OCS Study • MMS 2001-070 Methods for Performing Monitoring, Impact, and Ecological Studies on Rocky Shores Final Technical Summary Final Study Report U.S. Department of the Interior Minerals Management Service Pacific OCS Region Final Technical Summary – Murray et al. 2 Methods for Performing Monitoring, Impact, and Ecological Studies on Rocky Shores Final Technical Summary Final Study Report Authors Steven N. Murray Richard F. Ambrose Principal Investigators and Megan N. Dethier Prepared under MMS Cooperative Agreement No. 14-35-0001-30761 by Southern California Educational Initiative Marine Science Institute University of California Santa Barbara, CA 93106 U.S. Department of the Interior Minerals Management Service Camarillo Pacific OCS Region March 2002 3 Final Technical Summary – Murray et al. Disclaimer This report has been reviewed by the Pacific Outer Continental Shelf Region, Minerals Management Service, U.S. Department of the Interior and approved for publication. The opinions, findings, conclusions, or recommendations in this report are those of the author, and do not necessarily reflect the views and policies of the Minerals Management Service. Mention of trade names or commercial products does not constitute an endorsement or recommendation for use. This report has not been edited for conformity with Minerals Management Service editorial standards. Availability of Report Extra copies of the report may be obtained from: U.S. Dept. of the Interior Minerals Management Service Pacific OCS Region 770 Paseo Camarillo Camarillo, CA 93010 Phone: 805-389-7621 A PDF file of this report is available at: http://www.coastalresearchcenter.ucsb.edu/SCEI/ Suggested Citation The suggested citation for this report is: Murray, Steven N., Ambrose, Richard F., and Megan N. Dethier. Methods for Performing Monitoring, Impact, and Ecological Studies on Rocky Shores. MMS OCS Study 2001-070. Coastal Research Center, Marine Science Institute, University of California, Santa Barbara, California. MMS Cooperative Agreement Number 14-35-0001-30761. 217 pages. 4 TABLE OF CONTENTS FINAL TECHNICAL SUMMARY 1 FINAL STUDY REPORT: Methods for Performing Monitoring, Impact, and Ecological Studies on Rocky Shores by S.N. Murray, R.F. Ambrose, and M.N. Dethier 3 Acknowledgements 3 About the Authors 5 Foreward 7 Chapter 1. Designing Rocky Intertidal Monitoring and Impact Field Studies: A Brief Overview by Steven N. Murray 8-21 Introduction 9 Design Elements for Rocky Intertidal Field Studies 10 Study Types and Goals 11 Study Designs 12 One-Time or “One-Off” Baseline Studies 13 Impact Studies 13 Monitoring Programs 17 Literature Cited 19 Chapter 2. Site Classification and Selection by Megan N. Dethier 22-47 Introduction 23 Classifying Shorelines 24 Geophysical Features 25 Wave Energy 25 Aspect and Slope 28 Topographical Heterogeneity and Rock Type 28 Sand Burial and Scour 29 Salinity 30 Human Disturbance 30 Mapping Methods 31 Habitat Types 33 Methods for Site Selection 36 Monitoring Studies 36 Impact Studies 39 Numbers of Sampling Sites 40 Summary 41 Literature Cited 42 5 Final Technical Summary – Murray et al. Chapter 3. Biological Units by Megan N. Dethier 48-73 Introduction 49 Species-Level Sampling 49 Down-a-Level: Individual-Based Sampling 55 Up-a-Level: Supra-Species Sampling 56 Higher Taxonomic Categories 57 Functional Groups 58 Community-Level Metrics 60 Summary 66 Literature Cited 67 Chapter 4. Sampling Design by Richard F. Ambrose 74-97 Introduction 75 Statistical Considerations 75 Assumptions 75 Statistical Power 77 Location of Sampling Units 79 Distribution of Sampling Effort 79 Establishing Sample Locations 79 Random 79 Systematic 81 Targeted 82 Stratification 82 Comparison of Approaches 85 One-Time (“One-Off”) versus Repeated Assessments 86 Fixed Plots 87 Comparison of Fixed versus Non-fixed Plots 89 Number of Samples: How Many is Enough? 90 Impact Assessment 93 Summary 94 Literature Cited 95 6 Chapter 5. Transects, Quadrats, and Other Sampling Units by Richard F. Ambrose 98-122 Introduction 99 Quadrat or Plot-Based Methods 99 Line Transects 100 Plots or Quadrats 104 Comparing Transects and Quadrats 107 Size of Sampling Units 108 Plotless Designs 110 Distance Sampling Methods 111 Timed Search 113 Special Habitats 114 Tidepools 115 Boulderfields 115 Summary 118 Literature Cited 119 Chapter 6. Quantifying Abundance: Density and Cover by Steven N. Murray 123-154 Introduction 124 Rapid Surveys 124 Plotless and Line Transect Methods 128 Plot or Quadrat-Based Methods 130 Density 130 Cover 132 Field Methods: Visual Scanning 136 Field Methods: Point Contacts 137 Photographic Sampling 140 35-mm Photographic Sampling 141 Video Sampling 145 Laboratory Assessment of Photographic Samples 146 Summary 148 Literature Cited 150 7 Final Technical Summary – Murray et al. Chapter 7. Quantifying Abundance: Biomass by Steven N. Murray 155-169 Introduction 156 Harvesting Procedures 159 Biomass Determination 163 Wet Biomass 163 Dry Biomass 164 Ash-Free Dry Biomass 165 Summary 167 Literature Cited 167 Chapter 8. Individual-Based Parameters: Age-Determination, Growth Rates, Size Structure, and Reproduction By Steven N. Murray 170-206 Introduction 171 Seaweeds 173 Growth Rates and Age Determination 173 Growth Rates 173 Age Determination 174 Population Size Structure 176 Sex or Phase Ratios 178 Reproductive Output 179 Macroinvertebrates 182 Growth Rates 182 Marking Animals with Tags 183 Measuring Growth 185 Age Determination 187 Annuli and Growth Rings 187 Age Calculation from Growth Rates 188 Population Size Structure 189 Size-Frequency Profiles 189 Growth Rates from Size-Frequency Profiles 191 Reproductive Condition and Output 193 Summary 197 Literature Cited 199 Subject Index 207 Taxonomic Index 216 8 Methods for Performing Monitoring, Impact, and Ecological Studies on Rocky Shores FINAL TECHNICAL SUMMARY STUDY TITLE: Methods for Performing Monitoring, Impact, and Ecological Studies on Rocky Shores REPORT TITLE: Methods for Performing Monitoring, Impact, and Ecological Studies on Rocky Shores CONTRACT NUMBER: 14-35-0001-30761 SPONSORING OCS REGION: Pacific APPLICABLE PLANNING AREA: Pacific Coast of North America including Alaska; Other areas where rocky shores occur FISCAL YEAR OF PROJECT FUNDING: FY 96 COMPLETION DATE OF REPORT: March 2002 COSTS: FY 96 - $43,825 (CSUF) and $58,108 (UCLA), FY 97 – no cost, FY 98 – no cost, FY 99 – no cost, FY 00 – no cost, FY 01 – no cost CUMULATIVE PROJECT COST: $101,933 PROJECT MANAGER: Steven N. Murray AFFILIATION: California State University, Fullerton ADDRESS: Department of Biological Sciences, California State University, 800 North State College Blvd., Fullerton, CA 92834-6850 PRINCIPAL INVESTIGATORS: 1Steven N. Murray and 2Richard F. Ambrose ADDRESSES: 1Department of Biological Sciences, California State University, 800 North State College Blvd., Fullerton, CA 92834-6850; 2Department of Environmental Health Sciences, University of California, Box 951772, Los Angeles, CA 90095-1772 KEY WORDS: Rocky Intertidal; Monitoring Studies; Impact Studies; Benthic Sampling Programs, Benthic Study Designs; Site Selection; Marine Invertebrates, Seaweeds, Seagrasses BACKGROUND: This book describes and discusses methods and approaches for performing monitoring, impact, and ecological studies of rocky intertidal populations and communities. Emphasis is placed on intertidal macroinvertebrates, seaweeds, and seagrasses. Developing effective sampling procedures to detect ecologically meaningful changes in population and community parameters is often challenging in rocky intertidal habitats. This project grew out of 1 Final Technical Summary – Murray et al. discussions held at a workshop on rocky intertidal monitoring programs and a symposium on this topic convened at an annual meeting of the Southern California Academy of Sciences. The contents and organization of this book were developed by the three authors (Steven N. Murray, Richard F. Ambrose, and Megan N. Dethier), who individually authored its chapters. OBJECTIVES: The objectives of this volume are to provide descriptions and analyses of methods and approaches for sampling rocky intertidal macroinvertebrate and macrophyte populations and communities. Emphasis has been placed on procedures used in monitoring and impact studies. A goal of this work is to identify sampling issues and concerns and to facilitate decision-making for parties involved in developing rocky intertidal sampling programs. DESCRIPTION: This volume attempts to improve understanding of the various approaches used in executing rocky intertidal sampling programs. Included are discussions of the principles of designing effective monitoring and impact studies, site selection, the taxonomic or other biological units chosen for sampling, sampling layouts and designs, the use of transects, quadrats, and other sampling units, methods for quantifying species abundances, and methods for determining growth rates, age, population size structure, and reproductive condition. The volume consists of a total of eight chapters, and includes besides the volume cover, eight chapter cover photos, 52 photos and figures, and 11 tables. The volume also contains a taxonomic and subject index. SIGNIFICANT CONCLUSIONS: The discussions of sampling and study approaches represent key contributions to the literature available to individuals interested in designing, executing, and evaluating rocky intertidal sampling programs. The various methods and techniques are described and sufficiently evaluated for readers to determine the best approaches