This document is made available electronically by the Minnesota Legislative Reference Library as part of an ongoing digital archiving project. http://www.leg.state.mn.us/lrl/lrl.asp The Condition of Rivers and Streams in Minnesota Based on Probabilistic Surveys, 1995-2011 April 2014 Authors April Lueck Scott Niemela Contributors/acknowledgements Daniel Helwig Glenn Skuta Tony Olson Tom Kincaid The MPCA is reducing printing and mailing costs John Genet by using the Internet to distribute reports and Joel Chirhart information to wider audience. Visit our Kristofor Parson website for more information. John Sandburg MPCA reports are printed on 100% post- Andrew Petersen consumer recycled content paper North Biological Monitoring Unit manufactured without chlorine or chlorine South Biological Monitoring Unit derivatives. Minnesota Pollution Control Agency 520 Lafayette Road North | Saint Paul, MN 55155-4194 | www.pca.state.mn.us | 651-296-6300 Toll free 800-657-3864 | TTY 651-282-5332 This report is available in alternative formats upon request, and online at www.pca.state.mn.us . Document number: wq-bsm1-08 Contents Executive summary .................................................................................................................................... 1 Introduction ............................................................................................................................................... 3 Methods ..................................................................................................................................................... 6 Site selection ........................................................................................................................................... 6 Sampling protocol ................................................................................................................................... 6 Threshold establishment ........................................................................................................................ 7 Index of biological integrity ................................................................................................................. 7 Water chemistry .................................................................................................................................. 8 Habitat ................................................................................................................................................. 9 Statistical methods ................................................................................................................................. 9 Results ........................................................................................................................................................ 11 Condition estimations ............................................................................................................................. 11 Site conditions ..................................................................................................................................... 11 Water chemistry .................................................................................................................................. 17 Biological ............................................................................................................................................. 21 Cumulative distribution functions .......................................................................................................... 25 Minnesota habitat assessment ........................................................................................................... 25 Human disturbance score ................................................................................................................... 25 Watershed land use ............................................................................................................................. 27 Water chemistry .................................................................................................................................. 29 Biological ............................................................................................................................................. 32 Cumulative distribution functions test ................................................................................................... 34 Factors influencing biological condition ................................................................................................. 36 Biological cumulative distribution functions test ................................................................................ 36 Condition probability analysis ................................................................................................................ 38 Watershed land use ............................................................................................................................. 40 Habitat ................................................................................................................................................. 47 Water chemistry .................................................................................................................................. 54 Discussion................................................................................................................................................... 61 Bibliography ............................................................................................................................................... 63 Appendix .................................................................................................................................................... 66 Appendix 1. Variable abbreviations and explanations .............................................................................. 66 Appendix 2. CDF test p-values ................................................................................................................... 69 Appendix 3. Change estimate values ......................................................................................................... 72 Appendix 4. Condition estimates comparison of significant differences among the basin and ecoregion surveys ...................................................................................................................................... 76 Appendix 5. Fish community CDF test p-values ......................................................................................... 77 Appendix 6. Invertebrate CDF test p-values .............................................................................................. 78 Appendix 7. Site location information and weighting ............................................................................... 79 Appendix 8. Water chemistry concentrations .......................................................................................... 112 Figures Figure 1. Site locations for the basin (left) and ecoregion (right) surveys .................................................... 4 Figure 2. Box plot of MSHA scores - Good= > 66 - Fair - < 45 = Poor ............................................................ 9 Figure 3. Site status, estimated percent of stream miles for the basin and ecoregion .............................. 12 Figure 4. Stream order, estimated percent of stream miles ...................................................................... 13 Figure 5. MSHA, estimated percentage of stream miles ............................................................................ 15 Figure 6. Channel condition estimated percentage of stream miles .......................................................... 16 Figure 7. Total suspended solids estimated percentage of stream miles .................................................. 18 Figure 8. Nitrogen estimated percentage of stream miles ......................................................................... 19 Figure 9. Phosphorus estimated percentage of stream miles .................................................................... 20 Figure 10. Estimated percentage of stream miles that meet fish IBI thresholds ....................................... 22 Figure 11. Estimated percentage of stream miles that meet macroinvertebrate IBI thresholds ............... 23 Figure 12. Estimated percentage of stream miles that meet both fish and macroinvertebrate IBI thresholds at a single site ........................................................................................................................... 24 Figure 13. MSHA score, estimated percent of stream miles with MSHA values that are equal to, or greater than a given value .......................................................................................................................... 26 Figure 14. Percent disturbance within site reach watershed, estimated percent of stream miles with disturbance percentage equal to, or greater than a given value ............................................................... 26 Figure 15. Human disturbance score, estimated percent of stream miles with human disturbance values equal to, or greater than a given value ........................................................................................... 27 Figure 16. Percent agriculture land use in watershed, estimated percent of stream miles with percent agriculture land use values equal to, or greater than a given value ............................................