

fail

----

----

moderate

HIGHLAND

Savage River

pass

----

----

----

pass

----

----

----

HIGHLAND

Seneca Creek

fail

moderate

high

low

indeterminate

----

----

----

HIGHLAND

Town Creek

pass

----

----

----

indeterminate

----

moderate

----

HIGHLAND

Upper Monocacy fail River

low

low

----

indeterminate

----

----

----

HIGHLAND

Wills Creek

indetermi low nate

----

----

fail

low

----

----

HIGHLAND

Youghiogheny River

indetermi ---nate

----

----

indeterminate

----

----

high

----

*PSUs status as passing, indeterminate, or failing biocriteria is shown for benthic and fish separately.


21

FINAL

5.0 DISCUSSION The stressor identification method developed by the team and adopted by MDE is based on current scientific knowledge, the best available data, and Maryland’s biocriteria methods. The study team drew from the current US EPA (2002) stressor identification guidance and scientific literature to develop the stressor identification conceptual framework and subsequent approach. The statewide MBSS provided a quality-assured data set of water quality and physical habitat information coincident with the state’s biological condition information. The method was designed to use the same composite indicator approach for stressor information as is used for biological information in Maryland’s biocriteria. The MBSS benthic and fish IBIs are used in Maryland’s biological criteria because they are effective integrators of biota affected by stressors over time (Southerland et al. 2005). The challenge in identifying the stressors affecting these biota is that the water quality and physical habitat data collected by the MBSS are not comprehensive (i.e., they do not include all possible stressors). Therefore, it is to be expected that the method will not identify stressors for all of Maryland’s impaired watersheds, nor is it expected that the stressors identified will include all the stressors present. At the same time, the variables measured by the MBSS do address, at least in part, major common stressors to Maryland streams such as flow regime, sediments, nutrients, thermal impacts, and chemical pollution. Consistent with US EPA guidance, using stressor surrogate variables collected at the same sites that the IBIs were scored means that the stress and biological condition are coincident in space and time (though not necessarily that the cause preceded the impact). While this approach cannot eliminate stressors as being present, it can produce a rigorous weight of evidence. The final conceptual framework for stressor identification developed for this method had to accommodate the lack of breadth of variables available from the MBSS and the lack of precision in these variables as surrogates of stressors. The strength of the method is that it rigorously evaluates the relationship of each surrogate variable with biological condition. Only those variables that made ecological and empirical sense were included in the method. In addition, the thresholds for each variable were selected to represent the amount of stress that is sufficient to produce the effect and the thresholds were validated or modified based on the scientific literature (consistent with US EPA guidance). The weakness of the method is that some variables overlap as surrogates for different stressors, and therefore stressor categories (candidate causes) that were originally separate had to be combined. For example, the method provides a likelihood that either flow regime or terrestrial sediment (or both) is affecting a watershed, but does not differentiate between the two. Lastly, the variable values collected by the MBSS have an inherent variability just as the IBI scores do. Therefore, it is more reliable to identify likely stressors at the scale of 10 or more sites (i.e., the scale of Maryland watersheds or small watersheds combined in PSUs. The MBSS Round 2 design is based on 10 or more randomly selected sites within Stream Disturbance Index Development Report Document Version: June 15, 2007

22

FINAL each of the 84 PSUs. IBI scores at the site level have a variability shown in repeat samples (R2 of 0.80); the mean IBI in a watershed reaches a robust average with 10 random sites. In addition to the statistical and ecological appropriateness of the data, conducting the analysis at the watershed scale is consistent with MDE’s need to address watershed impairments on the 303(d) list. The watershed-based stressor identification approach described above is not limited to a particular scale; it only requires that enough representative information be available (e.g., random site results for the appropriate variables). The approach is also not limited to the current list of selected variables. As new information (e.g., from remote sensing or stream walks) becomes available and is shown to be an effective surrogate for stress on biota, it can be added to the appropriate stressor categories within the stream disturbance index method. In this way, the stressor identification approach adopted by MDE is an evolving method, one that provides a balanced weight of evidence given the best available information.


23

FINAL

REFERENCES Cade, B. S., and B. R. Noon. 2003. A Gentle Introduction to Quantile Regression for Ecologists. Frontiers in Ecology and Environmental Science 1: 412-420. CFR (Code of Federal Regulations). 2007. 40 CFR 130.7. http://a257.g.akamaitech.net/7/257/2422/22jul20061500/edocket.access.gpo.gov/cfr_ 2006/julqtr/40cfr130.7.htm (Accessed March, 2007). COMAR (Code of Maryland Regulations). 2007. 26.08.02. http://www.dsd.state.md.us/comar/26/26.08.02.02.htm (Accessed March, 2007). DNR (Department of Natural Resources). 2007. Maryland Biological Stream Survey. http://www.dnr.state.md.us/streams/mbss/index.html (Accessed March 2007). Holt, J. 2006. Development of a Decision Matrix for Biological Impairments. Baltimore, MD: Maryland Department of the Environment. MDE (Maryland Department of the Environment). 2007. Maryland’s 2006 Integrated Report. http://www.mde.state.md.us/Programs/WaterPrograms/TMDL/Maryland%20303%20 dlist/2006_303d_list_final.asp (Accessed March, 2007). Southerland, M. T., G. .M. Rogers, M. J. Kline, R. P. Morgan, D. .M. Boward, P. F. Kazyak, R. J. Klauda, and S. A. Stranko. 2005. Maryland Biological Stream Survey 2000-2004 Volume 16: New Biological Indicators to Better Assess the Condition of Maryland Streams. Annapolis, MD: Maryland Department of Natural Resources, Monitoring and Non-Tidal Assessment. Stranko, S. A., M. K. Hurd, and R. J. Klauda. 2005. Applying a Large, Statewide Database to the Assessment, Stressor Diagnosis, and Restoration of Stream Fish Communities. Environmental Monitoring and Assessment 23: 99-121. US EPA (U.S. Environmental Protection Agency). 2002. Stressor Identification Guidance Document. Washington, DC: U.S. Environmental Protection Agency, Office of Water and Office of Research and Development.


24

FINAL

Appendix A


A1

FINAL

APPENDIX A MBSS STREAM SITE AND CATCHMENT VARIABLES ASSOCIATED WITH EACH OF THE PREDICTIONS IN THE STRESSOR IDENTIFICATION FRAMEWORK


A-1

FINAL

Table A-1: MBSS Stream Site and Catchment Variables for the Flow Regime Candidate Cause A. Flow Regime Cause

#

Prediction

A

1

Dominance of pioneer taxa.

fibi pabdom bibi pabdom

Variables

2

Community composition temporally variable.

None

3

Community composition variable along stream length.

None

Comments

Because of the randomized site selection very few stream reaches has more than 1 sample, and thus the dissimilarity within reaches can not be estimated with adequate precision, if at all

4

Stream banks unstable.

Erodsv

On either bank

5

High bank erosion.

Erodex

Sum of both banks

6

Low embeddedness.

Embed

7

Stream not at equilibrium.

Pending

8

Frequent high discharge.

None

9

Frequent low discharge.

None

Should use some ratio of wetwid and thalde. Average of 0, 25, 50, and 75 m measurements.

10 High temperature.

temp_fld

11 High salinity near fall line.

cond_fld

12 Large proportion of watershed developed.

Impsurf

12 Low Density Urban

WB_LURB

12 High Density Urban

WB_HURB

MDE Whole Basin

12 Low intensity developed

WB_LOWI

MDE Whole Basin

12 Transportation

WB_TRAN

MDE Whole Basin

12 Transportation

60M_TRAN

MDE 60M Buffer

13 Large groundwater/ surface water withdrawals.

None

14 Channelization present.

chan_yn

MDE Whole Basin

*MBSS variable names are defined in Rogers et al. (2005). Land use variable abbreviations include WB for whole basin upstream of the site or 60M for the upstream riparian area. Further explanation and limitations of each variable are listed in the comments.


A-2

FINAL

Table A-2: MBSS Stream Site and Catchment Variables for the Terrestrial Sediment Candidate Cause B. Terrestrial Sediment Cause

#

Prediction

B

1

Biological impairment predicted by MDE sediment model.

Variables

2

Embeddedness identified as stressor using Embed predicted fish tolerance thesholds.

3

Decreased proportion of taxa or feeding groups sensitive to fine sediment.

Pending

4

High embeddedness.

Embed

Comments

None

Need to identify specific taxa.

5

High % fine substrate.

epi_sub

6

Homogeneous substrate.

Instrhab

7

High phosphorus due to sediments of terrestrial origin.

None

8

Limited vegetative buffer.

rv_wid_r riv_wid_l

Total of both banks

8

natural grass

60M_GRAS

MDE 60M Buffer

8

Forest

60M_FRST

MDE 60M Buffer

8

Wetland

60M_WETL

MDE 60M Buffer

8

Barren

60M_BARR

MDE 60M Buffer

8

pasture/hay

60M_PHAY

MDE 60M Buffer

8

Croplands

60M_CROP

MDE 60M Buffer

9

High riparian agriculture.

adj_cv_L adj_cv_R

Where cover is crop

9

Agriculture

60M_AGRI

MDE 60M Buffer

9

pasture/hay

60M_PHAY

MDE 60M Buffer

9

Croplands

60M_CROP

MDE 60M Buffer

adj_cv_L adj_cv_R

Where cover is housing, parking lot, or paved road


60M_LURB

MDE 60M Buffer


60M_HURB

MDE 60M Buffer


60M_LOWI

MDE 60M Buffer

10 High riparian urban.

11 Presence of high TSS NPDES dischargers. None


A-3

FINAL

Table A-3: MBSS Stream Site and Catchment Variables for the Energy Source Candidate Cause C. Energy source Cause

#

C

1

Prediction Shift in feeding strategies.

Variables Pending

Comments Need to identify specific taxa.

2

Increased prevalence of algae.

None

Data not available for this analysis.

3

Increased SAV.

SAV

This is recorded as present, absent, or exotic. Entered as a binary variable for present or absent.

4

Poor stream shading.

Shading

5

Increased primary production.

DOC_lab

6

Increased pH due to increased CO2 removal.

pH_lab

7

Low dissolved oxygen.

DO_fld

8

Decreased woody debris.

Woodinst

9

Poor stream shading.

adj_cv_L adj_cv_R

Entered as a binary variable for cover = 0 on either side (Y/N)

10 High temperature.

temp_fld

11 Low proportion of wooded riparian.

adj_cv_L adj_cv_R rv_wid_r rv_wid_l

Where cover = FR, sum of width on both banks

11 natural grass

60M_GRAS

MDE 60M Buffer

11 Forest

60M_FRST

MDE 60M Buffer

11 Barren

60M_BARR

MDE 60M Buffer

11 pasture/hay

60M_PHAY

MDE 60M Buffer

11 Croplands

60M_CROP

MDE 60M Buffer

12 High whole basin agriculture.

Agri

12 Agriculture

WB_AGRI

MDE Whole Basin

12 pasture/hay

WB_PHAY

MDE Whole Basin

12 Croplands

WB_CROP

MDE Whole Basin

13 High whole basin residential.

high_res


WB_LURB


WB_HURB

MDE Whole Basin


WB_LOWI

MDE Whole Basin

14 Presence of high nutrient NPDES dischargers.

None


A-4

MDE Whole Basin

FINAL

Table A-4: MBSS Stream Site and Catchment Variables for the Oxygen Consuming and Thermal Waste Candidate Cause D. Oxygen Consuming and Thermal Waste Cause

#

Prediction

D

1

Oxygen identified as stressor using predicted fish tolerance thresholds.

Proportion of spp eliminated by DO min from model

Variables

2

Nutrients identified as stressor using predicted fish tolerance thresholds*.

Proportion of spp eliminated by NO3 max from model

3

Biotic index score low.

Hilsenhoff Index

4

Presence of nuisance tolerant algae.

None

Data not available for this analysis

5

Gleying present from reduction of iron to ferrous form (Fe2+)

None

Data not available for this analysis

6

High temperature.

temp_fld

7

Low dissolved oxygen.

DO_fld

8

High dissolved organic carbon (DOC)*.

DOC_lab

9

High ammonia.

NH3_lab

10 Low sulfate.

SO4_lab


Agri

Comments

11 Agriculture

WB_AGRI

MDE Whole Basin

11 pasture/hay

WB_PHAY

MDE Whole Basin

11 Croplands

WB_CROP

MDE Whole Basin

12 High whole basin urban.

Urban


WB_LURB

MDE Whole Basin


WB_HURB

MDE Whole Basin


WB_LOWI

MDE Whole Basin

13 Presence of high BOD NPDES dischargers.

None


A-5

FINAL

Table A-5: MBSS Stream Site and Catchment Variables for the Inorganic Pollutants Candidate Cause E. Inorganic Pollutants Cause

#

Prediction

E

1

Acidity identified as stressor using predicted fish tolerance thresholds.

Variables

Comments

2

Decreased proportion of acid sensitive fish Proportion of species species. eliminated by pH min and ANC min from model

3

Decrease proportion of Gastropoda*.

Pending

Data set needs updating

4

Decrease proportion of Amphipoda*.

Pending

Data set needs updating

5

Decrease proportion of Unionidae*. (bivalve)

un_pres

Compared live or recent shells present versus old shells present or none.

6

Deposits on substrate.

None

Proportion of species eliminated by pH min and ANC min from model

7

High acidity.

pH_lab

8

Low acid neutralizing capacity (ANC).

ANC_lab

9

High conductance.

Cond_lab

10 Presence of high/low pH NPDES dischargers.

None


Agri

11 Agriculture

WB_AGRI

MDE Whole Basin

11 Croplands

WB_CROP

MDE Whole Basin

12 High whole basin urban.

Urban


WB_LURB

MDE Whole Basin


WB_HURB

MDE Whole Basin

13 High coal mining activity.

surfmine(Y/N)

13 Extractive

WB_EXTR


A-6

MDE Whole Basin

FINAL

Table A-6: MBSS Stream Site and Catchment Variables for the Organic Pollutants Candidate Cause Organic Pollutants Cause

#

Prediction

F

1

Dominance of pioneer taxa.

Pending

Variables

2

Community composition temporally variable.

None

3

Absence of large fish individuals.

gfis length

4

Absence of macrophytes.

SAV

5

Increased anomalies.

Anomaly

6

Fish kills related to water chemistry.

None

7

Exceedance of water quality criteria for one or more pollutants.

None

8

High industrial land use.

high_com

8

High Density Urban

WB_HURB

9

High whole basin agriculture.

Agri

9

Agriculture

WB_AGRI

Comments Need to identify specific taxa.

This is problematic due to differences in species composition, stream size, and fishing pressure among streams In Round 2, it was just flagged (yes/no - of the 30 Species X we caught, were there any anomalies?)

MDE Whole Basin MDE Whole Basin

10 High density of road crossings.

Culvpres

Road crossing variable pending

10 Transportation

WB_TRAN

MDE Whole Basin

10 Transportation

60M_TRAN

MDE 60M Buffer

11 Presence of high toxic* NPDES dischargers.

None

Reference Rogers, G. and E. Franks. 2005. Data Dictionary for Round 2 of the Maryland Biological Stream Survey, 2000-2004. Annapolis, MD: Maryland Department of Natural Resources.


A-7

FINAL

Appendix B


B1

FINAL

APPENDIX B CANDIDATE STRESSOR IDENTIFICATION APPROACHES


B-1

FINAL 1.0 CANDIDATE STRESSOR IDENTIFICATION APPROACHES All cooperators from MDE, Versar, and the University of Maryland, plus Scott Stranko of Maryland DNR and Dr. Sue Norton of U. S. EPA attended an initial meeting held in March 2005 to begin the stressor identification development process. At the meeting, Dr. Norton presented U.S. EPA’s Causal Analysis/Diagnosis Decision Information System (CADDIS) approach to stressor identification. Mr. Stranko presented his Prediction and Diagnosis Model that uses MBSS fish tolerance data (Stranko et al. 2005), and John Holt of MDE presented his Framework for Addressing Biological Impairments. The team decided to develop an approach for identifying stressors in Maryland watersheds using MBSS data. MDE agreed to better define management objectives and establish guidelines for the data to be used. Versar agreed to try to merge the sediment TMDL model and Stranko et al. (2005) fish PDM into a strawman approach. 1.1 Identifying Stressors by Proportion of Fish Species Lost Versar developed a preliminary approach that used the Stranko et al. (2005) fish tolerance model. Figure B-1 shows the minimum dissolved oxygen concentrations at which fish species are expected to be present in the Coastal Plain watersheds. Superimposed on the list of species are the 50th and 10th percentiles of fish species eliminated at the indicated DO levels. Figure B-2 shows the proportion of stream miles in each watershed that exceed the 50th and 10th percentiles of fish species eliminated by low dissolved oxygen. Comparable graphs were prepared for each of the variables predicted by the fish model. The team felt that this approach was hard to interpret and decided to pursue other approaches. Determining a threshold for fish species lost was problematic, as it is not codified in the state biocriteria regulations. This approach is also somewhat limited by the variables for which fish tolerance models have been developed. Thirdly, the approach requires that the results for each variable be compiled within each watershed (this is an obstacle for other approaches as well).


B-2

Wicomico River Youghiogheny River

Upper Pocomoke River Western Branch

Upper Monocacy River

Upper Chester River Upper Choptank River

Least Sensitive

Town Creek Tuckahoe Creek

South River/West River St. Mary's River

Rocky Gorge Dam Sassafras River/Stillpond-Fairlee

Potomac Upper Tidal/Oxon Creek

Potomac River (Frederick County) Potomac River MO Co

Potomac Lower Tidal/Potomac Middle Potomac R WA Co/Marsh

Piscataway Creek Pocomoke Sound/Tangier Sound/Big

Nanjemoy Creek Nanticoke River

Middle Chester River Middle Patuxent River Miles River/Wye River

Marshyhope Creek Mattawoman Creek

Lower Winters Run/Atkisson Reservoir Magothy/Severn River

Lower Pocomoke River Lower Wicomico/Monie Bay/Wicomico

Loch Raven Reservoir Lower Elk River/Bohemia River/Upper Elk

Little Gunpowder Falls

Honga River/Little Choptank/Lower Jones Falls

Gilbert Swamp Gunpowder River/Lower Gunpowder

50th Percentile

5.5 5.6 5.8 6.5

SJAWMINW

Fifteen Mile Creek Fishing Bay/Transquaking River

5.3

SPTLSHIN

Eastern Bay/Kent Narrows/Lower Evitts Creek

4.4

RIVRCHUB

0.90

4.4

SPFNSHIN

Corsica River/Southeast Creek Deer Creek

SEALAMPR

Dividing Creek/Nassawango Creek

MARGMDTM

Casselman River Catoctin Creek

3.1

CUTLMINW

2.5

SATFINSH

2.1

SWSHINER

1.2

TADPMADT

1.2

SWMPDART

1.2

CRKCHBSK

B-3

1.2

TESSDART

1.2

WHTSUCKR

1.2

ROSYDACE

Stream Disturbance Index Development Report Document Version: June 15, 2007 1.2

REDBRSUN

Conewago Creek/Double Pipe Creek Conococheague

1.2

COMSHINR

Breton/St. Clements Bays Bush River/Bynum Run

1.2

CREKCHUB

Assawoman/Isle of Back River

1.2

BKNODACE

Bodkin Creek/Baltimore Harbor

1.2 1.2

CHAIN PICKEREL

Aberdeen Proving Ground/Swan Creek Anacostia River

1

FALLFISH

1

LSTBKLMP

BANDED SUNFISH

1

PIRATE PERCH

1

BLSPSUNF

0.8

MUDSUNFISH

0.8

PUMPSEED

0.8

RED PICKEREL

0.8

AMEREEL

0.3

GOLDEN SHINER

E. MUDMINNOW

Proportion of stream miles that exceed threshold for a percentage of predicted species

FINAL

Minimum Dissolved Oxygen Concentrations for Predicted Species In The Coastal Plain

10th Percentile

Most Sensitive

Figure B-1: Minimum dissolved oxygen (DO) concentrations for predicted species in the Coastal Plain (per Stranko et al. 2005)

Minimum Dissolved Oxygen

1.00

0.80

>= 10% of predicted fish species eliminated >= 50% of predicted fish species eliminated

0.70

0.60

0.50

0.40

0.30

0.20

0.10

0.00

Figure B-2: Proportion of stream miles in each watershed that exceed 10th and 50th percentile of predicted fish species eliminated (per Stranko et al. 2005)

FINAL 1.2 Setting Stressor Thresholds Using Quantile Regression In July 2005, Versar presented an approach that used quantile regression to identify limiting factors for biota as represented by the benthic macroinvertebrate metric Ephemeroptera, Plecoptera, and Trichoptera (EPT). MBSS variables included in the MDE sediment impairment model ─ embeddedness, instream habitat, and riffle run ─ were analyzed within selected watersheds. Figure B-3 illustrates how quantile regression works (from Cade and Noon 2003). Quantile regression is performed at specific quantiles, such as the 90th, in order to better describe the slope and intercept of limiting factors. Figure B-4 shows the EPT vs. sediment variable results in the Middle Chester River watershed superimposed on the 10th, 25th, 50th, 75th, and 95th quartiles for the Coastal Plain. Figure B-5 shows how the relationship of EPT to embeddedness, instream habitat, and riffle run varies for the subset of sites with chloride concentrations > 50 mg/l. These results led to an extensive discussion of how both natural variability (e.g., the relationship of embeddedness to slope and altitude) and interacting stressors can confound the analysis. While non-parametric quantile regression is fairly robust for these data, developing “better” metrics, such as embeddedness adjusted for slope, by looking at reference (forested) watersheds in different regions and stream types would be quite challenging. The option of developing a multivariate approach was deemed not statistically tractable nor intuitive enough for implementation. However, the team agreed that quantile regression was promising and ultimately used it to identify robust variables for inclusion in the final methodology. Quantile Regression – the Idea 120 100 80 60 40 20 0 120 100 80 60 40 20 0 120 100 80 60 40 20 0

Ideal: only measured factor limiting

0

20

40

60

80

100

1 unmeasured factor limiting at some sites

0

20

40

60

80

100

2 unmeasured factors limiting at some sites 0

20

40

60

80

100

120 100 80 60 40 20 0

Unmeasured factors limiting at many sites 0

20

40

60

80

100

Adapted from: Cade, B.S., and B.R. Noon. 2003. A gentle introduction to quantile regression for ecologists. Frontiers in Ecology and Environmental Science 1:412-420.

Figure B-3: How quantile regression works (adapted from Cade and Noon 2003) Stream Disturbance Index B-4 Development Report Document Version: June 15, 2007

FINAL

Number of EPT Taxa

Middle Chester River

20

20

20

15

15

15

10

10

10

5

5

5

0

0

0

0

20

40

60

80

100

Embeddedness

0

5

10

15

Instream Habitat

20

0

5

10

15

20

Riffle/Run

Figure B-4: EPT vs. sediment variable results in Middle Chester River over quantiles derived from all Coastal Plain sites


B-5

FINAL

Number of EPT Taxa

Examples of Confounding Factors – Chloride > 50 mg/l

20

20

20

15

15

15

10

10

10

5

5

5

0

0

0

0

20

40

60

80

Embeddedness

100

0

5

10

15

Instream Habitat

20

0

5

10

15

20

Riffle/Run

Figure B-5: EPT vs. sediment variable for subset of sites with chloride > 50 over quantiles derived from all Coastal Plain sites 1.3 Weight-of-Evidence Method for Identifying Stressors by Watershed After lengthy discussions, the team decided to focus the study on analyzing individual MBSS variables in order to develop a threshold for each variable based on a comparison with reference conditions in the region. Sites with B-IBI scores meeting biocriteria (> 3 + confidence limit) were originally chosen to serve as the best available “reference condition” benchmark. Specifically, the cutoff was based on IBIs where the estimated lower bound of the 90% confidence interval was greater than 3.0. The resultant value was about 3.1-3.2. Versar presented the following approach: •

Identify variables from the MBSS (and other sources as available) that match predictions in MDE framework

•

Graph the distribution of values for all MBSS sites passing biocriteria (i.e., those sites where the lower bound of the confidence interval is greater than 3) and identify the 75th percentile; do this separately for each ecoregion

•

Plot all sites within each single or combined 8-digit watershed (PSU) against the benchmark distribution Stream Disturbance Index B-6 Development Report Document Version: June 15, 2007

FINAL

•

Estimate the proportion of scores outside the 75th percentile

•

Identify the threshold proportion of bad sites that characterizes watersheds that have passed biocriteria vs. watersheds that failed biocriteria (e.g., more than 50% of sites outside the 75th percentile of benchmark sites)

•

Score the prediction as “met” for the watersheds where the proportion of bad sites exceed the threshold (for variables showing good discrimination)

•

Combine the predictions met within each stressor category to provide weight of evidence that the candidate cause represented by that category is likely resulting in impairment of the watershed

The general approach of the analysis was to identify watersheds or PSUs (the primary sampling unit for Round 2 of the Maryland Biological Stream Survey) where measures of selected variables were outside of the normal range for unimpaired streams in the geographic region (Coastal Plain, Eastern Piedmont, or Highlands). For each variable tested, we selected the set of values associated with sites where the benthic IBI was significantly greater than 3, which consequently reflected the natural variation in that variable for streams that were not impaired. The uncertainty in IBI values measured for each site was estimated based on a small set of sites that were resampled one or more times during the survey. The mean coefficient of variation for benthic IBIs from these replicated samples within sites was 8%. Therefore, we calculated an approximate oneway lower 90% confidence interval for each IBI score based on a single sample as IBI − 1.28* 0.08* IBI , to account for within-site variability, and selected sites where the lower confidence interval was greater than or equal to 3.0 (note that z0.10 = 1.28). Data from these sites were used as indicators of the normal range of scores within a region for each variable tested. Variables sampled from individual watersheds were judged to be outside the normal range for unimpaired streams in a region if they were greater than the 75th percentile of the normal scores (where an increase in magnitude of the variable indicated impairment) or if they were lower than the 25th percentile (where a decrease in magnitude indicated impairment). The hypothesis that the distribution of sample values for the variable of interest in each watershed was shifted in a direction that would indicate impairment was tested using one of two analyses. For binary variables (i.e., variables such as channelization where the response was either yes or no), a one-way proportions test was performed (Agresti 1990). For other variables, a one-sided Wilcoxon exact test was performed, and exact probabilities were calculated (Hollander and Wolfe 1973). Watersheds where statistical tests were significant at the 0.05 level were identified as likely affected by the stressor associated with the variable tested. In addition, the extent to which watersheds had sample values that differed from the average condition for nonimpaired sites in a region was tested by calculating the proportion of sites sampled that were outside the 25th or 75th percentile, as appropriate. Stream Disturbance Index Development Report Document Version: June 15, 2007

B-7

FINAL The most difficult challenge involved in developing an approach to identifying stressors likely affecting impaired watersheds was how to combine the lines of evidence into a weight of evidence (i.e., how to combine the results for each variable in a stressor category). The team debated this over several months and considered the following options: •

Case-by-case evaluation of results for each watershed to produce a unique narrative based on best professional judgment

•

Simple two-step rule based on (1) flagging variables where the number of sites with variable values exceeding the reference site values is > 50% and the p measure (significance) of “exceeding” the reference distribution is < 0.05 and (2) more than half the variables in a stressor category are flagged

•

Modification of the simple two-step rule that allows best professional judgment to review the flagged variables and determine if their combination warrants identifying the stressor category as likely affecting that watershed

•

Complex two-step rule that applies weights to each flagged variable based on (1) a pre-determined importance of that variable (from ecological theory) or (2) importance of that variable as derived from the magnitude of its exceedences

•

Composite rule that summarizes the p (significance) values for all variables in a stressor category using an established combined probability test (as in metanalysis)

References Agresti, A. 1990. Categorical Data Analysis. New York, NY: John Wiley and Sons. Hollander, M. and D. A. Wolfe. 1973. Nonparametric Statistical Inference. New York, NY: John Wiley and Sons.


B-8

FINAL

Appendix C


C1

APPENDIX C GRAPHS OF EACH CANDIDATE VARIABLE AS NUMBER OF EXCEEDANCES BEYOND THE 75TH REFERENCE PERCENTILE

C-1

C-2

●

13

8

6

40 2 8 16 3

1

9 9 9

20

●

10

8

11

10 3

17

0

19

16

9

5

11 2

8

100

3 1 3

9

7

3

7 7

● ● ● ● ● ●

10

2 9

0

8

80

9 4 8

3 2 0 0

7 8 11 10

10

0

10

5

7 12

2 1

12

4

3 3

4

0

6

●

0

0

13

3

5

5

10

7 4

4 1 1

6 9 9

2 3

8 7

4 6

0 4

4

2.0

10

●

3

10

6

2

3

7

8

1

7 11

0

6

8

6

0

7 0

2

1 8

9 5

10

2

3

8

3 10

0

4

●

10

7

3

0

10

800 1

600

400

200 7

1 0

3 3

6 7

3.0

6

3 11

2

2

7

2

6

7 5

9

6

5

9 9

4

7 16

3

3

5

8 14

10 8 13

5 0 0

6 6

3 4 7

17 16 3

0

6

4

10

0

10

4

13

1

3

7

8

1

16

14

9

6

7

6

7

4

5

2

10

8

1

6

1

4

9

8

0 2 5 0

10 8 9 10

3

0

4

5 3

7

4

10 5

8

●

7 7 6

2 0

3

7 9

0 2 5

10 8 11

5

1

5

2

10

3 3

18 8

2 2

7

6

5

6

8

3

1 5 9

0 0 6

11 10 4

8 4 0

6 11

50

3

1

0

5

0

14

15

9

2

4

12

6

3

6

2

3

2

7

3

7

7

2

0

2

6 10

10 10

5

5 3 4 4

5 7 6 7

13

0

6

8

2.5

8

10

2

12

8

4 1 2 2

5 10 8 10

5 1 2 0

8

2

10

4

7

0

4 3

7

0

0

5

South River/...

12 3

5

Lower Pocomoke R.

10 3

0 10

Piscataway Creek

4 10 7

16

Assawoman/Isle of Wight/...

20

14 4

5

9

Potomac Upper Tidal/...

3000 2 7

Fishing Bay/...

0

Pocomoke Sound/...

2000 11

Lower Wicomico/Monie Bay/...

● ● ●

7

Aberdeen Proving Ground/...

16

Patuxent R. (Upper)

0

0

17

Bodkin Creek/...

0 11 3 6

1 7

Anacostia R.

14 6 10

2

Magothy/...

● ● ●

8 7 4 7

4

Dividing Creek/...

0.0 6 10 8 6

8

Upper Choptank R.

9

Lower Elk River/...

5 3

Nanjemoy Creek

10

3 1

13

Port Tobacco R.

● ● ● ● ● ●

0 2 1 6

2

7

Nanticoke R.

●

13 2 1

Middle Chester R.

4 5 9

Eastern Bay/Kent Narrows/...

18 4 3

8

Sassafras River/...

9 4

10

Western Br.

0

7

Upper Pocomoke R.

0 9

8

Upper Chester R.

2 10

8

Honga River/Little Choptank/

9 9

9

Marshyhope Creek

●

11

5

Wicomico R.

0 2

Corsica River/...

●

Zekiah Swamp

10 3 3

6

Breton/...

2 7

Mattawoman Creek

6 10

Gilbert Swamp

30 ● ● ● ● ●

10

Tuckahoe Creek

pH

11

Miles River/...

ANC 5

Potomac Lower Tidal/...

0.5 8

Patuxent R. (Lower)

SO4 8

West Chesapeake Bay

0 8

Patuxent R. (Middle)

NH3 7

St. Mary's R.

DOC 1000

BIBI signif. > 3

% Abund. Dom. (fish)

Coastal 18 10

7 9

5

4

1

1 5

3 3 8

16

4000

20

17 17

4 9

3 6

1

4

5

5

5 2 2

2

1.5 13

4

1.0 7

5

5

10

40 10

13 10

4

10

9

8

1

8

0

2

10

4

8

2

1

60

2

2

5

4

8

1

40

0 7

12

80

20 4

13 9 13 19 9 8 6

●

●

2

10

3

10

20 9

●

6

0 9

●

8

6

60

10 19

● ● ● ● ● ● ● ●

18

19 8

8

0 9

4

10

0

6 6

●

4

20 5

4 3

● ●

3 1 0

5

5

0 7

2

6

0

10 10

9

100

13 10

4

10

0

1 7

4

0

0

0

7

9

10

10

4

0

3

10 0 0 0

1 3 1

5 4 3 0 2 0 0 2 1

6 10 10 8 10 10 8 12

3 0 0 0

10 10 10

1

7

20

9

10

7

5

9

11 8

2

12

5 5

5 1

5

0

3

4 8

0

9

9

5 1

0

10

0

10 2

18

1

0

20 14

20

8

3 5

0

4

0

9

10

0

3 2 3

5 0 0 0 8 5 2

9 10 20 12 5 8

6

10

3

9

9

3 3

10

7

1

1

3

11

4

7

12

8

5

1

10

9 9

1 1

1

7 3 0

11 10

1

9

60 6

0

0

0

2

1

3

20

5

0

10

12

6

2 2

30

6

2

1

16

18

7

5

2

●

1

10

0

19

0 0 0 0 0 0 0 0

9 9 10 10 10 11 8 10

350

1

3 5

3 2

1 0 1 0

0

7 2

10 8

4

6

80

5

7 5

3

5

6

5

3

0

10

1

6 1

5 2

8

0 1

8

0

9

1 2

9 8

18

10

13

10

10

8

10 7

15

9

0 1

3

5 2

6

3

2

17

3

11

9

8

7

5

0

0

7

0

4

0

5

0

8

0

10

10

1

10

1

10

10

South River/...

●

2 4

2

Lower Pocomoke R.

0 0 10

Piscataway Creek

3

6


12 1 0

10


0 0 0

10

Fishing Bay/...

3

17

Pocomoke Sound/...

●

17 0


4 2

8 0


250 8 0

Patuxent R. (Upper)

●

3 4

7

2

Bodkin Creek/...

●

1

11

3

Anacostia R.

● ●

1 3 1

9 0

Magothy/...

● ●

6 1

10

0

Dividing Creek/...

15 1

1

Upper Choptank R.

●

1

1

Lower Elk River/...

20 2 8

Nanjemoy Creek

40 ● ● ● ● ●

0 4

9

Port Tobacco R.

150 0

Nanticoke R.

0 10

2

Middle Chester R.

5 15

1


2

Sassafras River/...

1

12 1

Western Br.

1

6

1

Upper Pocomoke R.

●

7 9

1

Upper Chester R.

10 0 8 0


50 9

1

Marshyhope Creek

200 9

1

Wicomico R.

6 14 0

Corsica River/...

Fish Anomalies

1

Zekiah Swamp

● ●

0

Breton/...

●

18 1

Mattawoman Creek

5 10

Gilbert Swamp

0

Tuckahoe Creek

100 11 2

Miles River/...

0 18 2


0.0

Patuxent R. (Lower)

Mean Gamefish Length 300 2

West Chesapeake Bay

High Dens. Residential 1.0


High Commercial Land Use 2.0

St. Mary's R.

% Urban Development 3.0

BIBI signif. > 3

Agriculture

Coastal

●

4

2.5

●

4

1.5

●

0.5 1 1

8 8

1

6 0

5

1 1

0

3 0

0

0

2 2

13

25

20 8

15 ●

10 6

6 1

9

14 5

5

5 5

6

3 3

3 3 0

7

19 5 9 10

6 10

7

1

4

2

2

0

6

1

3

2

0

1

0

1

0

0

9

0

7

9

6

0.0

0.5

7

0.4

0.2

0.0

1.0

0.8

0.6

0.4

0.2

0.0 7 18

0 0 0 0 0 0 1 1 0 0 1 1 1 1 0 2 1 0 0 0 0 1 0 1 0 0 1 0 1 6 1 0 0 0 1 0 0

20 13 10 19 20 10 9 9 11 10 12 9 9 9 10 8 12 10 9 10 20 19 10 9 10 14 9 10 15 14 9 11 10 10 9 11

0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 1 0 0 1 0 0 0 0 0 0

20 13 10 19 20 10 10 10 11 10 13 10 10 10 9 10 13 10 9 10 20 19 10 10 10 13 10 10 15 20 10 11 10 10 10

●

9

4

7

1

6

6

12

15

2 5 6 10 10 7 10 9 10 12 3 9 10 20

9

0

4 8

9

8

5

5

10

0

8

●

2

6

5

4

4

3.0

1.0

8

0

2 2

12

8

3

8

0 3

2 8

●

6

3

6

2

●

2

●

8

5

3

5

1 4

4 5

3

3

6

9

3

5

10

4

12

2

10

6

5

9

7

1

9 2

9 7 17

10

4

7

6

1

8

16

3

7 7

3

2

0

7

4

2

4

7

5

13

13

6

9 8 12 10

2 3 2

15 10

4

7

6

5 3

11

7

10 6

1 0

8 13

7

11

10

2 6

2

2

7

4

4

9

6

10

8

1

13

5

1

8

1

5

6

1

3

1

5

3

6

9

5

6

5

2

4

5

2

South River/...

0.6 7 5 0

Lower Pocomoke R.

0

Piscataway Creek

0.8 10 10

1


1.0 12 8 4 3


7 8

0

Fishing Bay/...

5 0

Pocomoke Sound/...

6

0


0

7 5

0 1


10 2

2

Patuxent R. (Upper)

●

Bodkin Creek/...

1 10

3

Anacostia R.

19 0

5

Magothy/...

12 0 0

Dividing Creek/...

2

1

Upper Choptank R.

10

3

Lower Elk River/...

6

Nanjemoy Creek

13 0

Port Tobacco R.

● ●

Nanticoke R.

12 1

4

Middle Chester R.

0 6


14 2

Sassafras River/...

20

Western Br.

1 7

Upper Pocomoke R.

30

Upper Chester R.

2


●

Marshyhope Creek

● ● ● ●

Wicomico R.

25 12

Corsica River/...

3

Zekiah Swamp

3

Breton/...

●

Mattawoman Creek

Impervious Surface

●

Gilbert Swamp

Culvert Present

8

Tuckahoe Creek

19

Miles River/...

5


10

Patuxent R. (Lower)

15

West Chesapeake Bay

Surface Mine Present 0


Water Temp (C) 10

St. Mary's R.

Dissolved Oxygen 20

BIBI signif. > 3

Conductivity

Coastal

40 19

30 16 5

3

9 9

4

5 8

1

2 0

35

3 3

1 0

3 5

2

12 4

1

6

9 7

8

3

5

6

10

●

10

●

7

1 3 4

0

1 5 0

5 9 10 9 3 7

0

6

17

10

9

4

7

10

1

2.5

2.0

1.5

15

19

3

7

2

4

6

0

10

6

6 4 2

6 1

10 6

0 2 0

10 10 8 10

0 0 0 0 0

11 10 10 10 10

5 2 2

0 2

4 6 6 8

7 8

3

15 8

5

3

5

6

6

6

4

5

0

1

0

3

4

8

10

0 4

●

2

4

9 0

9

1

4 0

19

17

●

8 0

10

●

10

16 0

13

7

3 1

1

100 0

16

0

5

3

4

6

16

16 2 5

3

9 7 6

2

10 2 4

0 0

9

10

7 6

4

3

1

9

9 0

10

6

3

3

3 0

10

10

9 6

5

2

5 8

1 2

5

5

4

0

7

●

4

7

12 4

0

10

9

●

4

4 6

9 8

9 4 6

3

0

80

7

4

8 7 11

1 4 5 1

2 4

0

10 10

6

1

7

6 0

40

4

7

7 0

6 3

●

6

6

2 0

13

5

4

8

3

8 0

10 9

10

2

6

6 17

1

8 2

10 8

6

1 5 7

0 0

18 10

7

3

6 7

6

12

10 0

10

4

2

10

3

8

9

6

1

6 3

0

9

9

6

10 0

19

4

3

3

3

2

5

11

9 0

7

6

2 0

12

9

9

8

10

15

6

6

2

0

16

14

2

3 4

10 6

4 3

11

14

5

10 4 2

0 0

9

9

5

0

14

5 4

3

9

2

2

10

3

6

5

0

9

7

6

5

9

6

7

0

10

6

5

3

2

3

9

9 6

0

2 4

3 8

7 7

8 4 4

2 5

4 2

0

13

8

●

8 0

60

7

1

3

5

0

11

3

2

3

0

0

6

4

1

8

1 6

4

2

South River/...

●

14 10

Lower Pocomoke R.

4 12 4 5

4

Piscataway Creek

●

0 4

8

5

1


1 2

5


15 1 8 8

6

6

Fishing Bay/...

9 8

12

1 6

Pocomoke Sound/...

3 14 10

5

6


6 11

5

4


8

7

11

Patuxent R. (Upper)

80 10

Wood Instream

10

Bodkin Creek/...

0

3

9

Anacostia R.

1

6

2

4

Magothy/...

2 5

1

Dividing Creek/...

16 9

4

5

Upper Choptank R.

20 1 3

1

13

Lower Elk River/...

100 11 6

6 12

Nanjemoy Creek

19 9

Port Tobacco R.

2 7

6

7

Nanticoke R.

7

6

8

Middle Chester R.

0 5

1


10

1 8

Sassafras River/...

2 9 3

4

Western Br.

17 0 9

Upper Pocomoke R.

20 7 5 3

Upper Chester R.

15 3

3


3 3

4

Marshyhope Creek

12 6

Wicomico R.

20 14

Corsica River/...

0 10 5

Zekiah Swamp

5 3 6

Breton/...

40 10

Mattawoman Creek

15 2

Gilbert Swamp

5 9 7

Tuckahoe Creek

20 7

Miles River/...

60 5 11


0

Patuxent R. (Lower)

Instream Habitat

● ● ● ● ●

West Chesapeake Bay

Epifaunal Substrate

● ●


Embededdness

●

St. Mary's R.

Shading 50

BIBI signif. > 3

Hilsenhoff Index

Coastal

●

8

150

100

● ●

12 10 6

6

4 3 6 6 7

7 5 4 3 2

13 9 8

4 8

5 7

1

0 1

2 4 0

1 2 2

10 2 8

10 9 8

5 4

6 5 3

10

1 3 3 4 4

2 6

0

0 9

12 9

0 8

0 9

6 9 10

10 9 9 9 10

20

7

0 1 0

2 4

3

4

3

●

3

4

●

3

2

5

7

8

14

14

8

5

3

6

2

4

1

0

4

7

7

6

30

20

10

0

50

40

●

0

●

●

4

●

●

●

●

4

1

●

●

●

●

2

2

●

4

2

●

●

●

●

4

3

5

12

8

18

14

10

9

9

7

5

6

9

7

6

7

9

12

8

7

8

19

12

8

3

7

11

7

8

15

17

7

6

7

5

9

11

6

9

5

4

17

9

10

16

17

4

5

7

6

8

11

6

8

6

5

6

5

8

5

9

7

11

10

8

4

8

10

8

8

12

8

7

1

8

4

3

6

6

3

5

7

5

South River/...

0

12

Lower Pocomoke R.

0.0

● ● ●

3 0 0 0

10 9 9

0.6

1.0

0.8

0.6

0.4

0.2

0.0 0 0 0 0

17 13 9 19 14 10

0 0 0 0 0

17 13 9 19 15 0

●

0

0

0

6

3 8 4

0.8

1 7 0

1

0 9

5

5 7

0 0

8 9 10 4 10 8 8

0 0 0 0 0 0 0

10 9 9 10 5 11 9 0

●

●

0

2

0

0

13

5

0

0

8

13

● ●

● ●

2

0 0 0 0 0 0 0 0

6 7 10 12 8 8 8 19

1

●

0

0

4

14

1

13

9

8

4 3

●

6

5

7

0.2

2

8

12

1

6

6

6

8

5 5

7 5

4

5

0 7

1

9 3

5 5

1

2

7

1

6

3

0 0 0

9 15 20

1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

4 7 10 12 8 8 8 19 15 10 9 8 11 8 9 14 17 9 6 8 8 9 11 6 9 8 5

0 0 0 0 0 0 0.125 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0.058824 0 0 0

8 6 7 10 12 8 7.875 8 19 15 10 9 8 12 9 9 15 20 9 6 8 8 9 11 5.941176 9 8 5

3 1

0

5 5 3

0

1

1

0

3

1

2

1

0

1

7 6 7 0

8 8

8

8

2

3

9

2

6

7

3

Piscataway Creek

0.8 2


1

1


●

14 6 11

Fishing Bay/...

0 4 6

Pocomoke Sound/...

2


2


0.6 8

9

Patuxent R. (Upper)

19

6

Bodkin Creek/...

2

8

5

Anacostia R.

0.6 9

Magothy/...

8

8

Dividing Creek/...

1 8 7

Upper Choptank R.

1.0 12

4

Lower Elk River/...

10

Nanjemoy Creek

0.0 10

Port Tobacco R.

1 3

Nanticoke R.

14 10 6 5

4

Middle Chester R.

0.2 8


●

8

5

Sassafras River/...

5

Western Br.

●

6

7

Upper Pocomoke R.

●

3

Upper Chester R.

0.0 7


● ●

6 7

5

Marshyhope Creek

0.4

Wicomico R.

●

Corsica River/...

7 3

Zekiah Swamp

0.2 ● ● ●

Breton/...

0.4 12 4

Mattawoman Creek

0.4 4

Gilbert Swamp

% Abund. Dom. (inverts)

●

Tuckahoe Creek

1.0 5

Miles River/...

10


0.2 6

Patuxent R. (Lower)

% Fish Spp Excluded − ANC 0.8

West Chesapeake Bay

% Fish Spp Excluded − DO 1.0


% Fish Spp Excluded − NO3

●

St. Mary's R.

% Fish Spp Excluded − pH 0.6

BIBI signif. > 3

Minimum Buffer Width

Coastal 9 6

8 4

8

9 6

2

4 2 6 4

4 2 1

6 2

1

1

1 1 0 0 0

11 6 9 7 5

0

0

0

0

0

3

1

1 2

0.4 ●

1

●

1 1

●

2 2

0.8 3 1

●

1

3

●

1

1

3

0

2

7

2

● ●

0.4

0.0

2

10

0.6

11

0.2 10

●

17

0.12

6

4 4

0

13

0.02

12

19

16

5

10

18

15 9

10 2

20 10

●

10

0

6

5

7 7

10

0 11

7

4

6

1

5

11 10

●

3

0

8

4

8

3

8 6

0

12

8 10

1

10

5

8 10

1

9

5

5

5

10

8 6 8

0.15

8

0.08

8 4 5

0

7

0

7

5 8

6

0

0

5

13 6 11

6

0

10

5

5

10

8

9 12

9

0

5

4

2

5

1

1

7

12

4

17

0

0 0 0

10 10

7

1 2 0 0 0 0

10 9 10 20

2

2

10

2

0

10

10

9

7

9

18

2

18 17

10

7

0 8

6

0 10

2

3

7

10

3

5

6 6

0 11

3 0

1

1 4 9

19 4

1

0 0

3 2 2

7

10 10

7 1 0

9 14

2

0

9 2

0

0 10

1

9

2

0

0

13 17

0.6 0

0

7 16

14

4

6 20

20

18

8

4 10

2

7

0.10

5

2 10

7

●

5

4

0

9

7

0

5

10 4

1 8

0

1

3 5 7

7

1

0

10

3 8

2

1

9

2

10

10

10

4

10

10

10

16

20

8

6

10

10

11

2 0

7

3

7

0 10

5

5

6

5

20

0

3

0

●

4 2

0.20

3

3 3 8

1 3 3 1

6 10

0 1

10 9

3 16

2

4

1

0

6

11

7

10

4

6

6

10

South River/...

● ●

10 7 11

Lower Pocomoke R.

0 6

Piscataway Creek

0.2 5


0.00 3 3 9


0 6

Fishing Bay/...

7

Pocomoke Sound/...

8


7 5


14 10 19 0 5

Patuxent R. (Upper)

4 6

Bodkin Creek/...

5 5

Anacostia R.

0 2

Magothy/...

0.8 2

Dividing Creek/...

● ● ●

7 2

Upper Choptank R.

4 4

Lower Elk River/...

0

Nanjemoy Creek

1 5

Port Tobacco R.

● ●

1 5

Nanticoke R.

10

Middle Chester R.

3 0


0

Sassafras River/...

3

Western Br.

0.05 9 19

Upper Pocomoke R.

10

Upper Chester R.

0.6


10

Marshyhope Creek

20 13

Wicomico R.

0.2 9

Corsica River/...

18

Zekiah Swamp

15

Breton/...

0.4

Mattawoman Creek

0.8

Gilbert Swamp

0.04 10

Tuckahoe Creek

Basinwide Forest Cover 1.0

Miles River/...

0.00


0.10

Patuxent R. (Lower)

0.0

West Chesapeake Bay

Basinwide Agriculture 0.4


Basinwide Barren 0.0

St. Mary's R.

Basinwide Low−Intensity Dev.

0.06

BIBI signif. > 3

Basinwide Pasture/Hay

Bar Formation

Coastal

1.0

0.8

0.6

0.4

0.2

0.0 10 5 8 13 16 6 5 7 8 2 6 4 6 3 3 3 8 6 2 7 8 15 5 5 4 6 4 6 1 0 8 1 8 7 5 8 2 5 4 1

9 8 2 6 0 4 4 3 2 4 7 6 4 6 7 7 4 3 7 2 11 3 5 5 6 7 5 4 15 20 1 8 2 3 4 3 6 5 5 8

10 7

9 10

5

3 6

6 3

0 0

4 3

2 4

5 3

8

2 8 4

0 2

0 0 0 0

5 8 7

0

10

1 10 6

8 6

6

8

2

13

5

3

0

4

2

2

5

0.8

4

3

4

4

3

0

0

0

0

7

5

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Marshyhope Creek


Upper Chester R.

Upper Pocomoke R.

Western Br.

Sassafras River/...


Middle Chester R.

Nanticoke R.

Port Tobacco R.

Nanjemoy Creek

Lower Elk River/...

Upper Choptank R.

Dividing Creek/...

Magothy/...

Anacostia R.

Bodkin Creek/...

Patuxent R. (Upper)



Pocomoke Sound/...

Fishing Bay/...



Piscataway Creek

Lower Pocomoke R.

South River/...

0.00

Wicomico R.

0.05

Corsica River/...

0.0

Zekiah Swamp

0.0

Breton/...

0.2

Mattawoman Creek

0.4

Gilbert Swamp

0.0

Tuckahoe Creek

0.4

Miles River/...

0.6


●

Patuxent R. (Lower)

0.00

West Chesapeake Bay

60−m Low Density Urban

Basinwide Transportation 0.10


60−m High Intensity Urban 0.0

St. Mary's R.

60−m Extractive 1.0

BIBI signif. > 3

60−m Natural Grass

Basinwide Cropland Cover

Coastal

0.8 7

●

8

0

0.2 0

20

0.05

12

8

●

12

● ●

0

13

● ● ● ●

10

11

● ● ● ● ●

12

● ● ● ● ● ● ● ● ●

10

●

6

0.8

7

13 0

19

●

11

● ● ●

12 0

0

8 1

19

3

15

● ●

0

1

0

0

0

20

12

10

19

20

20

19 2

4

20

●

4

● ● ● ●

9

2 1 1 3

8 18 19 7

9 10

5

10 0

10

8

●

9

1

10

1 11

1

6

5 1

5

●

5

5

10

10

11

10

3

8

9

0

9

13

2

9 12

0.2

12

2

1

5

9

6 0 1

13 9

10

5

2

8 8

7

1

8

1

9

0

0

3

0

3

0

0

10

10

8

10

10

10

10 10

7

3

7

13

10

10

10

4 8

0.6 8

6

0

0 0

4

6

8

0

6

7

10

2 7

2 5

10

6 10

2 6

0 0

10

10

10 13

1 3 5

7 8

10 4

6

20 9

2

7

20 16

6 8 3

3 7

0.4 0 4

1

0 0

2

4

8

2

9

1

7

9

10

4

10

8

0

6 15

2

18

8

12

10

17

1

15

3

7

0

10

5

5

3

20

0

3 7

10

1

10

1

9

13 0 0

10 10

13

7

3

0

3

3

7

7

3

10

12

0

13

2

12

10

10

0

10

5

10

2

1

10

3

10

3

12

10

3

0.4

0

1

2

0

0

0

0

7

0

0

0

1

1

1

8

9

11

10

9

10

20

13

10

10

10

13

9

9

10

10

0

16

2

6

0

0.8

1

11

20 10

14 6

14

3 6

1

1 5

7

14

16

10

2

2

4

7

● ● ● ●

5

4

9

5

7

0

6

0

0.10 3 1

1 0 0 0 0

10

3

8

4

9

10

0

0 6 0

4

20

9

4

20

11

7

9

4

4

9

7

6

4

5

6

11

10

7

0 3

4

10

9

6

10

10

10

0.15 5

4 4

7 3

2

3 1

0 0

6 6

10 7

7 3

●

15 5

●

1

3 1

1 5

0 1 0

17

0.6

8 1

15 5

4 8

10 6

2 1

5

0.3

0.2

0.1 3 6 5 5 6 9 5 2 5 8 8

3

0

0

0

0

0

1

1

0

3

0

17

10

9

9

10

10

10

9

10

7

9

0.25

8

0.20

0.15

20

10

9

10

10

9

2

0.0 9

● ● ●

12 0

0.02

7

0 19

0

19 15

20

4 9

3

7

0.8

16

9

10

19

17

5 3 1

7 9

0

7

0.2

10

0 11

0.20

6

0

9

2 10

9

0

10

5 12

10

2

13 6

0

1

9

4 6

10

9

3 0 2

10 8

0.08

9

● ●

2

5

3

5

9

1

1

6

11

●

9

3

0.05 1

6

7

●

2

3

8

11

8

10

6

7

4

5 1

7

3

9 1

9

3

2

8 4

5

1

2

1 2

6

4

●

3 8

●

●

5

1

2

●

4 6

9

5

1 1

●

17

4

9 4

1

8

●

1

5

2 2 1

8 19

0.06

4

●

4

2

16

3

3

0

9

4

3

0 0

2

14

6

6

3

8

5 3 10

0

10

6

3

4 0

1

2 7

5 6

19 8

9 17 13

2

0 2

6

7

3 10

3

10

3

3 2

5

3 7

7 3

4

6

16

1

3

6

13

1

7

4

2

0

8

1

6

0

0 10

14

0

3

0

4

0

0

16

0.12 7

8

0

3

4

5 4 4

18

15 13 5

0.3

12

9

0

20

4 3 5

6 13 15

7

4

0

5

1

10

8

9

4

2

4

17

8

8 11

0 0 5

9

8

2

7

6

8

2

9

7

7

16

4

8

10

4

11

6

10

16

20

10

7

0

0.8

5

0.25

1 3

8 6

2

4

5

2

4

1

9 5

6

0.6 4

18 4

0

6

8

4

14

5

6

2

4

6

2

7

4 7

7 3

1

4

5

8 8

11

1

0

4

2

4

5

●

0

10

3

10

8

3

4

South River/...

5 10 0

5 4

Lower Pocomoke R.

●

1 3

5 5

Piscataway Creek

5 8


10 11 19 0 4

10


10 1 19

8 9

Fishing Bay/...

11 2 0 5

2

Pocomoke Sound/...

0 3

4


● ● ● ● ●

10 3


0.00 1 3 8

Patuxent R. (Upper)

0 7

Bodkin Creek/...

● ●

9 10

Anacostia R.

6 10

Magothy/...

0.00 7

Dividing Creek/...

0.2 11 6

Upper Choptank R.

● ●

12 7 4 7

Lower Elk River/...

18 8 2

Nanjemoy Creek

5

Port Tobacco R.

2 5 7

3

Nanticoke R.

0.6 10

Middle Chester R.

9 2 7

6


0.4 12

Sassafras River/...

●

10

Western Br.

0.4 8 11

9

Upper Pocomoke R.

0.1 3

10

Upper Chester R.

0.10 11 1


3

Marshyhope Creek

0.8

Wicomico R.

2

19

Corsica River/...

0.2 17

Zekiah Swamp

● ● ● ● ● ●

8

Breton/...

0.04 5

11

Mattawoman Creek

60−m Forest

15

Gilbert Swamp

60−m Wetland 1.0

Tuckahoe Creek

0.15

Miles River/...

0.0


0.4

Patuxent R. (Lower)

0.0

West Chesapeake Bay

60−m Agriculture 0.6 ●


60−m Barren 0.0

St. Mary's R.

60−m Low Intensity Dev. 0.2

BIBI signif. > 3

60−m Pasture/Hay

Coastal 5 8

3 6

10 1 2

0 0

1 2

4 6

9 1

5

0.5 10

0.4

4

10 8

5 9 6 5 8 3

5 2 6

9 10

9

7 4

2 2

1

0 0

5 0

9

●

1

●

2

7

4 2

11 1 10

1 1 1 5 1

10 9 9 5 8

7

16 5

0.10

5 4

6

6

2

3

2

6

4

7

11

7

8

10

3

4

6

0

1

2

0

6

20

8

4

9 0 0 0

0

1

12

10 0

10

6 0

60

19

4

7

14 0

17

5 0

10

0

2

4

11 0

● ● ●

●

0

0

7

4 11

0 0

●

20

0

5

9

6

13 0

●

7

5 0

● ● ● ●

0

● ● ●

7

4 0

13

0

3

11

4

8 0

8

13

0

●

10

0

5

5

3

4 9

10

0

11

0

1

7

3

2

3 3

10

0

10

0

2

9

6

9 8

10

0

0

5

7

3 3

0

10

0

9

6

4 4

9

10

0

0

1

10

9

7

4

2

6

0

10

0

1

9

10

3

6

40 10

0

19

0

5

8

8

8

10 13

0

13

0

3

8

2

11

9

80

0

0

80

18

7

1

10

10

9

0

0

17

8

15

8 9

10

0

10

0

0

9

10

1 7

10

10

0

9

10

0

2

5

8

2

5

3

3

10 10

0

20

0

1

10

6

13

6

8

0

7 8

0 10

10

0

1

12

5

10

20

0

9

9

10

0.2

4

14 10 10

0 0 0

10

0

7

10

6

4

16

3

10

0

10

0

3

11

5

0

20 10

4

9

0

10 10

0

1

17

5

5

16

0

10

0

1

9

7

0

8

0 3

6

10

0

19

0

1

7

8

3

3

1

8

10 0

11

0

5

7

9

3

6

4

6

0

16

0

1

2

13

9

10 0

0

0

16

●

4

7

9

8

7

8

7

9

7

3

11

6

6

10

19

0

10

0

3

6

1

0

3

4

2

0

10

0

10

11

0

10

0

2

0

3

0

1

1

11

9

9

7

0

0

14 10

0

2

2

South River/...

18 0 10 13

9

Lower Pocomoke R.

● ● ●

9 7

10

0

Piscataway Creek

0 20 7 2

2 0


20 19 0

4 2


●

10 10 7

3

Fishing Bay/...

0 13 2 1

10

18

Pocomoke Sound/...

60 8 4

4 0


●

19

12


40 1

3 0

Patuxent R. (Upper)

●

2 2

Bodkin Creek/...

0.1 10 2

Anacostia R.

1

Magothy/...

0 8

Dividing Creek/...

● ●

Upper Choptank R.

6

Lower Elk River/...

10 0

6 0

Nanjemoy Creek

60 17 1

Port Tobacco R.

100 9 2 13

0

Nanticoke R.

8 10

7

Middle Chester R.

0 2 11

0


8

Sassafras River/...

●

20 12 1 10

0

Western Br.

●

5

Upper Pocomoke R.

●

Upper Chester R.

●


0.6

Marshyhope Creek

20 15 1 20 0

Wicomico R.

40 ● ● ● ● ● ● ●

1 19 0

Corsica River/...

●

5 10 1

Zekiah Swamp

0.0 2

Breton/...

● ● ●

12 0

Mattawoman Creek

● ● ●

0

Gilbert Swamp

● ● ● ● ● ●

Tuckahoe Creek

60−m Croplands

●

Miles River/...

0


60−m Transportation

0

Patuxent R. (Lower)

0 20

West Chesapeake Bay

% Gastropods 0.2


% Amphipods 0.0

St. Mary's R.

% Scrapers 0.4

BIBI signif. > 3

Mn Benthic Tolerance (1−10)

Coastal

9 18

4 4 9

●

9 7

1

2 6

1 0

9

11

0.3

5 5

1

3 8 1 3 1

9 7 8

10

20

20 11

10 10

10 10 10

0

13

80 20 10

10

10 11

10 10

10 10

0

2

3

3 6 3

4

4

●

3

1

10

7

7

9

6

9

7

3

3

1

3

3

7

3

3

Riparian Agriculture

3 1 3 6 5 5 0 4 4 13 7 0 0 1 2 1 0 1 0 0 1 5 2 5 0 2 0 6 1

19

11

10

17

19

5

5

7

9

9

11

7

9

7

4

5

8

10

5

6

7

13

10

10

9

12

9

10

15

20

10

10

5

8

5

11

8

10

4

9

3

4

0

1

0

0

0

0

3

0

0

1

1

0

0

1

1

1

0

1

0

1

0

0

4

1

0

2

3

7

2

3

4

0

1

2

0

2

1

1

17

9

10

18

20

10

10

10

8

10

13

9

9

10

10

9

12

9

9

9

20

19

10

10

6

13

10

8

13

13

8

8

6

10

9

9

10

8

9

9

Upper Pocomoke R.

Western Br.

Sassafras River/...


Middle Chester R.

Nanticoke R.

Port Tobacco R.

Nanjemoy Creek

Lower Elk River/...

Upper Choptank R.

Dividing Creek/...

Magothy/...

Anacostia R.

Bodkin Creek/...

Patuxent R. (Upper)



Pocomoke Sound/...

Fishing Bay/...



Piscataway Creek

Lower Pocomoke R.

South River/...

0.0 2

Upper Chester R.

0.2 1


0.4 2

Marshyhope Creek

0.6 3

Wicomico R.

0.8 5

Corsica River/...

1.0 5

Zekiah Swamp

0.0 1

Breton/...

0.2 2

Mattawoman Creek

0.4 0

Gilbert Swamp

0.6 2

Tuckahoe Creek

0.8 1

Miles River/...

1.0


0

Patuxent R. (Lower)

60

West Chesapeake Bay

0


Channelization

Erosion Extent 150

St. Mary's R.

Combined Buffer Width 80

BIBI signif. > 3

Riparian Urban

Erosion Severity

Coastal

1.0

0.8

0.6

0.4

0.2

0.0 8

3 3

9 11 6 9 10 5 5 4 2 3 5 4 10 0 0 5 2 6 2 3 7 1 7 6 9 6 0 4 7 8 5 3 1 3 1 6 2 10 0 5

10 2 4 10 6 5 4 6 8 3 8 6 0 9 10 5 10 3 7 6 12 17 3 4 1 7 9 6 9 12 4 6 9 7 8 5 6 0 9 4

●

4 2 1 5 2 2 3 3 5

100 5 3

20 ● ●

●

5

100

50

1.0

0.8

0.6

0.4

0.2

0.0 16 9 7 11 11 8 8 9 10 3 11 5

0 1 0 1 2 2 5 3 0 0 2 1

20 12 10 18 18 8 5 7 11 10 11

17 9 10 17 17 4 5 7 6 8 11

●

●

●

●

40

4

6 5 3 5

3 4

2

●

●

8

●

●

0 0

●

●

0

1 4

● ●

4

●

●

2 2 2

2 2

●

4 3 9 10 5 10 6 6 4 17 18 7 10 9 8 9 9 13 18 7 9 9 9 6 11 5

1 4 6 5 10 4 1 0 0 10 0 1 2 7 6 1 10 8 2 6 5 10 7 6 7 0 7 0

9 9 6 4 5 3 6 8 10 20 10 10 9 8 7 4 9 6 12 8 5 5 0 3 5 3 10 3 10

6 8 6 5 6 5 8 5 9 7 11 10 8 4 8 10 8 8 12 8 7 1 8 4 4 7 6 3 5

7 5

4

3

0

2

1

0

13

5 3

6 6

2

1

9

2

0

8

8 2

1 1

2

3

0

5

6

2 1 3

0 1

0 0

0

8 0 9

9 3

3

9

2

3 6

7

No Buffer >= 1 bank

SAV present 0.8

0.6

0.4

0.2

0.0

1.0

0.8

0.6

0.4

0.2

0.0

100

80

60 2

40 0

20

2

1 1 2 11 3 5 2 3 4 6 3 1 5 7 7 6 3 5 5 15 6 0 3 5 3 6 1 2 7 2 5 5 3 3 0 3 4 0 2

16 12 9 17 9 7 5 8 8 6 7 7 9 5 3 3 7 7 4 5 5 14 10 7 5 11 4 9 14 13 8 6 5 7 7 11 7 6 10 8

1 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 6 0 0 0 1 2 0 0 2 1 0 0 0 3 1 1 1 1 1 0 1 0 5 2

19 13 10 19 20 10 10 10 11 10 13 10 10 10 9 10 7 10 9 10 19 18 10 10 8 13 10 10 16 17 9 9 9 9 9 11 9 10 5 8

17 11 10 18 19 6 8 7 8 10 11 8 9 7 5 4 9 8 8 7 15 18 9 9 5 11 9 7 10 8 8 5 8 4 8 8 10 6 9

4 1

1 4 2 3 3

Potomac Lower Tidal/... Miles River/... Tuckahoe Creek Gilbert Swamp Mattawoman Creek

2 1 3 5 6 4 2 1 3 5 2 1 1 5 3 1 3 6 12 2 6 8 2 6 3 2

Corsica River/... Wicomico R. Marshyhope Creek Honga River/Little Choptank/ Upper Chester R. Upper Pocomoke R. Western Br. Sassafras River/... Eastern Bay/Kent Narrows/... Middle Chester R. Nanticoke R. Port Tobacco R. Nanjemoy Creek Lower Elk River/... Upper Choptank R. Dividing Creek/... Magothy/... Anacostia R. Bodkin Creek/... Patuxent R. (Upper) Aberdeen Proving Ground/... Lower Wicomico/Monie Bay/... Pocomoke Sound/... Fishing Bay/... Potomac Upper Tidal/... Assawoman/Isle of Wight/...

0

Piscataway Creek

2

Zekiah Swamp

Breton/...

1

Patuxent R. (Lower)

West Chesapeake Bay

4

South River/...

1.0

Lower Pocomoke R.

3


0 St. Mary's R.

BIBI signif. > 3

Forest Buffer (m both sides)

Coastal

0

Epiedmnt 7

8

9

13 23

9

24

14

11 8

5

9

5 0

7 1

2 7

11

10

8

3

pH

10 14

10

8

8

9

0

0 4

7

2

6 5

6

6

2

1

2

2

3

1

5

3

5 2

17

5000 4000 ANC

3000

15

2000

10

29

●

12

9

10

13 7

●

●

1000

10 10

7

8

● ●

9 8

18

2

2

9

19 6

9

4

2

10 0 0

0

0

1

2

3

2

2

2

9

0

0

0

0

0

1

3

10

50 40 SO4

7

30

3

●

8 7

7

4

4

9

16

6

9

6

● ● ●

20

0

●

● ●

4

3

9 2

10

5

1 0

0

10

3

1

0

6

27

8

7

10

8 16

4 10

4 10

19

5

4

2 3 3

16 2

0.6 0.5 10 3

NH3

0.4 0.3 10

4

0.2 0.1

6 ●

3

6

5

●

3

●

4

15

7

5

3

8

10

5

4

3

5

0

7

6

28

● ● ●

0.0

6

3

7

6

8

7

5

3

4

4

7

13

6

4

11

10

10

9

4

9

12 10 6 10

6

12 ● ● ● ●

4

10

8

8 9

8

9

7

9

●

● ●

2

2

1

1

9

10

3

0 2 19

0 3

1

9

9

100

9

4

12

7

4

7

9

1

0 1

25

7

4

3

5

5

6

3

5

3

3

7

3

2

3

5

2

1 1

80

3 0

0

60 0

40

Patapsco R. Lower N. Br.

9 11

Little Patuxent R.

7

Gwynns Falls

7

Lower Winters Run/...

Bush River/...

7

Back R.

Jones Falls

6

11


6

Lower Susquehanna River/...

21

Deer Creek

10

Brighton Dam

12

Prettyboy Reservoir

7


Rocky Gorge Dam

9

Northeast River/...

8

8

Gunpowder River/...

10

10

Broad Creek

Liberty Reservoir

Middle Patuxent R.

7

22

Rock Creek/...

5

6

20

BIBI signif. > 3


4

1

● ● ●

S Br. Patapsco

DOC

8

1

0

4

●

●

15

● ●

● ● ● ● ● ●

16

6

15

80

● ● ●

9

● ● ● ● ●

9

2

0 7

3

1

9

2

40 2

4

9 2 4 6

8 6 4

7

3

12

19

8 5

9

6

6

2

● ●

15

1

10

8 3

2

6

4 2

5

● ●

1

3

9

8

●

● ●

2

1 3 3 7 1 0 6

9 7 8 13 9 11 22

15

5

1 2

9 9 23

80

25

6

4 1 1

1 5

3

10 2

3

2 6

5

6

10

15

5

12

7

60 3

7

20

8

3

2

5

0

30

13

●

5

14

2

9

13

10

10 10

250

8 13

1

8

50

1

18

9

4

7

4

6

2

0

13

300

6

3

20

8

4

8

5

4

3

0

1

1

1

1

60 10

2

3

2

40

1

14

11

8

1 2

6

4

10 3 2 1

14 9 10

10

2

10

12

4

1

12

2

3

12

Gunpowder River/...

3

11

0

Little Patuxent R.

3

7 2

Rock Creek/...

16 1

27 0

Gwynns Falls

20 2


100 8 3 11

0


100 8

1

Bush River/...

10 17

Back R.

2 11

1


20 ● ● ● ● ● ●

10

0


Fish Anomalies 2

Jones Falls

1 0 2

Deer Creek

40 1 6 0

Brighton Dam

200 2

Prettyboy Reservoir

50 1


0 6 9

S Br. Patapsco

150 29

Rocky Gorge Dam

0 9

Northeast River/...

Mean Gamefish Length 0 2

Broad Creek

High Dens. Residential

1

Liberty Reservoir

High Commercial Land Use 1

Middle Patuxent R.

% Urban Development 4

BIBI signif. > 3

Agriculture

Epiedmnt

6 1

5

●

3

3

1

●

1

0

9

5

1

3 2

5

1 0 0

1 3

11

10 6

10

2 8

6 4

8

11

9

10 8

12 6

0 10

4

9

0 11

●

16

10

●

7

3

2

1

1

0

0

0

0

8

● ●

0

9

12

10

6

0.8

●

● ●

3 4

1

5

0.2

0.0

16

9

8 2

1

20

9

5

7 15

4

10

7

1

5

10

9

14

3

1.0

0.8

0.6

0.4

0.2

0.0

1.0

0.8

0.6

0.4

0.2

0.0 2 15 9 8 4 6 11 9 8 24 3 6 14

2 2 0 0 0 0 2 1 1 1 0 0 0

8 29 10 10 10 11 18 9 10 27 10 11

0 0 0 0 0 0 0 0 0 0 0

10 31 10 10 10 11 20 10 11 28 10

5

2

5 7 7

11

9 21

10

3

9

4

4

7

0

15

1

3

0

7

9

22 8

16 10

25 23 6

0.6

2

5

6

5 7 3

2 6

3

5 5

5

3

3 3

6

8

5

10 8

5

3

3

9

5

1

7

2

1.0

0

6

7

4

13

5

5

1

9

7

0

Gunpowder River/...

● ● ● ● ● ● ●

1

Little Patuxent R.

10

Rock Creek/...

7

Gwynns Falls

● ●

5


40


● ●

9 6

Bush River/...

0.4 16

Back R.

●

2


●


30

Jones Falls

10 1

Deer Creek

●

Brighton Dam

Impervious Surface 10

Prettyboy Reservoir

28


3

S Br. Patapsco

8

Rocky Gorge Dam

Culvert Present

● ● ●

Northeast River/...

15

Broad Creek


Liberty Reservoir

Water Temp (C) 25

Middle Patuxent R.

Dissolved Oxygen 0

BIBI signif. > 3

Conductivity

Epiedmnt 10

9 11

8 14 11 7

3 0

●

9 5

4

2 0 1 1 1 2 2

1 2 1 0 0 1 0 2

17 9 8 9 16 10 11 13 8

0 0 0 0 0 1 0 0 0 0

11 17 10 10 10 15 10 12 13 10

4

4 6

3 2

0

0 6

9 7

7 9

8 7

6

15 7

4

0

1

0

7

8

10

7

5

11

6

10

9

12

9

●

2

0

1

0

5

●

5

60

28

9 27

●

9

4

2 3

●

100

20

9

●

17

14 7

10

5 12

4 5

●

●

5 6

6

3

40

10

9

10

●

0

5

5

5

3 10

8

6

11

8 8

13 6

0

4

9

6

6

4 5

16 4 7 10

15

●

18

4

6

5

21

●

10

9

18

4

6

22

11

40

●

7

7

7 8

5

5

6 14

1

20

3

4

5

6

6

10

9

6

8

7

12

1 4

4

8

4

1

11

8

3

7

0 2

12

5

●

2

9

7

2

10

7

2

6

1

4 4

9

8 8

2 6

2

3 6

8

7

4

1

4 4 9

8 11

1

13

2 7

2

10

9

3

11

10

1

1

Gunpowder River/...

10 6 7

5 5

Little Patuxent R.

●

10

6

6

Rock Creek/...

26 13

8

8

Gwynns Falls

9 5


7

1

7


6 0

4

Bush River/...

60 3

6

Back R.

Wood Instream 40


100 9 1

20


0 22 1

10

Jones Falls

5 2 10

Deer Creek

6 5

13

Brighton Dam

20 10 9

Prettyboy Reservoir

0 4 5 10


20 7

S Br. Patapsco

Instream Habitat

5

Rocky Gorge Dam

8 21

Northeast River/...

0 5

Broad Creek

Epifaunal Substrate 0

Liberty Reservoir

Embededdness 10 ● ● ●

Middle Patuxent R.

Shading 20

BIBI signif. > 3

Hilsenhoff Index

Epiedmnt

120 13

100

80

60

11 12 10 5

5 2 0 4

3 8 8 8 5

9 1

1 4 2

●

4 4 4

4

7 5

5 6

8 5

7 8

15 3

6 5 2

●

5

6 4

7 5

5

9 6

●

4 5

80 6

1 3 3

0 0

3 1

7

11 10 9 7 4

12 11 8

80

2 0 0

3

3

3

1

3

2

2

4

3

14

10

8

7

12

4

2

0

0

1

3

0

0.6

0.4

0.2

0.0

1.0

0.8

0.6

0.4

0.2

0.0 0 0 0 0 0 0 0 0 0 0 0 0 0

9 31 10 9 10 10 17 10 11 20 7 11

0.0625 0 0 0 0 0 0 0 0 0 0

8.9375 31 10 9 10 10 17 10 11 20 7

3

11

5 8 8

9

3

2

1.0

0.8

0.6

0.4

0.2

0.0 0 0 0 0 0 0 0 0 0 0 0 0 0

9 29 10 9 10 7 17 6 11 16 7 11 15 10 9 10 13 10 12 11 9

0 0 0.1 0 0 0 0 0 0 0 0 0 0 0 1 0 1 0 0 0 0

9

31

9.9

9

10

10

17

10

11

20

7

11

16

10

8

10

12

10

12

11

9

7

20

5

7

8

8

12

5

10

17

8

7

11

3

8

8

7

9

8

9

7

0

20

2

2

8

5

8

0

7

●

8 3 6

15

2

11

2

3

6

7

5 6

2

7

4

Gunpowder River/...

0.8 8 19 3

Little Patuxent R.

1.0 24 9

9

Rock Creek/...

0.2 8

3

Gwynns Falls

10 6


0

2


9

Bush River/...

1 2

Back R.

1 2


9

5


3

Jones Falls

●

Deer Creek

7

Brighton Dam

0.6

Prettyboy Reservoir

0.00 2



●

S Br. Patapsco

% Fish Spp Excluded − ANC

●

Rocky Gorge Dam

% Fish Spp Excluded − DO

●

Northeast River/...

0.10

Broad Creek

0.15

Liberty Reservoir

% Fish Spp Excluded − NO3 0.4

Middle Patuxent R.

% Fish Spp Excluded − pH 0.8

BIBI signif. > 3


Epiedmnt 7 8 6 7

10 5 3

10

2 4

0 0 0 0 0 0 0 0

16 10 9 10 13 10 12 11 9

0 0.45 0.25 1.066667 0 0 0 0 0 0

11 15.55 9.75 7.933333 10 13 10 12 11 9

3

0.25 4

0.20 4

●

●

●

●

●

1

0.05

50

40

30

1

3

1

2

3

3

0.00 10

0.05

●

● ●

0.00

1

0.6

0.0

12

7 1

30

● ●

28

9

8

3

30 1

0.2

2

●

● ●

9

2

9

1

0.2 9

7

9 3

●

4 5

6

19

5

1

2 17

1

11

3 3

3

6 8

6

3

8 2

9

10 17 19 10

● ●

2

6

7

0.8

9 23

25

9

8

17 8

3

2

1

2

18 7

4

6

8

10

10

10

10

10

10

15

10

12

11

9

Gunpowder River/...

9 7

Little Patuxent R.

1 7

Rock Creek/...

1 10

Gwynns Falls

0.0 6


6


8

Bush River/...

9

Back R.

0.8

0.6

0.4

0.2

0.0

2 18

●

●

20 8

9 6

14 0 8 8 6 9 5 0 5 5 4 7 0 0 3 6 6 5 9 5

4 17 10 1 2 5 10 5 11 23 4 7 9 10 10 7 8 4 7 4 4

5 5 3

7


Bar Formation 1.0 5

3


14

Jones Falls

●

Deer Creek

11 4

Brighton Dam

0.8 1

Prettyboy Reservoir

0.02 4


0.04 6

S Br. Patapsco

0.4

Rocky Gorge Dam

0.2

Northeast River/...


Broad Creek

Basinwide Agriculture

●

Liberty Reservoir


Middle Patuxent R.

Basinwide Low−Intensity Dev. 0.8

BIBI signif. > 3


Epiedmnt

6 2

9 11

2

4

9 12

0

15

5

9

7

4

0

2

10

2

10

12

2

6 10 3 9

0.4

0

7

10

5

5

5

10

0

2

10

0.08

9

9

8

0

15

1 4

12

9

1

0

8

0

10

3 5

7

15

1

7 8

0.6

12

8

0.10

1

7

9

8 5

1 0

13

2 0

5

3

0

0 0

0

0 0

10 10

3 8

●

0.06 1 3

●

5

1 4

1

9

8

0.15 6

13

9

9

2

0

4

●

10

2

7

2

2

1

0.4

0

0

0

0

0

0

Epiedmnt 5

Basinwide Cropland Cover

9

0.3 8

6 2

1 2

1

0.2

1

1

0

0

0

0 0

0.1 0

0

0

0

15

10

12

13

0 4

0.0

10

8 23

9

11

19

0

19

5 11

10

9

16

10

9

10

10

Basinwide Transportation

5

0.25 0.20

7 5

0.15

5

8 4 ● ● ● ● ● ●

9

3

0.10 8

11

6

16

4

10

3

6

8

4

10

2

4

0.05 0 6

2

0.00

6

6

15

6

12

8

1

5

1

5 12

25

3

7

9

8 11

10

9 6

0.6

●

● ●

0.4

16

4

7

9 4

● ●

0

● ●

2

● ● ●

2 3

0.2

0

0

1

0.0

15

10

8

4 8

15

7

11

24

1

4

13

4

4

3

1

3

2

1

11

13

60−m High Intensity Urban

6

11

6

10

0.8

3

6

4

1.0 60−m Low Density Urban

9

4

0.5 0.4

6

9

9

10

12

0.3 4

●

4

0.2

7 2

0.1

7

7

7

7

4

●

4

● ●

1

1

9

9

1

2

10

26

0

0.0

3

18

6

9

15

6

1

4

10

3

4

0.025

2

1

5

2

6

0

2

0

12

11

10

4

60−m Extractive

0.020 0.015 0.010 4

0.005

7 1

5 0

0.000

0

0

0

0

0

0

0

0

1

0

0

10

10

10

11

19

10

11

28

9

11

17

10

26

6

10

9

10

3

19

0.6 0.5 0.4

11

0.3

●

10

0.2 17 ●

10

● ● ● ● ● ● ● ● ●

28

31

13

14

12

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Deer Creek

Jones Falls



Back R.

Bush River/...



Gwynns Falls

Rock Creek/...

Little Patuxent R.

Gunpowder River/...

10

Brighton Dam

10

Prettyboy Reservoir

10


10

S Br. Patapsco

11

Rocky Gorge Dam

10

Northeast River/...

10

Broad Creek

10

Liberty Reservoir

0.0

10

10

11

Middle Patuxent R.

0.1

BIBI signif. > 3


0

●

Epiedmnt 9

1.0

1

6 7

9

5

8

3

9

10

6

0.8 60−m Forest

21

15

17

2 10 6 3

3

0.6

3

1

1

0.4 1 4

0.2

5

3

1 4

2

10

9

●

0.0

7

2

7 14

5

7

9

11

8

7

6

10

0.5

60−m Wetland

0.4 31

0.3 28

0.2 0.1 ● ●

10

10

10

10

19

0

0

0

0

0

0

0

0

10 0

1.0

12

17

11

11 10

0.0

14

0

0

11

10

10 0

0

0

0

0

13

10

0

0

10 0

0

0

11 ●

3 7

60−m Agriculture

0.8 5 7

0.6

5

6

3 1 3

0.4

1

0

0 0

0.2

0 5

10

0.0 0.15

60−m Barren

1

7

5 24

18

4

3

0

0

10

8

0

0

17

10

11

10

10

10

10

14

10

11

10

6

1

7

2 ●

0.10

0.05

3

5

●

6

●

4

5

● ● ● ● ● ● ● ● ●

0.00

2 8

25

2

5

8

5

4

3

3

3 0

0 6

8

16

10

6

24

10

6

2

1

15

9

1 7

9

0 11

8

6

12

10

17 5

60−m Low Intensity Dev.

0.25 0.20 9

0.15

5 13

0.10

1 ●

4 9

6

0.05

1

5 ●

7

● ●

0.00

5

1

1

5

9

9

6

9

2

1

3

4

1

12

0 3

14

6

18

9

7

27

6

5

14

1

5

4

3

5

10 ●

3 7

0.6 6

8

4 3

0.4 0.2

0

0

18

10

11

10

10

10

10

14

10

10

9

7

Deer Creek

Jones Falls



Back R.

Bush River/...



Gwynns Falls

Rock Creek/...

Little Patuxent R.

Gunpowder River/...

Brighton Dam

Prettyboy Reservoir

Northeast River/...


Broad Creek

0

8

S Br. Patapsco

4

Rocky Gorge Dam

6

0

0

9

18 23

Liberty Reservoir

Middle Patuxent R.

3

0

6

10 7

4

0

0

0.0

2 2

1

4

BIBI signif. > 3

60−m Pasture/Hay

0.8

Epiedmnt 11

60−m Croplands

0.30 0.25

6 3

●

● ●

0.20

●

10

● ●

0.15 3 3

0.10

2

1

2

1

1 0

0 0

0.05

0

0

0

0

0

0

10

12

0

0.00

10

20

4

7

7

9

17

7

10

18

0.25

10

11

16

10

10

10

8

14

13

9

9


●

0.20

3 11

9

7 4

4

0.15

6 6

3

0.10

6

2

4

●

7

0.05

1 3

0.00

6

8

●

1

2

10

26

4 3

20

6

9

7

9

16

6

2

5

10

2

6

7

5

4

4

6

20 ●

% Gastropods

30

20 10

10 12 31

●

0

● ● ● ●

10 0

10

10

10 0

0

0

0

28 11 0

0

10

11

0

0

0

10

0

11

17

0

0

10 0

0

13

10

16

10

0

0

0

10 0

0

0

28

60 10

% Amphipods

50

10

40 10

30

●

11

● ●

20

31 17 10

●

10

● ●

0

10 11

●

10

10

10

0

0

10 20

10

11

0

0

0

● ● ● ● ●

0

0

0

0

12

10 0

0

16 0

0

0

60

0

0

0

0

% Scrapers

0

6 4

4

4

2

● ●

1 3

30

0

4

50 40

0

13

5

●

2

6 6

20

2

2

2 2

1

1 0

0

0

16

10

13

7

10 8

0

8

29

6

4

4

10

16

23

8

6

10

15

10

6

9

6

11

8

8

10

8 8

7

8

6

6

3

2

2

8

8

5

5

0

3

3 4

8

7 10

16

●

11

8

3 3

4

10

3

15

7

2 6

2

3

1

5

5

8 25

2

Gunpowder River/...

Little Patuxent R.

Rock Creek/...

Gwynns Falls



Bush River/...

Back R.



Jones Falls

Deer Creek

Brighton Dam

Prettyboy Reservoir


S Br. Patapsco

Rocky Gorge Dam

Northeast River/...

Broad Creek

Liberty Reservoir

Middle Patuxent R.

2

BIBI signif. > 3


10

10

0.8

0.6

0.4

0.2

0.0

1.0

0.8

0.6

0.4

0.2

0.0 11 5

1 4 2 3

9

27

8

1

7

9

24

11

20

1

0

0

1

9

10

10

10 5 1 1 2 1 0 0 0 0 0 0 0

9

10

23

9

10

15

9

10

10

16

10

12

13

10

1

0

0

3

3

3

1

5

4

3

8

4

3

5

3

19

10

11

25

7

8

16

5

6

7

8

6

9

8

7

Gunpowder River/...

8 1

Little Patuxent R.

7 7

Rock Creek/...

1 6

Gwynns Falls

0 3


0 3


2 11

Bush River/...

5

Back R.

8


3

Jones Falls

3

0.8

0.6

0.4

0.2

0.0 21 5 7 10 7 14 8 10 16 6 5 13 7 7 7 9 4 10 12 7

1 10 5 2 0 4 5 2 1 12 3 6 3 3 3 3 5 6 2 1 2

5 4 5

2

7

1.0

0.8

0.6

0.4

0.2

0.0 7 29 14

2 4 1 0 0 1 2 2

8 27 9 10 10 10 18

6 20 5 7 8 8 12 26 5

0 2 3

8 11 26

5 10 17


3

Deer Creek

Erosion Severity 1.0 9

5

Brighton Dam

5

Prettyboy Reservoir

10


1.0 4

S Br. Patapsco

40

Rocky Gorge Dam

Erosion Extent 150

Northeast River/...

Channelization 100

Broad Creek

Liberty Reservoir


Middle Patuxent R.

Riparian Agriculture 0

BIBI signif. > 3

Riparian Urban

Epiedmnt

4 4 3

2 2 1

0

20 1

6

●

●

2

0 0

0 0

50 4 6 6 11

11 12 8 9 10 13 10 9

2 2 5 4 1 6 3 5 2 5

7 9 15 5 6 9 10 7 7 11 5

7 8 11 3 7 8 9 8 9 9 7

●

9

100

80

60 1

●

3 2 3 3

●

2 2

7 4

3

No Buffer >= 1 bank

SAV present

0 0 2 5

4 31 9 6 8 11 10 10 11 22 9 10 14 10 9 7 14 10 12 11 5

2 1 1 0 1 1 3 2 0 3 1 1 3 1 0 0 1 0 1 0 0

8 30 9 10 9 10 17 8 11 25 9 10 14 9 10 10 15 10 11 13 10

10 31 10 10 10 11 20 10 11 28 10 11 17 10 10 10 16 10 12 13 10

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Rock Creek/... Little Patuxent R. Gunpowder River/...

0

2

Gwynns Falls

20 3


40 1


60 0

Bush River/...

80 3

Back R.

100 1


0.0 1


0.2 6

Jones Falls

0.4 0

Deer Creek

0.6 0

Brighton Dam

0.8 10

Prettyboy Reservoir

1.0 0


0.0 2

S Br. Patapsco

0.2 4

Rocky Gorge Dam

0.4 1

Northeast River/...

0.6 0

Broad Creek

0.8 6

Liberty Reservoir

1.0

Middle Patuxent R.

BIBI signif. > 3


Epiedmnt

Highland 10

28 11

9

16 13 ● ●

13

8

13 5

pH

5

8

10

8

6 8

36

11

6 8

10

5

0 0

●

7

3

1

4

6

17

10 16

7 6

44

0

0

3 2

5

4

●

1 7

5

6

5 5

4

7

5

3 4

4

36

6000

17

10

16

●

11

10

16

●

4000

17

ANC

48 31 15

2000

5

5

15

●

9

● ● ● ● ● ●

0

13

5

7 10

7 3

5

5

4

5

1

5

5

0

9

7

4

10

5

0

0 3

5

0

1

0

600

2

0

0 3

4

15

500

SO4

400 27

300

7 4

200

7

10

10

100

●

●

● ● ● ● ● ●

0

10

0

16

0

1

10

4

11

13

11

6

3

4

1 3

9

3

4

2

9

15

6

0

6

13

5

18

9

7

4 8

11

5 35

13

3

14

6

11

14

8

NH3

6 4 2 17

8

0

8

4

1

2

2

12

6

19

9

12

2

4

10

2

8

6

0

8

9

0

8

3

13

9

7

10 7

23

9

4

8

8

28

3

14

● ● ●

6

1

5

22

23

7

5

3

7

20 23

DOC

15

27

10

12 6

5

9

●

●

13 0

0

7

6

3

11

10

9

4

6

7 0

0

11

14

8

4

5

3

0

0

0

7

10

10

10

3

5

2

3

0

0

17

10

2

4

1

6

4

6 3

8

3

1

11

7

4

1

3

10

9

39

17

3

3

8

9

7

7

10

5

2

0

80 60

5 6

40

7 6

13

Upper Monocacy R.

23

Evitts Creek

41

Potomac R WA Co/Marsh Run/...

10

Lower Monocacy R.

12

Seneca Creek

29

Antietam Creek

11

Potomac R. MO Co

Potomac R. (Frederick County

9

15

Conococheague

Wills Creek

Little Youghiogheny/...

Potomac R. Upper N. Br.

Potomac R. AL Co/...

5

7

Casselman R.

Catoctin Creek

Savage R.

7

Fifteen Mile Creek

Little Conococheague/...

Town Creek

Potomac R. (Lower N. Branch)

14

10

13

8

Georges Creek

6

20

Youghiogheny R.

6

Conewago Creek/...

9

BIBI signif. > 3


100

0

40

0 2

8

●

● ● ● ●

1

1

19

9

● ●

● ● ●

19

17 5

8 9

3

3

4

8

10

100

1 7

●

3

6

1

18

9

19

11

10

2

7

8

10

●

12 1 0

1

●

0 0 1 0 0 2 0 0 1

20 10 19 11 14 12 10 10 9

7 2 0 3

8 10 7

5

20

9 6

4

5

0

4

0 2

●

4 3

9 14

8

10

0

10

11

1

4 0 0 3

13 17 7

15

7

30

3

5

3

12

7

●

1

7

3

0

●

2 11

10

7

1

4

10

11

9

5

19

8

10

10

1 3

10

2

11

3

7

0 7

23

6

7

3

7 1

12

0 9

43

35

15

20

10

4

12

8

14

14

47

31

9

14

9

38

16

7

3

17

4

6

5

7

4

23

10

1

5

0

Conewago Creek/...

16 1 3

Upper Monocacy R.

● ● ● ● ● ● ●

3 4

Evitts Creek

3


7

Lower Monocacy R.

1

Seneca Creek

60 5

Antietam Creek

●

Potomac R. MO Co

1 1


4 2 1

Conococheague

2

Georges Creek

350

Youghiogheny R.

80 1 1


100

Wills Creek

0 11


250


Mean Gamefish Length 300

Casselman R.

10

Catoctin Creek

0

Savage R.

●

Fifteen Mile Creek

●


High Dens. Residential 50


High Commercial Land Use 200

Town Creek

% Urban Development 0

BIBI signif. > 3

Agriculture

Fish Anomalies

Highland

1.0

0.8

0.6

0.4

0.2

0.0 0 0 0 2 0 0 0 1 0 0 0 0 1 0 1 5 3 0 9 1 1 4 11

16 10 20 7 13 12 10 9 10 10 9 17 9 10 9 25 12 14 40 31 9 14 4

●

6 2 4 5

5 8 4

6

5 7

150

0 3 0

4 3

8

8

6

4 6

7 4 4

15 13

10

26

10

5 4

6

10 11

60 21

50 11

40

6

6

24 9 6

9

13

10

4

7

17

●

●

24

●

8

4

2

2

0

1

0

0

2

1

12

9

16

7

12

3

7

5

3

3

6

13

7

Wills Creek


Youghiogheny R.

Georges Creek

6

1.0 1

0.8

0.6

0.4

0.2

0.0

1.0

0.8

0.6

0.4

0.2

0.0 5

30

●

12 3 5

17 8 9 6 7 10 6 4 10 13 7 1 4 10 10 3 13 16

1 4 0 0 0 1 1 0 1 0 0 0 0 0 2 1 3 2

19 9 16 11 14 14 9 9 10 9 13 17 10 10 11 29 16 12

0 0 1 0 0 0 1 6 0 1 0 1 5 0 0 0 0

20 10 19 11 14 14 9 4 10 9 13 16 5 10 11 31 17

24 5

6

● ● ●

8 5

20

●

8

● ●

10

●

4

7

4

3

● ●

4 13

5

1 7

4

4

1 3 0

0

16

12

1

4

0

●

7

2 0

10

16 4

1 5

15

9

6

2

3 3

14

12 13

0

3

2 5

4 6

9 10 5

8 6

4

3

1.0

3 5

9

7 19

6 8

4

3

4

5

8

3

20

4

10 16

10

9

10 11

11

3

33

4

3

16

8

2

4

40 21 5

5

9

7

3

Conewago Creek/...

19 8

Upper Monocacy R.

1 1

Evitts Creek

37


●

Lower Monocacy R.

6

Seneca Creek

10

Antietam Creek

Impervious Surface 20

Potomac R. MO Co

Culvert Present

3



Conococheague

8


0.0


0.5

Casselman R.

4

●

Catoctin Creek

10

Savage R.

●

Fifteen Mile Creek

10


25


Water Temp (C) 0 ● ● ●

Town Creek

Dissolved Oxygen 5

BIBI signif. > 3

Conductivity

Highland 21 12

9

7 24

7 5

●

3 9 13

5 10 4

4 1 1 0

48 36 9 18 17

0 3 0 0 0 0

15 47 40 10 19 17

7 21 10

1 10

0

4 6 8 5

28 16

7 8

●

8

9 8

11

8

0

3

3

9

3

7

11

6

1.5

6

24

10

7

11

11

12

2

9

0

12

3

14

15

5 6

2 3

40

20 16

0 14

100 9

●

20

●

8

2

8 9 17

40

3

4

15

9 13

5

●

6

11 11

60

0 6

11

1

5

10

7

10

6

8

7

4

11 8

0

8

4

2

8

5 10

1

0

13 7

2

9

2

7

7

8

12

6 6

5 6

7

6

10

14

0 0

15 9

6

2

4

10

100

3

7

12

5

12 9

5

0

5

4

5

2

5

0

4

12

9

5

5

2

1

0

4

20

4

8

8

28

1

10

2

0

22

6

7

9

10

2

7

10

3

12

10

3

0 0

10 27

6

4

6 10

3

11 20

12 2

11

5

14 34

3

37

8

4

0

5

7

4

2

7

28

1

1

2

0

4

5

8

12

9

3

17

23

0

20

5

10

29 17

13

15

7

0

Conewago Creek/...

5

0

14

Upper Monocacy R.

60 10

Evitts Creek

5 7 9

0


3

0

Lower Monocacy R.

11 15

Seneca Creek

20

Antietam Creek

10 0

Potomac R. MO Co

9


9

Conococheague

●

Georges Creek

15

Youghiogheny R.

20 6 0


8 10

16 0

Wills Creek

5 12


20


12

4 0

Casselman R.

Wood Instream

16

Catoctin Creek

8 0

Savage R.

20 0

Fifteen Mile Creek

Instream Habitat

0


Epifaunal Substrate 0


Embededdness 5

Town Creek

Shading 10

BIBI signif. > 3

Hilsenhoff Index

Highland

10 10 30

17 33

10 13 49

●

●

10 10 18

9 10 15

0 0

6 10

15 0

1 1

1

4 22 4

8 12 5

5 24 10

8 4

1 9

0 0 1

3

3 1

4 6 8

9 25

9 22 6

15 7

8 6

80 2 2

4 2

0 2

1 7 8 11 8

19

7 8

80

5

1

2

3

2

3

2

4

5

7

12

3

29

12

7

17

3

2

1

0

17

3

7

13

Highland 5


1.5

1.0

11

6 34

8 8

13

●

8

● ●

4

4

5

0.5

26

7

●

5

5

6

5

4

1

3

2

3

2

12

0.0

12

6

12

10

2

8

7

8

10

6

1

3 11

6

9

16

2

14

6

6 13

1

1.0 1

0.8 0.6 ●

0.4

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

6

7

16

8

10

10

8

7

8

8

2

13

7

8

10

30

12

11

43

26

8

14

13

0

0

0

0

0

0

0

0

0

0

0

0

0

0.25

0

0

0

0

0

0

0

0

0.083333

6

9

16

8

10

10

9

10

8

8

2

14

9

7.75

10

30

12

11

43

27

8

14

12.916667

0

0

0

0

0

0

0

0

0

0

0

0

0

0.666667 0.833333

0

0

0

0.25

0

0

0.555556

0

6

9

16

8

10

10

9

10

8

8

2

14

9

7.333333 9.166667

30

12

11

42.75

27

8

13.444444

13

0

1

0

0

0

0

1

3

0

0

0

0.833333

1

0

0

0

1

0

0

1

0

0.0625

0

6

8

16

8

10

10

8

7

8

8

2

13.166667

8

8

10

30

11

11

43

26

8

13.9375

13

15

7

13

8

13

4

6

8

6

5

7

11

5

6

3

11

8

8

14

14

3

7

7

4

7

4

6

7

7

12

7

11

10

Potomac R. MO Co

Antietam Creek

Seneca Creek

Lower Monocacy R.


Evitts Creek

Upper Monocacy R.

Conewago Creek/...

0

0.0


0.2

Conococheague

% Fish Spp Excluded − ANC

20 9

5

% Fish Spp Excluded − DO

4

4 ●

1.0 0.8 0.6 0.4 0.2

% Fish Spp Excluded − NO3

0.0

1.0 0.8 0.6 0.4 0.2 0.0

% Fish Spp Excluded − pH

1.0 0.8 0.6 0.4 0.2 0.0

50 1

40 30

●

●

20 ●

10

●

● ●

3

● ● ● ●

5

5

Georges Creek

5

Youghiogheny R.

4


2

Wills Creek

Fifteen Mile Creek

4



10


2

Casselman R.

2

Catoctin Creek

3

Savage R.

5


●

Town Creek

0

BIBI signif. > 3


●

9

20

10

11

2

7

10

2

9

13

10

10

2

1

5

4

4

1

24

10

7

Georges Creek

Conococheague


Potomac R. MO Co

Antietam Creek

Seneca Creek

Lower Monocacy R.


Evitts Creek

Upper Monocacy R.

Basinwide Agriculture


Bar Formation 1.0

0.8

0.6

0.4

0.2

0.0 13 7 11 7 11 0 0 3 4 5 5 8 6 0 8 13 1 6 28 12 8 8 6

3 3 9 2 2 12 10 7 6 4 5 9 4 10 2 17 14 8 21 20 2 10 9

19 9 20 11 7 13 3

11 19

0

0.4

0.0

0.4

0.2

18

●

17

● ●

9

● ●

3

9

● ● ● ●

1 20

1

20

0

1

1

20

9

19

0 10

6

11

3 9

8

● ●

●

11

2 6

1 3

5

2

0

9

1

1 5

● ● ●

7

9

0.8 0

1

● ●

0.8

● ●

●

0 0 2

10

5

3

8

12

2

3 0 0

10 13

2

0

7

1

0

13

3

8

4

12

12

9

0 0 0 3 4 0

10 10 10 7 9 17

3

5

0 10

7

3

0.04

0

7

3

0 2 0

8 10

0

5

5

0.08

7

11

1

0.05

6

10

1

31 14

9

15

4

5

● ●

47

11 42

11

6

15

2

10 6

8

1

8

5

11

8

2

●

2

13

0

27

3

36

0 10

0.15

7

13

12

3

0

0

24

3

16

7

26

10

1

3

8

Conewago Creek/...

17

Youghiogheny R.

0.0


● ●

Wills Creek

0.2


0.4


0.6

Casselman R.

0.00

Catoctin Creek

● ●

Savage R.

0.00

Fifteen Mile Creek

● ● ●


0.0



Town Creek

Basinwide Low−Intensity Dev.

0.02

BIBI signif. > 3


Highland

8 9

2 7

0

1 3 0

0 0

●

10

0.2 ●

21

15 17

8 17

8 16 9

0.6 ●

●

● ● ●

●

8

1

2 5

0 0

11

14

7

0.10 39

●

6

5 27 2 4 10

10

0.06 48

26 14

15 5 7

15

17

4

49

17

●

12

●

11

●

● ●

8

13

●

16

0

0

0.0

0.0

● ● ● ●

●

9

1

0 0

20 10

1

3

17

● ● ● ● ● ●

9 17

17

14

●

10

●

3

11

●

8 10

●

●

12

10 6

9

5

0.2

7

0

0

0

0

4

0

20

10

20

11

10

14

20

10

20

0

0

0

0

0

0

0

14 6

●

8

8

0.2

10

10

10

13

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Conewago Creek/...

● ● ● ●

19

Upper Monocacy R.

0

1 4

5

Evitts Creek

●

3


1

8

Lower Monocacy R.

3

1 10

Seneca Creek

● ● ●

20

Antietam Creek

●

9

Potomac R. MO Co

0.1 17


0.1 0

Conococheague

0.00 3

Georges Creek

0.1 ●

Youghiogheny R.

0.0 6


●

Wills Creek

●


Basinwide Cropland Cover 0.5


0.2

Casselman R.

0.6

Catoctin Creek

0.00

Savage R.

0.05

Fifteen Mile Creek

Basinwide Transportation 0.0


60−m Low Density Urban 0.2


60−m High Intensity Urban 0.3

Town Creek

60−m Extractive 0.4

BIBI signif. > 3


Highland

0.6 9 8

12

0 3

10 6

8 7

10

0.8

0.4

8

10

1

3

9

7 4

7

3

0 0

10 13

●

3 0 5 1

5 12

0

5

6

4 13

4

12

5

2 2

8

1

11

0.01

1

2

0

2

9

8

13

15

9

8 3

9 7

9

5

2

0

7

7

14

11

16

11 7 5

●

●

5 7

●

1 2 5

1 2

1 29

0.10 20

2

3

3

1

0

9

11

10

11

11

12

14

26

0.6 9

3

31

8

10

1

8

2

0.3

5

0.04

0.03

0.02

3 2 7

3

1

13

14

0.4 48

13

5

16

8

25

48

10

15

12

1 0

24

0.15

12

6

18

10

9

8

5

7

2 14 6

0

0

40

10

17

14 5

0.25 15

0.20 37

4 2

16 28 12

10

0 9 5

19 13

34 3

●

9 13 12

22 9

2 0

14

8 25

17 4

10

7 26

6 6 3

3 0 10 5

8 7

11 10

1

2

18

15

16

0.5

50

0.3

10

40

19

10

17

Highland 18

9

19

11

13

2

1.0

7

9

5

13

6

7

2

6

8

15 3

2

60−m Forest

0.8 1

0.6

2

0

0

0 1

1

0

3

1

0

5

0.4

1

1

●

● ● ● ●

0.2

3

25

8

11 10

12

0.0

14 11

30

15

7

44

11

16

31

60−m Wetland

0.3 10

0.2

17

●

10

0.1

17 10

●

15 ● ●

0.0

● ● ● ● ●

20

10

0

0

14

20

11

0

0

0

14

0

0

0

0

10

13

0

0

10

11

0

0

10 0

0

50

40

16 0

0

19 10

0

0

0

0

0

1.0

17 10 12

60−m Agriculture

0.8

38

9

6

10

8 18

11

0.6

0

15 ● ●

6 ● ●

0.4

4

● ● ●

5

4

2

● ● ● ●

0.2

2

1

1

0

0

0

0

0

1

0.0

15

8

19

11

12

2

6

10

4

9

13

11

1

10

16

5

5

12

22

6

11

7

60−m Barren

0.08

8

0.06

23

0.04

32 5

0.02

4 ●

0.00

14

● ● ● ● ● ● ● ● ●

13

3

5

7 0

1

10

19

3 4

11

9

0

0

1

2

4

0

1

10

10

9

8

9

17

9

5

7

8

14

8 5

2 7

18

37

5

5

9

8

60−m Low Intensity Dev.

11 42

0.06 11 ●

0.04

10

6

25

27

15

13

7

14

●

●

0.02

● ● ● ●

● ● ● ●

0.00

1

19

1

9

2

1

6

0 19

11

12

3

3

4

3

0

0

10

10

0 3

4

10

11

7

3

4

3

4

8

15

6

5

2

17 45

0.8 0.6

12 26

12 ●

0.4 ● ● ●

● ●

●

5

● ●

1

● ● ● ●

9

4

3

1

5

0

4

0

15

9

15

11

13

2

7

10

4

10

13

13

10

1

1

5

5

3

5

22

6

9

Fifteen Mile Creek

Savage R.

Catoctin Creek

Casselman R.



Wills Creek


Youghiogheny R.

Georges Creek

Conococheague


Potomac R. MO Co

Antietam Creek

Seneca Creek

Lower Monocacy R.


Evitts Creek

Upper Monocacy R.

0


0


0

Town Creek

0

0.0

18

11

● ●

Conewago Creek/...

0.2

BIBI signif. > 3

60−m Pasture/Hay

10 10

6

40

0

●

3

0

● ●

● ● ●

0

15

3 0

●

0

40

9

12

8 13

● ● ●

0

10

0

16

5

2

9 8

10

0

●

20

0

4

●

2

8 11

14

0

1

2

9

7 2

7

4

11 14 14

0 0

0

20

13

4 8

0

11

0

2

9

●

10

14

0

9

0

0

10

10

3

4

7

4

10

0

5

9

11

6

8

1

5

20 10 10 10

0 0 0

10

0

5

8

10

4

7

13

3

12

20

0

2

11

6

11

9

7

11

10

13 17

0 0

10

0

15

3

4

10

5

0

0

60

0

6

7

4

5

6

1

7 3

0

0

60

7

9 0

11

0

80

9

9

4 28

14

6

0

100

0

29

10

1

8

10

17

3

0

16

8

3

11

0.3

9

●

0 0

17 15

0

2

15

15

9

46

24

31

0

10

0

2

44

22

26

14

10

0

31

0

32

3

2

4

8

6

0

80

0

10

42

5

13

11

40

0

●

10

0

3

1

0

0

10

19

8

6

1

8

4

5

Conewago Creek/...

● ●

4

Upper Monocacy R.

0 4

Evitts Creek

● ● ● ● ●

9 10


8 2

Lower Monocacy R.

●

Seneca Creek

0.6

Antietam Creek

6 16 5

Potomac R. MO Co

0.2 6


0.0 4 3

Conococheague

0

Georges Creek

0.4

Youghiogheny R.

0.1 12


● ● ●

10

2

Wills Creek

11


●

16


60−m Croplands

● ●

Casselman R.


● ● ●

8

Catoctin Creek

0 14 1

Savage R.

20 4

Fifteen Mile Creek

% Gastropods

6


2 ● ●


% Amphipods 0.0

Town Creek

% Scrapers 0.2

BIBI signif. > 3


Highland 9

6 18

6

5 8

6 6 8

0 0 1 9

13

6 4

2 6 10 26 8 7

3 3 0

10

12 19

10 11 15

20 17 50

10 17

10

0

40 19

17

50 10 17

● ●

13 10

0

2

4 1 8

2

6

1

3

0

14

28

14

35

14

16

2

0

1

2

0.6

0.4

0.2

0.0

100 ●

●

1

●

●

● ●

●

3

●

●

5

●

5

19 8 13 8 8 9 6 7 6 14 10 8 5 12 12 5 15 20 9 15

3 2 7 0 0 3 1 1 3 3 0 0 2 1 0 3 3 4 6 10 3 3 1

17 8 13 11 14 11 9 9 7 7 13 17 8 9 11 28 14 11 44 30 7 16 16

15 7 14 9 13 4 6 8 6 5 10 12 5 6 4 23 8 8 25 20 3 7 7

4 7 8 9 7 25 20 7 12 10

1.0

0.8

0.6

0.4

0.2

0.0

1.0

0.8

0.6

0.4

0.2

0.0 6 2

2 0 1 0

18

10

19

1

1

19

9 10 4 2 4

0 5 2 0 3 0 0 0 0 1 3 0 1 4 7 7 0 4 4

11

14

9

8

10

7

10

13

17

10

9

8

31

16

11

43

33

10

15

13

3

0

1

0

1

0

0

2

0

2

1

0

0

1

3

2

7

4

3

2

1

17

11

13

14

9

10

10

8

13

15

9

10

11

30

14

13

43

36

7

17

16

5

Conewago Creek/...

0.8 9

3

Upper Monocacy R.

1

Evitts Creek

●


0.6

0.4

0.2

0.0 4 1 2 4 4 2 2 5 5 4 0 3 5 22 4 9 35 18 3 3 12

7 6 16 8 11 8 6 8 8 4 5 13 10 7 5 8 11 5 14 14 7 15 3

34 12

18

Lower Monocacy R.

5

Seneca Creek

●

Antietam Creek

0.8 4

3

Potomac R. MO Co

● ●


1.0 11

5 1

Conococheague

● ●

Georges Creek

Erosion Severity 1.0 9

4

Youghiogheny R.

1


●

Wills Creek

2


0 4


20

Casselman R.

Erosion Extent 100

Catoctin Creek

40

Savage R.

Channelization 50

Fifteen Mile Creek

60


80



Town Creek

Riparian Agriculture 150

BIBI signif. > 3

Riparian Urban

Highland

●

3

9 13

2

5 3

4

1 1

0 0 2

0.0

100

80

60

40 0

20

1

4 0 1 4 1 3 3 3 8 0 2 6

12 10 20 8 13 12 9 9 7 9 9 13 10 9 7 30 14 12 47 32 10 17 11

5 2 3 1 0 4 2 1 1 0 0 3 0 3 3 3 5 4 11 6 2 3 4

15 8 17 10 14 10 8 9 9 10 13 14 10 7 8 28 12 11 39 34 8 16 13

16 7 15 10 14 8 6 9 6 8 13 14 8 4 5 21 8 9 25 25 6 9 5

3 2 6 6 10 9 6 25 15 4 10 12

4 1 4 2

Casselman R. Potomac R. Upper N. Br. Little Youghiogheny/... Wills Creek Potomac R. AL Co/...

6

Catoctin Creek

Savage R.

4

Conewago Creek/...

0.2 1

Upper Monocacy R.

0.4 3

Evitts Creek

0.6 1


0.8 1

Lower Monocacy R.

1.0 2

Seneca Creek

0.0 1

Antietam Creek

0.2 3

Potomac R. MO Co

0.4 0


0.6 0

Conococheague

5

Fifteen Mile Creek

SAV present 0.8 8

Georges Creek

3


No Buffer >= 1 bank 1.0

Youghiogheny R.

4


0 Town Creek

BIBI signif. > 3


Highland

0

FINAL

Appendix D


D1

FINAL

APPENDIX D CANDIDATE VARIABLES SELECTED FOR FURTHER ANALYSIS


D-1

FINAL Table D-1: Candidate Variables Selected for Further Analysis HIGHLANDS Impervious Surface Benthic Dominants Catchment Forest Catchment Transportation Riparian Transportation Erosion Severity Erosion Extent B: Terrestrial Sediment Epifaunal Substrate Epifaunal Substrate Epifaunal Substrate Riparian High Urban Riparian High Urban Riparian High Urban Riparian Low Urban Riparian Low Urban Riparian Low Urban Riparian Forest Riparian Forest Riparian Forest Riparian Crop Riparian Crop Minimum Buffer Width Minimum Buffer Width Embeddedness Instream Habitat Riparian Pasture/Hay C and D: Energy Source DOC DOC DOC and Oxygen DO DO Shading Consumption/Thermal SO4 SO4 SO4 Waste Riparian Forest Riparian Forest Riparian Forest Catchment High Urban Catchment High Urban Catchment High Urban Catchment Low Urban Catchment Low Urban Catchment Low Urban No Buffer Temperature Temperature NH3 HBI HBI Riparian Crop Riparian Crop NH3 SAV Riparian Pasture/Hay Catchment Pasture/Hay E: Inorganic Pollutants Conductivity Conductivity Conductivity pH Riparian Extractive Riparian Extractive F: Organic Pollutants HBI Catchment High Urban Catchment High Urban Catchment Transportation Catchment Transportation Riparian Transportation Riparian Transportation Anomalies * Candidate variables selected for further analysis showed the best relationships between divergence from variable values at reference sites and degradation of watersheds A: Flow Regime

COASTAL Impervious Surface Catchment High Urban Catchment Low Urban


D-2

EPIDEDMONT Impervious Surface Benthic Dominants Catchment Forest Catchment Transportation Riparian Transportation Channelization

FINAL

Appendix E


E1

FINAL

APPENDIX E QUANTILE REGRESSIONS (90TH OR 10TH) OF CANDIDATE STRESSOR IDENTIFICATION VARIABLES


E-1

FINAL

Figure E-1: Highland Bank Stability, Benthic Tolerance, and Embeddedness Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

E-2

FINAL

Figure E-2: Highland Epifaunal Substrate, Instream Habitat, and Turbidity Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

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Figure E-3: Highland HBI, Shading, and DO Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

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Figure E-4: Highland Temperature, TN, and NH3 Values vs. IBI Score Regressions


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Figure E-5: Highland TP, DOC, and Conductivity Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

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Figure E-6: Highland pH Values vs. IBI Score Regressions


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Figure E-7: Piedmont Bank Stability, Benthic Tolerance, and Embeddedness Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

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Figure E-8: Piedmont Epifaunal Substrate, Instream Habitat, and Turbidity Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

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Figure E-9: Piedmont HBI, Shading, and DO Values vs. IBI Score Regressions


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Figure E-10: Piedmont Temperature, TN, and NH3 Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

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Figure E-11: Piedmont TP, DOC, Conductivity Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

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Figure E-12: Piedmont pH Values vs. IBI Score Regressions


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Figure E-13: Coastal Plain Bank Stability, Benthic Tolerance, and Embeddedness Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

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Figure E-14: Coastal Plain Epifaunal Substrate, Instream Habitat, and Turbidity Values vs. IBI Score Regressions Stream Disturbance Index E-15 Development Report Document Version: June 15, 2007

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Figure E-15: Coastal Plain Temperature, TN, and NH3 Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

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Figure E-16: Coastal Plain TP, DOC, and Conductivity Values vs. IBI Score Regressions Stream Disturbance Index Development Report Document Version: June 15, 2007

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Figure E-17: Coastal Plain pH Values vs. IBI Score Regressions


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Appendix F


F1

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Appendix F Stream Disturbance Indicator Results By Watershed


F1

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Antietam Creek Benthic Stressor Summary

A:Sediment/Flow

1.0

5

0.8

0.6 Score

Confidence in mean