California State University, Monterey Bay Digital Commons @ CSUMB SNS Master's Theses School of Natural Sciences Spring 2010 Effectiveness of RIVPACS Predictive Models to Evaluate Diatom Response to Nutrient Stress in Coastal California Streams Charles Ritz California State University, Monterey Bay Follow this and additional works at: https://digitalcommons.csumb.edu/sns_theses Recommended Citation Ritz, Charles, "Effectiveness of RIVPACS Predictive Models to Evaluate Diatom Response to Nutrient Stress in Coastal California Streams" (2010). SNS Master's Theses. 19. https://digitalcommons.csumb.edu/sns_theses/19 This Master's Thesis (Open Access) is brought to you for free and open access by the School of Natural Sciences at Digital Commons @ CSUMB. It has been accepted for inclusion in SNS Master's Theses by an authorized administrator of Digital Commons @ CSUMB. For more information, please contact [email protected]. EFFECTIVENESS OF RIVPACS PREDICTIVE MODELS TO EVALUATE DIATOM RESPONSE TO NUTRIENT STRESS IN COASTAL CALIFORNIA STREAMS A Thesis Presented to the Faculty ofthe Division ofScience and Environmental Policy California State University Monterey Bay In Partial Fulfillment ofthe Requirements for the Degree Master of Science in Coastal and Watershed Science and Policy by Charles Ritz Spring 2010 CALIFORNIA STATE UNIVERSITY MONTEREY BAY The Undersigned Faculty Committee Approves the Thesis ofCharles Ritz: EFFECTIVENESS OF RIVPACS PREDICTIVE MODELS TO EVALUATE DIATOM RESPONSE TO NUTRIENT STRESS IN COASTAL CALIFORNIA STREAMS ~-/-/j?~-"--,­ Marc Los Huertos, Committee Chair Division ofScience and Environmental Policy, CSUMB ~0-~ Fred Watson,---------------- Division ofScience and Environmental Policy, CSUMB _--+--=??~~"",--,-f(. tJ~ r Peter Ode, California Department of Fish Game Staff Environmental Scientist ~~-~ Marsha Moroh, Dean College ofScience, Media Arts and Technology, CSUMB May 2010 111 Copyright © 2010 by Charles Ritz All Rights Reserved IV You cannot step twice into the same stream. For as you are stepping in, other waters are ever flowing on to you. Heraclitus ofEphesus (c.535 - 475 Be) v ABSTRACT Effectiveness ofRIVPACS Predictive Models to Evaluate Diatom Response to Nutrient Stress in Coastal California Streams by Charles Ritz Master of Science in Coastal and Watershed Science and Policy California State University Monterey Bay, 2010 The goal ofthis project was to determine ifpredictive models ofdiatom assemblages would provide an effective method to report on biological degradation in streams along the Central Coast of California. This project focused on nutrient stress to evaluate stream water­ quality degradation. I employed the River Invertebrate Prediction and Classification System (RIVPACS) model with diatom assemblages. Diatoms were an accessible indicator of nutrient stress occurring in abundance on Central Coast streams. Diatom samples from 190 stream sites were used to construct and test the RIVP ACS model. The RIVP ACS methodology used a reference condition approach to compare assemblages at reference sites to observed assemblages at degraded test sites. Reference sites were used to train the predictive model and develop an expected taxa count. A ratio ofobserved taxa to expected taxa (OE) was the concluding measure ofbiological integrity at each site. I used the OE scores to test the postulate that degraded sites had diatom assemblages dissimilar from the reference site diatom assemblages. The RIVPACS model did not performed well. The model suffered from low precision ofreference site OE scores (mean SD 0.22) and lack of accuracy to consistently predict low OE scores at known degraded sites. However, the model was able to identify likely trends. For example, agricultural land use sites trended toward lower OE scores indicating possible biological degradation. The uncertainty in the RIVP ACS model did not provide a definitive measure ofmodel effectiveness. I concluded the assessment model was limited by the quality ofreference streams and the temporal variability and spatial patchiness ofdiatom assemblages. I recommended further evaluations the explore the application ofdiatom assemblages to assess streams on the Central Coast. vi TABLE OF CONTENTS PAGE ABSTRACT ......................................................................................................................................................... V LIST OF TABLES ......................................................................................................................................... VIII LIST OF FIGURES .......................................................................................................................................... IX ACKNOWLEDGEMENTS................................................................................................................................ X CHAPTER 1 ....................................................................................................................................................... 12 WHY USE BIOASSESSMENTS TO TEST WATER QUALITY? ............................................................... 12 STREAM BIOASSESSMENTS ............................................................................................................................... 12 Appropriate biological indicators: ............................................................................................................. 13 BIOASSESSMENT RATIONALE ........................................................................................................................... 13 BIOASSESSMENT APPLICATION ........................................................................................................................ 14 BIOASSESSMENTS AND NUTRIENT ENRICHMENT: A POLITICAL PERSPECTIVE ................................................. 15 Legal Origins for Clean Water ................................................................................................................... 15 Nutrients Enrichment in California ............................................................................................................ 17 BrOASSESSMENT AND NUTRIENT ENRICHMENT: A SCIENTIFIC PERSPECTIVE ................................................... 18 Algal Characteristics .................................................................................................................................. 18 Ecosystem Processes .................................................................................................................................. 19 Diatoms and Nutrients ................................................................................................................................ 19 RIVPCAS MODEL ........................................................................................................................................... 20 IMPLICAnON OF A RIVPACS APPLICAnON IN COASTAL CALIFORNIA ............................................................ 22 CHAPTER 2 ....................................................................................................................................................... 23 EFFECTIVENESS OF RIVPACS TO EVALUATE DIATOM RESPONSE TO NUTRIENT STRESS IN COASTAL CALIFORNIA STREAMS............................................................................................................ 23 INTRODUCTION................................................................................................................................................. 23 METHODS ......................................................................................................................................................... 27 Study Area................................................................................................................................................... 27 Sampling Design and Sample Collection. ................................................................................................... 29 Predictor Variables .................................................................... ................................................................ 30 Reference Site Selection .............................................................................................................................. 31 Vll Predictive Model Construction ................................................................................................................... 33 Selection andAssessment ofPredictive Model ........................................................................................... 38 RESULTS........................................................................................................................................................... 39 Model Prediction ........................................................................................................................................ 41 DISCUSSION...................................................................................................................................................... 47 CONCLUSION .................................................................................................................................................... 52 REFEREN CES ................................................................................................................................................... 53 APPENDICIES..................................................................................................................................................