GEOLOGICAL SURVEY OF ALABAMA Berry H. (Nick) Tew, Jr. State Geologist ECOSYSTEMS INVESTIGATIONS PROGRAM CALIBRATION OF THE INDEX OF BIOTIC INTEGRITY FOR THE PLATEAU ICHTHYOREGION IN ALABAMA OPEN-FILE REPORT 1111 by Patrick E. O'Neil and Thomas E. Shepard Prepared in cooperation with the Alabama Department of Environmental Management and the Alabama Department of Conservation and Natural Resources Tuscaloosa, Alabama 2011 TABLE OF CONTENTS Abstract ............................................................ 1 Introduction.......................................................... 2 Acknowledgments .................................................... 6 Objectives........................................................... 7 Study area .......................................................... 7 Plateau ichthyoregion ............................................ 7 Methods ............................................................ 9 IBI sample collection ............................................. 9 Habitat measures............................................... 11 Habitat metrics ........................................... 12 The human disturbance gradient ................................... 16 IBI metrics and scoring criteria..................................... 20 Designation of guilds....................................... 21 Results and discussion................................................ 23 Sampling sites and collection results . 23 Selection and scoring of Plateau IBI metrics . 40 Metrics selected for the Plateau IBI ................................. 46 1. Number of native species ................................. 46 2. Number of cyprinid species ............................... 47 3. Number of sucker species................................. 50 4. Number of Lepomis species ............................... 50 5. Number of darter + madtom species . 50 6. Percent dominant species................................. 53 7. Percent as tolerant species................................ 53 8. Percent as Lepomis ..................................... 56 9. Percent as omnivores and herbivores . 56 10. Percent as top carnivores ................................ 60 11. Percent with DELT+hybrids............................... 60 12. Percent as simple lithophilic spawners . 62 IBI development for the Plateau ichthyoregion . 62 Conclusions ........................................................ 76 References cited..................................................... 77 Appendix A. Habitat evaluation forms..................................... 82 Appendix B. Reproduction and trophic guild classifications for Alabama fishes . 85 Appendix C. Plateau ichthyoregion fish community sampling data ......................................................... 96 TABLES Table 1. IBI sampling sites in the Plateau ichthyoregion, 2008-11 . 25 Table 2. Fish species collected in the Black Warrior, Coosa, and Tennessee River systems ...................................................... 29 ii Table 3. Rapid habitat assessment scores for sites in the Plateau ichthyoregion . 33 Table 4. Human disturbance metrics for sites in the Plateau ichthyoregion . 36 Table 5. LDI-weighted human disturbance metrics for sites in the Plateau ichthyoregion .................................................. 38 Table 6. Correlation coefficients between candidate IBI metrics and habitat assessment metrics ............................................. 41 Table 7. Correlation coefficients between candidate IBI metrics and human disturbance metrics ............................................. 42 Table 8. Statistical and responsive measures for candidate IBI metrics . 44 Table 9. Redundancy analysis for Plateau ichthyoregion IBI metrics . 45 Table 10. Fish community values for Plateau IBI metrics . 65 Table 11. Scores for Plateau IBI metrics . 67 Table 12. IBI integrity classes for the Plateau, Southern Plains, Tennessee Valley, and Ridge and Valley/Piedmont ichthyoregions . 69 FIGURES Figure 1. Preliminary ichthyoregion classification for Alabama . 5 Figure 2. Ecoregions and river systems in Alabama . 8 Figure 3. Conceptual model illustrating the relationship between disturbance, stressor, and response. .......................................... 17 Figure 4. Location of IBI sampling sites in the Plateau ichthyoregion . 24 Figure 5. Frequency distribution of sampling sites in the Plateau ichthyoregion by watershed area and human disturbance . 28 Figure 6. Relationships between the IBI metric number of native species and watershed area, disturbance, and habitat. 48 Figure 7. Relationships between the IBI metric number of cyprinid species and watershed area, disturbance, and habitat . 49 Figure 8. Relationships between the IBI metric number of sucker species and watershed area, disturbance, and habitat . 51 Figure 9. Relationships between the IBI metric number of Lepomis species and watershed area, disturbance, and habitat . 52 Figure 10. Relationships between the IBI metric number of darter+madtom species and watershed area, disturbance, and habitat . 54 Figure 11. Relationships between the IBI metric percent dominant species and watershed area, disturbance, and habitat . 55 Figure 12. Relationships between the IBI metric percent tolerant species and watershed area, disturbance, and habitat . 57 Figure 13. Relationships between the IBI metric percent Lepomis and watershed area, disturbance, and habitat ..................................... 58 Figure 14. Relationships between the IBI metric percent omnivores-herbivores and watershed area, disturbance, and habitat. 59 iii Figure 15. Relationships between the IBI metric percent top carnivores and watershed area, disturbance, and habitat . 61 Figure 16. Relationships between the IBI metric percent DELT + hybrids and watershed area, disturbance, and habitat . 63 Figure 17. Relationships between the IBI metric percent simple lithophilic spawners and watershed area, disturbance, and habitat . 64 Figure 18. Frequency distribution of IBI integrity classes for sites in the Plateau ichthyoregion .................................................. 69 Figure 19. Comparison of the IBI in level IV ecoregions and drainages relative to habitat quality and a comparison of IBI scores for small and large watersheds relative to habitat quality ......................................... 70 Figure 20. Comparison of the IBI in level IV ecoregions and drainages relative to human disturbance and a comparison of IBI scores for small and large watersheds relative to human disturbance . 72 Figure 21. Tiered aquatic life use relationships between the IBI, habitat quality, and human disturbance for sites in the Plateau ichthyoregion . 73 Figure 22. Biological condition gradient models for the Plateau ichthyoregion . 75 iv ABSTRACT The Plateau ichthyoregion in north Alabama was sampled from 2008 through 2011 to develop data for creating and calibrating the Index of Biotic Integrity (IBI). Eighty-seven sites were selected to represent a range of watershed areas and levels of human disturbance. Watershed areas at sampled sites ranged from 3.90 mi2 up to 921 mi2 with 36 percent (33 sites) of the watersheds <20 mi2, 40 percent (36 sites) ranging from 21 to 100 mi22, and 24 percent (22 sites) >100 mi in area. Rapid habitat assessments were completed for each sample and eight measures of human disturbance were derived for each site from a geographic information system (GIS). Thirty-four candidate IBI metrics were screened for inclusion in the IBI by evaluating their relationship to the habitat assessment and human disturbance metrics. Both human disturbance metrics and habitat metrics were correlated with IBI metrics. Twelve metrics were selected for the Plateau IBI: number of native species, number of cyprinid species, number of sucker species, number of Lepomis species, number of darter+madtom species, percent of the dominant species, percent of tolerant species, percent of Lepomis species, percent of omnivores and herbivores, percent of top carnivores, percent with DELT+hybrids (DELT=deformities, eroded fins, lesions, tumors) and the percent of simple lithophilic spawners. Only disturbance measures were effective in discriminating sites with good biological condition from sites with poor condition. Habitat measures did not discriminate sites with good biological condition from sites with poor biological condition. Thirty-four percent of the sites scored in the poor to very poor range, 38 percent in the fair range, and 28 percent in the good to excellent range. The range of scores for each integrity class of the Plateau IBI were similar to those developed for the Southern Plains and Ridge and Valley/Piedmont IBI and slightly higher than criteria developed for the Tennessee Valley IBI. The Plateau IBI integrity classes were applied to the USEPA biological condition gradient concept for tiered aquatic life uses to model the response of biological condition to ecosystem stress in the region. This model can be used to better assess stream aquatic life use in Plateau streams and provide an additional water quality screening tool for locating and defining use-impaired streams. 1 INTRODUCTION The Geological Survey of Alabama (GSA), in cooperation with the Alabama Department of Environmental Management (ADEM) and the Wildlife and Freshwater Fisheries Division (WFFD) of the Alabama Department of Conservation and Natural Resources (ADCNR), has initiated a multi-year research effort to develop and calibrate a comprehensive fish community bioassessment tool, known as the Index